Settlement Reached in Mobil AV-1 Class-Action Lawsuit

Owners of Continental 360, 470, 520 and 550 engines that used AV-1 oil have only until November 14th to submit their comments or objections to the proposed settlement. Here's our overview and analysis of this complex settlement, together with links to the full text of the relevant court-approved documents.


On October 25, 1995, a preliminary settlement agreement was reachedin the federal class-action lawsuit filed against Mobil Corporationby Malvern Gross and Paul Jimison. As previously reportedin AVweb, the plaintiffs claim that Mobil AV-1 syntheticoil may have caused substantial damage to a large number of big-boreTeledyne-Continental engines, and that all potentially affectedengines should be inspected and, if necessary, repaired at Mobil’sexpense.

This settlement affects all U.S. owners of Continental 550, 520,470, and 360 series engines in which Mobil AV-1 oil was used formore than 150 hours. Since the federal judge certified this asa “non opt-out” class, this settlement represents theonly recourse that owners of AV-1 engines will have against Mobil.

The court has scheduled a hearing on November 28, 1995, for finalapproval of the proposed settlement, and has established a deadlineof November 14, 1995, for class members to submit comments orobjections to the proposed settlement…an extraordinarily short”comment period” considering the complexity of the issuesinvolved.

Meantime, Mobil is mailing out notices to approximately 50,000owners of Continental engines, and has started accepting ownerclaims under the settlement. The terms of the settlement are ratherinvolved and technical, but our short summary and analysis appearsbelow. The full text of the court-approved settlement notice,repair and inspection protocol,and claim formare also available here, as well as the Plaintiff’s press releaseannouncing the settlement.. We suggest that all owners of AV-1engines familiarize themselves with these documents immediately.

Summary of the Settlement

The terms of the settlement are set forth in a complicated 19-pagedocument entitled “Mobil AV-1 Engine Inspection and Repair Protocol“which provides, in summary, that:

  1. Qualified Engines. Claimants must submit an AV-1 claimform plus engine logs, aircraft logs, and invoices to prove thatthey own an aircraft powered by one of the covered TCM enginesin which AV-1 oil was used for more than 150 hours. For such “QualifiedAV-1 Engines,” Mobil shall pay for inspection and, if necessary,repair as defined in the protocol.

  2. Sluggish/Abnormal Propeller Operation. If the ownerhas experienced sluggish or abnormal propeller operation, thepropeller may be removed and the prop and crankshaft bore inspectedfor sludge build-up. If sludge is found, an oil transfer collarleakage test may be performed. Engines that fail this test shallget a teardown inspection per #7.

  3. Axial Crankshaft Test. If the propeller has been removedin connection with #2 or if cylinder have been removed in connectionwith #5, an axial crankshaft test shall be performed to determineif excessive axial crankshaft play exists. If it does, the engineshall get a teardown inspection per #7.

  4. Top End Inspection. If the engine has had either (a)a dramatic increase in oil consumption (doubling over 150 hours)or (b) an abnormally large decrease in compression (15% over 150hours) or (c) a dynamic compression test below the allowable limitestablished by TCM, it is eligible for cylinder replacement. Ifone or two cylinders have low compression, they will be replaced;if three or more have low compression, all cylinders will be replacedper #5. A crankcase pressure test shall also be performed.

  5. Top End Overhaul. Engines with a dramatic increasein oil consumption or low compression on three or more cylindersor failing the crankcase pressure test shall have all its cylindersreplaced as follows. Engines at 50% of TBO or less with cylindersexceeding new limits will get new cylinder kits. Engines beyond50% of TBO with cylinders exceeding service limits will also getnew cylinders.

  6. Connecting Rod Bearing Test. If cylinders are removedper #5, connecting rod bearing play will be measured. One or morereadings beyond TCM service limits will require connecting rodremoval and inspection. Three or more such readings will requirea teardown inspection per #7.

  7. Teardown Inspection. Engines failing the tests of sections#2, #3, or #6 shall be removed from the aircraft and torn down.Mobil shall pay for R&R, teardown, and replacement of partswhich are normally replaced after a complete teardown, includinga new VAR crankshaft if the engine has a non-VAR crank, but willnot pay for camshafts, lifters, or accessories.

  8. Out-of-Protocol Inspection/Repair. If the A&P mechanicconducting the inspection protocol recommends further inspectionor repair beyond what is called for in the written protocol, thereis a procedure for obtaining approval from Mobil or, failing that,from a Special Master approved by the court.

  9. Oil Pan Cleaning. Engines having sludge in the propelleror crankshaft per #2 or receiving a top overhaul per #5 may havethe oil pan cleaned of sludge provided this can be done withoutremoving the engine from the aircraft.

  10. SOAP Analysis. Engines that do not undergo a teardowninspection per #7 may undergo a spectrographic oil analysis programfor the next 150 hours or two years at Mobil’s expense at a labapproved by Mobil.

  11. Reimbursement, Loss of Use, Past Repairs. Mobil willreimburse owners for loss-of-use based on the actual use of theaircraft during the past year. Class members who have paid forengine repairs prior to the settlement as a result of loss ofcompression, increase in oil consumption, or propeller sluggishnessmay also qualify for reimbursement of costs incurred plus lossof use.

Owners desiring more information, claim forms, or wishing to submitcomments or objections to the propsed settlement should immediatelycontact class counsel Michael F. Ram at Lieff, Cabraser, Heimann& Bernstein in San Francisco, telephone 800-956-1009, facimile415-956-1008, or by e-mail at [email protected].

AVweb Comment

In general, we believe that this settlement is fair to owners,and find it remarkable that it was arrived at with such rapidityin a court system whose timetables are normally calibrated inyears and decades. A few things bother us, such as the fact thatan owner with bottom-end damage due to AV-1 use does not reallyhave the option under the protocol of exchanging his damaged enginefor a factory reman. But on the whole, we applaud the outcome.

Owners need to be extremely careful about how they and their mechanicdeal with this protocol. For example, one of the questions onMobil’s AV-1 claim form asks whether the claimant has experiencedsluggish or abnormal propeller operation. If the claimant answers”no” to this question, he is precluded under the protocolfrom pulling the propeller and inspecting for sludge build-upwhich, if found, would justify a transfer collar test and possibleteardown and overhaul under the protocol.

Any owner of an AV-1 engine who doesn’t answer “yes”to the “sluggish propeller” question and have his A&Ppull the prop (a very quick and painless procedure) should havehis head examined. The same is true for the “dramatic risein oil consumption” question.

Owners should also make sure that they and their A&P fullyunderstand and take advantage of item #8 of the protocol (“Outof Protocol Inspection and Repair”), which permits the mechanicto recommend and possibly even insist upon inspection and repairbeyond the strict written criteria of the protocol. Be sure yourmechanic interprets this clause liberally, and remind him thatwhen all is said and done, it will be his signature assuring thatthe engine is airworthy and approved for return to service.