Example of a UH-1H helicopter. Santa Barbara County Helicopter 308. N205KS. Photo by John Goldin in 2020.The Federal Aviation Administration (FAA) has issued an airworthiness directive (AD) requiring inspection or replacement of the main driveshaft in a model of helicopter often seen working on wildland fires. Prompted by multiple reports of failure, it applies to certain type certificated Model UH-1H restricted category helicopters that have KAflex main driveshaft part number (P/N) SKCP2180-1, SKCP2281-1, SKCP2281-1R, or SKCP2281-103 installed.
The AD requires establishing a limit to replace the driveshafts, and one-time and repetitive inspections. If the main driveshaft has accumulated 5,000 or more total hours in service (TIS), before further flight it must be replaced or overhauled.
The AD referenced two in-flight failures of the driveshaft that occurred during logging operations in 1997 and 2015.
Agencies that routinely use UH-1H helicopters for wildfire suppression include Santa Barbara County (CA), Kern County (CA), Orange County (CA), and the states of Washington, California, and Montana.
The FAA estimates the cost of replacing the driveshaft is $54,000 if new, or $38,000 for one that has been overhauled.
Thanks and a tip of the hat go out to Gerald.
8 Comments
One should always be careful about naming agencies that use UH-1 series helicopters as having Restricted category aircraft. Many do not and have un-type certificated machines. The FAA airworthiness directives ( as they state clearly) only apply to type certificated products that are in the domain of civil aviation. While it may be prudent or even critical for public operators of un-type certificated aircraft to comply with the requirements of ADs, they are not required to do so. I believe both Kern and Orange county have un- typed Hueys, as well as CALFIRE. There are also many public agencies that have un-typed Hueys that do not use them for fire.
While we are mentioning Kern and Orange counties….why don’t we mention Montana DNRC and others. While Public Aircraft Operations may “enjoy” the benefit of not coming in under FAA rulings, the issue while rear its ugly head in the FEPP and Public Aircraft Operations pilots and aircraft mechanics are certainly going to be aware of this AD and may not hang their tickets “just because.”
When the Allied Signal / Honeywell T53 spur gear issue was a big deal 20+ years ago….operators, Army , FEPP, and Public Aircraft operators worth their salt were sure monitoring the issue.
Something like $54K “issues” of driveshafts and monitoring whether one is governed by FAA or not, I wouldn’t be all gigity over PAO not having to comply. I sure would be watching it like most of us in the Army and Army Reserve / Guard AASF world were doing even if we weren’t under FAA regulation…
Since both mechanics and pilots working on/flying un certificated Public Aircraft are not exercising their FAA certificates when operating, or maintaining the aircraft, I’m curious as to why you think they may not “hang their tickets” ? “Tickets” are not at risk in these situations.
Pilots and Mechanics who are flying/working on un certificated Public Aircraft are not exercising their
certificates when doing so. Not sure as to how that might cause them to “hang their tickets”. “Tickets” are not required in these instances.
Just because they are not required to comply with this AD, I’d be surprised if they don’t anyway.
Funny…..some of those folks working on “uncertified” Public Aircraft are required to have an A&P (unless a Part 145 type) when those outfits are looking to hire pilots and A&Ps. May not be “exercising ” their tickets as I and many have called them. I realize they are “not required to comply” but again…just because one is Public Aircraft does not exempt folks from the AD…but hey, WTH do I know, right??
Yes, of course employers are going to establish a standard for hiring and that would be the FAA certification, but that in no way means that they are required per FAR. There is much confusion regarding PAO ops and PAO ops with non certificated aircraft. Again, FAA certificates are not required to operate, or maintain these aircraft by the FAA, the employer can chose to require whatever they want for pilots and mechanics .
I’m sure you are aware that the military has been operating FAA registered aircraft with standard airworthiness certificates for some time now. While in most cases the military chooses to maintain them per FARS with FAA certificated mechanics, they are most always operated by pilots with no FAA certification. Again, the PAO can choose to operate however they want.
Again, yes, un certificated PAO aircraft are totally exempt from the AD, but will most likely comply with it as written. Do not confuse “should” with “shall”
It isn’t just that they are conducting PAOs. It’s that the aircraft I mentioned are not certificated by the FAA, their manuals are not approved by the FAA and their maintenance does not need to have an A&P signature. Unless somone applies for and obtains a type certificate, it maynot conduct civil operations. Things are very different if you have a certificated aircraft that slips in and out of public operations.
Repair stations should not use their repair station number when working on non- certificated aircraft and their A&P employees are supposed to put an employee number or their name. And company name. They should also be careful around using the word ” airworthy” when retuning an un typed aircraft to service, as that is defined in part by meeting it’s type design.
Correct, certificated airmen should choose the wording carefully when making maintenance entries for these aircraft. For instance, while I might conduct the scope and detail of an annual inspection, it would be described in the maintenance records as a “periodic inspection using XXXX as a guide. I print my name,not my certificate number. Easy peasy
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