NAR HPR Recovery Systems & Deployment 4

Question 1

When two independent altimeters are used for redundancy, how should their vent holes be configured?

Accepted Answer

Each altimeter bay should have its own static vent to prevent cross-contamination

Answer

Each altimeter should sense pressure through its own static port to prevent one altimeter's pyro firing event from pressurizing the other's sensor.

Question 2

A rocket experiences a 'zipper' failure. What does this describe?

Accepted Answer

The shock cord rips through the airframe tube on deployment

Answer

Zipper failure occurs when a taut shock cord under snatch force tears longitudinally through the airframe tube wall, destroying the rocket.

Question 3

What is the purpose of a 'nomex chute protector' in a recovery bay?

Accepted Answer

To shield the parachute from hot ejection gases during deployment

Answer

Nomex (aramid) is heat-resistant and wraps around the parachute to protect it from scorching by the hot gases produced by the ejection charge.

Question 4

Which condition would cause a barometric altimeter to misread altitude and potentially fire recovery events at the wrong time?

Accepted Answer

A cracked or unsealed avionics bay allowing dynamic pressure inside

Answer

If the avionics bay is not sealed from ram air or body tube pressure, the altimeter receives incorrect pressure readings, corrupting altitude calculations.

Question 5

How should a shock cord be attached to prevent zipper failure in high-power rockets?

Accepted Answer

Anchor to a bulkhead or rail button with a load-spreading anchor plate

Answer

Anchoring the shock cord to a structural bulkhead or anchor plate distributes the load and prevents it from cutting through the airframe tube wall.

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

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

NAR HPR Recovery Systems & Deployment 4