MitchS Posted February 1, 2016 Report Posted February 1, 2016 I have been looking around here, and I'm not finding a specific answer to this, so if I'm missing something sorry! I have a 1968 M20C and I'm coming up on my next annual. My gear biscuits still look good, but I'm seeing signs/reports here that they should be replaced after __ years, or other similar bits of feedback. But i"m having trouble finding that guidance, as well as I'm having trouble with what exactly kind of biscuits are there? It appears that Lord makes them, but it appears that they are actually for E+ models, not the C. Thoughts? Links/Advice? Quote
smwash02 Posted February 1, 2016 Report Posted February 1, 2016 In the manual there's a set of guidelines you can use to determine if they're airworthy. That said, mine passed even though they were 49 years old. (They got replaced) '66 was the year they moved to the 'new' style and you'll want 11 of Lord J-11968-14 I'm not an A&P/IA, but in a C you can probably get 15 years out of them before you need to look into replacing them. Expect everyone to have a different answer. It depends on lots of factors -- climate, loading, how you land, etc as to how quickly they'll start to go out. Quote
MitchS Posted February 1, 2016 Author Report Posted February 1, 2016 Just now, smwash02 said: In the manual there's a set of guidelines you can use to determine if they're airworthy. That said, mine passed even though they were 49 years old. (They got replaced) '66 was the year they moved to the 'new' style and you'll want 11 of Lord J-11968-14 I'm not an A&P/IA, but in a C you can probably get 15 years out of them before you need to look into replacing them. Expect everyone to have a different answer. It depends on lots of factors -- climate, loading, how you land, etc as to how quickly they'll start to go out. Awesome thanks! I think I need to get one of those service manuals....it would help me become a more informed owner anyway. Thankfully....my landings aren't usually too horrible....but it is loaded up quite often Quote
Guest Posted February 1, 2016 Report Posted February 1, 2016 You or your maintenance shop should have a maintenance manual for your plane. If your plane has the old Firestone discs you will have 5 on the mains and 4 on the nose. Lord discs have 4 on the mains and 3 on the nose. If you have Firestones you will need some conversion parts from Lasar, also your A&P will needs the compression tools to replace them. The problem with lighter airplanes is the rubber goes rock hard long before they deteriorate, so the still meet the compression limits and appear OK. New ones will improve the ride during taxi. Clarence Quote
MitchS Posted February 1, 2016 Author Report Posted February 1, 2016 5 hours ago, M20Doc said: You or your maintenance shop should have a maintenance manual for your plane. If your plane has the old Firestone discs you will have 5 on the mains and 4 on the nose. Lord discs have 4 on the mains and 3 on the nose. If you have Firestones you will need some conversion parts from Lasar, also your A&P will needs the compression tools to replace them. The problem with lighter airplanes is the rubber goes rock hard long before they deteriorate, so the still meet the compression limits and appear OK. New ones will improve the ride during taxi. Clarence Awesome, that helps!! Quote
Hank Posted February 1, 2016 Report Posted February 1, 2016 Landings are also better with new biscuits . . . When I replaced mine in Dec '13, they had the manufacture date of "06-69" molded into them. But they were upside down, and I somehow read it as "09-96" so I wasn't too worried. Swap them out, you will like it [just not the price!]. 1 Quote
cliffy Posted February 2, 2016 Report Posted February 2, 2016 Wouldn't it be nice if we could still use the truck engine biscuits that Al Mooney used originally in the Mite? Maybe $5 each! Quote
Guest Posted February 2, 2016 Report Posted February 2, 2016 1 hour ago, cliffy said: Wouldn't it be nice if we could still use the truck engine biscuits that Al Mooney used originally in the Mite? Maybe $5 each! I wish that were true. There is no supplier for them anymore. A fellow in Ohio makes them in small batches$150.00 each for $900.00 per set. Clarence Quote
par Posted February 3, 2016 Report Posted February 3, 2016 Had mine replaced just a few weeks ago during the annual. I've only done 2 landings since then but they were definitely some of my smoother ones. I can't really tell much a difference on the ground or notice any difference in the sitting height/angle. Either way, I will probably sell the plane before I ever have to worry about it again. Quote
Yetti Posted February 3, 2016 Report Posted February 3, 2016 I still think there is room for some enterprising person to make a conversion to firestone air bags Quote
cliffy Posted February 3, 2016 Report Posted February 3, 2016 The airbags might expand too much at altitude :-) Quote
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