LGM Graphix

My Feedback: (22)

Recently I had an experience that could have gone very very badly. I also had a lesson I learned many years ago be further reinforced.

While enjoying a day of flying, my 3rd flight of the day went horribly wrong. On takeoff, while climbing out, I lost my elevator control. The servo had shorted out and seized during the climb out. At first I feared a lockout, but I realized I still had aileron, rudder, and throttle control. Since I still had those controls, my first thought was that I would have some ability to direct the crash to the best possible location. I could still control altitude with throttle (remember, throttle controls altitude, elevator controls attitude). After pointing the model away from the flight line I was still in control of the circuit. Being that it was only myself, a spotter, and the landowner there, I opted to fly a circuit to assess what could possibly be wrong. At this point I at least felt confident that I could set the aircraft down with some control in order to at least minimize any property damage. (Note, had this been at a busy event with spectators, or even a significant number of other modelers, my decision likely would have been to roll the model away from the flightline as soon as I noticed a failed surface and put the model in so as not to risk anybody else).
After flying circuits for approximately 5 minutes I had a good idea of the way the airplane was reacting with no elevator control. In the end, I was able to get lined up to land, and while I bounced the hell out of the airplane, bent a couple gear parts, and ended up with some cracks in gear mounts etc, I was able to save the model with minimal damage.

This was an airplane that had somebody ever asked me if it was possible I'd have said not a chance.

When I was learning to fly, my father (who taught me) always said, "Never stop flying your airplane". You need to either be able to fly it safely, or at least be able to fly it away from the crowd in a crash situation. I have been in a couple of situations where it was tempting to shut off the transmitter and just start walking to where we thought the airplane would end up, but was able to at the very least control the crash by listening to those words.
Those words echoed in my head again during this most recent experience and I'm happy to say that my airplane will fly again.
What was the cause of the problem? I really have no idea except that the servo on the elevator shorted out and the motor in it seized completely. When we looked inside, the wires were melted leading into the servo case and the plastic of the servo case was melted. When I unhooked the pushrod there was no binding, nothing that could have stalled the servo. It wasn't a power issue (example, failed regulator) as the airplane has 6V nimh packs and it is a 6V servo.

I have left the brand of servo out of this post as I do not want to start any of the typical brand X vs Y vs Z wars here, it could potentially happen to any servo I suppose.
Needless to say, I'm glad I didn't go with the initial knee jerk reaction of "I'm totally screwed" and give up. I absolutely had luck on my side, had my elevator been neutral, any more up, any down, basically probably anything outside of where it was, the situation would likely have been very different. It's not something I ever want to deal with again, that's all I know for absolute sure!

As I say, my reactions (I would hope) would have been much different if the situation was that of a busy event or one where there were more people at risk. I believe that I would have done nothing further than point the airplane away from the flight line and ditch it, however, every situation has it's outcome, and sometimes what you think you will do when you are simply thinking of a potential situation is different than what happens in the moment.

Anyway, my point is, even when things go wrong, if you have the chance, assess the situation and don't give up, you might be able to save the situation.

madmodelman

Glad you managed to save it Jeremy, you are bang on about never give up flying, I was testing a new jet last weekend and a buddy was testing a new 1/4 scale Spitfire.

After trimming he decided to loop followed by a roll, at that point one aileron started fluttering and he lost control. I screamed at him "try the rudder if you have it" this he did having by now lost the second aileron, to make it worse on the approach the gear failed to deploy followed by a good grass belly landing just damaging a radiator and an expensive prop.

Turns out he had used Spekky DS 821's on aileron and of course just stripped the plastic gears which earned him a right bo......ing!

I would not believe a big scale model like that would fly without ailerons, but it did, hence as you say, "never give up flying"
Gary

basimpsn

My Feedback: (5)

Yep never stop working them stick, The second video was a full size very sad,, even though the plane crash, they never give up.

http://www.youtube.com/watch?v=rjnUY...eature=related

http://www.youtube.com/watch?v=wxH_J...x=2&playnext=1

Nhalyn

Congratulations and thanks for the lesson... Great job and it's a good idea to remember that to us...

MajorTomski

Congrats on the save!

Like you several years ago at a club event a newbie asked me to fly his new Kadet LT40. I gave it an external look over, started it up and went to fly. With in 3 minutes I'd lost ailerons, elevator and throttle.

To the good side I did have a rudder only airplane that was climbing when wings level.

Got a good 20 minute lesson in rudder only flying and managed to land on the field with no damage.

The cause of this failure was the newbie left the screws out of the servo arm holes, the three we lost popped of the output shaft of the servos.

I now inspect inside and out!

Moerig

Sounds like the motor gave out. Coreless motors due to their construction are prone to the cage binding if the center magnet core goes out of alignment. That is why a crashed or even dropped onto concrete servo could be a risk to use. No real way of telling from the outside. Brushless servos should be more robust I suppose.

LGM Graphix

My Feedback: (22)

I've sent the servo back to the manufacture to have them look at it and see if they can figure out what caused the failure. This was a new servo, only 5 flights on it, never dropped, crashed or otherwise...... Hopefully they can figure out why it failed, though I suspect more than likely they'll just bin it and send me another one, without knowing what caused the failure though, I have no confidence in this particular servo at this point

Eddie P

My Feedback: (4)

Thanks for the write-up. Great save and good, clean thinking under pressure!!

FenderBean

Like we say in the Apache community fly it to the crash site!

TCHIEF

My Feedback: (15)

I had a simular situation

I apperently bumped an aileron on my Falcon 120 and it popped the linkage off of the servo so I reinstalled it but didnt look to see where it went on the servo arm (I didnt trim off the other three horns ) put a new keeper on it and went on to fly it . Took off and started to climb out turned to the right and it started to climb wiggled the aileron stick and had no aileron so I let it climb full throttle staight up menwhile my spotter is saying shut it down .While thats happening I start thinking wait a min if it locked out why do i still have throttle and elevator so I let it level off at 500- 600 ft and started to see if rudder would turn it .Now the falcon or at least mine wont hold a knife edge for crap but it will fly three channel.I set it down on the runway and the only thing that was said by the guys watching it was why the short flight
I started to walk up to the jet and moved the ailerons and the were working The only thing was both of them were working in the same direction if I moved the stick to the right they both went down and to the left they went up

basimpsn

My Feedback: (5)

Florida jet 04 I lost the complete right elevator stab with servo on a flyby. The left elevator start acting like aileron when i try to give up input. The fight was on to bring her back to the runway. Only when i landed and taxi to the pits I saw the damage.

http://www.rcuniverse.com/forum/m_17...tm.htm#1724529

Whizbang

I was flying a pattern plane ( .60 size Dirty Birdy ) many years ago when after executing a stall turn I discovered on the way down that I had no elevator. In all my years of flying the hardest thing I haveever had to dowas to push the throttle up while that airplane was pointed straight at the ground. The speed built up, eventually the nose came up, and after feeling it out a bit I was able to land it breaking only a prop. Keep your wits about you and don't give up!

Bryan

LGM Graphix

My Feedback: (22)

I heard back from the, we'll call it, "Manufacture" of the servo that failed. They told me it was a "little ball of solder loose in the case that caused a short".... I don't know if I believe that, or if that's their standard answer when really what they want to say is "we don't know why it failed". Either way, it leaves me feeling less than confident in that servo, although they sent me a brand new one.

Mike Mangus

Out of the hundreds of thousands of servos that are made each year, there is bound to be a few that malfunction, slip through the quality control process, or simply had a bad componant that slipped through yet another quality control process. Sometimes, we are the unlucky ones to get that servo.

Even with a 99.9% success rate, that .1% of hundreds of thousands is still a goodly amount. Heh.

c_makhija

If you do not mind giving us the servo number, it could save some of us a jet in future.

Chatty.