L3 attempt failures -- more than "that sucks"

[FredA]

In another thread there is a story about an L3 attempt gone bad -- bad in a preventable way -- and the TAP's comment postmortem was "that sucks."
That sucks is an understatement.
But what really sucks is the [apparent] lack of up-front guidance from the TAPs.

IMHO, L3-cert failures should be SUPER RARE.
You've got two of what we call "the best of the best" watching over the build from start to finish.
How do these go south?
I can see random, weird failures - but ripping the fins off a kit that is inappropriate for M-power is pretty inexcusable in my book.
How did the project get as far as it did?

Does HQ track L3 attempt failures?
Do we remove TAPs with high failure rates? I think we should!

And before you flame me:
Yes, I was a TAP.
I know what it's like -- all sorts of projects, all sorts of personalities.
That doesn't make failure acceptable.

CRASHES SHOULD NEVER HAPPEN.
L3 cert flights should be one of the safest flights of the day.

 

[NateB]

Was that phrase the only feedback? Or just the initial reaction? Why assume there was no further guidance or ideas after looking at the pieces and thinking about it?

 

[Cameron Anderson]

How was the kit not M worthy when Loc has a video of a Goblin flying on an M on their website?

The L3 process isn't a flyer building a kit exactly the way their TAPs would, or even orecisely how they want. TAPs are just a backstop to prevent egregious errors resulting from playing in a part of the flight envelope new flyers haven't been before. How can TAPs test flyers if they hold their hand the entire way and make them follow a lockstep program not their own?

TAPs offer guidance and experience, but failures are still going to happen, even at L3.

I don't see an issue with the failure your so hot about.

 

[rharshberger]

3/8" plywood or more likely 9mm Baltic Birch if a fine choice for most rockets with wood fins, the issue with the Goblin is that the fin planform is a long chord and susceptible to flutter, on a cardboard and wood rocket special attention needs to be paid to the fins and the airframe joint. What did the previous flyer who flew a M1297 successfully in this same rocket do differently that it survived, or was it a one time he got away with it? Carboard and Wood rockets for L3 are fine IMO but they are harder to build to survive the rigors of a flight on a M motor than a comparable Fiberglass rocket. Most TAPS and L3CC's are experienced enough to know this (or should be). While TAP's offer guidance a structural failure of the type mention in the other thread really shouldn't occur unless there was something unforseen, and plywood fins and flutter is definitely easy to forsee.

 

[boatgeek]

Also consider what is actually helpful to the candidate in the moment. I know a bunch of people who would rather commiserate immediately after a failure and then deal with details of what went wrong and how to fix them later. “That sucks” may have been exactly what the flier needed to hear.

Tracking TAPs to see who has a higher failure rate seems like a lot of work for not very much gain. It seems like there are other places that could get better results with that effort. Tracking unplanned ejection charge firing during assembly, for example.

 

[Flyfalcons]

Even NASA and SpaceX blow up stuff from time to time. If there was no risk of failing then this hobby would be boring.

 

[Rocketjunkie]

Here's how I built my 7.5" Goblin with 3/8" plywood fins in 2010. https://www.rocketryforum.com/threads/almost-a-goblin.8709/ Prepped but no motor weight was 24 lb. See the L3 thread this thread is referring to for motor choices and altitudes. Flew successfully on K to N power.

 

[DAllen]

You are making a lot of stupid and grossly inaccurate assumptions about my TAPs and the feedback they gave Fred. Please stop being a troll.

In case you weren't paying attention in the other thread: They have given me A LOT more feedback than just, "that sucks." The reason I am NOT going into detail about any of the TAP feedback I got is because you will use it to pick it apart and Monday-Morning quarterback it. I donno why you insist on doing this - maybe to stroke your own ego? So buzz off with this crap and delete this thread.

 

[tim cubbedge]

Nothing to be gained by this thread other than anger. Locked.