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New RV-8 Landing Gear Bolts and Nuts PIREP

Christer

Christer

Well Known Member
I received new bolts, nuts and washers from Genuine Aircraft Hardware for my RV-8 landing gear. I had spoken with Tom Brink and he suggested using the MS21250-06028 bolts (200ksi), MS21299C6 chamfered washer and MS21299-6 washers both hardened (260ksi) and a DHE-45079-6NM nut rated at 220 ksi. All are 12 point so access in the gear tower was much easier, which was one of the driving forces behind the change. I was very pleased with the installation and the ease which it all went together. This setup is significantly stronger that the stock Van's recommended bolt and nut combination. The nut also has an elastic lock feature (can't recall the name). Each installation is slightly different with regard to bolt length, but mine worked with the one listed above. The nut is fully engaged, but only a thread showing.
 
Glad to see that you are using this hardware, I have the same. Not flying yet but am confident that there will be no problems with this setup. Tom with gahco was the man who put this together for me after I saw the problems and consulted with him. Thanks Tom.

Bird
 
Don Patrick said:
Just curious, will these work for the grove gear as well?

Cheers,

Don
Click to expand...

Grove gear are thicker than stock Vans, so the bolt lengths are different. I used the bolts that came with the Grove gear along with NAS1804-6 nuts. The install was frankly a piece if cake. I had the nuts and bolts in solo and asked a friend to come torque from below while I held the nuts with a shorty 12 point box wrench in the towers (tower mod done). The NAS1804-6 nuts made the whole thing a non event. Took an hour.

The added benefit is the nuts are available locally at Straight Flight (KAPA) for $2.50 each, which is a third of GAHCO's price and no shipping. I think they were actually cheaper than that but Straight Flight has a $10 minimum and I only needed 4 nuts. I had a perplexed look on my face when he handed me the nuts and receipt. I asked if he was certain these were NAS-1804-6 nuts and he said, "Yes, they aren't exactly rare...why?" RV guys are paying quite a bit more for these nuts, says I. He smiled....They are just NAS nuts...silly experimental guys.

I believe the grove gear comes with 1804's now... but mine didn't.
 
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confused a little

Ok I am just about to mount the landing gear parts in my fuselage from an older QB Kit. am I missing something, It sounds like I need to use different bolts than the one's supplied, is this correct

Levi
 
laplander0 said:
Ok I am just about to mount the landing gear parts in my fuselage from an older QB Kit. am I missing something, It sounds like I need to use different bolts than the one's supplied, is this correct

Levi
Click to expand...

At issue is that several RV-8 operators have discovered that the nuts holding the landing gear legs into the fuselage at the side-of-body are loose. The mechanism seems to have been that the nuts are getting overstressed in tension and jumping a thread or two.

Here is a forum thread about tests that Steve Smith and I did to evaluate the tensile capacity of several types of nuts that could be used in the RV-8 gear. The nuts supplied with the kit failed at 12,500 lbs force; the nuts that Steve used in his aircraft instead are the ones that failed at 16,200 lbs force, about a 30% strength improvement.

This other thread has practical examples of two instances where the gear nuts skipped threads under tension.

Edited to add: The limiting factor seems to be the nuts, but stronger bolts can be good too. GAHCO can set you up.

Thanks, Bob K.
 
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Just a friendly warning. Don't use the 12pt MS bolts (or the hex-recess NAS bolts) without the appropriate chamfered washer(!!!).
 
confusion gone

thanks so much, that cleared up the confusion, I can't believe some people don't pay their honor due's. Little tidbits of infor like this are way more valuable than the yearly due's

thanks
Levi
 
Clarification please....

I changed the grove gear hardware to the following:

NAS 6606-36 bolts
NAS 1804-6 12 point nuts

I also have the chamfered washers to go with them.

What I'm not clear on is where the chamfered washer goes....under the bolt head or under the nut? Been looking for photos and info on the net and can't find a whole lot. It seems to fit nicely under the head and makes sense, but just not sure.

Thanks


Don
 
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