A Landing Gear Feature

I had the luxury and misfortune to maintain a couple of IAI Astra SPXs for the last nine years. The gear and brake systems on this aircraft are simple and straightforward yet we encountered a gear problem that took almost a year and a half to correct. On one of the Astras, the red light in the gear handle would remain on after gear retraction.

The first occurrence of this landing gear feature was on a departure from the Texas/Mexico border on the way to St. Louis. The crew phoned the maintenance staff to discuss the problem. The crew could have landed at home base, written up the discrepancy, and gone home. They elected to continue and deliver the passengers to their destination. Even at gear transition speed, this was the fastest way to get the passengers to their destination. We had structure, power, and when flown at gear transition speeds, all the elements for safe flight.

When the gear was extended at destination, the aircraft once again conformed to the type design with no obvious discrepancy. The gear retraction was normal on the deadhead flight home. The crew wrote the gear glitch up on our information item sheets to inform other flight crews and maintenance techs.

This allowed other crews to understand what was happening when the glitch occurred again. The flight crews quickly found that the problem would not occur if we had the gear in the hole before we hit 150 kts on climb-out. The gear speed was higher than that and the aircraft accelerated very quickly when not at gross, so the flight crew had to be on their game to get the gear up quickly.

If for any reason the gear did not completely retract and we were stuck with the red light on, the situation could be corrected by slowing down below 150 kts or by unloading the aircraft. The crew hates to slow down and the passengers hate to have the aircraft unloaded to reduce the normal G-force. The flight crews used the 150 kts portion of the feature to operate glitch free while we investigated the cause.

As the story goes, we had the aircraft on jacks dozens of times and ran more gear cycles than we could count. We had Galaxy tech reps (dating myself) on hand for most of the work and had IAI engineers on hand at least twice in an attempt to resolve the issue. Here you begin to see the progression from discrepancy to glitch, to issue, and finally to "feature." We checked rigging over and over according to the IAI maintenance manuals. We ran every test the engineers could dream up. That didn’t turn out to be too many. None of that helped and we continued to operate with the "feature."

Finally in an act of desperation/hope, I decided to use the downtime of a C-check to start over. I asked Mark Ooley, one of the excellent contract maintenance techs that we use, to completely disregard all the work we had previously accomplished and use basic maintenance principals to see what could be done.

By this time, we had deduced that the feature lived in the right main gear and was a problem with the fuselage door going into its lock. The gear doors on Astras are manually linked to each respective gear. The manufacturer’s maintenance manual has reference points for rod lengths and adjustment directions. Mark took everything apart, checked all the linkage side to side, made matching adjustments, and reassembled everything. The only things he didn’t do were "beat to fit" and "paint to match" but after all, it wasn’t a DC-3. The story ends with a successful resolution using techniques and adjustment that were in opposition to the manufacturer’s maintenance data.

Let’s break down this story into some important elements. First, our department operated on the principles of safe flight, legal conformity, and customer satisfaction.

Second, our maintenance group and our flight ops group have an excellent relationship. When a tech tells a pilot something about the aircraft, the pilot listens. When the flight crews go to the trouble to write something down about the aircraft, maintenance treats the information as real. We would all rather that everything goes perfectly and we just tell the latest jokes but when things aren’t perfect we get serious. In my opinion, a good crew takes care of the airplane and a great crew is also an extension of the maintenance team.

Third, our maintenance team exhausted all manufacturer’s guidance to eliminate the feature. This proved to be very time consuming and unsuccessful.

Sometimes you just have to fix the airplane and the techs on the scene turn out to be smarter and more diligent than any of the manufacturers’ experts. At this point legal conformity has to come through the back door. We write up the steps required to actually fix the aircraft and send them to the manufacturers’ tech support department where they magically get turned into an engineering approval and eventually becomes a maintenance approval for return to service. Now you are good to go.