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Looked it up, Univair $866.27 + crating+shipping + covering. we're taloking about a $2K deal here on how many thousands of AC. For 2 failures that had strobes and floats.
The NTSB cannot even tell us how many hours are on the failed rudders. It is funny Piper issues a SB on an airplane that do not even acknowledge ever existed. As Steve said there is no talk of an AD at this point, and it is not required as a SB. There have been no fatalities from any of the failed rudders as opposed to the strut failures.
The NTSB cannot even tell us how many hours are on the failed rudders. It is funny Piper issues a SB on an airplane that do not even acknowledge ever existed. As Steve said there is no talk of an AD at this point, and it is not required as a SB. There have been no fatalities from any of the failed rudders as opposed to the strut failures.
It is reportable, but what would require it to be even a SB? Piper used this same Part Number rudder on almost every fabric covered plane they built, but only 5 failures in all of those years with well over 20,000 built. All of those failures were on planes with larger engines then they were certified with, and none of them were on Short Wing Pipers.
So, I must have missed your point. Yes it is required to be reported but does it need to be anything more than a SB?
Similar but different.
At work we maintain two Bell 407’s. Last June a tour company in Hawaii had one that the tail boom departed mid flight. Miraculously everyone survived. But now there’s a mandatory SB to check torque on the tail boom attach hardware and a proposal to make that an AD.
The said aircraft had 23,000 hours on it. It was calculated that after the 2009 mandatory SB to replace the tail boom attach hardware we figured out that the bolts probably had around 10,000 hours on them. That’s four times the TTAF on both of our 407’s.
So due to one outlier aircraft (how many helicopters have over 20,000 hours on them? Even our Hueys at 60 plus years old only have 8,000-10,000 hours on them) the entire fleet will likely have to do torque checks at every 100 hour.
I believe the service bulletin is a way for Piper to cover their behind. The information is out there and I now know there could be an issue so I can add that to my inspection checklist.
Would not the elevators also be subject to this issue? They have an aerodynamic counterbalance just like the rudder. This counterbalance creates a twisting moment on the rudder and elevator posts. As the beacon is on the rudder post centerline, I am not sure that it is a major contributor to the cracking. Have all the damaged rudders had a beacon? Many Pipers had their white nav light on the rudder. We just recovered our rudder that has a coffee grinder beacon mounted since the aircraft was new and there was no evidence of rust or cracking. The rudder has approximately 3,000 hours TSN. I know that the fatigue cracking is based on several factors with with cycles (hours) probably the greatest contributor. Any of you engineering types have a calculation as to the number of cycles on the material in question before a failure mode? The SB is kind of a farce as we already know that 99.9% of the affected aircraft have the old steel in the rudder. The only reason that I see to accomplish this SB is to examine the rudder post for defects. Then, you either ignore the SB, develop an approved repair or replace the rudder with one that meets the service bulletin requirements. Not very helpful. It will probably be ignored like SB 819 until the next recover. During a 100 or Annual inspection I would get a ladder and give all of the counter balances a pretty good wiggle. Might not hurt to also accomplish during a preflight. I would be onboard with contributing to developing an AMOC. I have a spare rudder with approximately 2400 hours TSN that I will contribute to the cause.
N2709P
I think I’ll skip the test then, and assume it’s not 4130, and just do the sleeve at some point soon, as Steve and others have suggested.
Calculating cycles of stress would be a shot in the dark, the cycles would have varying magnitude and frequency, mainly due to conditions flown in. I’m based in the Rockies, so I spend alot of time at or below 100mph and getting tossed around. Hence everything gets a “tug test” during every pre-flight.
The ship is a 1960 and totally restored, back in service 2007 with about 1200 hrs since. Never on floats, but who knows?
I’d certainly toss a few bucks in the hat if someone can come up with an AMOC such as the sleeve. We’ll need this to stand in the event of an AD.
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Re: SB1379 - Rudder Inspection
Originally Posted by Wag-builder
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