Aerodynamics: Airfoil Basics

Administrative Matters

• Mobile phones must be silenced and taken outside the classroom for calls.
• The training session includes 2 tea breaks and 1 lunch break.
• Attendance will be marked three times: morning, after lunch, and at the end of the day.
• A SkillsFuture Singapore survey will be conducted at the end of the training.
• In the event of a fire alarm, remain calm and wait for instructions.

Path to UAPL

• The training consists of 6 modules: CAAS Theory, Practical Training, and AFE Assessment.
• A license application will be submitted via CAPELS after completing the training.

UAPL Training Modules

• Module 1: General UAS Knowledge
  • Introduction to UAS
  • UA categories (Aeroplane, Rotorcraft, Powered-Lift, Airship)
  • UAS applications (Military, Civil, Law Enforcement, Agriculture, Aerial Photography, Surveying and Mapping, Search and Rescue)
• Module 2: UAS Components and Systems
  • Power and Electrical System
    • Batteries (LiPo, Li-ion)
    • Power Distribution Board (PDB)
  • Propulsion System
    • Motor (Brushless, DC)
    • Electronic Speed Controllers (ESCs)
    • Propellers
  • Flight Control System & Navigation System
    • Flight Controller
    • Various sensors (Inertial Measurement Unit, GPS, Barometer)
  • Ground Control System (GCS)
    • Ground-based hardware and software
  • Command and Control (C2) System
    • Radio Control Transmitter (RC Tx)
    • Radio Receiver (Rx)

UAS Components and Systems

• Power and Electrical System
  • Batteries: LiPo (Lighter, 2-3 years, High energy density, Highest voltage under load)
  • Power Distribution Board (PDB): connects all electrical components, distributes power from the battery
• Propulsion System
  • Motor: Brushless, DC, adjacent motor spins at opposite directions
  • Electronic Speed Controllers (ESCs): interprets inputs from the flight controller, converts them into pulses to govern the motor's speed
  • Propellers: convert powerplant's spinning motion into controlled forward motion
• Flight Control System & Navigation System
  • Flight Controller: interprets inputs from sensors, remote pilot's controller commands
  • Various sensors: Inertial Measurement Unit (Accelerometer, Gyroscope, Magnetic Compass), GPS, Barometer
• Ground Control System (GCS)
  • Ground-based hardware and software for communication with and control of the UA
• Command and Control (C2) System
  • Radio Control Transmitter (RC Tx): transmits radio signals to the receiver
  • Radio Receiver (Rx): receives radio signals, translates them into flight commands or flight mode activation

UA Flight Control Modes

• Manual/Rates: most difficult to operate, requires compensation to maintain attitude, altitude, and position
• Attitude hold: keeps the UA level when the control sticks are centred
• Altitude hold: keeps the UA at a constant altitude/height
• GPS mode: position hold, autonomous flight modes, and return-to-home functions
• Return-to-Home: automatically climbs to a predetermined altitude, then flies to the home point
• Avoidance collision: avoids obstacles and separates if necessary
• Headless mode: allows control without considering the UA's orientation

Importance of Flying Within Radio Line of Sight

• Flying out of visual line of sight (VLOS) or radio line of sight (RLOS) is not recommended
• Risks: loss of telemetry readouts, loss of situational awareness, over-reliance on automatic retrieval systems
• ANA 101: UA pilot must ensure the unmanned aircraft is within visual line of sight at all times unless the UA pilot license allows operation beyond visual line of sight### Radio Signals and Obstructions
• Hills can obstruct radio signals, making reception impossible
• Buildings and vegetation can also affect radio signals, with trees and foliage weakening signals especially when wet
• Radio signals can be reflected or absorbed by buildings

Preventing Interference

• Ensure no other UA is operating in the vicinity
• Select a channel far away from the interference source
• Avoid interference between RC Tx and other wireless equipment
• Turn off Wi-Fi on mobile devices
• Fly in open areas

Link Loss

• Link loss can result in UA triggering RTH failsafe
• In some cases, RTH may not function properly, leading to a drone flyaway situation

Preventing Link Loss

• Switch on RC Tx before powering on the aircraft to ensure a valid link
• Set a home point before take-off and ensure at least 6-7 GPS satellites are locked
• Check for compass interference
• Keep the drone in line of sight and monitor its surroundings
• Reset the home point when moving
• Set an appropriate RTH altitude to avoid crashes

Principles of Flight

Forces of Flight

• Newton's first law: an object at rest will stay at rest, and an object in motion will stay in motion unless acted on by a net external force
• Newton's second law: the rate of change of momentum is directly proportional to the force applied and occurs in the same direction
• Newton's third law: all forces between two objects exist in equal magnitude and opposite direction

Four Forces Acting on an UA

• Lift: upward force created by wings or propellers
• Weight: downward force due to gravity
• Thrust: forward force created by propellers or engines
• Drag: force opposing thrust, created by air resistance and shape/size of the aircraft

Aerodynamics

• Airfoil: body shaped to produce an aerodynamic reaction (lift) perpendicular to its direction of motion
• Bernoulli Principle: higher air speed = reduced air pressure, lower air speed = increased air pressure
• Angle of Attack: angle between the chord of the aerofoil and the relative wind direction

Air Law

Air Navigation Act

• An Act to provide for the control and regulation of aviation to maintain safety and security in civil aviation
• Implementation of Singapore's obligations under the Chicago Convention and other international agreements

Air Navigation Regulations

• To be discussed...### Air Navigation Act (Chapter 6) and AN 101
• Applicability of UAS provisions within the Act
• Permit needed for certain overflight by unmanned aircraft
• Absolute prohibition of carriage of dangerous materials on unmanned aircraft
• Discharge from unmanned aircraft
• Dangerous activity involving aircraft
• Flying without satisfying safety requirements
• Trespassing at aerodromes
• Penalty for dangerous flying

Offences and Penalties

• Trespassing of aerodromes: Fine not exceeding $5,000
• Operating a registrable UA that is not registered: Fine up to $10,000 or imprisonment not exceeding 6 months, or both
• Failure to produce a valid UABT, UAPL, Activity or Operator Permit: Fine not exceeding $40,000 or imprisonment not exceeding 15 months, or both
• Failure to report accidents: Fine not exceeding $50,000 or imprisonment not exceeding 2 years, or both
• Unauthorised photography over Protected areas: Fine not exceeding $50,000 or imprisonment not exceeding 2 years, or both
• Unauthorised flight over any Protected area: Fine not exceeding $50,000 or imprisonment not exceeding 2 years, or both
• Prohibited use of psychoactive substances: Fine not exceeding $100,000 or imprisonment not exceeding 5 years, or both
• Unauthorised discharge from unmanned aircraft: Fine not exceeding $100,000 or imprisonment not exceeding 5 years, or both
• Carriage of dangerous materials on unmanned aircraft: Fine not exceeding $100,000 or imprisonment not exceeding 5 years, or both
• Dangerous flying: Fine not exceeding $100,000 or imprisonment not exceeding 10 years, or both

Purposes of UAS Operations

• Recreation Purpose: Any activity engaged in for enjoyment, relaxation, or leisure, but not taking part in organised group activities, recreational activities provided in the course of carrying on a business, or flying displays
• Education Purpose: Any lecture, tutorial, seminar, demonstration, class, or similar activity on unmanned aircraft, offered or provided by an education institution mentioned in section 45 of the Private Education Act 2009 to students enrolled in that education institution
• Non-Recreation or Non-Education Purpose: Deemed as for Commercial or Business purpose, subject to more stringent regulations under ANA 101

UA Registration

• All UA with a total weight exceeding 250 grams must be registered with CAAS before flying
• Registration involves a two-step process: purchasing a registration label and completing online registration
• The registrant must be at least 16 years old
• Registration labels can be purchased online or at designated SingPost post offices
• A fee of $25 will be collected for each registration label

UA Registration Labels

• Labels must be affixed on the outer surface of a non-detachable part of the UA
• Labels must be clearly visible
• Registration labels are non-transferrable
• Labels must be removed and destroyed upon de-registration

UA Deregistration

• De-registration is required when the UA is lost or damaged beyond repair
• De-registration is required when the registration label is damaged or becomes illegible
• De-registration is required when the UA is sold or given to another person

Operator Permit

• An Operator Permit is granted by CAAS to an organisation or individual if the applicant has demonstrated that they can operate the UA safely
• The permit is valid for up to one year
• The assessment includes the applicant's organisational set-up, procedures to manage safety, airworthiness of each UA, and competency of personnel

Activity Permit (AP)

• An Activity Permit is granted by CAAS for a single activity or a block of repeated activities
• There are two types of Activity Permits: Class 1 and Class 2 AP
• Class 1 AP is required for UA activities conducted for purposes that are not recreational or educational in nature, or if the UA is over 25 kilograms in total mass
• Class 2 AP is required for UA activities conducted outdoors if the UA is 25 kilograms or below in total mass, and when the planned activity meets specific conditions

Unmanned Aircraft Pilot Licence (UAPL)

• There are two classes of UAPL: Class A and Class B
• Class A UAPL allows operation of UA with a total mass that does not exceed 25 kg
• Class B UAPL allows operation of UA with a total mass that exceeds 25 kg
• There are 4 categories of UA within each class of UAPL: Aeroplane, Rotorcraft, Powered-lift, and Airship

UAPL – Proficiency Check

• All UAPL holders must pass a proficiency check conducted by an AFE from an approved UATO
• The check must be completed at least once every 4 years from the date on which the category was specified on the UAPL
• Class B UAPL holders require refresher training at least once a year

Responsibilities of UAPL

• UA pilot must be aware of the performance specifications and operating limitations of the unmanned aircraft
• UA pilot must comply with the performance specifications and operating limitations of the unmanned aircraft
• UA pilot must ensure that the unmanned aircraft is within visual line of sight at all times

Navigation & Meteorology

• Geographic Coordinate System: Latitude and longitude, UTM map projection
• Global Navigation Satellite System: A system that provides location information
• Other Navigation System: Altimetry terms, types of cloud and wind, interpreting weather information

Learn about the cross-sectional shape of a wing, airfoil's role in producing aerodynamic force, and its application in propellers. Understand the relationship between airfoil and airflow.