Yep. It's more annoying on final approach. Slowing down seems to fix it when that happens. With age the spoilers warp. Probably also why yours has had a second spring added to the spoiler for closing. >From Rob's and my experience it is due to the rear edge of the spoiler >catching on the rebate in the wings skin. Fine when they were new and straight >but not so good at age.
You will have noticed that when the spoiler starts to open it slides rearwards first as it lifts. This is a function of the drive geometry. We chamfered the rear bottom edge of the spoiler with sand paper on on sending block. Also had to scrape the inside corner of the rebate in the wing clean off 20 years of Thai Airforce quality maintenance. We used a Stanley knife blade for this. On one wing we also had to chamfer the top edge of the rebate. We did this by dragging a Stanley blade at 90deg to the wing along this edge to scrape a chamfer. The idea is to make sure all this creates a ramp affect for the spoiler to pop up over the wing surface in that initial rearward sliding movement as the spoiler opens. Placing cardboard a couple of mm thick under the length of the back edge of the spoiler then operating will prove if the problems described are the true cause. Cheers. Nige. ----- Original Message ----- From: neville swan To: [email protected] Sent: Tuesday, November 02, 2010 6:06 AM Subject: [DOG mailing list] Re:Sticking airbrake Hi All. Has anyone come across the problem of an airbrake that wont extend? No problem until last weekend when, during the DI, I found it impossible to extend the brakes with the cockpit handle, using a fairly hefty pulling force. I had to slide a feeler gauge under the rear edge brfore I could open the starboard brake panel (the port one is not a problem). I could not see anything amiss and added a small rubber 'buffer' to lift the rear edge a couple of mm., but it did not make any difference. Almost feels as if the torque tube is 'over centre'. Any ideas? Incidently, my brake panels have a small spring at the inboard ends, presumeably to help keep them closed. One panel has had an extra spring added about 3/4 out (not the sticking one). What is the norm? Neville.
