"With my hand still on the gear handle I looked at Jose and said, 'Uh-oh. I think we have a problem here with the gear'."
Pilots never really want those experiences that get their hearts pumping, but unusual or abnormal situations in the cockpit always challenge our skills and knowledge. It reminds us why we go through so much training.
Abnormal Event #1
A few months back, we were flying the Learjet to Grand Junction, CO. On this particular flight we did not have any passengers on board and that turned out to be a good thing. The flight started off unusual. As we were rolling down the runway when we departed for Grand Junction there was suddenly a very loud sound of harsh, blowing air rushing into the cockpit area. This incoming air was also very warm. I expected Jose to abort the takeoff, but he continued the roll. We took off and I raised the gear. He told me that it sounded like the pressurization had reverted to Emergency Air (or, emergency pressurization). This blows hot bleed air directly from the jet engines into the cabin. The compressed air bypasses the heat exchanger and cooling system. Its a way to keep the cabin pressurized if there is a blockage somewhere in the normal pressurization lines. It's very hot air, but up at altitude it will at least keep people from passing out.
He immediately had me turn off the bleed air. This shuts off all bleed air coming into the cabin. After about fifteen seconds we cycled it back on and the pressurization seemed to be working normally again. We decided that with the system working again, there was no real reason to return for a landing. He told me that sometimes those valves get stuck. In this case, the valves got stuck in the emergency air position.
Abnormal Event #2
The rest of the flight was routine and uneventful, until we began our approach to land. With the captain's normal call-out command of, "Gear down, flaps twenty, before landing checklist," I lowered the gear handle. The normal procedure is for you to keep your hand on the gear handle until your indicator lights show that all three landing gear are down and locked. This was not the indication I saw. Two green lights for the two main gear were illuminated, but there was no green light for the nose wheel. With my hand still on the gear handle I looked at Jose and said, "Uh-oh. I think we have a problem here with the gear." He looked over and agreed with me.
The first thing we checked was the indicator bulbs. He pressed the gear indicator lights test switch. All three gear lights illuminated, which means that the light bulb was not the problem. He then asked me to cycle the gear. So, I raised the gear handle and then lowered it once again. Nope. Same indications. We had a possible nose gear stuck up in the belly of this Learjet.
With my heart rate increasing, my emergency procedures training from Flight Safety International immediately kicked in. Without saying anything, I reached for the emergency checklist in anticipation that he was going to call for it any second. He did, of course. In a multi-crew airplane, the plan, when something goes wrong, is that one pilot will fly the airplane while the other pilot works through the appropriate checklist. First, I needed to advise the tower that we were experiencing a problem with our gear and we needed to depart their airspace. The tower approved or request, of course.
Emergency Checklist Time!
Having departed the area and with Jose flying the jet, I flipped over to the section titled, "Landing Gear Malfunction." The checklist requires first that you check to make sure that the gear motor circuit breaker is in. The breaker was in. If the CB is indeed in and you still do not have all three wheels indicating down and locked, the checklist calls for you to manually lower the gear with the manual gear handle.
Jose was not completely convinced that the nose gear wasn't down. We thought it through for a minute, trying to recall our knowledge of the systems. As he thought through what our next move was going to be, I kept eyeballing our fuel gauge. A Learjet 24 has straight turbojet engines and it is not an efficient gas consumer, especially at such low altitudes. I knew that circling the airport at 13,000 feet, the engines were gulping up our Jet-A fuel. We decided that we had enough fuel to circle like were for another 30 minutes or so. After 30 minutes, we were landing regardless of what the condition of the nose gear was in.
With a Shadow of a Doubt
As we circled over the airport, we made occasional turns in order to keep us in the immediate area of the airport. At one point, Jose was glancing out his window during a turn. Suddenly, he exclaimed, "I've got the nose gear shadow on the wing!" We were turning just right so that with the position of the sun in the sky and our bank angle relative to the sun's position, the shadow of the nose gear landed right on the left wing tip tank. From what he could tell with the shadow, the nose gear appeared to be nice and forward, as it should be. He wanted a double-check on the shadow, so he once again positioned the airplane in a bank that would reveal the shadow. He confirmed that it really looked nice and forward. I think this knowledge slowed both of our heart rates down a few notches, but we were also basing this off of a shadow. The shadow technique is not found on any checklist, but it was the first real positive indication that our nose gear was in fact down and locked.
"Cleared for Low Approach"
During this whole time, we had been in radio contact with the Learjet maintenance supervisor on the ground. We asked him if he would take a look at our nose gear if we did a low approach over the runway. I called tower and requested a low approach over the runway for inspection of the gear. With tower's approval, Jose set up final approach for the runway with flaps set to 20 degrees. We came down and leveled off at about 100 feet above the runway. I called out our airspeed to him in order to maintain a safe flying condition; we maintained 150 knots. The maintenance supervisor radioed that the nose gear appeared normal.
Upon the captain's request, I asked the tower if we could remain in the traffic pattern because we intended to land. The tower asked me if we had a positive indication in the cockpit that all three gear were down and locked. I knew where he was going with this question. I knew that if I gave him any indication that we did not positively have all three gear lights, he would be rolling the crash trucks into position. I of course told him that we still only had lights for the two main gears. As I predicted, he rolled the crash fire trucks. From the air, I watched the trucks come out of their hiding place. Its kind of spooky to look down and see fire trucks positioning near the runway as they get ready for your airplane to land.
Time to Dance
I asked Jose what our plan was upon touchdown. He told me that he would keep the nose wheel off of the ground as long as aerodynamically possible. He told me that my job would be to pull the handle for the drag chute if he called for it. Most Learjet 24s have a drag parachute that can be deployed out of the tail if you need to decelerate quickly on the runway in an emergency situation. I really never wanted to have to pull that handle, but I thought, "Today might be the day I pull it."
He made a beautiful touchdown. I was shocked at how long he was able to keep the nose wheel off as we rolled down the runway on the two main wheels. We continued to decelerate and the nose began to slowly get lower and lower. At last, he had no more aft movement available on the control wheel and the nose slowly dropped below the horizon. Gasp! And then, the nose stopped dropping and it was obvious that the nose wheel was down and locked. Finally, it was time to resume breathing.
I learned a lot that day. Although I have had gear malfunctions in other airplanes before, this was my first "real" situation in a turbine aircraft and in a crew environment. I think we did it right. Jose and I relied upon Crew Resource Management (CRM). We never lost our situational awareness and we followed the old adage, "aviate, navigate, investigate, communicate." We maintained aircraft control, followed the checklist, and used all of the resources available to us. I'm actually glad to have had that experience; it increased my confidence in our ability to handle abnormal situations. It's funny because only a few months before that day, I had remarked to Jose that we had pretty much experienced smooth sailing in this Learjet and we needed a few "interesting" events to test our true colors. I guess that will teach me to not cultivate premonitions about future flights.
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