had an "iteresting" L2 certification flight, a PML Endeavor on a J350. It went up about 100 ft, and then went off at an angle. It continued up, arced over and started down, and down, and down. When the parachute finally came out, most people thought it would be damaged, but it was found in perfect shape about half a mile away.
Ready to take off:
formatting link
Missed most of the rocket, but you can see the J350 in action:
It's crap like this that really makes me wonder who should be able to sign off on a cert. (I checked out your links) You could drop your bird from
100' without a chute on to the grass field you used and not have any damage!
Your cert was a failure, and if you want to take pride in it, I can't stop you, but any reasonable cert team would have laughed you off the field if you claimed a "good flight" for this. You got your merit badge, but you didn't earn it...
(former NAR section advisor and TRA Prefect - currently just TRA L3)
Really? Was it a perfect flight? By no means. Was it a 'safe' flight? It certainly appears that way, based on both the description and the pictures. Firstly, there was no indication of what the 'angle' was. Secondly, if the angle was sufficent that the ejection charge did, indeed, deploy the recovery system in a safe manner, then the individual performed a safe flight.
He certainly had one that was close to the margins -- and got very lucky. If the rocket wasn't stable, it wouldn't have ejected the recovery system in time. If it was too much of an angle, it wouldn't have ejected in time. If the ejection charge was too long, the rocket would have been damaged. If the angle was such that there was a dangerous situation, it appears that would have been discussed.
There's no indication as to what went wrong with the flight to cause it to c*ck after a 100' initial flight -- it might be a bad reload, or improper assembly, or any of a number of other things. However, if it wasn't a bent/cracked fin (which would have disqualified the certification since the model would not be ready to fly again), then according to the certification procedures, this was a valid flight.
The procedures have been hashed out over a period of time. As indicated above, they don't require a 'perfect' flight, but a 'safe' flight. All indications are that this flight was 'safe'.
I have to admit that if I'd been doing the certification, I would have been going over the rocket with a fine-tooth comb to find any damage, and attempting to discover if there was a motor or assembly failure, but that information wasn't provided here. Given the information provided, this was a (borderline) safe certification flight.
This isn't any different than someone passing their driving test with a
70% (presuming that's the minimum passing grade). Would I want to drive with that person, or am I thrilled that they're on the road? No, but the line is drawn at a point, and that's where it is. The same is true for HPR certification -- he got lucky that everything worked, but the point is that the safety margins ALLOWED it to work.
This reminds me of the old joke about what do they call the guy who graduates last in his class at medical school...
If the person signing off on the certification had chosen not to do so, I would have supported that decision, because AFAIK that person has the final say, period. My point was that according to the description of the flight and the rules, that 'should' be ruled a safe flight -- but the certifying person does have the 'final say'.
If you disagree with that assessment, then the rules need to be changed
-- for example, a rule that initial ejection should occur within 2 seconds of apogee, or something similar. Barring that, the flight appears to have conformed to the rules, as stated.
The rocket landed safley in a field a half mile from the nearest person. I have no idea how anyone could consider that unsafe. An angle could be anyting from 1 degree to 179 degrees. A number of other rockets went off at a similar angle, none of them came anywhere near the spectators. If the flight was unsafe, I would not have presented it for certification, and if i had it would not have been certified. There was absolutly no talk of not certifying the flight. Except for some residue and dirt, it is impssible to tell that the rocket has even been flown.
Congrats on the cert, Jim. Don't let the Monday Morning Quarterback get you down. It seems to be a rule of rmr that any post about a cert flight that even hints at anything remotely out of the ordinary will generate responses condemning the flyer, the person who signed the cert, the cert process, the national org, the local club, the RSO, etc.
-- and predictions of the downfall of Rocketry As We Know It. =20
Probably if the rocket had gone over people with that flight profile, most would be saying it was an unsafe slight. I think the question is would you have considered it unsafe if that had happened? If so, it should not be considered sucessful. When something malfunctions as in the case being discussed, the direction it will go is unpredictable. A good flight is a good flight no matter where it goes.
Would be curious if the next flight is routine. That would point to the particular motor being the issue. Everyone should lighten up as the flight did turn out successful for Jim, the field looked like it was wide open and he did say there were no spectators near the model. How many folks would confess to flight failures after achieving certification? I mean one can certify and then go out and experiment and if the area is isolated the danger is minimized. I sure as heck wouldn't spend a bunch of time and money on a model to see it crash. Trying to pimp the guy to look for a "hairline" fin crack is inappropriate. Kurt Savegnago
If the model went up 100' tumbled out of control it would be an obvious DNR. Jim didn't say what angle it went off to. If it cocked
30 or 45 degrees and continued on would that be wrong? What if the model simply hit a wind gust? What will be interesting is if Jim does another flight on the model and it performs normal that would point to the random nature of the the flight parameters. The flight was completed to the letter of the rules. I am assuming here that the model is stable and suffered an external pertubation.
Thank you Randy, and others. Several other rockets had similar turns in their flights. I assume it was a gust of wind. No one even mentioned it at the time. It only became an issue when someone who was not there, and who hates the hobby and everyone in it, made it an issue.
That's what Dale was asking about and a logical conclusion. Sounds like the wind was not in your favor. Any idea on what the wind speed was at the time of launch?
Congrats! If it was me, I'd take it.
Bear Bryant: "There's no such thing as an ugly win."
From this I am ASSUMING (yes I said it!) that winds aloft even 100 ft up were much different than surface winds. From flying enough in South Dakota winds aloft are much different than surface winds. When I certified L2 surface winds about 5 kts. my AMRAAM 3 on a J350 went up 5345' AGL it drifted on it's chute approximately 5 miles. Suburban recovery and my daughters peregrine eyballs found it in perfect shape. I had increased to the next size larger chute that day as the ground was typically gumbo concrete up on the bluff and did not want a prang for the cert flight. I was instructed to go down to a 24" chute to reduce drift, by a person that suposidly would know better. Later this same person reduced thir chute size as mine drifted away and he broke 2 G10 fins on contact with the prairie. Ground based weather observations (winds, temps, clouds, precips) are just that and do not always determine weather aloft. Just ask a Cessna pilot that ices up at 8000 MSL when surface temps are 50 degrees F.
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