Hybrid motor development and static testing information/legality

[Rocketer01]

I have been reading Rocket Propulsion Elements 8th Edition recently and have developed an interest in the use of hybrid engines. I am thinking about the prospect of developing a small gaseous N2O/Solid grain engine that I could use one day in a flight.

I have a pyrotechnics license, my L1 and understand that you need to be L2 certified (which I plan to get apply for the next suitable flight event) to fly a HPR rocket which utilises a hybrid engine and its needs to be a research event. However, I cannot find anything on the legality of constructing such a motor and eventually conducting static tests? (only info of the use at a launch).

Any insight into this is highly appreciated.

[Rocketer01]

Side note, I'm in NSW

[Voyager]

Fellow forum member strud can probably help out with these questions. Also read up on Tripoli’s experimental/research launch requirements.

For further technical information check out http://www.aspirespace.org.uk/.

[drew]

Hi Rocketeer01,

Voyager is correct in terms of Strud being able to help with hybrid questions. With that said from an Australian legality/regulation perspective hybrids basically don't exist. So, from my understanding, there's nothing in Australian legislation that bars you from constructing and static firing a home made hybrid motor. There's been active home made hybrid development in Australia off and on for over 20 years? Troy could probably speak to this as well, along with PK.

Cheers,

drew

[PK]

If nothing goes bang, then the only regulatory issues relate to the manufacturing of pressure vessels. All states have regulations regarding this. NSW's are actually pretty sensible. There's a risk factor which is a function of the volume of the vessel, the operating pressure, and what's in it. That factor determines the level of compliance for the thing, small hybrids tend to drop off the bottom of this scale.

Make no mistake though. If it goes bang, and gaseous NOX goes bang (and is a poor choice of oxidiser as a result), or someone complains. There will be no shortage of regulation that will be brought to bear.

[Rocketer01]

Thanks allot everyone for the replies, I will take all of that into consideration and the legality explanation makes a lot of sense. I will start looking into the pressure vessel legislation and see what needs to be done. I will also remember to get in contact with Strud if I come across any problems in the future. Thanks again.

[Kryten]

Also: "Cases (including hybrid cylinders), front and rear closures, and nozzles shall not be fabricated of steel or other frangible materials (e.g. PVC)."
(extract from Tripoli Safe Launch Practices)