Level 2 Attempt and failure

So, this hurt. A lot. I do not enjoy failing. But things can and do go wrong. I attempted my NAR L2 Certification flight yesterday. It did not go well. Recovery system failure. Flight logs show the recovery gear was deployed appropriately, but never opened. Both flight computers match their data almost exactly except for starting altitude. 30 foot difference there, but all other events match exactly. Max altitude- 2914 feet @ 14 seconds, max V- 484 fps or 330 mph @ 1.75 seconds, gees- 8.59.

Here's what I think happened with my observation of it coming down: The drogue was a bit tangled, so the rocket came in butt first. The e-bay with attached nose cone above it at the end of the shock cord. Main charge goes off and the nose cone is sent "up" with the main. The burrito for the main is right under the nose cone, now falling at about 60 feet per second. The main never gets into clean air, so the burrito never opens and the entire project meets the desert floor. The sustainer hit first, the the e-bay nicked the sustainer before driving into the ground. The weighted nose cone then smashed into the e-bay, crushing the payload tube before hitting the ground itself. I was too upset to think to take a picture of the landing, but here's the damage.

Sustainer top:


Payload top:


Payload/e-bay rivets:


Nose:


Video of the flight, with audio of my reaction of the landing at the end...
[video=youtube;S_H0olysE50]https://www.youtube.com/watch?v=S_H0olysE50[/video]

I am sad, but I have learned. Here's to hoping my second attempt goes better.

Is that the Patriot that had the beautiful paint? Sorry to hear. Hope you can repair it & good luck with your next attempt.

Sorry to hear about that. Good part is majority of the rocket survived. How many grams of black powder did you use for the ejections?

I went to ROCstock last week and it was very hot and humid. I noticed a lot of rockets lawn darting at the event. I checked my rocket while waiting in line to set up and noticed that the pressure from the heat was so great that I couldn't remove the nose cone which was loose when I arrived. If I didn't observe what was happening at the event, I probably would have lost mine. I had to keep rotating the nose loose before removing it to make some adjustments. There are so many factors to consider just before launch.

Hey don't beat yourself up (too badly) - we all have been there with failed recovery. You are on the right path reviewing what went wrong and how to prevent in the future. Rockets can be rebuilt or replaced.

Very sorry to hear this. :cry: That was/is a gorgeous bird. But, you still have the goal in front of you, and every experience is a learning experience. Lord knows, I have seen Level 3 rocketeers with 30 years of experience have a failed deployment and send a 75# rocket six feet into the ground. I guess if it worked perfectly every time, it would get old.

Don't worry, you'll get your L2.

Wayco said:

As I said at the launch, it took me two tries to achieve my Level 2. My L-3 TAP said it all, "The up part is easy, coming down is much harder".
After inspecting your N/C at the launch, another thought occurred to me, did you have your chute attached to the N/C eyebolt? If it was attached to the shock cord, make sure it's attached far enough away from the N/C that the separation forces pull it out of where it was trapped.

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No, but it was attached close. That is a change I am making. The 'chute will now be attached at least 1.5x as far from the nose as the shroud lines are long.

Tonimus said:

No, but it was attached close. That is a change I am making. The 'chute will now be attached at least 1.5x as far from the nose as the shroud lines are long.

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Please explain why for us noobs out here in the sticks. Is there an issue with attaching the chute directly to the nosecone?

W7AMI said:

Please explain why for us noobs out here in the sticks. Is there an issue with attaching the chute directly to the nosecone?

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I am not a noob, and have been doing it that way for a couple decades worth of high power, and twice that long when taking low and mid power into account. For the record, I am 47, and built and flew my first rocket when I was 5-6 years old with the help of my Dad.

W7AMI said:

Please explain why for us noobs out here in the sticks. Is there an issue with attaching the chute directly to the nosecone?

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The issue lies in a rather unique set of circumstances. If the 'chute had been attached further from the nose cone, it MAY have been able to open. This has not been an issue for me previously, during many flights. I personally consider it a freak accident, but by changing the anchor point, I may be able to prevent it in the future. To repeat what I said to my buddy at the launch, I could've made the same launch a dozen times and not had the same failure.

W7AMI said:

Please explain why for us noobs out here in the sticks. Is there an issue with attaching the chute directly to the nosecone?

Click to expand...

By attaching it 1.5 times the length of the shroud lines on your chute, you can use the separation force of your N/C being "launched" away from your payload tube by the ejection charge. Larger rockets have more mass and momentum generated by the black powder charge and the larger nosecone separating during ejection. Tony's rocket had a large eyebolt recessed into the shoulder of his N/C, and a couple of shear pins sticking into that area. I have had shear pins snag a chute and keep it from deploying. Between the weight of the N/C and the weight of the rest of the rocket on opposite ends of the shock cord, with enough black powder, you can create quite a jerk on the cord, and if the attachment point is down the cord a ways, it will pull the chute out.
If you are flying a smaller rocket with a N/C that has the anchor point outside or on the bottom of the shoulder, this is not an issue.

Wayco said:

Tony's rocket had a large eyebolt recessed into the shoulder of his N/C, and a couple of shear pins sticking into that area. I have had shear pins snag a chute and keep it from deploying.

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After we spoke about it, I thought about it some more. I had the charges between the 'chute and the nose cone, so I don't think the shear pins caught it, but rather the aerodynamic forces pushing the burrito into the shoulder caused the problem.

Different possibility, same solution either way.

Sorry to hear about the mishap. Don't give up, you'll get it!

If you are sticking with the cable cutter burrito method for your next attempt, along with making sure your shock cord is long enough, you may want to consider attaching a small pilot to the main, if you have a top loop. I use this method with cable cutter burrito deployments for the very reason of avoiding a delayed release with a burrito. I have very limited flights using this method but there are others who have come to the same conclusion and use something similar. It just takes a small pilot with a short 2-3 foot harness on it to get into clean air and once that cable cutter goes it will pull the main out just like that.

I don't have a cable cutter. I just think the regularly wrapped burrito failed to open due to the way the assembly came down.

No getting bummed! Failure is part of science. I have had many flights with partial or complete recovery failure, but quite happy with where I am at and what I have learned. Try, try again.

All advice aside, you have my sympathy. My L2 attempt will be with my first DD build, and I lose sleep worrying about exactly this stuff.

Joe, what club do you fly out of?

I have seen an instance where the chute protector rode up the shroud lines to the point where the chute never opened. the fix, secure the protector to the shock cord(quick link from hankie to the same attachment point as the chute).
Rex

Or plastic zip tie. Or a knot.

Rex R said:

I have seen an instance where the chute protector rode up the shroud lines to the point where the chute never opened. the fix, secure the protector to the shock cord(quick link from hankie to the same attachment point as the chute).
Rex

Click to expand...

I always secure the protector. The burrito was still mostly intact when I found the rocket. Stuck under the nose, it never opened.

Bat-mite said:

Joe, what club do you fly out of?

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None, at the moment. I flew with NOVAAR and NARHAMS and got my L1 at Red Glare when I lived the in eastern panhandle of West Virginia, but I've since moved to upstate South Carolina (two years ago) and have yet to present myself to any of the area clubs. (I say "area" clubs because there are no local ones.) I've been building, but I have flown anything in much too long. I should go fly some low power at Pickens High School where there are some big enough sports fields.

EDIT: OK, I just updated my profile information, which still said I live in WV, but is now correct.