Gear Troubles
by Mike Heijmans
Today I had some trouble with my landing gear and it almost resulted in a bent plane. It all started yesterday evening when I did my first solo in the plane. I noticed that it felt like it took a little bit longer than usual for the gear to come up into the wells. It was slightly longer, but enough for my brain to think “that seemed a little longer than usual”. I had an indication of full retraction so I continued my flight. When I arrived at my destination, I extended the gear and there was no issue there. So maybe it was a case of “auto-rough”. The phenomenon of a pilot perceiving a issue with the engine when he/she is over an area where landing is not possible. Usually occurs when flying a single engine piston plane over water and away from gliding distance to land. Anyway, It was, after all, my first solo in the 1967 Debonair (and in a retractable gear plane). Maybe my mind was playing tricks on me.
I took off on my way back home and this time when I retracted the gear, it felt like it took a little longer than the previous retraction. When I was approaching KARR (my home airport), I extended the gear and there were no problems. It happened quick and I got the lock indications. I had an uneventful landing and headed to my hangar. When I got it pushed back into the hangar, I inspected the gear closely and everything looked great. I had my suspicions but nothing looked out of sorts. I decided to take it up to the shop first thing in the morning to get it checked out by a professional.
So this morning, I got up super early to fly the plane over to 3CK and to arrive when Finefield Aviation opened at 7:00 A.M. When I took off, I timed the gear retraction and it took all of 30 seconds to retract this time! Oh yea, that’s bad for sure. I was glad to be flying to the shop. When I got in the pattern at 3CK I extended the gear and it went right down with no delay and I got a down indication. My Debonair has a single light to indicate that the main gear is down and the nose wheel is a mechanical indication on the floor. I had the green light and the floor read “DN”.
Here’s where I made a mistake and it almost cost me my beautiful (new to me) plane. I should have cranked the handcrank for the gear to the mechanical stop. Craig Bailey, our area BPPP instructor and the man that did all my transition training, told me to always crank it to the stops if your alternator fails because the 12 volts from the battery is barely enough to push the nose wheel to full mechanical lock. He explained how the gear system is designed and rigged so the motor shuts off a bit early and the gear coasts into the locks utilizing the momentum. This was done to save the gear motor from harsh stops and to help it last longer. If it doesn’t have enough momentum (like lower voltage or the motor is weak), you are likely to have a nose wheel collapse on landing. This is because the nose gear is fighting wind on extension and a weak motor will surely not provide enough momentum for it to coast to the lock. The problem is, the only scenario that stuck in my head was the alternator outage scenario (probably because it’s the one we talked about most and it is, in fact, the most likely scenario to occur), so I didn’t think to crank it down in my current situation. I mean, the gear seems to be working and the alternator is pumping the full 14 volts.
When I touched down at 3CK, I had the best landing I have made in the Debonair to date and it was a beautiful greaser. Like a butterfly with sore feet. I taxied to the shop and the plane was put up on jacks right away. When Jim was putting it up on jacks, he mentioned that the gear door hadn’t fully closed on the extension. I didn’t think much of it at the moment, until he got in the cockpit and cranked it down to the stops on the handcrank which sucked the door into place… a full half turn! WHOA! That’s the moment I realized that the weak motor is no different than not having the alternator! In fact, the reason the alternator failure is bad is because the lower voltage makes the motor weak. I realized that I was very close to having my own nose wheel collapse this morning. What if my landing wasn’t so soft?! What if there was a heavy cross wind and I had to plop it down? What if, what if, WHAT IF?! How close was I to turning my plane into a runway plow this morning?! I know I was incredibly lucky today for sure. That’s not even up for debate.
It turns out that the motor had some internal issues as evidenced by the state of the brushes. I opted to have the motor sent out to be rebuilt and a loaner was swapped in while we await my motor’s return.
Moral of the story here is, if you suspect an issue with the gear, crank it down to the stops.
ANY SUSPICION OF AN ISSUE: crank it down!
Never risk it! Next time lady luck may be busy helping another pilot and you’ll find yourself sobbing on the runway next to your bent up bird.
Photos
Subscribe via RSS