NAR HPR Electronics & Avionics 5

Question 1

What is 'apogee delay' and why might a flyer enable it on their altimeter?

Accepted Answer

A brief pause after apogee detection before firing the drogue, to confirm the rocket is truly descending

Answer

Apogee delay adds a short wait after the pressure sensor detects apogee to confirm the rocket is actually descending, reducing false fires from pressure fluctuations.

Question 2

When an altimeter is described as 'MACH immune' or 'MACH lockout capable,' what problem does this feature address?

Accepted Answer

It locks out apogee detection during transonic flight where shock waves cause false pressure readings

Answer

Transonic and supersonic shock waves cause pressure spikes that can mimic apogee; Mach lockout disables apogee detection until the rocket slows to subsonic speed.

Question 3

What does a flyer typically verify during a 'pyro continuity check' on the launch pad?

Accepted Answer

That each pyro channel shows a continuous circuit through its connected e-match

Answer

Continuity checks confirm that each firing circuit has an unbroken electrical path through the e-match, ensuring the altimeter can fire the charge when commanded.

Question 4

What is the advantage of using a telemetry-capable altimeter that transmits live data to the ground?

Accepted Answer

It allows the flyer to monitor altitude, velocity, and event status in real time during flight

Answer

Live telemetry lets the flyer see real-time altitude, velocity, and pyro event confirmations, helping diagnose deployment issues immediately after flight.

Question 5

Why must avionics bay vent holes have a combined area proportional to the bay volume in HPR design?

Accepted Answer

Sufficient vent area ensures the internal pressure equalizes with ambient quickly for accurate altitude sensing

Answer

Vent holes must be large enough to allow rapid pressure equalization so the barometric sensor reads true ambient pressure without lag-induced errors.

(NAR HPR) NAR High-Power Rocketry Certification Practice Test

(NAR HPR) NAR High-Power Rocketry Certification Practice Test

NAR HPR Electronics & Avionics 5