Chapter 4

Chapter 4 - Loading & Performance #

Introduction #

  • REMOTE PIC is in charge of all safety for the sUAS
    • anything placed on or carried by the drone must be attached securely
  • use the manufacturers recommendation for testing & evaluation performance
  • Must check weather conditions prior & during the flight
  • Main control system
    • alerion
    • elevator
    • rudder
  • Secondary control system
    • spoiler
    • leading edge
    • trim
    • wing flaps

Questions #

  • Remote pic must ensure objects carried on the sUAS are secure
  • The rudder operates the yaw on a sUAS airplane

Determining Speed & Altitude #

  • cannot be flown faster than 100mph or 87knots
  • use gps to tell speed
  • use timing between two fixed positions to tell speed
  • use a radar gun to measure speed
  • use an anemometer with inertial information from onboard sensor
  • KEY TERMS:
    • Dead Reckoning : navigation by means of computations based on time, airspeed, distance, and direction
    • Pilotage : Navigation by landmarks or checkpoints
    • Wind Triangle : navigation by triangulation
  • Determine altitude from the ground :
    • calibrated altitude reporting device
    • gps device
    • have sUAS 400 feet away and tell the visual size
    • if cs has measure of 400 feet fly the sUAS directly overhead to see its visual perspective
    • use known local terrain
    • Sectional chart tells you altitude and terrain and structures

Questions #

  • you are operating sUAS that does not have gps or installed ground speed limiter how can you determine the speed you are operating? :: Dead Reckoning
  • Remote pilot can determine the altitude of terrain & structures in the sectional chart
  • Your sUAS does not have Gps or altimeter, how do you determine altitude :: Gain a visual perspective of what 400 feet looks like on the ground before flight

Loading #

  • make sure the sUAS is corrected loaded & balanced.
  • take into consideration wind, altitude, heat, humidity in terms of aircraft performance and weight capacity.
    • need to reduce weight to make sure there is good performance
  • change of weight during flight will also effect aircraft performance
    • eg : dropping off package, releasing agriculture spray, etc
  • Make sure weight is evenly balanced across the sUAS before & after loads

Computing Weight & Balance #

  • Key terms
    • Empty Weight : Weight including airfame, powersource, fixed equipment, and unusable fuel
    • Useful Load : Includes power source, & payload/ mission equipment
    • Arm : Horizontal distance from datum line to a point of the sUAS
      • Forward : (-)
      • Backward : (+)
    • Moment : Weight of an object * is arm expressed in pound-inches (lbs-in)\
      • Weight * Arm = Moment
  • Excess weight consequences
    • reduce rate of climb
    • lower max altitude
    • shorter endurance
    • reduced maneuverability

Questions #

  • when loading cameras & other equipment mount the items in a manner that does not adversely affect the center of gravity
  • To ensure sUAS center of gravity are not exceeded follow loading instructions in Pilot’s Operating Handbook or sUAS Flight Manual
  • Shorter endurance is a consequence of overweight sUAS
  • Remote PIC is responsible for using the most recent weight and balance data for sUAS
  • Operations outside weight & balance limitation may result in loss of control
  • sUAS with rearward center of gravity is less stable at all speeds

Load Factor #

  • 1g is the pull of gravity
  • Load factor : load imposed on wings or rotor in flight
  • Aircraft stall when critical angle of attack is exceeded
    • occurs when performing sharp maneuver or pitching up/down too steeply

Questions #

  • when operating sUAS the remote pic should consider the load factor in wings/rotors may increase anytime the aircraft is subjected to maneuvers other than straight and level flight
  • Amount of excess load on the wing of an airplane depends on the speed of the airplanes
  • turns increase the load factor on sUAS

Stalls #

  • chord line: straights line from leading edge to trailing edge
  • airfoil: structure that produces a useful reaction to air
  • relative wind:wind that is experiences by the airfoil
  • angle of attack : angle between chord line and relative path of airfoil
  • critical angle of attack:angle at which stall occurs

Questions #

  • term critical angle of attack is defined as the angle between wing chord line and relative wind
  • angle of attack at which an airfoil will stall is the critical angle of attack
  • stall occurs when smooth airflow over the wing is disrupted and lift degenerates rapid when wing exceed its critical angle of attack
  • increase in load factor will cause a sUAS to stall at higher speed
  • in a 45 degree banking turn a sUAS will stall at a higher seed

Performance #

  • follow all manufacturer recommendations
  • Remote PIC should be familiar with
    • operating environment
    • available information regarding safe and recommended operation of sUAS
    • conditions that may impact the performance of sUAS
  • PIC is responsible every flight can be safe

Questions #

  • uphill terrain slope increases launch distance