"D" CHECK PART 5: YELLOW GUCK

“D” CHECK”

Part 5

YELLOW WING BOLT GUCK

One of the final parts of the Falcon 20 “D” inspection involved the wing bolts. All these years later I don’t recall how many wing bolts there actually were on each side. My Falcon 20 maintenance manuals do not give much information either. So, we’ll just say it was more than 12 and less than 18… somewhere in that neighborhood.

For weeks we’d been warned that the worst part of this job was gonna be the wing bolts… and they were right. In order to get the job done they needed two mechanics who could dedicate themselves just to this task for about 3 or 4 days- plus overtime. A fellow named Jim volunteered and I was volunteered by the shop A.I. Their reasoning in using me was the fact that I was hired on at near minimum wage and working under the shop certificate. Thus, they could charge $28 an hour for my labor while just paying me about $2.50 an hour. Additionally, I was well known as the model boat maker and was very handy with tiny parts and tools. This job was similar to dental work.

Our first task took the greatest time. The bolt recesses were filled with the hard crusty brown junk that was similar to that used inside the fuel tanks, but certainly a different formula. It was designed to keep all forms of fluids and moisture away from the bolts and effectively make them corrosion proof over the life of the aircraft. Since no other Falcon 20 had ever gone as far as a “D” inspection, the folks at Dassault wanted to know how well that crap was actually holding up plus they had a new method for re-sealing the bolts. Now we had to chip out that hard brown stuff and completely clean both the bolts and the recesses.

We were told VERY clearly, “No matter what you do, don’t scratch the bolts.” Each bolt was different diameter, numbered for its position and cadmium plated. The smallest scratch on any part of a bolt made either while uncovering it, removing it, or handling it would condemn the bolt and it would have to be removed and replaced. Thus we picked and chipped away with the greatest of care. Finally we ended up working with dental tools to get the last of the hardened crust removed so the bolts cold be inspected. As best I can recall we damaged just three. Yet about four others showed corrosion- and I’m talking near microscopic spots, not huge areas of rust. Bill, our A.I. would look at one and say, “Nope- that one’s gotta go.” And when it was removed I’d look at it and couldn’t see a thing wrong. Then he’d take the tip of his pen and carefully point out the spot of rust that I would never have noticed. Such is the sharp eye of an inspector. Replacement for the scored bolts was another matter. New bolts had to be installed with the A.I. watching and torqued carefully to a very specific value WITHOUT compromising the cadmium plating. Then each replacement had to be properly stated in the aircraft logbook. Of course I was not certified to take part in any such replacement.

Once the inspection was over Jim and I were told to come into work the next day wearing clothes that would have to be thrown away and to bring fresh clothing to wear home at the end of our task. Personally I picked out a pair of bell-bottom jeans from the 70s that I’d never wear again and a shirt that a cheating former girlfriend had given me and I was good to go. Jim had some nasty coveralls that were so filthy they’d make you reflex vomit. We were also told that we’d get no breaks and no lunch because once we started we had to keep going until it was all finished. We did, however, get time and a half for the whole day… so who could argue?

Arriving at Hangar 6 that morning we were presented with a series of purple Styrofoam forms that were shaped like half of an egg. Each had a dimple molded into it that was the size of a wing bolt head and each was exactly the size of the recess where the bolts were located. With that came some bright yellow gunk that was called Mastinox Compound. I was told that it was a rubberized sealant that never hardens. It was non-corrosive and was supposed to keep all moisture away from the bolts. We had to, by hand, smear that stuff around each bolt head and work it in to make sure that there were no air bubbles. When the bolt was well covered, we had to take one of the Styrofoam half-eggs, fill its recess with the compound, smear some on the surface and shove it into the recess where the bolt was waiting. The compound oozed out and we had to carefully cover the exposed flat side with more compound. Above all, we were not supposed to rush the job.

Looking back, we should have been wearing rubber gloves. But it was 1985 and instead we went at it, Jim on the right side wing and me on the left, with our bare hands. As it turned out the hardest part was not touching anything else with your hands! When that yellow guck got on something it was there to stay- and it showed up real good too. Heaven forbid you should put your hand on the aircraft fuselage, or worse yet- scratch your head. Of course they brown papered the wing for a huge area and taped brown paper to the fuselage up to the tops of the windows- we needed that. By mid day we had that stuff all over us, but I was focused so hard on doing the task properly that I really didn’t notice. The brown paper that was taped to the aircraft fuselage and wings was covered with hand prints and slopped guck. We finished about mid-afternoon, both at nearly the same time. Sliding off the wing, I looked over at Jim and we both said, “Now how do we get this shit off of us?”

They hadn’t thought of that.

Aside from working the radios on the engine runs, those wing bolts were the last major thing I had to do in the “D” inspection. Weeks later I was back in Daytona at Embry-Riddle finishing my degree in Aeronautical Science along with my multi-engine commercial instrument ratings. Sitting in a Turbine Engines class I was still picking little bits of Mastinox Compound out from under my fingernails (no foolin’ folks). The instructor flashed a slide up on the screen of a CF-700 engine.

“I’ll bet none of you have any experience with the aircraft that uses this engine…” he said.

I raised my hand.

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