Electronics & Avionics Flashcards

What is the recommended method for securing an altimeter sled inside an avionics bay to prevent vibration damage?

Answer: Foam padding and standoffs with nylon screws

Foam padding absorbs vibration and shock while nylon standoffs and screws secure the sled without creating rigid stress points that could crack the board.

Why do some NAR HPR flyers use two independent altimeters with separate battery supplies?

Answer: Redundancy ensures recovery deployment if one system fails

Redundant independent altimeters with separate power supplies ensure parachute deployment even if one altimeter or battery fails during flight.

What parameter do most barometric altimeters use to detect apogee?

Answer: Rate of pressure change transitioning from decreasing to increasing

Barometric altimeters detect apogee when atmospheric pressure stops decreasing and begins increasing, indicating the rocket has stopped climbing.

What is the purpose of a 'motor delay' setting available on some avionics systems?

Answer: It prevents apogee detection for a set time to avoid triggering during fast coast phases

A motor delay (or lockout time) prevents false apogee detection caused by pressure transients during the motor burn coast transition.

Which connector type is most commonly used in HPR avionics bays for pyro circuit connections due to its positive locking mechanism?

Answer: JST or Deans connectors with locking tabs

JST or Deans-style connectors with positive locking tabs resist vibration-induced disconnection and are compact enough for tight avionics bays.

After a flight, a flyer notices their altimeter recorded a main deployment at 1,100 ft instead of the programmed 800 ft. What is the most likely cause?

Answer: The vent hole was partially obstructed, slowing pressure equalization

A partially blocked vent hole delays pressure equalization inside the airframe, causing the altimeter to read a higher apparent altitude than actual.

What is the correct action when an altimeter emits a rapid beeping sequence after powering on during pre-flight?

Answer: Consult the altimeter manual — rapid beeping often signals an error condition

Most altimeters use beep codes to communicate status and errors; a rapid or unexpected sequence must be decoded from the manual before flight.