Regulatory Brief -- ECi Connecting Rod AD

Regulatory Brief

ECi Connecting Rod AD

The issue

On October 5, the FAA proposed a new airworthiness directive (AD) for certain Lycoming 360- and 540-series engines with ECi connecting rods installed. The FAA claims the proposed AD would affect about 2,800 engines that have been overhauled or repaired since new.

The importance to our members

The FAA said the proposal resulted from reports of connecting rods with excessive variation in the circularity of journal bores. The agency is concerned about connecting rod fatigue leading to engine failures. The affected engines are installed in popular airplanes such as Cessna 172s, Beech Sundowners, Grumman Tigers, and several Piper and Mooney models.

For connecting rods with 1,500 or more hours time-in-service (TIS), owners would have to replace the parts within 50 hours after the effective date of the AD. For connecting rods with fewer than 1,500 hours TIS, owners would have to replace the parts before accumulating 1,500 hours. The FAA estimates repairs would cost about $700.

Most recent Web posting

AOPA requests the FAA to withdraw AD proposal for certain Lycoming engines

AOPA filed comments this week opposing a proposed airworthiness directive (AD) against certain Lycoming 360- and 540-series engines that have ECi connecting rods installed. AOPA requested that the FAA withdraw the AD and issue a special airworthiness information bulletin.

"The FAA is basing this AD on one engine failure in which an unrelated problem, possibly an oil blockage, could have caused or contributed to the failure," said Luis Gutierrez, AOPA director of regulatory and certification policy. "AOPA has found no evidence that shows the engine connecting rods fail to meet safe, FAA-approved limits."

The proposed AD would affect about 2,800 engines, according to the FAA; however, ECi says the number should be much lower. The affected engines are installed in popular airplanes such as Cessna 172s, Beech Sundowners, Grumman Tigers, and several Piper and Mooney models.

AOPA also opposes the FAA's application of automobile standards to aircraft, particularly because this issue has implications for all reciprocating engine connecting rod bores. The FAA used Society of Automotive Engineers standards, but AOPA says a study of the differences between air-cooled (aircraft) and water-cooled (automobile) engines should be done before applying automotive standards to aircraft.

"The FAA has blindsided AOPA, ECi, and the general aviation community in spite of an agreement to utilize the airworthiness concern process to gather all of the GA community input before making a decision as to whether an AD is warranted," Gutierrez said. "The agency should undertake a study that includes industry participation."

Significant provisions

This AD applies to Lycoming 360- and 540-series reciprocating engines specified in Table 1 of this AD with Engine Components Incorporated (ECi) connecting rods, part number (P/N) AEL 11750 installed.
These engines are installed on, but not limited to, the aircraft listed in Table 2 of this AD.
If your engine has not been overhauled or had any repair since new, no further action is required.
If your engine was overhauled or repaired since new, do the following:
- Before further flight inspect the maintenance records and engine logbook to determine if the overhaul or repair facility used ECi connecting rods, P/N AEL 11750.
- If the connecting rods are not ECi, P/N AEL 11750, no further action is required.
- If the connecting rods are ECi, P/N AEL 11750, and if the serial number is 54/7 or higher, no further action is required.
- If the connecting rods are ECi, P/N AEL 11750, and if the serial number is 54/6 or lower, do the following:
If the connecting rod has 1,500 or more hours time-in-service (TIS), replace the connecting rod with a connecting rod that has a SN 54/7 or higher, or that has a P/N not specified in this AD within 50 hours TIS after the effective date of this AD.
If the connecting rod has fewer than 1,500 hours TIS, replace the connecting rod with a connecting rod that has a SN 54/7 or higher, or that has a P/N not specified in this AD before accumulating 1,500 hours TIS on the connecting rod.
After the effective date of this AD, do not install any ECi connecting rod, P/N AEL 11750, that has SN 54/6 or lower into any engine.

AOPA's position

AOPA filed formal comments with the FAA requesting that the agency withdraw its proposed AD because the FAA fails to show that an unsafe condition exists in ECi connecting rods. The FAA is proposing this AD entirely on reports of excessive variation in circularity of the journal bores stemming from a single connecting rod failure event. AOPA reviewed the data provided by ECi, test results, accident reports, and other correspondence, and the only reports of connecting rod variation we found are those pertaining to this one engine failure where unrelated oil starvation, possibly from oil blockage, may have caused or contributed to the failure. AOPA is not aware of any other reports of engine failure or damaged connecting rods attributable to variation in circularity of the journal bores. All indications are that the waviness or scalloping was within the FAA-approved limits and within tolerances typically found at an overhaul facility. There have been no reports of scalloping outside of these FAA-approved limits. AOPA believes that the scalloping marks found on the ECi connecting rod may be a normal part of engine wear and unlikely to be an unsafe condition. AOPA recommended that the FAA undertake a study that includes industry participation (OEM, PMA, suppliers, etc.) to determine the impact of the scalloping of the connecting rod bore. This study will allow for the participation of all the pertinent parties to assist in objectively finding a solution to the issue. In the interim the FAA should consider an alternative solution like a special airworthiness information bulletin (SAIB) to inspect the connecting rods at overhaul and replace or repair to a defined standard, if heavy scalloping is noted.

Status

December 5, 2005, AOPA filed formal comments requesting the withdrawal of the proposed AD.
October 5, 2005, the FAA issued a proposed AD that calls for the replacement of ECi connecting rods in certain Lycoming 360 and 540 engines.