Clarification on Life Limited Parts

[N2285U]

Need some help from the experts. I am looking at a B2B with roughly 1650 hours TT and need some help with determining what the actual retirement schedule is of various components. I do not have the logs in from of me; just time sheet life limit/airframe hours when installed/hours on component when installed/remaining time:

1. Overrunning Clutch CL-40237-2. 2500/1200/0/2050 - Does this really have 2050 remaining? If so, is there a calender date or use time where it has to be inspected? Is anyone able to inspect them or can new ones be purchased?

2. Tail rotor gear box 278-200 3200/0/0/1600 - I seem to remember that the tail rotor gear box was suspect in the B2B.

3. I am told the tail rotor blades are the "new" style. Not sure what that indicates.

Lastly, I realize Harold and Gary have parts, but is the factory intending to support these machines in the US?

Thanks!

[bryancobb]

Here's the way it comes down:
1) The dash 2 Formsprag is a a 2500 hour part but it contains 2 subassemblies inside it that make it work.
a) The 10-11 freewheeling clutch and
b) The 10-2 Clutch Cage
The 10-2 takes a beating and is the first thing in the Formsprag to wear out. It must be replaced every 300 for the Formsprag to be airworthy.
The Formsprag is not FIELD SERVICEABLE so unless a repair station is willing to be responsible to yellow tag the Formsprag after it comes back from rebuilding BY THE FORMSPRAG company, then you are out of luck at 300HRS.
If you need one of these, you can probably find one with a yellow tag. If you ask a lot of questions about its' history or how it GOT a yellow tag, you may not get answers that make you feel any better. I don't remember any accidents in Brantlys related to Formsprag failure.

If I remember right, the Formsprag company has voiced the posibility of remanufacturing these clutches, although they ARE NOT interested in recertifying them for Aviation Service. An FAA Repair Center would have to do that. I was not the person who contacted Formsprag and I don't remember who it was.

2) The Tail Rotor gearboxes are both 3250 hour parts. No way out here, throw 'em away at 3250 TT. There are folks who say the 3250 only applies to certan parts of the boxes, and use their JUDGEMENT to yellow tag them under those circumstances. Common sense tells you that the life limit on the type certificte never considered that folks would be cannibalizing several gearboxes to make one good one that can be yellow tagged and put in the air. Again, I don't know of any accidents that blamed the T/R gearboxes Proper, for the accident. Driveshafts yes, Gearboxes no.

There was never ANY problems with these. They are like TANKS and as long as the gear lash is right, they will go 'till the end of time.
The problem was with the short drive shaft. If not set-up absolutely perfect, the forces that flex the ends of this little shaft causes it to twist into where the drive bolts penetrate through it, close to each end.

3) My understanding is that the T/R blades do not have a life limit and are ON CONDITION. I always had it in my mind that my "OLD" style T/R blades expired at 2500hrs but that is not stated in the FAA Type Certificate. I must have seen that number in a service bulletin or something. But the TypeCertificate rules. NEW style T/R bldes means that the MANDATORY dye-penetrant A.D. only has to be done at 300hr intervals instead of 100hrs on the "OLD" style. The new style is easy to tell from the old style. On the new style, the round part at the root of the blade that houses the bearings, is one diameter. On the old style, that round portion has a step near the root so it is one diameter until it gets about 5/8 from the root and then gets about 1/4" larger in diameter.

Hope this helps.

[9121u]

THATS right Bryan exactly how the FAA states it for time life-parts .there is a FAA web sight that you guys can go on for mandatory time life parts for any helicopter. or if it has a shelf life.this is the stuff has to go by. thats what i found out to.HAVE FUN BE SAFE.

[scrapper]

Caveat > newbie here, don't even own one yet - Was told today the theory with tail rotors problems may be or probable origin is from tails that hit the ground and were harmed same in accidents. When worked on, a main gear was hot pressed assembled and the repairs may leave them vulnerable to the problems that popped up.

Reading the accident reports is very revealing. Mostly it appears there were obvious errors - lack of proper maintenance, inexperience, and simple piolet error. I could be wrong but think conscientious maintenance, staying on the side of caution and this should be relatively safe.

I am 220#s, was 190 4 yrs ago, going to go down to 195.

Scrap

[scrapper]

Might anyone have a Time-Life parts limit schedlue and rebuild requirement for the B2B in electronic form? If so could you email it to me?

Having trouble finding teh factoiry requirements or the FFA document.

Thanks.
'Scrap

[bryancobb]

Look to the left of where you are reading right now and click on "Type Certificate" under "Reference."