Aircraft Ground Servicing Operations, TO 00-25-172 PDF

Downloaded from http://www.everyspec.com TO 00-25-172 CHAPTER 1 INTRODUCT...

Downloaded from http://www.everyspec.com TO 00-25-172 CHAPTER 1 INTRODUCTION 1.1 PURPOSE. 1.4.2 Aircraft Servicing Supervisor. The person responsi- ble for the aircraft fuel servicing operations. The individual This technical order provides guidance to help minimize shall be task trained and certified as required by the Career injury and property damage mishaps associated with aircraft Field Education and Training Plan (CFETP) and any other ground servicing operations and other allied support functions MAJCOM or local maintenance/training directives. accomplished concurrently with ground servicing. Addition- ally, this technical order provides information on the nature of, 1.4.3 Bonding. Electrically connecting two or more compo- and methods to minimize electrical hazards associated with nents of a system to equalize voltage potential. servicing operations. 1.4.4 Cathodic Protection. A means of protecting metals 1.2 SCOPE. from corrosion by making the metal the cathode of an electro- lytic cell. Pipelines, tanks, and steel piers (wharves) are often This technical order applies to all USAF aircraft ground ser- protected in this manner. vicing operations as well as servicing of non-USAF aircraft when performed at USAF or non-USAF installations by 1.4.5 Chief Servicing Supervisor (CSS) (Chapter 5). USAF personnel, or under USAF control. Excluded is the ser- The person responsible for on-site supervision of all aspects of vicing of air launched missiles and stores. Where procedures concurrent fuel servicing operations. The individual shall in this technical order conflict with Mission/Design/Series receive familiarization training on safety requirements and (MDS) specific technical order procedures, the MDS specific potential hazards of concurrent servicing operations and be technical order shall take precedence. Technical order changes certified as required by MAJCOM and local maintenance/ are submitted in accordance with TO 00-5-1. training directives. 1.3 RESPONSIBILITIES. 1.4.6 Concurrent Servicing (Commercial, Contract, Cargo, Passenger Aircraft). The simultaneous servicing of Commanders, managers, and supervisors shall ensure that all fuel or oxygen with either passengers on board or the perfor- aircraft servicing personnel under their supervision are knowl- mance of minor maintenance, fleet servicing, or baggage or edgeable of requirements in applicable directives and technical cargo loading/unloading. orders, proficient in accomplishing servicing operations and exercise safe practices during ground servicing operations. 1.4.7 Concurrent Servicing Area. The area within an imaginary circle around the aircraft that includes the fuel ser- 1.4 DEFINITIONS. vicing safety zones and extends at least 10 feet outboard of the aircraft wingtips, tail, and nose. The following definitions apply in regards to the text of this technical order. 1.4.8 Concurrent Servicing Operations (CSO) Support- ing Combat Sortie Generation (CSG). The simultaneous Shall and Will - Indicate mandatory requirements. Will fueling, and munitions/ammunition loading/unloading, aircraft is also used to express a declaration of purpose. reconfiguration, aircraft -6 TO inspections, and other aircraft servicing such as oil, nitrogen, and hydraulic fluid. Oxygen Should - Indicates a preferred method of accomplish- servicing will not be accomplished during fuel servicing. ment. 1.4.8.1 CSOs Requiring a Concurrent Servicing Super- May - Indicates an acceptable or suggested means of visor (CSS). The key function requiring the CSS is refuel- accomplishment. ing/defueling. When no refuel/defuel operations are taking place concurrent with any other maintenance/munitions tasks, 1.4.1 Aircraft Fuel Servicing. The movement of fuel to or a CSS is not required. from an external source to or from an aircraft, including the time during which fueling connections and disconnections are 1.4.8.1.1 Simultaneous fuel servicing with aircraft -6 and made (bond wires and nozzles). This also includes checks -6WC inspections. made to verify fuel quantity and time to clean up or neutralize any spilled fuel. 1.4.8.1.2 Simultaneous fuel servicing with munitions/ammu- nition loading/unloading. Change 7 1-1  Downloaded from http://www.everyspec.com TO 00-25-172 1.4.8.1.3 Simultaneous fuel servicing with aircraft reconfigu- maintain fuel flow. Releasing the positive hand pressure stops ration. fuel flow. 1.4.8.1.4 Simultaneous fuel servicing and other aircraft ser- 1.4.11 Defueling. The movement of fuel from an aircraft to vicing such as oil, nitrogen, and hydraulic fluid. an external source. 1.4.8.1.5 Simultaneous fuel servicing with loading/unloading 1.4.12 Flashpoint. The lowest temperature at which vapors of munitions/ammunition, aircraft reconfiguration, aircraft -6 arising from fuel will ignite (momentarily flash) on applica- TO inspections, and other aircraft servicing such as oil, nitro- tion of a flame or spark. gen, and hydraulic fluild. 1.4.13 Fuel Servicing Hose. NOTE 1.4.13.1 Soft (Collapsible). Rubber hose conforming to Electrical “power-on” portions of -6 inspections are MIL-H-26521, flexible, capable of being completely flattened not authorized during concurrent munitions loading/ and coiled for ease of storage and handling. unloading and fuel servicing operations. Power-on portions of -6 inspections are accomplished prior to 1.4.13.2 Semi-hard (Noncollapsible). Rubber hose con- or upon completion of the concurrent munitions load- forming to MIL-H-6615 and MIL-H-370, braided, loomed, or ing/unloading and fuel servicing operation. plied reinforcement, not capable of being coiled easily. 1.4.8.2 CSOs Not Requiring a Concurrent Servicing 1.4.13.3 Hard (Noncollapsible). Rubber hose conforming to MIL-H-27516 and MIL-H-26894, braided, loomed, or plied Supervisor (CSS). reinforcement with a steel spiral wire wound between rein- forcing members. 1.4.8.2.1 Any or all simultaneous munitions/ammunition loading/unloading with aircraft -6 and -6WC TO inspections, 1.4.14 Fuel Servicing Safety Zone (FSSZ). The area aircraft reconfiguration, and other aircraft servicing such as within 50 feet of a pressurized fuel carrying servicing compo- oil, nitrogen, and hydraulic fluid. (When no refuel/defuel oper- nent, i.e., servicing hose, fuel nozzle, Single-Point Receptacle ations are taking place concurrent with any other maintenance/ (SPR), hydrant hose cart, ramp hydrant connection point, etc., munitions tasks, a CSS is not required). and 25 feet around aircraft fuel vent outlets. NOTE 1.4.15 Fuel Servicing Vehicle. A mobile self-propelled vehicle designed with a power take-off and filter separator to When a CSS is not required the weapons load crew transport, receive, and dispense fuel. The most common type chief is responsible for and controls all actions con- of fuel servicing unit in the Air Force inventory is R-11. cerning the aircraft during loading and unloading op- erations. See AFI 21-101, Chapter 4 for detailed 1.4.16 Fuel Spill. Dripping, splashing or overflow of fuel. responsibilities. The fuel spill classifications are: 1.4.9 Concurrent Servicing Supervisor (CSS) Combat 1.4.16.1 Class I spills involve an area less than two feet in Sortie Generation (CSG). (Chapter 6). The on-site supervi- any plane dimension (direction). Using agency fireguards, sor responsible for all aspects of fuel servicing, munitions/ determine if these spills create a fire hazard to the aircraft or ammunition loading/unloading, aircraft reconfiguration, air- equipment. Generally, these spills need only be monitored craft -6 TO inspections, and other aircraft servicing performed until the aircraft is dispatched. during CSOs. The key function requiring the CSS is refueling/ defueling. When no refuel/defuel operations are taking place 1.4.16.2 Class II spills involve an area not over 10 feet in concurrent with any other maintenance/munitions tasks, a CSS any plane dimension (direction), or not over 50 square feet and is not required. The individual shall receive training on safety not of a continuing nature. Post the area, using agency fire- requirements and potential hazards of concurrent servicing guards, and immediately notify the fire protection organization operations and be certified as required by AFI 21-101, MAJ- and the base agency responsible for cleanup of hazardous COM, and local maintenance/training directives. spills. 1.4.10 Deadman Control. An electrically, hydraulically, 1.4.16.3 Class III spills involve an area over 10 feet in any mechanically, or pneumatically operated switch or valve plane dimension (direction) or over 50 square feet in total area requiring continuous positive hand pressure by the operator to or of a continuing nature. Post the area, using agency fire- guards, and immediately notify the fire protection organization and the base agency responsible for cleanup of hazardous 1-2 Change 7  Downloaded from http://www.everyspec.com TO 00-25-172 spills. These conditions shall be considered a ramp mishap 1.4.26 Intrinsically Safe Radio. A radio incapable of caus- (accident or incident). The senior fire official will respond ing ignition of a mixture of flammable or combustible material with the personnel, vehicle(s) and equipment necessary to con- in the air in its most easily ignitable concentration. This radio trol and contain the hazardous condition until the local/base is suitable for use in Class I, Division 1 (Zone 1), Group D agency responsible for cleanup can properly dispose of the hazardous areas in which fuel vapors exist. The radio must hazardous material(s). contain a label reflecting compliance with NFPA 70 for use in Class I, Division 1 (Zone 1) locations. Radios built according 1.4.17 Flow Through Revetment (FTR). An open ramp to Military Standard 810 meet the intrinsic safe requirements parking area with protective earth filled steel walls several feet of NFPA 70. thick designed to protect the aircraft. 1.4.27 Lateral Control Pit. An area below ground level 1.4.18 Grounding (Electrostatic). A path or means to adjacent to the parking ramp containing components of the remove any electrostatic charge buildup on a conductive hydrant system and controlling one or more hydrant outlets. object by connecting that conductive object to earth. 1.4.28 Lateral Control Pit Switch. An on/off explosion 1.4.19 Hose Cart (MH-2 Series). A trailer-mounted unit proof switch, usually located at the hydrant control pit. containing a filter separator, meter, hoses, and nozzles for con- necting the hydrant outlet to the aircraft. It may be used with 1.4.29 Lateral Control Pit Emergency Switch. A switch the Type II system or Type I modified system. It may be located at the control pit which overrides all other on/off equipped with a Y-adapter to permit refueling two aircraft at switches and shuts down the entire hydrant system. Type II the same time. It may also be used to refuel commercial air- craft requiring simultaneous servicing into both wings. hydrant systems also have an emergency switch at each outlet. 1.4.20 Hot Pad Refueling Supervisor. A person (five- 1.4.30 Liquid Oxygen (LOX) Servicing Safety Zone. The level or higher) with overall supervisory responsibility for area within 20 feet of pressurized LOX servicing equipment, simultaneous hot refueling operations. servicing hose, aircraft servicing connection point or vents. 1.4.21 Hot Refueling/Defueling. The transfer of fuel into 1.4.31 Pantograph. A fuel servicing system consisting of or out of the fuel tanks of an aircraft with one or more aircraft multiple rigid sections of tubing interconnected by articulating engine operating. and swivel couplings with fuel flow controlled by a deadman switch. 1.4.22 Hot Refueling/Defueling Area. The area within 50 feet of a hot refueling/defueling operation. Refer to Table 3-2 1.4.32 Ramp Grounds. Ground rods used on ramps or for specific requirements. aprons for protection against stray electrical currents, electri- cal faults, lightning, and static electricity. 1.4.23 Hydrant Hose Truck. A self-propelled aircraft fuel servicing unit capable of dispensing up to 1200 GPM, 1.4.33 Rapid Defueling. A means to rapidly off load fuel equipped with inlet and discharge hoses, meter, filter/separa- from aircraft either by operating an outboard engine or exter- tor, various pressure and flow control valves, and safety nal hydraulic test stand to power on-board refueling pumps. devices. Hydrant Hose Trucks (HHT) are also known as Hydrant Servicing Vehicles (HSV). 1.4.34 Refueling. The movement of fuel from an external source to an aircraft. 1.4.24 Hydrant Operator. A person (AFSC 2F0X1) who activates electrical and/or magnetic switches and valves neces- 1.4.35 Remote Control Fuel Switch. A portable pushbut- sary for fuel to flow from the hydrant system to the aircraft on ton on/off explosion-proof switch attached to the hydrant out- the Type I, Type II, Type III, and Type IV hydrant systems. let by an insulated, flexible control cable and used to start and Operates hydrant hose truck, hose cart, or pantograph. The stop fuel flow. This may also be a magnetic switch with a Type IV operator is positioned at the control pit, maintains lanyard. visual contact with all crew members, monitors pressure gauges and the meter in the hydrant pit. In an emergency or 1.4.36 Servicing Crew Member. A person who performs upon signal from the aircraft refueling or pad-refueling super- duties required by the specific servicing checklist under the visor, they activate the emergency electrical shutdown switch supervision of the oxygen, refuel/defuel supervisor, or chief and the fire suppression system. servicing supervisor. For C-9 medical evaluation aircraft only, the Chief Servicing Supervisor (CSS) can also function as the 1.4.25 Hydrant Outlet. A fueling valve located on the park- Refueling Panel Operator (RPO) and the Single Point Recep- ing ramp where the fuel hose or hose cart is connected. tacle Monitor (SPRM). In this case, a person in AFSC Change 7 1-3  Downloaded from http://www.everyspec.com TO 00-25-172 4NOXX or X8AOO can perform duties as a safety observer in 1.4.39 Supervisory Contractor Representative (SCR). front of the C-9 aircraft but must be on intercom with the CSS The person responsible for the control of contractor personnel and the aircrew. involved in concurrent servicing operations, fuel nozzle con- nection/disconnection, and operation of refueling control panel 1.4.37 Combat Sortie Generation. Combat sortie genera- on commercial aircraft. tion is a process by which mission capable fighter aircraft are generated in a minimum amount of time, during peacetime or 1.4.40 Support Equipment (SE). All equipment required wartime, through separate 2AXXX and 2WXXX tasks or by on the ground to make a weapon system, command and con- Concurrent Servicing Operations (CSO). Combat sortie gener- trol system, subsystem, or end item of equipment operational ation may include fueling, munitions/ammunition loading/ in its intended environment. unloading, aircraft reconfiguration, -6 TO inspections, and other servicing requirements. 1.4.41 Switch Loading. The introduction of a low volatility fuel such as JP-8 into a tank containing a residue of a higher 1.4.38 Shelters. volatility fuel such as JP-4, and vice versa. 1.4.38.1 Aircraft Alert Shelter. A covered unhardened/ 1.4.42 Transferring of Fuel. The movement of fuel within unprotected structure with or without doors from which a mis- the aircraft internal fuel system. This term also applies to bulk sion ready aircraft can be launched. Aircraft are expected to movement of fuel. start engine within the shelter and taxi out of the shelter under their own power. Some shelters are designed to allow the air- 1.5 REPORTING OF HAZARDS. craft to taxi in as well. Some shelters provide protection from the elements, others are complete hangars. Any potential hazard shall be reported to local supervision. Examples of hazards that should be reported are: 1.4.38.2 Hardened Aircraft Shelters (HAS)/Protective Aircraft Shelters (PAS). Refer to Figure 4-1. a. Glowing or crackling fuel. 1.4.38.2.1 First Generation Shelters. These shelters have b. Visible areas or sparks from any source. two manually operated, vertically hinged, prow-shaped, recessed, metal aircraft entry doors. Usable floor space is 48 c. Electrical shocks to personnel. feet by 75 feet. d. Aircraft with defective grounding/bonding receptacles. 1.4.38.2.2 Modified First Generation Shelters. These shelters have one electrically operated, side opening, roller e. Fluid leaks, mists, or sprays supported, prow-shaped, externally mounted, metal aircraft entry door. Usable floor space is 48 feet by 100 feet. 1.6 RECOVERABLE PRODUCTS. 1.4.38.2.3 Second Generation Shelters. These shelters Recoverable products resulting from ground handling and ser- have two electrically operated, side opening, roller supported, vicing of aircraft/equipment will be handled in accordance externally mounted, reinforced concrete panel aircraft entry with federal, state, and local environmental directives or laws. doors. Usable floor space is 82 feet by 124 feet. Refer to AFI 23-502, Recoverable and Unusable Liquid Petro- leum Products, and TO 42B-1-23, Management of Recover- 1.4.38.2.4 Third Generation Shelters. Same as second able and Waste Liquid Petroleum Products. generation except usable floor space is 71 feet by 120 feet. 1.7 FUEL OR OIL SPILLS. 1.4.38.2.5 Protective Aircraft Canopy Shelters (PACS). These “carport type” shelters have fabric-covered canopies Fuel or oil spills will be reported to the base fire department designed to protect personnel and aircraft from the elements. and the civil engineering pollution control response team as They do not have doors or walls. required by local directives. Implement spill control proce- dures in accordance with local directives. 1-4 Change 7  Downloaded from http://www.everyspec.com TO 00-25-172 CHAPTER 2 ELECTROSTATIC HAZARDS AND STATIC GROUNDING AND BONDING 2.1 INTRODUCTION. electrostatic hazard. Under low humidity conditions, almost all Air Force issued garments can produce a static charge of suffi- Fire or explosion hazards are always present where fuels are cient potential to cause a discharge. The wearing of multiple handled. The grounding or bonding of all conductive parts of garment layers in itself does not cause an excessive static the system are an effective means of controlling hazards cre- charge to develop. However, never remove any garment while ated by electrostatic energy. Grounding is the process of con- in the refueling area. Antistatic finishes are not permanent and necting one or more metallic objects and ground conductors to are gradually removed by laundering or dry cleaning. In addi- ground electrodes. Bonding is the process of connecting two tion, antistatic finishes are not as effective in low humidity or more metallic objects together by means of a conductor. conditions or at low temperatures. Moisture increases the elec- Bonding is done to equalize electrostatic potential between trical conductivity of clothing and this is why high humidity two or more conductive objects. conditions minimize static build-up problems. Body perspira- tion has the same effect by adding moisture to undergarments 2.2 ELECTROSTATIC CHARGES. and outer clothing. Insulated foot wear limits the dissipation of static charges to the ground. Both rubber soles and composi- Static electricity is frequently generated when two materials tion soles are relatively poor conductors but most have suffi- are brought into contact and then separated. Removing items ciently low resistances to dissipate static charge. The same is of clothing, dust blowing across a surface, a liquid flowing true for gloves. In most cases, personnel can dissipate static through a pipe, and moving vehicles are common means of charges through gloves or soles, but, as an added precaution, producing a static charge. Static electricity has been the igni- personnel should touch a grounding/bonding point with their tion source for many petroleum fires. Protection against static bare hand. Personnel wearing Chemical Warfare Defense charge buildup is obtained by dissipating static charges Ensembles (CWDEs) do not need to remove any clothing to through proper connections to the ground or equalizing static dissipate static buildup. They can adequately ground or bond charges through effective bonding. themselves directly through the CWDE boot or glove. Cloth- ing having a surface resistivity of less than 1012 ohms per 2.3 STRAY CURRENTS. square or an inside-to-outside resistance of less than 1010 ohms will dissipate static charges through normal grounding Electrical currents flowing through paths other than their procedures or equalize static charges through normal bonding intended circuits, or any extraneous current in the earth are procedures. Many aircraft have avionics Line Replaceable stray currents. Since Air Force fixed refueling systems are in Units (LRUs) having electronic components that are sensitive contact with the earth, stray currents sometimes take paths to static discharges. When removing or replacing these units, through the conducting parts of the system. Grounding or personnel should electrostatically equalize themselves with the bonding does not eliminate stray currents. aircraft prior to touching the LRUs. The preferred contact/ equalization point is just inside the applicable avionics bay. 2.4 COMBUSTION. When handling or carrying the LRUs, avoid touching any con- nector pins or jacks because they might be directly connected Combustion requires fuel vapors, air (oxygen), and an ignition to sensitive electronic components. Any connector or jack source. Flammable vapors exist over the surface of JP-4 at caps/covers should be installed whenever the LRUs are dis- -10ºF and above, and aviation gasoline at -50ºF and above. connected from the aircraft. Once the LRUs are in the avionics Ignition of these vapors can be caused either by a spark or shop for repairs, standard safeguards as outlined in MDS spe- flame. When the proper ratio of fuel vapor and air is present, cific technical orders and TO 00-25-234 will suffice to prevent ignition will result in fire or explosion. Energy levels associ- electrostatic damage. When handling munitions or explosive ated with electrostatic discharges may be sufficient to ignite devices, avoid touching bare electrical primers, exposed pro- fuel vapors. pellants, and explosive chemicals. 2.5 ELECTROSTATIC CHARGING OF PERSONNEL. 2.6 TANK FILLING. The normal activity of personnel involved in refueling opera- During the tank filling process, the electrical potential of the tions can generate static electricity charges on their clothing. liquid fuel surface may reach thousands of volts. A spark may- Humidity greatly affects the static electricity characteristics of discharge from the surface of the liquid to the internal surfaces clothing materials. The lower the humidity, the higher the of the tank or any other object in the tank such as piping, Change 7 2-1  Downloaded from http://www.everyspec.com TO 00-25-172 fittings, or foreign material. If the fuel vapor-air mixture above 2.8 OTHER SOURCES OF STATIC ELECTRICITY. the liquid surface is in the explosive range, such a spark will provide ignition with disastrous results. Objects in a fuel tank Operating aircraft engines, rotor blades, and propeller blades, will collect a charge from the fuels and become similar to an can generate high static electricity voltages. These static electrical condenser (capacitor) plate. The potential required sources are especially hazardous because the static voltages for a discharge from these floating objects to the tank is less may be generated continuously as long as the engines/blades than that required to cause a discharge from the liquid surface continue to operate. to the tank. Therefore, the hazard is greatly increased by the presence of such objects. The Air Force now incorporates a 2.9 GROUNDING AND BONDING POLICY. conductivity additive to decrease the relaxation time of elec- trostatic charges in order to preclude these problems. Also, the Grounding is not required for parked aircraft or aircraft fuel use of a higher flash point fuel such as JP-8 or JP-5 in lieu of servicing operations unless required by specific MDS techni- JP-4, when permitted by the applicable aircraft technical cal orders. Aircraft will be bonded to fuel servicing equipment orders, reduces the vapor ignition hazard. Research has sug- at all times during fuel servicing operations. Hydrant fuel ser- gested that if fuel flow is kept below the following maximum vicing vehicles and hosecarts will also be bonded to the rates, hazardous levels of static electricity charges will not hydrant system in addition to bonding to the aircraft. (This occur: hydrant-servicing vehicle or hosecart bonding requirement applies only when the aircraft is not grounded.) NOTE These limits do not apply for JP fuels having anti- static additives with at least 50 Conductivity Units (CU). Aircraft/equipment must be grounded and/or bonded Nozzle/Hose/ Gallons/Minute prior to connecting the single point nozzle to the air- Pipe Diameter craft; however, the hydrant coupler will be connected 0.75 inches 32 to the hydrant outlet prior to bonding the hydrant- 1.50 inches 125 servicing vehicle to the aircraft. 2.00 inches 191 3.00 inches 260 4.00 inches 385 5.00 inches 542 6.00 inches 693 Grounding/Bonding clamps/plugs shall not be al- lowed to drag across the ramp. Clamps/plugs shall be 2.7 LIGHTNING. carried to reels on equipment. Even if an aircraft were statically grounded, a severe hazard to NOTE servicing personnel could exist if lightning strikes the aircraft or within several hundred feet of the aircraft. Servicing per- If the bonding wire becomes disconnected, recon- sonnel should be evacuated from the area when there is danger nect it immediately. The sequence makes no differ- of a direct or close proximity lightning strike. Personnel inside ence. an aircraft will be in no danger as long as all aircraft doors, hatches, and canopies are closed. Potentials in the range of Bonding is not required for all-metal pantograph, several million volts exist between clouds and earth. High as long as there is a continuous metal structure points such as vertical stabilizers and antenna masts are most from the fuel servicing equipment to the aircraft. susceptible to strikes. These strikes are of short duration (approximately 1/100 second duration per strike) and even a. Grounding of aircraft or supporting servicing equipment though high energy levels exist, the ramp grounding system during either fuel servicing, Liquid Nitrogen (LIN) ser- will generally conduct the energy safely to earth. An electrical vicing, or Gaseous Nitrogen (N2) servicing is not storm can be dangerous even if several miles from the servic- required. Recent electrostatic studies have demonstrated ing area. that grounding aircraft or supporting servicing equip- ment for these situations is unnecessary. Unless required by specific MDS technical orders, grounding is not required for aircraft except when aircraft are: 2-2 Change 12  Downloaded from http://www.everyspec.com TO 00-25-172 (1) Undergoing munitions loading/unloading operations. (2) A multiple receptacle junction box may be con- structed to reduce the number of grounding/bonding (2) Undergoing electrostatic painting, bead blasting or cables around a work site. The multiple receptacle fuel system repair. junction boxes must be built from a high quality con- ductive material. The receptacles installed in the (3) Connected to a hangar electrical power source. (This junction box must be female extension jacks, NSN requirement does not apply to portable ground power 5935-00-432-9340. All multiple receptacle junction units, including MD/4MO mobile electric power boxes will be given a continuity test at the time of units, inside hangars.) Locations with low humidity fabrication and at any time afterwards when a lack of may want to ground an aircraft one time after land- continuity is suspected due to damage or corrosion. ing to dissipate any static charges generated on the Resistance between the body or frame of the junc- aircraft while flying through dust or precipitation. tion box and the installed female extension jacks This will be accomplished by momentarily connect- shall not exceed 10 ohms. ing a cable from an earth ground to any unpainted metallic aircraft surface. 2.10 GROUNDING. b. Overwing (open port) fuel servicing operations require a The proper connection sequence to ground an aircraft using a bonding wire between the fuel source and the aircraft, clamp-plug unit is (1) attach a grounding clamp to the earth and a separate bonding wire for each open port fuel grounding point, (2) insert the plug of the other end of the nozzle. The first bonding wire equalizes static charges clamp-plug unit into an aircraft receptacle jack assembly or that accumulate while fuel is flowing during fuel servic- attach the clamp of the other end of the clamp-plug unit to an ing operations. If the nozzle is attached to a conductive unpainted metal portion of the aircraft. braided hose, this first bonding wire is not necessary. The second bonding wire prevents a charged fuel nozzle 2.11 AIRCRAFT INSTALLED ELECTRICAL RECEPTA- from creating a spark at the open fuel port when the fuel CLES FOR GROUNDING AND BONDING. nozzle first touches the aircraft. Ladders used for over- wing refueling do not require bonding to the aircraft. Aircraft system managers, in coordination with lead com- mands, shall ensure applicable aircraft technical orders include c. Drop, external, ferry, Benson, and weapons bay fuel a requirement to inspect aircraft electrical receptacles during tanks do not need to be grounded when stored, parked, or at appropriate maintenance interval or after receptacle or during other periods when in-tank work is not being maintenance. The inspection methods and frequency will also accomplished. be included in the specific aircraft technical orders. In the absence of any inspection methods listed in aircraft technical d. The connecting of more than one grounding/bonding orders, receptacles will be inspected and tested in the follow- cable by any means (clamp-to-clamp, clamp-to-handle, ing manner: etc.) using any method (stacking, piggy-backing, nose- to-nose, etc.) is not authorized, except as specified in (1) a. Visually inspect for loosely mounted receptacles and or (2) below. evidence of corrosion on washers, lugs, nuts, and the aircraft skin. There shall be no free axial movement of (1) A conversion jumper may be constructed to provide the contact tip in the plug due to clearance between the bonding capability for over-the-wing fuel servicing contact (spring) tip and plug. Free axial movement indi- nozzles when aircraft to be serviced are not equipped cates the contact spring is not maintaining a proper con- with electrical jack assembly receptacles. Conver- nection with the plug. sion jumpers will be made from only the parts listed below and assembled as follows: connect an electri- b. Inspect and test for electrical resistance as follows: cal ground wire rope (cable), NSN 4010-00-575- 6234 or NSN 4010-00-286-2681, to terminals of a (1) Electrical resistance between receptacles and clean female extension jack, NSN 5935-00-432-9340; cut aircraft skin shall be one ohm or less on an 815AFA electrical ground wire rope (cable) to length bridge or equivalent. required; place a red warning streamer, NSN 8345- 00-673-9992, on cable and then install an electrical (2) A stainless steel plug, part No. MS3493, NSN ground clip, NSN 5999-00-134-5844 or NSN 5999- 5935-00-572-5174, will be inserted into the recepta- 00-204-8350 on free end of cable. Perform a conti- cle jack assembly. Check to ensure it is firmly nuity check to make sure conversion jumper is elec- seated. Electrical resistance measured between the trically interconnected throughout assembly. plug and cleaned aircraft skin must be one ohm or Change 10 2-3  Downloaded from http://www.everyspec.com TO 00-25-172 less, but not zero. The aircraft technical order is a. Clamp (part No. M83413/7-1). Replace clamp if jaws applicable if it specifies a value less than one ohm. A are deformed, spring is weak, or other defect is evident clamp, part No. M83413/7-1, may be substituted for that would prevent a good connection. The M83413/7-1 the steel plug on aircraft not equipped with the jack will be used unless there is insufficient space in a assembly, part No. MS90298, when attached to des- ground connection pit. If an M83413/7-1 will not fit, ignated grounding lugs on an unpainted part of the then a robust ‘alligator’ type clamp can be used. aircraft landing gear. b. Plug (part No. MS3493 only). Inspect the electrical (3) A firm pull will be required to withdraw the plug ground/bond plug for corrosion, weakness, or loose nut from the receptacle. Approximate pull will measure and replace if heavily dented or deformed, particularly 8 - 14 pounds on a spring scale, NSN 6635-00-578- around the portion which connects with the aircraft 5286, or equivalent. A pull of less than eight pounds grounding/bonding receptacle. indicates a weak or damaged receptacle and will be replaced. A pull of over 14 pounds indicates a possi- c. Cable (3/32 inch, NSN 4010-00-286-2681 or NSN ble corroded receptacle which might warrant 4010-00-575-6234 only). Replace cable if more than replacement. one-third of the cable wires are broken. If electrical con- tinuity is suspect, the cable will be checked and repaired NOTE if found to be bad. A locally fabricated tool assembly may be used to NOTE assist in resistance test on aircraft installed ground- ing/bonding receptacles. The assembly consists of a Deteriorated plastic coating does not affect the elec- grounding/bonding plug, NSN 5935-00-572-5174, trical capability of the cable. grounding/bonding cable, NSN 4010-00-286-2681, six inches in length, and a wire rope swaging sleeve, d. Clamp-Plug Unit. The primary unit used by Air Force NSN 4030-00-132-9163. Assemble as follows: install activities consists of a clamp and plug attached to oppo- one end of six-inch grounding/bonding cable into site ends of a sufficient length of 3/32-inch cable. The grounding/bonding plug jam nut. Using opposite end unused handle of the clamp can be equipped with a of six-inch grounding/bonding cable, form a loop sufficient length of 3/32-inch cable terminating into a ending near grounding/bonding plug jam nut. Secure plug. A warning streamer ‘‘REMOVE BEFORE loop by placing both ends of grounding/bonding ca- FLIGHT’’ will be attached to the plug end of the cable. ble in a wire rope swaging sleeve and crimp. The Other clamp-plug unit configurations may be used as loop can now be used as connection point for spring mission needs dictate as long as specified hardware is scale to conduct pull resistance test. used to construct them. The cable retainer (cap) of the two-piece plug and cap assembly design may be spot (4) Defective jack assemblies will be replaced with part welded to prevent loosening of the cable and possible No. MS90298 receptacles. Latest assembly has a loss of continuity. one-half inch curved base on contact. Outdated air- craft jack assemblies which are to be replaced are e. Locally-fabricated clamp-plug units will be checked one-fourth inch across contact base with two solder with a multimeter for continuity prior to being placed lugs and a right angle bend near the end of contact. into service. The continuity check test points should be from the inside of clamp jaws to end of plug. A continu- c. After receptacles meet the criteria outlined in step b, ity check should be performed any time a lack of conti- continuity check will be accomplished to assure all are nuity is suspect due to corrosion buildup or damage. A electrically interconnected through the aircraft airframe nominal 100-foot length of 3/32-inch diameter stainless and/or skin. For this test, use a portable static ground- steel cable will have a maximum allowable resistance of ing/bonding cable. Resistance of the portable grounding 10 ohms. cable shall be balanced out prior to use. In all cases, the resistance between receptacles should be one ohm or f. When grounding is required for bare base operation, less. grounding rod, NSN 5975-00-240-3859, will be used. 2.12 GROUNDING/BONDING HARDWARE. g. Static Grounding/Bonding Reel Inspection Criteria. All installed static discharge reels shall be given a continu- The following hardware items will be used and inspected as ity test at the time of initial installation and at any time a indicated: lack of continuity is suspected due to damage or corro- 2-4 Change 10  Downloaded from http://www.everyspec.com TO 00-25-172 sion. The test will be accomplished by extending the Weapons loading personnel will ground or bond themselves entire length of the cable and measuring the continuity when entering fuel servicing safety zone and before handling between the plug or inside the clamp jaws to the equip- electrically-primed munitions. Always avoid touching the ment frame on which the reel is mounted. Resistance primers of electrically-primed munitions (i.e., impulse car- between these two points shall not exceed 10 ohms. tridges and 20 MM ammunition). Personnel entering a fuel Prior to each use, the grounding reel shall be visually servicing or weapons loading area should also ground or bond inspected for security of mounting on a rigid base and themselves to the closest piece of grounded or bonded aircraft evidence of any corrosion or damage. or equipment. 2.13 PERSONNEL GROUNDING/BONDING. 2.13.1 CWDE Resistance Tests. Chemical Warfare Defense Ensemble (CWDE) resistance tests have shown that Personnel will use grounding or bonding techniques to dissi- static charges can be effectively dissipated through CWDE pate or equalize static charges that have accumulated during gloves (preferred) which have resistances of approximately ground servicing operations. During an aircraft fuel servicing 10,000 ohms. Personnel can ground or bond themselves operation, a static spark in the wrong place could ignite a fuel directly through the glove of CWDE; therefore, removal of vapor concentration. Fortunately, normal fuel servicing opera- any of the ensembles for grounding or bonding purposes is not tions have ignitable flammable vapor concentrations only near required. aircraft fuel vent outlets. These vapor concentrations generally dissipate rapidly to levels that are too lean to be ignited. An 2.13.2 Servicing Fuel with Personnel Armor ((Flak Vest) aircraft fuel system failure, however, could result in fuel spill- or Individual Body Armor (IBA)). When servicing aircraft, ing from vent outlets or from other locations. This increases personnel armor should not be worn while performing fuel possibility of an ignition from a static spark. Therefore, prior servicing operations except in actual combat. Tests have to any fuel servicing or munitions loading/unloading opera- shown that static charges cannot be effectively dissipated by tion, personnel involved in the operation will ground or bond normal grounding or bonding procedures. Personnel armor themselves to a suitable grounding/bonding point or to a bare acts as an electrical insulator with an extremely high resis- (unpainted) portion of the aircraft. This bonding point should tance. Personnel armor will generate and accumulate a static be at least three feet from any aircraft fuel vent outlet. If a charge during a person’s normal movement. This accumulated spark occurs during the initial grounding or bonding proce- charge will then be equalized on the person’s body. When dure, then atmosphere conditions are ideal for additional static normal grounding or bonding procedures are used, the charge charge accumulations; therefore, under this condition, person- on the person’s body will be dissipated or equalized, but the nel will ground or bond themselves periodically. If no spark charge on the personnel armor will not. An individual wearing occurs during the initial grounding or bonding procedure (or personnel armor will always ground or bond himself when other symptoms do not occur), then additional grounding or approaching an aircraft and prior to beginning work. If no bonding is not necessary. All personnel will avoid grounding spark occurs during bonding or grounding, then conditions are or bonding themselves within three feet of aircraft fuel vent not present to accumulate a static charge with sufficient energy outlets. In addition, personnel conducting aircraft fuel vent to be hazardous; therefore, normal work may begin. If a spark checks will ground or bond themselves above waist level and does occur during bonding or grounding, the individual will at least three feet from fuel vent outlet prior to checking vent. ground or bond frequently during all work phases. Change 12 2-5/(2-6 blank) Downloaded from http://www.everyspec.com  Downloaded from http://www.everyspec.com TO 00-25-172 CHAPTER 3 GENERAL PROCEDURES 3.1 HOUSEKEEPING. 3.3 REFUELING. A clean work area makes a safer, more efficient operation. Pressurized refueling operations present a potential hazard for High standards of cleanliness shall be maintained in the haz- pressure leaks in equipment, pipes, and hoses. These failures ardous environment of aircraft ground servicing. Aircraft may cause a fine spray or mist to be present. If there is an parking areas, servicing aprons, fuel-servicing vehicles/equip- ignition source, there could be a fire regardless of the fuel’s ment, and Support Equipment (SE) compartments and sur- flash point temperature. Constant vigilance is needed to elimi- faces shall be kept free of debris and accumulation of oil, nate potential ignition sources from the servicing operations. hydraulic fluids, grease, or fuel. Personnel shall not be sub- A very small energy spark, for example, can ignite JP-4 fuel jected to increased risk to catch servicing fluids. If a spill vapors. The energy associated with metal tools being dropped occurs, it shall be controlled in accordance with local direc- on concrete, sparks generated when grounding or bonding tives once the aircraft and surrounding area are made safe. equipment, static electricity generated by personnel, the arcing Safe fuel servicing depends on keeping fuels in controlled of electrical/ mechanical equipment, and sparks/hot particles areas, not allowing spillage, and in keeping all ignition sources from an engine exhaust will ignite JP-4 fuel vapors. The less away from designated servicing areas. volatile petroleum products, such as JP-5 or JP-8 fuels, hydraulic fluids, or lubricants will not normally ignite unless 3.2 AIRCRAFT FLUIDS AND FUELS. the fluid is in direct contact with the ignition source. However, when JP-5 and JP-8 are discharged under pressure as a mist or The servicing of aircraft jet fuels, hydraulic fluids, and lubri- spray, it can ignite/flash as readily as JP-4. Open flames, elec- cants, presents a potential fire or explosion hazard. Flammable trical arcing, and hot surfaces are all potential ignition sources. mixtures can be formed by the vapors from JP-4 fuel, or from a spray or mist from a pressurized leak. Flammable vapors are 3.4 HOT SURFACES. present when the temperature of JP-4 fuel is greater than -10ºF. The vapor concentration depends on both the fuel tem- During refueling operations, the most common ignition perature and the ambient temperature. As the temperature sources present are hot surfaces above 750ºF, such as hot increases, the vapor concentration increases. The temperature brakes, bleed air ducts, hot engine, and APU surfaces. In many at which the concentration of vapors is sufficient to form a servicing operations, the hot surface may be present on the flammable mixture without propagating is known as the flash support equipment. If any heated metal object glows at all point temperature (-10ºF for JP-4). The term Lower Flamma- (any color) then its temperature is at least 900ºF and therefore ble or Explosive Limit (LFL or LEL) is the minimum concen- it is an ignition source. Once a fire starts, the spread is quite tration of vapor-to-air where flame will occur with an ignition rapid. The flame temperature is approximately 2000ºF and is source and continue to propagate. The Upper Flammable or well in excess of the melting temperature of aluminum alloys Explosive Limit (UFL or UEL) is the maximum vapor-to-air (1000ºF). Therefore, it is necessary to have fire-fighting equip- concentration above which propagation of flame will not ment immediately available as specified in Table 3-1. occur. These flammability limits (1.3 percent to 7.0 percent by volume) are established under controlled laboratory conditions 3.5 SERVICING SUPERVISOR. and are not directly applicable to servicing of aircraft. The fuel vapors, being heavier than air, tend to cling to the ground. At Fuel and water servicing will be conducted under the direct some distance above the fuel surface, the mixture of fuel control of the servicing supervisor. This supervisor will be vapors and air is flammable. Therefore, it is necessary to treat completely familiar with this technical order and the applica- any JP-4 fuel spill as being flammable. For comparison, JP-8 ble aircraft -2 technical order(s). In addition, this supervisor fuel has a much higher flash point and is relatively safer to must demonstrate a thorough knowledge of all equipment and use. The flash point of JP-8 is +100ºF, if the fuel temperature systems involved in the servicing operations and be qualified/ is less, JP-8 vapors will not be present above the surface of the certified in accordance with command directives. This super- fuel. Special care is still required for JP-5 and JP-8 fuels visor will insure that all applicable safety precautions and because many of the current Air Force aircraft use the fuel as a technical order requirements are taken and/or observed prior heat sink. These aircraft may have JP-5 and JP-8 fuel at 160ºF to, during, and after all servicing operations. This supervisor well above the flash point. Even during concurrent or hot- shall be responsible for assigning, monitoring, directing, and refueling operations the temperature of the JP-5 and JP-8 may controlling the duties of personnel under his or her supervision be well above the flash point and will behave just like JP-4. as follows: 3-1  Downloaded from http://www.everyspec.com TO 00-25-172 a. Check the markings on the refueling equipment to ver- ed from the SPR with the nozzle crank handle in the ify that the correct grade of fuel is being supplied to the open position is defective and must be removed from aircraft. service immediately. On aircraft with Refueling Teams, the team member connecting the refueling re- b. Control the movement and correct positioning of aircraft ceptacle will be responsible for testing the strainer and servicing equipment to, from, and within the servic- quick disconnect locking device for positive engage- ing areas. ment and assuring the refueling nozzle is securely locked. c. Verify the positioning and type of fire extinguishers. i. During over the wing/open port fuel servicing, ensure d. Evacuate non-essential personnel and equipment. the nozzle bonding wire is installed prior to opening the filler cap and that the fuel nozzle operator does not e. Shutdown powered SE not essential to servicing. If nec- block or jam the nozzle in the open position or leave it essary, move SE to a point where it will not obstruct unattended. operations. j. Ensure communication is available through Mainte- f. Verify that the correct grounding/bonding sequence is nance Operation Center (MOC) and/or the Command accomplished. Post to Fire Protection Agencies. g. Establish and maintain either visual or voice contact k. Ensure personnel are thoroughly familiar with and qual- with the control panel operator and/or servicing equip- ified to perform safe servicing operations. ment operator(s). If the aircraft is equipped with inter- com communications for ground operations, it will be l. Implement immediate shut down procedures if an used to maintain, voice contact with fuel panel opera- abnormal condition (i.e., power loss or fuel gage mal- tor(s) at all times during servicing. function) occurs during fuel servicing. NOTE 3.6 FUEL SERVICING SAFETY ZONE (FSSZ). For commercially contracted cargo-only aircraft This is the area within 50 feet of a pressurized fuel carrying where the fuel control panel/fuel system control servicing component; i.e., servicing hose, fuel nozzle, SPR, mechanism is located on the outside of the aircraft, hydrant hose cart, ramp hydrant connection point, etc., and 25 use of the aircraft intercom system by servicing feet around aircraft fuel vent outlets. (Aircraft interiors are not ground crews is not required. If any personnel (flight considered part of the FSSZ unless canopies, ramps, or doors or ground crew members) are to remain on board the are open exposing part of the aircraft interior to a spilled or aircraft during fuel servicing operations, then voice sprayed fuel hazard.) The fuel servicing safety zone is estab- contact must be established and maintained between lished and maintained during pressurization and movement of the personnel remaining on board the aircraft and the fuel. See Figure 3-1 for an example of the bomber pit refuel- fuel control panel operator(s) at all times during the ing safety zone and Figure 3-2 for an example of the fighter fuel servicing operation. refueling safety zone. During fuel movement, active ignition sources shall be removed and kept out of the fuel servicing h. For single point servicing, the fuel-servicing supervisor safety zone. Some examples of active ignition sources are will ensure the Single Point Receptacle (SPR) nozzle is open flames, sparks from internal combustion engines, and properly connected to the aircraft fueling receptacle. electrical arcing. NOTE 3.7 THE AIRCRAFT BEING SERVICED. Connect the SPR nozzle to the aircraft. With the SPR Non-essential aircraft electrical systems, including radar, shall nozzle crank handle in the closed position, check the not be activated on the aircraft during servicing operations strainer coupling quick disconnect device for positive unless absolutely required for servicing. However, if required, locking. Prior to pressurizing the hose, be sure the aircrew members may operate UHF/VHF cockpit radios. The nozzle is securely locked to the aircraft by attempting power off portion of aircrew walkaround inspections may be to remove the nozzle with the nozzle crank handle in performed when essential to meet established operational turn- the open position. Any nozzle that can be disconnect- around requirements. 3-2 Change 7  Downloaded from http://www.everyspec.com TO 00-25-172 3.8 ADJACENT AIRCRAFT. servicing operations, unless otherwise specified in the applicable aircraft and equipment repair technical Aircraft parked as prescribed in AFH 32-1084 and which orders, or when TO 31Z-10-4 procedures are used to intrude into the fuel servicing safety zone shall not be: insure a safe distance. Satellite communications (SATCOM) radios may be operated in the transmit a. Involved in engine starts or engine trim operations. mode if the antenna beam is pointed at least ten degrees above the horizon. b. Radiating electromagnetic energy. c. Do not start servicing operations (any movement of fuel, c. Using NDI or welding equipment. water, environmental fluid, oil, hydraulic fluid, oxygen, nitrogen, or hydrazine) whenever one of the following d. Involved in any maintenance requiring: conditions exists. If servicing operations are already in (1) Energizing or de-energizing external electrical cir- progress, terminate as soon as practical: cuits. (1) When a lightning advisory has been issued indicat- (2) Disconnecting combustible fluid carrying lines, ing an electrical storm is within five nautical miles except those equipped with non-spill, quick discon- (5.75 miles) of the servicing area. nects. (2) Winds reach velocities hazardous to the aircraft or e. Moved under its own power. servicing operations. Specific high wind restrictions will be developed by base-level personnel for each NOTE base supporting a flying mission. However, normal maintenance, including pre/post- (3) Fire in the vicinity is generating hot ashes. flight inspections involving internal aircraft electrical power, may be performed on adjacent aircraft provid- (4) In those cases where on-scene fire protection is ing there are no spilled flammable liquids. required, if an aircraft crash/fire occurs at the same airfield, servicing operations already underway will 3.9 SERVICING CONSTRAINTS. be stopped and fuel-servicing equipment will be dis- connected. No new servicing operations will be The following constraints apply during servicing operations: started until the crash/fire is declared under control a. During servicing, only those personnel actually required by the base Fire Chief or Senior Fire Officer (SFO), for the operation shall remain in the fuel servicing safety his designated representative, or the on-scene com- zone. Aircrews on commercial contract cargo-only air- mander, and the required level of fire protection is craft may remain on board the aircraft during servicing available to support servicing operations. operations. Personnel receiving training on specific tasks required to complete the fuel-servicing operation (5) In those cases where on-scene fire protection is are allowed in the FSSZ if they are under the direct required, in the event of an In-Flight Emergency control and supervision of the fuel servicing supervisor. (IFE) or crash warning resulting in the departure of Quality inspectors may enter the FSSZ to perform qual- the on-scene fire vehicle, servicing operations ity assurance functions. Personnel performing autho- already underway must be stopped. No new servic- rized functions on adjacent aircraft, which intrude into ing operations may be started without the concur- the FSSZ, may remain on duty with the adjacent air- rence of the base Fire Chief, his designated craft. The servicing supervisor will coordinate with all representative, or the on-scene commander, or until affected personnel so that these restrictions are the IFE or crash warning has been cancelled. As a observed. There shall be no smoking within 50 feet of condition of continuance during IFEs, either an oper- any aircraft or servicing operation. Servicing operations ational fixed, skid mounted, or portable Aqueous shall not begin if any indication of ‘‘hot brakes’’ are Film Forming Foam (AFFF) fire suppression system noted. discharging through oscillating nozzles or at least one fully manned aircraft rescue and fire fighting b. Aircraft radar and High Frequency (HF) radios shall not vehicle must be positioned at the aircraft fuel servic- be operated in the transmit mode within 300 feet of ing scene. Change 7 3-3  Downloaded from http://www.everyspec.com TO 00-25-172 Figure 3-1. Bomber Refueling Safety Zone Example 3-4  Downloaded from http://www.everyspec.com TO 00-25-172 Figure 3-2. Fighter Refueling Safety Zone Example Change 5 3-5  Downloaded from http://www.everyspec.com TO 00-25-172 f. If hot brakes are suspected, an aircraft hot brake check will be performed prior to fuel servicing. Temperature can be measured by temperature sensitive substances (temp sticks) or by infrared heat sensors. Fuel servicing In freezing weather, touching a metal surface with shall not start until the brake temperature is below bare skin can cause the skin to stick to the cold sur- 750 ºF, except for the A-10, C-5, C-17, C-130, C-141, face, resulting in a painful injury. One way to avoid E-4, F-15, and HH-60 aircraft. These aircraft are this is to touch the aircraft grounding/bonding con- exempted because of the location, direction, and dis- nector with a warm metal object, such as a coin held tance of the fuel vent outlets from the aircraft landing in the bare hand. gear brake assemblies. The F-22 can be refueled with brake temperatures exceeding 750 °F if an adequate d. Personnel in the FSSZ shall not wear footwear with shield is used to keep vented fuel from reaching the left exposed spark-producing nails or metal plates on the main landing gear brake assembly. walking surfaces. Any type of clothing may be worn as outer garments when fuel servicing aircraft with high g. If glowing or crackling fuel is noted when servicing flashpoint fuels (JP-5, JP-8, JP-10, JET A, JET A-1, or aircraft, immediately cease all servicing operations. diesel). However, when fuel servicing aircraft with low Report the incident to the servicing supervisor and to the flashpoint fuels (JP-4, JET B, AVGAS, or MOGAS), fire department. After the incident is investigated, clothing containing more than 65% of any combination recheck grounding connections, and resume flow at a or mixture of nylon, rayon, wool or polyester shall not slower rate and pressure. be worn as outer garments. Do not put on or remove outer garments in the fuel servicing safety zone. h. Operating external power units will be parked outside Matches or lighters will not be handled or removed from the fuel servicing safety zone which is at least 50 feet pockets during servicing operations. If flight crew mem- from the pressurized fuel carrying servicing components bers wearing Nomex and/or other authorized flight and at least 25 feet from aircraft fuel vent outlets. The clothing are required to assist in aircraft fuel servicing operating units will be positioned upwind from the fuel operations, they will first assure that they are at the servicing operation when possible. same potential as the aircraft. This is done by bare hand contact with the aircraft grounding/bonding connector, an unpainted aircraft surface, or a static ground before removing the fuel filler cap or while inserting the bond- ing jack on the fuel nozzle. These requirements also apply to draining aircraft fuel sumps. The aircraft settles as fuel is taken on board. Ensure adequate clearance exists between the aircraft and e. Laptop computers (including wireless versions), porta- maintenance stands or equipment positioned under ble digital assistants, pagers, cell phones, stray voltage any portion of the aircraft. detection devices, radios, night vision goggles, flash- lights (six volts or less) and cameras (including digital NOTE cameras) can be operated within the FSSZ. Camcorders may also be used in the FSSZ as long as the cathode ray Fiberglass is a non-conductive material (insulator) tube viewfinder (eyepiece) is de-energized. However, no that does not dissipate or transfer electrostatic charg- battery changes nor charging operations are allowed es when either grounded or bonded to conductive ob- within the FSSZ. Only night vision goggles and intrinsi- jects. Therefore, the grounding or bonding of cally safe devices can be operated within 10 feet of fiberglass ladders or work stands is not required. aircraft fuel vent outlets, open port refueling receptacles, fuel spills, or fuel trucks being filled (bottom loading or i. Bond conductive aircraft maintenance or work stands to from aircraft defueling). All other devices e.g., cell the aircraft when using the stand to access the aircraft phones, must be turned off (not placed on standby) fuel servicing receptacles or support the fuel hose dur- when within this ten foot zone. Trulink wireless inter- ing servicing operations. Other maintenance or work com and cordless Aircraft Wireless Intercom Systems stands, not used for fuel servicing, do not require either (AWIS) constructed by Communications - Applied bonding or grounding. Ladders used for overwing refu- Technology may be used anywhere within the FSSZ. eling do not require bonding to the aircraft. Centralized Aircraft Support Systems (CASS) can remain energized in the FSSZ, but electrical switches must not be operated. 3-6 Change 12  Downloaded from http://www.everyspec.com TO 00-25-172 l. Vehicle or support equipment engine backfires. m. Fuel filter pressure exceeds maximum authorized differ- ential pressure (coalescing; 15 psig, absorption of If any tank appears to fill abnormally slow or not at 15 psig) all, then stop all refueling immediately and investi- gate to determine what is causing the problem. The n. Defective deadman control valve. cause could be a blocked vent line or failed refuel shutoff valve or other malfunction. o. Defective nozzle. j. On aircraft equipped with individual fuel tank quantity gauges, monitor each gauge during refueling operation. 3.11 FIRE PROTECTION. k. Fuel servicing hoses can be routed under aircraft, but Fire protection is essential during aircraft servicing operations. avoid placing them near running engines and Auxiliary The level of fire protection is based on the hazard involved in Power Units (APU). If possible, avoid placing hoses the operation being conducted. Personnel involved in servic- forward of the aircraft landing gear, in case the aircraft ing operations shall be trained in the operation of fire extin- needs to be towed away for an emergency. For concur- guishers and installed fire suppression equipment systems. In rent servicing operations, place hoses to minimize dam- the event of a fire or fuel leak, servicing personnel are the first age from other servicing equipment. line of defense in protecting Air Force assets involved when fire department personnel are not available at the incident l. Ensure that the aircraft is properly chocked. Use MIL- scene. Servicing personnel must immediately notify the fire PRF-32058 or equivalent chocks. department and use available fire extinguishers (or other equipment) until the fire department arrives on scene. 3.10 SERVICING VEHICLES AND SUPPORT EQUIP- MENT (SE). a. Fire extinguishers. The 150-pound, Halon 1211 fire extinguisher is the primary flight line fire extinguisher. Do not service aircraft if any of the following safety discrep- Fire extinguisher requirements are outlined where ancies exist: appropriate in applicable paragraphs of this technical order and are summarized in Table 3-1. a. Defective servicing hose. b. Installed Fire Suppression Systems and Vehicle Standby. b. Fuel leaks. Certain aircraft servicing operations present increased hazards and require a greater level of fire protection c. Defective or bare electrical wiring. awareness and standby posturing. Hot refueling opera- tions require modular or installed fire suppression d. Defective throttle or PTO Interlock System. equipment employing AFFF. When such systems are not available, fire protection is provided by standby fire e. Defective hand or foot brakes. fighting vehicles and crews. Refer to applicable infor- mation in this technical order and to Table 3-1 for a f. Defective exhaust system. summary of installed fire suppression system require- ments and vehicle standby requirements. g. Aircraft or support equipment engine(s) is (are) over- heated. c. Fire Department Standby Requirements. Table 3-1 lists various fire protection requirements for Aircraft Rescue h. Defective or inoperative emergency shutoff switch. and Fire Fighting (ARFF) vehicles. Due to a limited amount of ARFF equipment available, on occasions the i. Defective shift linkage or gear shift indicator. fire chief or SFO is required to direct standby vehicles to emergencies. An example is when the fire department j. Defective tank vent valves. responds to an IFE. During IFEs, ARFF vehicles are pre-positioned along the runway when an emergency k. Vehicle air pressure below 90 psi. landing is anticipated. The following fire protection pol- icy applies during emergency situations. Change 12 3-7  Downloaded from http://www.everyspec.com TO 00-25-172 (1) Operations, which may continue. Concurrent Servic- evacuation flights with passengers/patients onboard, ing Operations (CSO) during Combat Sortie Genera- defueling when an aircraft has a fuel leak, is dam- tion may continue fuel servicing until the present aged from fire or impact, defueling into open con- CSO is completed. No fuel servicing portion of a tainers or drums, or defueling where safe distance new CSO may begin unless authorized by the wing criteria cannot be met or static grounding points are commander (or senior local operational commander) not available. These operations shall cease immedi- until the ARFF vehicle has returned to a standby ately. Fuel flow will be stopped and pressure posture. As a condition of continuance, there must relieved from the fueling system until the ARFF be an immediate means of recalling the fire depart- vehicle has returned to a standby posture. ment in case of an onsite emergency. Additionally, two 150-pound Halon 1211 extinguishers must be (3) The fire chief or SFO is the primary individual for located with one on each side of the aircraft. Servic- determining standby posturing requirements and ing personnel shall be trained in the use of these ARFF vehicle standby locations for the various air- extinguishers. Maintenance, fuel servicing, and air- craft operations. This will include having an ARFF crew personnel must exercise extra vigilance during vehicle on standby status in the fire station or other this time period. When the fire chief releases the location for operations listed in Table 3-1 as he ARFF vehicles from the emergency scene, they will deems appropriate. The goal for the fire chief is to reservice as necessary and return immediately to a not take away from other critical firefighter duties standby posture. i.e., training, equipment maintenance, etc., while still maintaining a heightened state of alert for aircraft (2) Operations which must cease. All aircraft hot refuel- involved in the listed operations. Final determination ing operations, concurrent fuel servicing of aircraft for standby requirements is at the discretion of the with passengers onboard, fuel servicing of medical installation commander. 3-8 Change 12  Downloaded from http://www.everyspec.com TO 00-25-172 Table 3-1. Fire Protection Equipment Requirements TYPE OF OPERATION FIRE PROTECTION REQUIREMENTS Do not use Halon, carbon dioxide, or water (Type A, B, or C Rated) fire extinguishers on or near fires involving munitions, pyrotechnics, or magnesium incendiaries (flares). Halon can be used on fires involving liquid oxygen (LOX), but it is less effective in extinguishing fires in oxygen-enriched environments; other agents, such as CO2 are preferred. The extinguishers listed in this Table should only be used for initial knockdown of fires on aircraft and equipment before the involvement of munitions, pyrotechnics, or magnesium incendiaries or to protect adjacent equipment and facilities. Always ensure you have the proper fire extinguisher for the class of fire hazard encoun- tered. The fire protection requirements listed in Table 3-1 shall not be exceeded without approval from the Fire Protection Flight. Failure to comply with this warning could result in personnel injury or death. Do not lay down the 150-pound Halon 1211-wheeled fire extinguisher. The flight line extinguisher must be utilized from the upright position. The laying down of the flight line extinguishers to prevent tipping or damage from engine exhaust subjects the extinguisher to fail to provide sufficient agent to suppress a fire. If flight line personnel are con- cerned regarding this situation, they should relocate the extinguisher outside of the exhaust zone. NOTE All references to the Halon 1211 extinguisher are for the 150-pound wheeled extinguisher, see AFI 91-501 for inspection criteria. Fire department standby vehicle posturing is not required when the operation involves the simulation of refueling. The fire department standby requirements contained in this TO apply for normal day-to-day operations. Under actual combat conditions, contingencies or emergencies, and MAJCOM directed and approved exercises; Concur- rent Servicing Operations during Combat Sortie Generation may be conducted with only two 150-pound Halon 1211 portable fire extinguishers. For any operations performed in SIMULATED Hardened Aircraft Shelters/Protective Aircraft Shelters (HAS/PAS), the fire protection equipment requirements will be the same as for those operations being conducted outside a hangar or shelter. The minimum distribution of Halon 1211 extinguishers indicated in the table should not be exceeded without approval of the Fire Protection Flight. 1. POL servicing vehicle-parking area. The Fire Protection Flight determines the type of extinguisher required for the associated hazards in accordance with NFPA 10. 2. Aircraft outside of hangar or shelter with no servicing being conducted. a. A/T-38, C-12, C-21, C-27, C-29, F-5, H-1, H-60, T-1, T-37, One Halon 1211 extinguisher per three aircraft. T-41, M/RQ-1K/L, RQ-1K/L, and U-2. AETC aircraft require one per two aircraft. b. F-4, F-15, F-16, F-22, F-117, H-53, RQ-4A, OA/A-10 and One Halon 1211 extinguisher per two aircraft. V-22. c. Airbus A300/310, B-1, B-2, B-52, B-727, B-757, One Halon 1211 extinguisher per aircraft. B-767, B-777, C-17, C-20, C-32, C-37, C-130, C-141, DC-9, DC-10, E-3, E-8, KC-135, L-1011, MD-90, and T-43. Change 12 3-9  Downloaded from http://www.everyspec.com TO 00-25-172 Table 3-1. Fire Protection Equipment Requirements - Continued TYPE OF OPERATION FIRE PROTECTION REQUIREMENTS d. C-5, E-4, VC-25, and B-747. Two Halon 1211 extinguishers per aircraft. e. Alert Aircraft: A/T-38, C-12, C-21, C-29, F-4, F-5, F-15, One Halon 1211 extinguisher per aircraft. F-16, F-117, H-1, H-53, H-60, OA/A-10, T-37, T-39, T-41 and U-2. f. Alert Aircraft: (Except DC-9 Series used for medical evacu- Two Halon 1211 extinguishers per aircraft. ation, refer to entry 3h. or 3i. when passenger(s) are on board). B-1, B-2, B-52, C-5, C-17, C-130, C-141, DC-9 Series, DC-10 Series, E-3, E-4, E-8, KC-135, T-43, VC-25, and B-747. 3. Aircraft being serviced outside of a hangar or shelter. a. No powered support equipment being operated. One Halon 1211 extinguisher per aircraft located in the Fuel Servicing Safety Zone (FSSZ). C-5, E-4, VC-25, and B-747 require two per aircraft. b. Powered support equipment being operated. One Halon 1211 extinguisher located in the FSSZ of the air- craft. C-5, E-4, VC-25 and B-747 requires two per aircraft. During fuel servicing, the use of aircraft APU/GTC without integral fire suppression capability will require a Halon 1211 extinguisher to be positioned in the FSSZ and to protect both the aircraft and APU/GTC exhaust port area. c. Cargo aircraft with nuclear weapons aboard. One Halon 1211 extinguisher per aircraft located in the FSSZ. Additionally, during loading and off loading operations, engine starts, or other aircraft servicing, a minimum of one ARFF vehicle, Air Force P-19 or equivalent ARFF vehicle meeting or exceeding P-19 capabilities is required to be in standby posture. Stand by ARFF vehicle will maintain a one- minute response time during taxi, takeoff and landing. The Base Fire Chief determines positioning for optimum response. d. Concurrent Servicing Operations during Sortie Genera- In addition to the requirements of 3a. or 3b. as applicable, an tion: Simultaneous refueling, munitions loading/unloading, ARFF vehicle (P-2//19/20/23) will be on flightline standby. It aircraft reconfiguration e.g. tanks, racks, pylons loading/ will be positioned for optimum response as determined by unloading, and other specified maintenance activities with all Base Fire Chief. engines shut down. e. Hot refueling: The transfer of fuel into the fuel tanks of an One Halon 1211 extinguisher positioned between the refueling aircraft with one or more engines on an aircraft operating with equipment and the refueling supervisor’s position. In addition, or without munitions on board. either a fixed or skid mounted AFFF system discharging through oscillating nozzles. An ARFF vehicle (P-2//19/20/23) may be substituted for the AFFF system. An ARFF vehicle will be on standby posture. The Base Fire Chief determines positioning for optimum response. f. Multiple hot refueling operations. An ARFF vehicle will be on standby posture. The Base Fire Chief determines positioning for optimum response. 3-10 Change 12  Downloaded from http://www.everyspec.com TO 00-25-172 Table 3-1. Fire Protection Equipment Requirements - Continued TYPE OF OPERATION FIRE PROTECTION REQUIREMENTS g. Concurrent fuel servicing of aircraft without passengers. One Halon 1211 fire extinguisher for each SPR connection (See Section 5.) location being used. An ARFF vehicle will be on standby pos- ture. The Base Fire Chief determines positioning for optimum response. When two or more aircraft are being concurrently serviced at different locations, an ARFF vehicle will be on standby posture. The Base Fire Chief determines positioning for optimum response. h. Concurrent fuel servicing of aircraft with passengers, (Com- NOTE mercial airports exempt). (See Section 5.) The Fire department shall be notified at least 15 min- utes prior to starting concurrent servicing operations. One Halon 1211 fire extinguisher for each SPR connection location being used. Additionally, when servicing with JP-4 or Jet B Fuel, an installed fire suppression system is required. If it is not available, an ARFF vehicle will be on standby posture. The Base Fire Chief determines positioning for optimum response. When two or more aircraft are being concurrently serviced at different locations, an ARFF vehicle will be on standby posture. The Base Fire Chief determines positioning for optimum response. i. Concurrent servicing of medica