56 Questions
What is the primary function of software in aircraft systems?
To provide the programming information required by the computers
Which of the following systems require continuous software updates?
Navigation and flight management systems
What is the purpose of assigning a Software Level to each aircraft equipment or system?
To relate to the severity of the effect of possible software errors on aircraft safety
What document defines the criteria for assigning Software Levels?
DO-178C Software Considerations in Airborne Systems and Equipment Certification
What is the function of a Multifunction Control Display Unit (MCDU) in an aircraft?
To communicate with multiple systems to update or input data, test and identify faults
What is the purpose of software in an aircraft's Built-In Test Equipment (BITE)?
To communicate with other systems to test and identify problems associated with the aircraft
What is the basis for assigning a Software Level to software in an aircraft system?
The potential of the software to cause safety-related failures identified by a system safety assessment
What is the requirement for software design based on its assigned Software Level?
It must be designed to meet strict specifications (probability of failure) based on its assigned level
What is the primary distinction between LSAP and Aeronautical Databases?
Regulatory status
What kind of software is Model/Engine Database (MEDB)?
LSAP software
What is the purpose of the Navigation Database (NDB)?
To provide navigation and route information for the Flight Management System (FMS)
What is the primary purpose of categorizing software into different levels of certification?
To assess the potential impact of software failure on aircraft safety
What is User-Modifiable Software (UMS) intended for?
Modification by the aircraft operator without review by the certification authority
Which level of certification is assigned to software whose failure would cause or contribute to a catastrophic failure of the aircraft?
Level A
What is the purpose of Operational Program Configuration (OPC)?
To enable or disable optional functions of the OPS
What is an Aircraft Configuration List (ACL)?
A list of modules, including LRUs, which use LSAPs applicable to a specific aircraft
What is the primary characteristic of Field-Loadable Software (FLS)?
It has its own unique part number
What is Software Media?
The means of transporting and distributing software for installation in the user equipment
What is the primary reason for using preloaded software?
To ensure software changes are made by the manufacturer
What is a Loadable Software Aircraft Part (LSAP)?
Software that is considered part of the aircraft approved design
What is a software version?
A specific software item at a designated revision status
Which of the following systems is typically classified as Level C software?
Navigation systems
What is User-Certifiable Software (UCS)?
Software that an operator or its designated party chooses to modify in accordance with approved guidelines
What is the primary difference between Field-Loadable Software (FLS) and preloaded software?
FLS can be loaded on an aircraft by maintenance personnel, while preloaded software cannot
What is Operational Program Software (OPS)?
Software that contains the program instructions for a Line-Replaceable Unit (LRU)
What is a Non-Loadable Software Aircraft Part or Aeronautical Database (ADB)?
Field-loadable software which is not part of the certified aircraft configuration
Which of the following is NOT a characteristic of Field-Loadable Software (FLS)?
It requires removal of the system or components from the aircraft for updates
What is the purpose of categorizing software into different levels?
To assess the potential impact of software failure on aircraft safety and pilot workload
What is the purpose of target hardware in FLS?
To accomplish aircraft navigational and manoeuvring tasks
What is the responsibility of the operator regarding software updates?
To obtain suitable documentation and ensure authenticity of software
What type of computer systems cannot be loaded using a data loader?
Computer systems with ROM, PROM and EPROM
What is the primary function of a data loader?
To facilitate software loading to any programmable computer system
What is the consequence of incorrect loading procedures in software loading?
A software mismatch or glitch
What are data loaders referred to as?
ADLs, PDLs, and PMATs
What is the most common method of software transfer used by data loaders?
Standard 3.5-in. disc (1.44 MB)
What is the purpose of a software or data loader?
To facilitate software loading to any programmable computer system
What type of software is used in a Flight Control Computer (FCC)?
BIOS-type software program
What is the importance of following maintenance manuals when loading software?
To ensure correct software loads and software configurations
What is the primary purpose of recording software replication in an Aircraft Software Replication Register?
To ensure that the original source of software copies can be traced and audited
What is the key aspect of operator procedures related to software configuration?
Being able to determine the equipment and software configuration of each aircraft at any time
What was the primary cause of the Air New Zealand Flight 901 disaster?
Unapproved changes to the aircraft's software
What should accompany all LSAP storage media containing software copies?
A copy of the accepted release documentation
What is the primary purpose of including software configuration procedures in the internal audit program?
To identify and mitigate potential risks associated with software changes
Which aircraft system is affected by changing software?
Multiple systems, including Engine, Navigational, and Flight control systems
What is the primary benefit of having a documented procedure for software configuration and embodiment?
Ensuring traceability and accountability of software changes
What is the primary consequence of loading unapproved software into an aircraft?
Catastrophic effects, including potential loss of life
What is the main purpose of an internal data loader?
To download information from a media format
What is the advantage of using Electronic Distribution of Software (EDS)?
Speed of distribution and removal of the need for physical transport media
What should be done with FLS and storage media known to contain defects?
Place them in quarantine for suitable disposal
What is required to accompany procured LSAP?
A JAA Form 1 or FAA 8130-3
What is the recommended action after loading LSAP?
All of the above
What is the purpose of the Aircraft Configuration List (ACL)?
To record FLS loading
What is the recommended method for replicating FLS?
Using the aircraft Type Design Organisation-approved FLS storage media replication process
What should be avoided when storing FLS and storage media?
All of the above
What is the purpose of sealing FLS storage media in dust- and lint-free material?
To prevent contamination from the environment
What is the recommended location for storing a copy of the Aircraft Configuration List (ACL)?
Both on the aircraft and in the operator's maintenance records system
Study Notes
Classification of Aircraft Software Systems
- Software is used in aircraft systems to provide programming information required by computers
- It is used by all computer-based systems on the aircraft, including:
- Engine control systems
- Bleed air control systems
- Power generation and control systems
- Fire protection systems
- Aircraft instrument displays
- Software updates are required as navigational requirements of the aircraft constantly change
Software Control
- Each aircraft equipment and system requiring software is assigned a Software Level (A, B, C, D, or E) based on its potential to cause safety-related failures
- Software Levels are assigned in accordance with the criteria defined in DO-178C and EUROCAE WG-120
- The five levels of certification are:
- Level A - Catastrophic (failure would cause or contribute to a catastrophic failure of the aircraft)
- Examples: flight control computer, fly-by-wire, full authority digital engine control, flight displays, air data systems
- Level B - Hazardous (failure would cause or contribute to a hazardous/severe failure condition)
- Examples: autopilot, auto throttle, ice protection, standby flight displays, instrument landing system, landing gear control
- Level C - Major (failure would cause or contribute to a major failure condition)
- Examples: navigation systems (GPS), yaw damper, environmental control systems
- Level D - Minor (failure would cause or contribute to a minor failure condition)
- Examples: flight data recorder, data acquisition system, cabin lighting
- Level E - No Effect (failure would have no effect on the aircraft or on pilot workload)
- Example: in-flight entertainment
- Level A - Catastrophic (failure would cause or contribute to a catastrophic failure of the aircraft)
Software Types
- There are two main types of aircraft software:
- Field-Loadable Software (FLS)
- Preloaded or Resident Software
- Field-Loadable Software (FLS) characteristics:
- Has its own unique part number
- May be an aircraft part
- Part number is verifiable on the aircraft by electronically accessing the target hardware memory
- Does not change the target hardware part number
- Can be uploaded regardless of the current software state and will not prevent a previous version from overwriting it
- Preloaded software cannot be changed without physically removing the system or components from the aircraft
Explanation of Software Terms
- Loadable Software Aircraft Part (LSAP):
- Software that is considered part of the aircraft approved design and therefore an aircraft part
- Requires release documentation (EASA Form 1, FAA 8130-3)
- Non-Loadable Software Aircraft Part or Aeronautical Database (ADB):
- Field-loadable software which is not part of the certified aircraft configuration
- May be routinely updated without a formal modification approval or STC
- Databases:
- Model/Engine Database (MEDB) is LSAP software that defines a customised performance database for the navigation system
- Aeronautical Database (ADB) is not classified as an aircraft part and is sometimes referred to as a non-LSAP
- Operator Modifiable Software (OMS):
- Consists of User-Modifiable Software (UMS) and User-Certifiable Software (UCS)
- Permits operators to modify a system function to suit preferred operational procedures, existing operational infrastructure or local conditions
- Supplier Controlled Software:
- Operational Program Software (OPS)
- Operational Program Configuration (OPC)
- Aircraft Configuration List (ACL):
- List of modules, including LRUs, which use LSAPs applicable to a specific aircraft
- May be contained in a drawing supplied by the Type Certificate Holder, in a Service Bulletin, in a Service Information Letter, in an Illustrated Parts Catalogue (IPC) or as part of a separate tracking system
This quiz covers the role of software in aircraft systems, including engine control, bleed air control, and power generation, as well as software updates and navigational requirements. It also explores software control in aircraft systems.
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