We have all seen Airworthiness Directives (ADs) in the past that made us fear the further demise of general aviation. I can think back to 2003 when the outrageous proposal on 400 Cessna series aircraft threatened huge costs regarding wing spar modifications. Costs were estimated to be more than $250 million. Who now knows for sure what AD 2005-12-12 and AD 2005-12-13 has and will cost owners of 400 series aircraft. Of course, we all remember the VAR crankshaft situation that back in 2002 required the removal and/or replacement of allegedly improperly heat-treated crankshafts that were supposed to be subject to failure. That was another huge expense for owners concerned. Now stand by for another one.
The FAA on Aug. 12, 2013, published its Notice of Proposed Rulemaking regarding certain cylinders installed on Continental IO-520, TSIO-520, IO-550 and IOF-550 engines and O-470 models that have been modified to use such cylinders by STC, for use on Continental engines. This proposed AD will be huge. The proposal states that the costs are estimated at more than $82 million (NPRM Docket 2012-02).
The basis for this massive inspection and removal program are random failure reports (they say 30) of ECi (now Danbury Aerospace-Airmotive Engineering Corporation, AEC in San Antonio) PMA cylinder assemblies. These were not ersatz cylinders. They were approved for use by the FAA through the PMA process. The AD applies to certain part number and series cylinders sold by AEC. The proposal describes two cracking characteristics: (1) a crack that starts in the internal dome radius of the cylinder and (2) cracking at the cylinder head to the barrel thread. These are the two most common locations for all cylinder cracks for years, no matter who made them.
The proposed AD goes on to say that these failures could result in head cracks, engine failure, and loss of the aircraft, and the FAA cites no specific example of aircraft loss. The manufacturer stated that no accidents or injuries were reported in any of the 30 incidents, which form the basis for the AD. Note that the proposal says could result. The manufacturer stated that more than 10,000 aircraft would be affected by this AD, and that a number of the damaged cylinders could be traced to improper engine operation not manufacturing defects. There is some dispute over whether these cylinders (ECi) had a lower failure rate than the OEM cylinders sold by Continental. The manufacturer stated further that it could be forced into bankruptcy by this AD, and that this action was a punitive, unnecessary, and inappropriate action against owners of the affected engines.
The proposal allows no repairs to any damaged cylinders that are removed. They must be discarded. Furthermore, with respect to cylinders with no apparent defects … they too must be removed and discarded. That is if they fall into the categories described in the proposed AD. So, even cylinders that appear to be perfectly serviceable must be discarded.
I am pleased my C182 has a low compression O-470 engine. There’s no high compression, no turbo, no fuel injection, and no threat of high cylinder head temps. It even runs fine on car gas. But pity the poor souls who have the T210, 300, and 400 series Cessnas. These owners could be faced with significant cylinder inspection, removal, and possible replacement of all their ECi cylinders if this AD were in fact published. The manufacturer says that 10,000 aircraft are involved. The costs alone would be significant even if there was an initial price adjustment for the cylinders, but the wholesale removal and trashing of hundreds of airworthy cylinders is outrageous. The NTSB never suggested anything of this sort in its analysis of the so-called failures.
Efforts should be taken to remove the AD or change it substantially.
The AD would require that these cylinders be removed from service at 1,000 hours time-in-service. About half the affected cylinders would be required to be removed from service within 25 hours if...
AOPA's comments warn that the drastic course proposed by the AD is not supported by the data, could cost much more than the FAA estimates and has the potential to cause more safety problems than it...
The General Aviation community has mobilized to oppose a proposed AD on TITAN® brand 520/550 series cylinders produced between 2002 and 2009.
Cylinder Differential Compression Testing Subject to Interpretation Teledyne Continental Motors May 2000 In its simplest terms, differential compression testing is a tool that...