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- Max launch angle (from vertical) for HPR: 20 degrees
- Max wind velocity allowable for launch ops: 20 miles per hour
- When higher winds cause the rocket to drift into the neighboring fields: limit flights to lower altitudes AND move launchpad closer to the wind source AND don't fly on days w/ problematic winds
- If you're on a 1500 x 1500 ft field with an FAA waiver up to 3000 ft AGL, and parachutes that slow the rocket to 20 ft/s: max wind speed should be 6 mph if the pads are upwind and the rocket vertical
Being safe on launch day
- When may onboard energetics and/or electronic controls be activated and when shall they be inhibited? Inhibited until in launching position and prior to removing from launch position. May be activated when non-essential personnel leave the pad area
- What equipment is required at launch sites? Fire suppression devices, first aid kits and a method of communicating with everyone on the launch site
- When flying an unproven design, it is not acceptable to: fly it as a "head-up" flight on the first flight
- Your HPR lands in a power line: you must leave it alone and call the power company
- Prohibited activity on launch day: consumption of alcohol, use of medication that could affect judgement, movement or stability
- Store HPR, motor reloading kits and pyrotechnics: at lease 25 feet from smoking, open flame, etc.
Going the distance
- For a launch site with min. dimensions = 1500 ft, the minimum distance between launch site boundary and the launcher (for a 320 N-s motor) is: 100 ft. AKA the "minimum personnel distance"
- Minimum personnel distance for O-impulse cluster: 2000 ft
- Min launch site dimensions: >/= 1/2 max expected altitude OR 1500 ft, whichever is larger
- Min distance allowable between HPR launch pad and freeway: 1500 ft
- Min safe distance from HPR with "I" motor: 1500 ft
- Min safe distance from HPR with 3 x "H" motors: 200 ft
- Min safe distance from HPR with 2 x "K" motors: 500 ft
- Distance around launcher for "J" powered model that must be cleared of easy-to-burn material, assuming the motor isn't "sparky": 50 feet
- (see above) for a 3-motor cluster of "J" motors, this must be: 75 feet
- (see above) for a single "J" motor that burns Ti (titanium) sponge to emit sparks: 75 feet
Ignite your passion for rocketry! (are you cringing at these puns yet??)
- Which of these igniters may be ignited by continuity test of some launch controllers? Flashbulbs, very low current electric matches
- Unless manufacturer instructs otherwise, igniters for clustered rocket motors should be wired together in: parallel
- When should igniters be checked for continuity? Only on the launch pad, while installed in a rocket motor
- When clustering combos of black powder and composite motors: composite motors ignited first (slower to ignite)
- If individual igniters are used for igniting clustered model's motors: launch control must provide additional current to ignite the additional igniters
- Advantages of using a "relay" type launch control: can deliver more power to motor igniters (shorter wires = higher power)
- Titanium sponge: ingredient used in some rocket motors that causes them to eject sparks in exhaust
- Not required feature of rocket motor ignition system: audible or visual indicator showing continuity through the rocket motor igniter
- Small hole is recommended near the top, below the nosecone/payload section in order to: vent internal pressure
- Parachute ejection system needs to vent to the outside for barometric readings in order to: give outside air pressure readings
- Parachute ejection systems that sense barometric pressure can malfunction during supersonic flight because: the outside pressure distribution is not continuous around the model
Things fall apart
- Most likely to cause CATO of black powder rocket motor: temperature cycling
- Petroleum-based lubricants should not be used with oxygen or nitrous-oxide systems used in hybrids. Why? Risk of spontaneous ignition or explosion
- Safety hazards associated with hybrid rocket motors: high pressure gas, low temperatures (frostbite)
- A rocket returned from flight with "zipper" damage (shock cord tears through the model) is caused by: parachute ejection occuring too soo, after motor burnout AND occuring too late after apogee
- A payload section (with a heavy payload) separates immediately after motor burnout. The cause: payload shoulder too loose AND rocket motor had failure of its delay system
- Consequences of inadequate motor retention: motor being ejected at apogee instead of the parachute AND motor being ejected from the cluster and flying on its own AND motor flying through the rocket, destroying it
- According to NAR, the vast majority of unsuccessful flights are because of: recovery system failures
Being responsible and all that
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