AD Affects 41,000 Turbocharged Aircraft


An AD that takes effect July 17 affects more than 41,000 turbocharged piston aircraft in service in the U.S. They’ll all have to be checked to see what kind of clamp is used to connect the turbocharger to the tailpipe. If it turns out to be a spot-welded, multi-segment exhaust pipe v-band coupling that has been in service more than 500 hours it will have to be replaced within a maximum of two years and inspected every 100 hours in the meantime.

Clamp failures have occurred in dozens of aircraft types and resulted in type-specific ADs but a General Aviation Joint Steering Committee working group figured out it was only the spot welded ones that were coming apart. Some clamps are riveted and those ones are not affected by this AD. When the clamps let go, they allow the venting of blazing hot exhaust gases into the engine compartment that can easily cause a fire. The FAA pegs the cost of the work at $570 per engine but AOPA says that’s light. FAA uses $85 an hour as the base labor rate but AOPA says its members are paying up to $180 for shop rates.

Russ Niles
Russ Niles is Editor-in-Chief of AVweb. He has been a pilot for 30 years and joined AVweb 22 years ago. He and his wife Marni live in southern British Columbia where they also operate a small winery.

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  1. Anyone with a turbocharged engine that doesn’t have their V clamps on a 500 hour replacement schedule is playing with fire, literally. Forget about whether they have rivets or spot welds, they all should be scrapped at 500 hours. I’ve had the V retainer break and the T bolts break. 500 hours is the MAXIMUM I would ever leave one of those clamps in service.

    • Wow. Just sold my late model T206HD after operating ~ 1000 hrs. Never say any documentation anywhere regarding Vband checks. Thx for the tip.

  2. I predict we will soon see an article saying that there is a huge shortage of V-band clamps in the country. Considering how critical these clamps are, a wise pilot or mechanic should probably stockpile a couple just in case.

  3. Am a retired A&P and remember seeing those spot welded clamps. The AD makes sense because they’re in a very tough working area and replacement is paramount to ensure safety from fires or don’t and wear a parachute while flying and hope for the best.

  4. This is an OVER REACH by the FAA. However since they are another agency, here to help, they have no oversight and can do whatever they like. The FAA only cited two instances of failures affecting 3 people! This is their justification for impacting 41,000 airplanes, NUTS. More people die in airliner seats every year but they don’t do anything about seat width or pitch. The reason these clamps fail is due to poor MX and overtorque desired by SOME aircraft manufactures. Aerostar uses 55″ lbs and thats PLENTY. Piper specifies 80 on some and thats crazy tight. No wonder they fail and crack and cup. The seal is created by proper alignment of the system, not how tight the clamp squeezes everything.

    It should be understood that this AD only affects the V-band at the turbo to tailpipe junction. NOT every clamp in the system or on the airplane.

    As copied from the AD “(d) Applicability

    This AD applies to all turbocharged, reciprocating engine-powered airplanes and helicopters and turbocharged, reciprocating engines, certificated in any category, with a spot-welded, multi-segment v-band coupling installed at the tailpipe to turbocharger exhaust housing flange,”

    My desire is to see the FAA go away. Airplanes crash every day, CERTIFIED ENGINES FAIL EVERY DAY, CERTIFIED PARTS FAIL EVERY DAY. The FAA is a waste of tax dollars and is doing everything it can to KILL GA. DEFUND THE FAA TODAY!

  5. FAA Where you when I had 8 engine failures in 16 years??????????????????????????????????????????????????????? Yeah! Nowhere Fxxxers! I was a 135 fly or fired pilot so F u you sissy A holes. You never fixed a BDX FAA CERTIFIED ATC CONTROLLEERS MISTAKE BY A REAL B727 PILOT!

    I DID!

    WHAT YOU DONE????????????????????????????????????????????????