Just 1 altimeter?

Hello everyone,

I just did my first dual deploy at RG. I used two Adept 22's, which performed flawlessly. I am converting another rocket to Dual Deploy, and have an old perfectflite laying around that I would like to use, but I only have one.

How many of you use a single altimeter on a regular basis with no backup? It is the norm to always have a backup? I would like to leave the adept 22's hooked up in the original rocket, so I don't have to swap back and fourth if I'm flying both rockets on the same day (typically I would)

Thanks,
Charles

I almost always use a single altimeter unless I have a bunch of room like a 3" and up rocket ill use two just for fun. If I can get a long enough delay I will leave the motor charge as a backup but haven't had a failure yet.

I think it all comes down to 'how safe' do you want to be? I'm sure I'm considered a noobie(8, maybe 10 DD's under my belt) but I always err on the side of saftey. Just think it's the wise thing to do.

Gary
L1
Sears572

I've flown two altimeters exactly once, and that was just for the practice. For people who haven't flown a LOT of DD, I am not at all convinced that two altimeters improves the odds of success. There are too many ways that a second altimeter can do things that mess up the flight if you haven't done everything right.

Commercial altimeters are quite reliable, and a single altimeter, set up correctly, is unlikely to be the failure point in your flight. If you set one up incorrectly, a second one also set up incorrectly isn't going to help you, obviously. The failure point in your DD flights is far more likely to be something you did wrong than something your altimeter did wrong, and having two altimeters roughly doubles the odds that you did something wrong. Go ahead and fly with just one.

I have flown several hundred dual deploy flights with only 1 altimeter. There have been 2 instances where a backup altimeter would have saved the rocket. I've destroyed many more by cato, etc.

Most of my rockets are 2.56" or less, so fitting one altimeter is enough work for me. The few DD mishaps I have had were due to bad home-made ematches and an unreliable chute burrito method I came up with. The altimeter itself was never a problem.

I always use a long-delay motor ejection backup for the drogue event to minimize the chance of a ballistic impact. We have all seen close calls near the flight line. (A ballistic stretch Minni Magg (not mine) that crashed a few feet from my car left a lasting impression on me.) An unsuccessful drogue event can cause serious damage to people, property, and the rocket itself. An unsuccessful main event is a lesser problem.

I've only flown single altimeters on DD flights. I've had three "issues" with DD and none of them were caused by the altimeter and only one resulted in the loss of a rocket. I've lost a lot more rockets to motor ejection issues then I ever did altimeters.

Most of the time I fly on a single altimeter. I do use 2 or more on bigger projects that have the space. I have had the backup cause problems with the primary charges.

JD

Most of the time I use only one. I do use the motor ejection for the back up. I fly mostly CTI motors so I don't adjust the delay. My Altimeter is my main deployment and the motor ejection for back up. At least the motor ejection will get rocket split apart and not have it come in hot.
GP

I fly one altimeter a lot just because putting a second in is a giant pain. The key is when you power it up at the pad is to take the time to count the beeps and make sure the altimeter is happy. I have an Adept22 and HiAlt45k and even when I am flying both I make sure everything is beeping out correctly. There have been a few times I almost put a rocket up but found out as it's sitting on the pad that not everything is right. My point is, if you take the time to ensure everything is exactly right, it sort eliminates the need to fly 2 alts.

Basically my L1 and L2 stuff gets one altimeter, my L3 birds get two, my big Harpoon usually gets three,, sometimes four, I have Arts, RRC2, Raven, and an Altac, all sound different,,

Recently I have been having issues with squibs not firing,, so I am starting to use Squibs, flash bulbs, and homemade as redundancy measures.

Tom

JDcluster said:

I have had the backup cause problems with the primary charges.

JD

Click to expand...

Can you explain this? I am trying to envision a scenario where this would be an issue.

Do you run two completely isolated systems, including e-matches and charges?

I fly redundant Altimeters about 90% of the time.

I fly with single altimeters all the time, except for my L3 cert where I flew 2. I have not had any problems with that. There was only one time where I thought I had a failure, and it turned out to be an error I made in prepping.

My thoughts:

I fly mostly 1 altimeter on everything up to 6in rockets, then when L's & M's & N's are involved ...2 alts. Even my 6in cluster I use just 1.

BUT... if flying a smaller 3 or 4in. [sometimes 54mm minimum] to extreme altitudes or speeds, 15,000ft or over I will use 2. 1 standard type that just does deployment & 1 that also has data download such as a Raven, R-das, or Stratologger for back up also.

If I'm going high & Xtreme I want to increase the odds of getting the hardware & rocket back.

Also when using a new unproven altimeter [for me] I always fly it alongside another altimeter that I have used before and know it functions correctly. Then after a successful flight will fly the new one by itself.

This has saved my butt & rocket twice!

By the way I love those Adept 22's got 5 of them.

The rocket had already deploy apogee charge, then the backup fire severing the shock cord anchors (both of them).
That was back in 1997...

JD

[/B]

patelldp said:

Can you explain this? I am trying to envision a scenario where this would be an issue.

Do you run two completely isolated systems, including e-matches and charges?

Click to expand...

Maggie and I both fly single alt. With that said, I agree with Jims position. Let the nature of the flight dictate the need.

I've got two rockets that I fly with a single altimeter every time it flies...it works fine, this day and age people have adapted to two alts being the standard.



Jim Scarpine typically flies his big rockets with 1 alt, but I'll let him explain that.




Braden