Tomo Posted April 22, 2015 Posted April 22, 2015 Was looking at the low wing Brumby that is online at a flight school the other day and saw this bolt... I know it's probably never likely to happen but it worries me a bit. This bolt is on the inside of the elevator servo, or balance tab, with a few mm clearance to the fixed part of the horizontal stabiliser. The first photo below shows the head of the bolt, the second photo shows the cavity that could very easily trap said bolt head if it ever came loose, even a small amount. Resulting in a jammed elevator... Anyone else noticed this? and have had any thoughts about it? Just looks like a potential problem that could possibly be eliminated by replacing bolt with something else, or at least tie-wiring it.
Keenaviator Posted April 22, 2015 Posted April 22, 2015 How old is this Brumby? Notice the fizz in the top photo?
Pearo Posted April 22, 2015 Posted April 22, 2015 I dont like the look of it either. Agree that it should be tie-wired.
Camel Posted April 22, 2015 Posted April 22, 2015 How old is this Brumby? Notice the fizz in the top photo? Looks like corrosion has started, I'm surprised. I also wonder how old it is and whether it is a hangared aircraft.
Marty_d Posted April 22, 2015 Posted April 22, 2015 I was wondering how people knew it wasn't tie-wired or a lock nut, given you can only see the bolt head. 1
dazza 38 Posted April 22, 2015 Posted April 22, 2015 It should be Ok, as mention above, it should be have a castle nut and a split pin as the locking medium. If however it is a Nylock nut, then yup it can be a cause of concern.
AVOCET Posted April 22, 2015 Posted April 22, 2015 Make a "check the bolt" part of your daily pre flight , After all , if the nut falls off the wheel ..... Mike
pylon500 Posted April 22, 2015 Posted April 22, 2015 Normally if a bolt and nyloc nut are done up somewhere, as a permanent fixture, it can be regarded as a set and forget item. However the bolt in question is possibly clamping a lead mass weight, and with time and vibration, lead can creep allowing the bolt to lose tension. Loose enough for the bolt to fowl the controls? Probably not, and very noticeable signs of the looseness would be apparent before the bolt had enough movement to bind. 2
Brumby Aircraft Posted May 1, 2015 Posted May 1, 2015 Dear Mr Tomo , In regards to your recent post that bolt goes through and holds a counter weight with a Nyloc nut that bolt does not turn and should never have lock wire or any form of castle nut as suggested . If you have a concern it is far better to contact the manufacturer than have any form of advice from forums or advise you that could lead to the incorrect advice . Paul Goard 4 1 1
dazza 38 Posted May 1, 2015 Posted May 1, 2015 Even though all factory aircraft use nyloc nuts in certain applications, there is no denying the fact that a castle nut with a cotter pin is more secure than a nyloc nut.
djpacro Posted May 1, 2015 Posted May 1, 2015 I have seen too many castle nuts with missing split pins. 1
dazza 38 Posted May 1, 2015 Posted May 1, 2015 I have seen too many castle nuts with missing split pins. They must not have been installed or not installed correctly. My 12 years working on military aircraft I never once found a cotter pin missing. It must be s civilian thing.
djpacro Posted May 1, 2015 Posted May 1, 2015 And missed at the duplicate inspection. I vaguely recall a serious military accident resulting from something like this. 1
dazza 38 Posted May 1, 2015 Posted May 1, 2015 All our critical systems like flight controls, fuel system etc had 3 inspection sign offs. Tradesman, Progressive Inspector then lastly the Independent inspector. Even with all of these safety steps in place nothing is infallible. But it is pretty close.
Tomo Posted May 1, 2015 Author Posted May 1, 2015 Dear Mr Tomo , In regards to your recent post that bolt goes through and holds a counter weight with a Nyloc nut that bolt does not turn and should never have lock wire or any form of castle nut as suggested . If you have a concern it is far better to contact the manufacturer than have any form of advice from forums or advise you that could lead to the incorrect advice . Paul Goard Thanks for that Paul, and I apologise if any harm was done by putting it on the forum. I was just curious to know how it was fitted and thought it was a good place to have a discussion. Which I think has been resolved and everyone is now the wiser to how they are built! all the best Tom 1
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