Landing Gear Emergency
27 September, 1999
Letīs start with a basic premise, unless the airplane is low on fuel, the weather is a major factor, or there is some other mechanical problem, a landing gear problem is NOT an emergency. At least not immediately. If the landing gear wonīt extend for whatever reason the most important thing is to know what you have to do and then do it. A gentle reminder, the first and most important thing to do is to fly the airplane!
In the 1980s a DC-10 crashed in the Florida Everglades because all three of the flight crew busied themselves trying to resolve a landing gear problem. While all three crew members were engaged, the autopilot disengaged, and the aircraft drifted down and crashed. It turns out, all aboard were killed because of a faulty gear light and the simple fact that no one or nothing was flying the airplane.
Itīs Not An Emergency
Letīs look at an example of a gear "emergency" in a Comanche. A number of years ago I was returning to my home airport, San Jose California, in relatively new (to me) Comanche. San Jose International Airport serves most of the major airlines and has mountain ranges parallel to the approach path on both the east and west sides. The weather was a high thin overcast with about 15 miles visibility. It was very dark and there was no moon. The time was approximately 00:30.
As I executed my pre-landing check list, I selected Gear Down and the landing gear only partially extended. When the Johnson Bar stopped in transit, I immediately switched the three position (up-off-down) landing gear switch to Off.
Regarding Johnson bars, I have a 1960 250 Comanche with the landing gear Johnson bar between the seats. The Johnson bar moves to the floorboards when the gear is up and almost vertically to the back of the nose wheel well when the gear is extended. Based on a tip from the Comanche Tips book, I always apply light pressure by pushing the bar every time I extend the gear. By assisting the gear, I have the opportunity to feel if any part of the mechanism is binding. When the gear extends into locked down position, there is a tactile thump as the gear reaches full extension. In addition, the position of the lever arm against the wheel well also can be used as a rough indication that the gear is completely extended.
I then turned the gear switch back on and selected Gear Up and when the gear had retracted, I selected Gear Down again. With the same result. The gear froze half way through the extension. This time I immediately turned the gear switch to Off.
It was surprising that the circuit breaker did not pop. There are two probable reasons that it didnīt pop. First, both times I selected Down, at the first sign of the gear stopping I immediately switched the gear switch to Off or Up so that the motor wasnīt running against a jam. Second, I later checked and found that the circuit breakers were very old (most were original) and might not have been usable or effective anyway. So I had my A&P replace all the circuit breakers.
Fly The Airplane First
I then notified the tower that I had a landing gear problem and turned east, away from the airport. My intent was to find a safe place to sort out the problem. I flew away from the approach and departure paths and began circling. Since there were high mountains only a few miles to the east, I devoted 80-90% of my time to flying the aircraft and the rest for resolving the problem. Had I been on an instrument approach in IMC, I would have notified the controller of the problem and asked for a clearance to depart to VFR conditions or to a holding pattern where I could take as much time as necessary to resolve the problem.
Use Your Resources
Luckily, I was not alone. Although not a pilot, my passenger Jon was an experienced Navy Air crewman and isnīt prone to nerves. I verbally set the priorities. I would fly the aircraft as my primary responsibility, and Jon would hold a flashlight and read the emergency gear extension check list. With Jonīs assistance, I would execute the checklist one step at a time.
Had I been alone, I would have done exactly the same thing. The only difference is that it would have taken me longer to fly, read the check list, and execute the items on the check list. I was over fairly dark landscape and the only outside references were the lights of San Jose to the west. I knew that I was in a situation where I could either lose outside reference when turning to the east or even accidentally fly into the mountains.
I had another card up my sleeve. Then, as now, I carry both Maurice Taylorīs phone number and the number of my A&P with me when I fly. On the oft chance that I ever need help, help is as close as a phone call away, especially with a cell phone on board.
It is funny, after my initial reaction, I didnīt feel pressure at all. I knew I had a problem, but I also had two hours of fuel remaining, a number of very long runways nearby, and someone to help me resolve the problem.
Follow Your Check List
I slowed the aircraft down to the recommended speed, executed the check list exactly as stated, with my passengerīs help pushing on the gear extension bar, the gear fell easily into position. I had a green gear gear down light indicating a successful extension. But now there was a question. Green light or not, was the gear actually locked down?
I called the tower again and asked for a flyby to verify that the gear looked extended. Was a flyby worth the risk? One theory is that no one on the ground will really be able to tell if the gear is actually locked down and the risk of low and slow flight isnīt worth it. Because the three gear switches are wired in series on the Comanche, if all three switches are working correctly then a green light indicates that all three gear are down. But if you are careful, as I was, there is nothing that can be hurt by a flyby. But maybe nothing gained. After the flyby, the tower responded that the gear all looked down and cleared me to land on runway 12L.
At this point, I believe I showed real common sense. First I knew I didnīt need to rush to get on the ground and second, I felt that landing on runway 30 was the better alternative. Runway 30 is usually the active runway and I had undoubtedly made at least 95% of my day landings and probably 99% of my night landings on 30. So I decided to use a runway where all the visual clues were familiar. I also told the tower that I requested landing clearance for runway 30L, the longest of the three runways. I wanted everything on my side. I made a normal approach to a soft field landing. The touchdown was so soft and smooth that neither my passenger nor I felt the mains roll on. Our first indication that we were on the ground was when the nose started dropping. I have never made another landing like that in any airplane. Shows you what concentration (or fear!) will do!
Be Careful When Taxiing
We taxied to my tie down. I have subsequently learned that I was still at risk of gear collapse when I was taxiing. Even though the gear was down with a green gear light showing it is still possible for the gear to collapse. I now know that when the emergency gear extension is used, it is very important that to treat the aircraft very carefully on the ground. It might even be better to stop the airplane on a taxi way and carefully tow it to a tie down. Certainly, it should never be taxied over rough ground, grass, or at any speed that might put side loads on the landing gear.
All Well, That Ends Well
The problem was in the transmission. Gears were broken and jammed. There was little evidence that this transmission had been serviced in many years. Webco repaired and returned the gearbox within five days. My Comanche has over 1,100 hours on it since that incident with good maintenance and without another gear problem.
After sharing this experience with a couple of other Comanche pilots I learned a really good way to get experience manually extending the gear. During the annual inspection when my airplane is up on jacks and the A&P is cycling the gear I often take the opportunity to actually practice a manual extension. There are some caveats on practicing this kind of extension that are covered in another article in this issue.
The important things to remember from this story are 1) Donīt panic. Treat any gear issue as a problem, not an emergency. 2) Fly the airplane first. 3) Use whatever resources (passengers, approach, local controller, your A&P, etc) are at your command. 4) Follow the emergency extension checklist. 5) After landing be extremely careful when taxiing. And above all, use common sense.
Use A Check List
One final and very important note. Many more general aviation aircraft have landed gear up because the pilot forgot to put the gear down in the first place than have landed gear up because of mechanical problems. Youīve heard it before and youīll hear it again. Use a Check List for all phases of flight! Use a Check List before every landing. The use of check lists is undoubtedly the cheapest flying insurance there is.