OWNERS 'TESTIMONIALS' - WHAT ARE THEY LIKE TO OWN & FLY

The primary forum for discussing all things Nipper. Feel free to ask questions.
Ross
Posts: 16

Re: OWNERS 'TESTIMONIALS' - WHAT ARE THEY LIKE TO OWN & FLY

Postby Ross » Thu Jul 30, 2020 2:18 pm

JimCrawford wrote:Hi Ross,

There is a mandatory inspection of the wing bolts under the LAA permit scheme in the UK. The bolts must be pulled and checked for cracks. If serviceable they can be refitted, otherwise new bolts are required. They aren't readily obtainable so an alternative is to use studs that used to be available from Airweld in the UK. This is the route I took as I didn't want to leave the aircraft without the wing secure while the bolts were tested. The rules in Tasmania for this may be different. If Airweld don't have any studs an alternative would be to make up your own as the originals were only standard AGS BSF bolts. The material spec is easily found and you could replicate the studs with suitable steel rod. You may be able to get AN UNF bolts of the required length from somewhere like Aircraft Spruce. Of course your bolts may be fine, the test scheme is in the LAA AD paperwork which you should be able to download from the website.

This state of affairs occurred when a Nipper crashed in the States and there was reason to believe the wing came off. After investigation the cause was found to be because the aircraft had collided with a bird (turkey buzzard?) that was substantial enough to wreck the aircraft. In the meantime, between crash and report, a concerned Nipper owner had his wing bolts tested to destruction and it was found that there was a crack under the head that had probably been there since manufacture. So the LAA mandated the inspection or replacement, in case there was a fault throughout the fleet.

Unfortunately the LAA didn't mandate reporting back about the tested bolts so there doesn't seem to be a record of how the tests went. Also there are probably many like me that took the easy way out with the studs and who have no idea whether the bolts are good or not. It would be interesting to find out.

I'll move the wheel stuff to the maintenance topic as this is getting a little away from owners testimonials.

Jim



Thanks Jim that's really great information, I will pull the bolts and consider the options.
Kind Regards Ross

Paul1954
Posts: 90
Location: Norfolk

Re: OWNERS 'TESTIMONIALS' - WHAT ARE THEY LIKE TO OWN & FLY

Postby Paul1954 » Fri Jul 01, 2022 8:45 am

Ross.

Are the stud threads required to be ‘cut’ or ‘roll’ formed?

As owners of Tiger Moth aircraft found out a few few years ago, such detail is important.

Neil Spooner
Posts: 625
Location: Ardleigh, Colchester, Essex, UK
Contact:

Re: OWNERS 'TESTIMONIALS' - WHAT ARE THEY LIKE TO OWN & FLY

Postby Neil Spooner » Fri Jul 01, 2022 1:04 pm

Only rolled threads allowed on such a critical fastener. Paul Gruellier at Airweld has them in stock.
The AD came about due to some bolts that were crack tested and found to be failing around the bolt head. Hence the studs do not need inspection, but the bolts do. Check the LAA TADS for the Nipper.
There is an LAA AD to comply with.
Regards
Neil
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