Re: Level 3 question

Yes you can use 2 that are the same. NAR would want redundancy plus a way to disarm the charges.

When I did mine, I was considering using 2 sets of charges but, found that most people use 2 ignitors from 2 altimiters going into one charge.

Good luck with it.

Phil Ste>I know that TRA requires redundant electronic deployment for all level

Phil Stein

Yes you can two of the same altimeters. I used two Altacc2c's in my level 3 flight

I'd rather use 2 totally different altimeters. That way you should be able to utilize most of the features that are incorporated into each unit. For instance I used a ALTS25 & an Olsen unit for my Level 3 the ALTS25 was the primary apogee charge while the Olsen was set for a 1.75 sec. delay past apogee Then for the Main the Olsen blew the main @ 1,400 ft with the ALTS25 deploying around 1,200ft or so.

Everything worked perfectly without any kind of damage.

Jeff Davenport

TRA: 4486 L3 NAR: 63238 L3

Redundant deployment is not required by TRA. See

Mark

snipped-for-privacy@msn.com (James Dean Cory, D.C.) wrote in news: snipped-for-privacy@posting.google.com:

I think what you're proposing is ok for both NAR and TRA. However, you leave yourself open to some failure modes that would be eliminated by using two different devices. I think the ultimate would be to use an accelerometer/baro altimeter as a primary device, with a timer or MAD as backup for the apogee event, and a baro altimeter as backup for the main alimeter. The drawbacks are extra expense as complexity, so you have to balance all that out with the odds of various failure modes.

Debra, what do you think of the AltAcc2c's? I have owned two of the AltAcc2 units and loved them - never had a failure of any kind in many flights.

Thanks,

I like the AltAcc very much and have 3 of them.

In my level 3 project I used single deployment at apogee. Since the rocket only did about 1000 ft. The rocket was a large tetraheadron about 100lbs ( It was an upscale of the quest DC-Y). So in my case I had a seperate ematches connected to each AltAcc for main only at apogee.

Debra Koloms TRA9021 Level 3

I am wondering if this is what HK724 is trying to protect us from? Big dumb rocket to ultra low altitude with moderately high power.

Jerry

Jerry - please elaborate. ML