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How do I remove stuck screws from inspection panels?

How do I remove stuck screws from inspection panels?

Before you progress to powered equipment on stuck screws, there are two hand tools that can prove almost indispensable. The first is a “speed wrench” or “speed handle”; the sort of U-shaped or “crank shaped” tool that you don’t see much anymore. You need one that is 3/8″ drive, with the round palm-pad handle on the other end. Most of the modern ones just have a roller handle on one end; good for spinning a socket, but no good for pushing on one. You may have to search a couple of flea markets in order to find an older one with the palm handle. Then you’ll need a 3/8″ drive bit-holder for it (one that holds standard screwdriver 1/4″ hex bits). And finally, some #2 Phillips screwdriver bits, plus a special square-drive bit. Both of these bit types need to be premium quality tools, ideally from a tool supply store. The #2 Phillips should be “semi-tulip” style as is commonly used for hardened drywall screws; the sides of the blades look slightly curved rather than completely straight. You’ll recognize what I mean when you see them. The sides of each blade should have slight serrations or scoring on them, to make them more slip resistant. The square drive bit is normally used with cabinet screws. These screws are heat treated steel, as they are often three inches long or more, and are being driven into hardwood frames. That gives you some idea of the quality nature of the bits used to drive them. And finally, you’ll need a small tube or container of “no slip” paste from someplace like Sears, or a small tube of fine valve-grinding compound from an auto parts store.

The game plan is to initially attempt normal removal. Do NOT let the screwdriver slip in the hole or round out the screw. If it doesn’t come loose with normal effort, put the #2 bit in the speed handle (with the hex bit holder), put a dab of compound on the bit, push it tightly into the screw, and turn it with the wrench handle. One of three things will happen.

1. Ideally, the screw will loosen (most will).

2. The screw head will snap off (and you then proceed to drill it out, as would have happened anyway). If the head snaps off, sometimes you can avoid drilling by proceeding with panel removal, then clamping vise grips on the stem of the screw that is sticking up inside the hole, and screwing it “in” until it comes out.

3. The screw head will “round out”. If this happens, switch to the square drive bit, add some more compound, and try one last time. The square drive bit fits surprisingly well in a Phillips screw that has been rounded out.

The above technique will remove 99% of stuck screws, without Dremel tool work or drilling. If you are dealing with screws that all seem too tight, just loosen them all first with the speed handle, so that the tool has an undamaged head to work with. Just take care that while you are pushing on the speed handle, you don’t damage any fragile structure. You can naturally afford to push harder in some places than in others.

If you do progress to powered removal or drilling, there are two things that work very well. One is a left-hand removal bit set from Sears. It has a special cutting head designed to turn to the left. It bites into the remains of the screw head, and tries to turn it out. It works very well. The other is a “left-hand” drill bit. They will have them at tool stores. They make excellent removal tools for both screws and broken bolts. You just start drilling into the screw or bolt, with the drill reversed (turning left). At some point, when the thread tension is relaxed enough in the fastener, it just starts screwing itself back out. The other is using a thin cut-off wheel in a Dremel, to cut a deep slit across the head of teh stuck screw. Then use a large slotted (common) screwdriver to remove the screw.

Most of the problems with the screws on our older aircraft are due to the fact that Beech used a premium style of self-locking, heat-treated anchor nuts. They don’t wear any with age and use, and in fact with a trace of age-related corrosion, they just grip tighter. You can clean them up with the tap tool and end the stuck-screw problem; just be careful not to tap so far as to remove all of the self locking grip. If that happens on a few it is no big deal; the rest will hold, and usuually you’ll see a loose screw hanging out before it comes all the way out. The latter is one reason why the half-inch screws are used in these plates when 3/8″ would be plenty long to hold. The extra length lets you see a loose screw before it departs, so you can retighten it. You won’t notice a completely missing screw on an underwing panel, as fast as you will one that is sticking out.

Some shops do use higher-powered drills with clutch settings. There are several reasons I don’t use them on airplanes. Examples are:
(A) They leave you at risk for a mis-set clutch, and the related damage potential.
(B) They are always significantly heavier; a real drawback while lying on the ground under a wing, with your arms extended to reach screws.
(C) They nearly always have a much larger body and battery size, making it hard to use them inside wheel wells and in some of the interior spaces.
(D) Most of them have a T-handle configuration, that makes it much more difficult to apply straight-line pressure on the head of a screw. The lower-power drills typically have the traditional pistol grip, which lets you slide the web of your hand up on the back of the drill, to push directly on the screw.

Best of luck! Others are welcome to expand on this answer with their favorite techniques.

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