Mobil AV-1 Engine Inspection and Repair Protocol

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If you've experienced engine problems related to Mobil's AV-1 oil, AVweb provides some helpful tips.

I. Threshold Level of AV-1 Use/Engine History Protocol

Teledyne-Continental IO-520, TSIO-520, GTSIO-520, IO-550, TSIO-550, GTSIO-550, O-470, IO-470, TSIO-470, O-360, IO-360 and TSIO-360 piston aircraft engines in which Mobil's AV-1 oil was used for inore than 150 hours, and were not completelv rebuilt or completely overhauled since discontinuance of AV-1 use, qualify to be inspected pursuant to this protocol. Such engines are "Qualified AV-1 Engines." Color copies of aircraft logs, original engine logs, maintenance records, current aircraft registration and certificate of airwothiness and a completed "AV-1 Claim Form" with executed authorization, must be submitted to the designated Mobil representative to establish qualification, not later than 3 months after Final Approval of this Settlement by the Court. Every claimant may make color photocopies of all submitted logs, invoices, and records, prior to their submission, at Mobil's expense. Original engine logs are to be submitted to Mobil, with color copies retained by claimant; color copies of airframe logs are to be submitted to Mobil, with originals retained by claimant. Mobil has the right to examine original airframe logs on demand, without notice. Upon receipt of a Mobil AV-1 Claim Form, Mobil will provide a copy to Class Counsel. All submissions of logs, records and invoices to Mobil shall be by Federal Express at Mobil's expense. Photocopy cost invoices shall be submitted to Mobil at the same time tbat origal documents are submitted, aad all original documents shall be returned to the claimants, along with a check for the claimant's photocopy expenses, by Federal Express, withiu a reasonable time which will in no instance exceed two weeks from receipt by Mobil. If there is any dispute as to qualification, all engine logs, aircraft logs and maintenance records shall be submitted to the Special Master whose decision shall be based solely on his determination of whether or not the engine has met the, minimum AV-1 use criteria as specified herein.

To implement the settlement at a reasonable cost to all parties, expedite handling of the claims, and support the Special Master resolution process, the information in claims files and in any computer database will be promptly copied and provided to Class Counsel upon request.


II. Propeller Operation Protocol - Experiencing Sluggish or Abnormal Propeller Operation

Any "Qualified AV-1 Engine" owner who is experiencing sluggish or abnormal propeller operation may have his or her propeller removed and the propeller, crankshaft bore and governor screen checked for sludge. If the mechanic/inspector determines that it is appropriate, the propeller, crankshaft bore and governor will be de-sludged. If after desludging the propeller, crankshaft bore and governor, the oil transfer holes are occluded by any sludge. or the propeller operation remains sluggish or abnormal following a test flight, the Oil Transfer Collar ge Test will be performed in accordance with the procedure attached as Exhibit "B", consistent with the engine manufacturer's recommendations. If the engine fails the Oil Transfer Collar Leakage Test, proceed to the Engine Teardown/Case Inspection Protocol, Section VIII below. If the Oil Transfer Collar Leakage Test is satisfied, proceed to the Axial Crankshaft Protocol described in Section III below. Where, as in the 360 series, there is an oil transfer bearing, an appropriate oil transfer bearing leakage test shall be employed, also as set forth below.

The Oil Transfer Collar Leakage bearing Test shall be performed in the following manner:

1 . Run the engine up to get the oil up to operating temp.

2. Tools required to perform leak check:
Cylinder differential tester.
Adapter plate for governor pad or rubber tip air nozzle.

3. Remove governor.

4. Attach compression tester to govemor pad with adapter plate or rubber tip nozzle. See location for oiI passage below.
360 serics engines - About 7:00 position looking at governor pad.
Permold 520 and 550 series engines - About 8:00 position looking at govemor pad.
Sandcast 470, 520 and 550 Series engines - About 11:00 position looking at govemor pad.

5 . Readings should be taken after an initial 80 pounds of input pressure is applied to oil passage. Allow pressure to stabilize for 15 seconds.

6. The following reading would be considered optimum for this test:
All IO-470, TSIO-470, IO-520, TSIO-520, IO-550 and TSIO-550 series engines with transfer collar on crankshaft: 30-65 pounds over 80 pounds. Readings below 30 pounds would be suspect.
All 0-470 and 360 Series which have front main bearing as transfer: 20-50 pounds over 80 pounds. Reading below 18 pounds would be suspect.
All GTSIO-520 series: 65-75 pounds over 80 pounds. Readings below 65 pounds would be suspect. Note: GTSIO-520 have a direct transfer tube to shaft which has very little leakage.
Caution: All engine run-up should be performed with governor installed to prevent dainage to transfer collar.

7. All work performed should be I/A/W Airframe Manufacturers instructions to return to service.

8. In the event of question as to the methods outlined above, it is suggested that the examining mechanic or inspector make direct contact with the Service Department of Teledyne Continenml Motors.


III. Axial Crankshaft Protocol

If the propeffer has been removed pursuant to the Propeller Operation Protocol described in Section III, or if the cylinders have been removed pursuant to the Top End Overhaul Protocol described in Section V, the Axial Crankshaft Test shall be performed in accordance with the following procedure and utilizing the following equipment:

Equipment: Dial indicator with a range of at least 0.050" and a resolution of at least 0.0005" shall be used. Suitable adapters and base shall be used to mount dial indicator in a steady, stable position with respect to the case halves. Appropriate large screwdriver or small prybar (not to exceed 15 inches) is required to serve as a lever to move crankshaft.

Procedure: Mount dial indicator solidly to crankcases with appropriate adapters to measure motion in the direction parallel to the crankshaft axis. Place indicating point on crankshaft flange of propeller, and adjust to approximate middle of indicating range. Without rotating the crankshaft, use a large screwdriver or small prybar, no longer than 15 inches in length as a lever between the crank flange and the case structure to move the crankshaft fore and aft a few times, with reasonable support force not to exceed 10 pounds manually applied.

Move crankshaft to rear most position in cases and note reading (1) on dial indicator. Use lever to move crankshaft to forward most position, and note reading (2) on dial indicator. Reverse procedure and return crankshaft to rear most position and note reading (3). Third reading should be within 0.0005 " of first reading. If not, repeat measurement.

Value recorded for test is absolute difference between first and second readings. Readings in excess of TCM Service Limits for axial play, as provided in the appropriate TCM overhaul manual require confirmation by Mobil representative, and, if accurate, will require performing the Engine Teardown/Case Inspection Protocol described in Section VII below. If readings are within limits, proceed to Top End Inspection Protocol described in Section IV below.


IV. Top End Inspection Protocol

All "Qualified AV-1 Engines," as defined in Section I, shall have a Top End Inspection which consists of the following:

1. A review of the engine history, including the claim form provided for in this Settlement, to determine whether the engine has an oil consumption problem. Such a problem must be evidenced by a dramatic increase in oil consumption. A "dramatic increase" means a sustained trend line with a doubling of oil consumption over 150 hours. An engine demonstrating such an increase will be given a Top End Overhaul, as described in Section V below.

2. If an engine does not demonstrate any oil consumption problem, the engine shall then be checked for low compression using either of the following tests:

(a) A dynamic seal check, performed in accordance with. TCM Service Bulletin M84-15: A gauge reading below the allowable limit, indicates that the cylinder shall be replaced. If three or more cylinders have readings below the allowable limit, the engine shall receive a Top End Overhaul, as described in Section V. If such a decrease appears in only one or two of the cylinders, only those cylinders shall be removed and replaced.

(b) A review of historical differential compression test data that shows an abnormally large (15%) and sudden decrease in the compression readings over 150 or fewer hours in service and a confirmation of the 'lower" readings by a subsequent test. This sudden change in readings must have occurred using the same compression test equipment. If the readings are from unknown or different test equipment or different testing facilities, then the dynamic seal check shall be perfomed. If an abnormally large and sudden decrease appears in three or more cylinders, the engine shall be given a Top End Overhaul as described in Section V. If such a decrease appears in only one or two of the cylinders, only those cylinders shall be removed and replaced.

(c) The crankcase pressure test described in TCM Service Bulletin M89-9 will be performed on every engine participating in these inspection protocols. If the cylinders are above the low allowable limit and the engine passes the crankcase pressure test, the cylinders will be deemed serviceable, and the engine shall proceed to the S.O.A.P. Protocol described in Section X below.

(d) At the completion of any inspection or repair which has involved the removal of a cylinder, the certified mechanic or F.A.A. approved facility which accomplished the inspection or repair shall place an entry in the subject engine logbook, in the standard form, that the certified mechanic or facility has examined the engine and found it to be airworthy.


V. Top End Overhaul Protocol

Any Qualified AV-1 Engine that demonstrates an oil consumption problem as defined in Section IV(1) above, or has three or more cylinders with compression problems as described in Section IV(2) above, or fails the crankcase pressure test, shall have all of its cylinders replaced as follows:

(a) Any engine which is 0 to 1/2 time of T.B.O. and has cylinders which, when removed and measured, exceed new limits, shall receive new cylinder kits. The replacement cylinders shall be equivalent to the replaced cylinders, i.e., steel to steel, cbrome to chrome. If the cylinders are still within new limits, the new cylinders shall not be replaced.

(b) Any engine which is 1/2 time to T.B.O. up to T.B.O. and has cylinders wliich are measured between service limits and new limits shall be deemed serviceable and shall not receive new cylinders. Cylinder components, such as piston rings, oil control rings, piston pins, bushings, and piston pin plugs shall be replaced as necessary. If the cylinders are measured to below service limits, the cylinders shall be replaced with new, equivalent cylinders, ie., steel to steel, chrome to chrome.

(c) When cylinders are removed for a top overhaul, or for an engine teardown/case inspection as provided for in Section VII., the inspecting mechanic will look at the camshaft. Mobil will not pay for the removal, replacement, or repair of the camshaft unless the Special Master finds that AV-1 caused damage to the camshaft.


VI. Connecting Rod Bearings Protocol

If cylinders are removed pursuant to the Top End Overhaul Protocol (Section V), the following protocol shall be performed while the cylinders are removed, in order to check the connecting rod bearing vertical clearance:

Equipment: Dial indicator with a range of at least 0.050" and a resolution of at least 0.0005" shall be used. Suitable adapters and base shall be used to mount dial indicator in a steady, stable position with respect to the case halves. Block to support small ends (wrist pin end) of connecting rods shall be used.

Procedure: Measure one connecting rod at a time. Rotate cra@haft such that rod containing bearing to be measured is at Bottom Dead Center. Mount dial solidly to crankcase half adjacent to bottom of connecting rod cap to be measured, with appropriate adapters to measure motion in the direction perpendicular (transverse) to the crankhaft axis. Support the wrist pin end of the subject connecting rod with supports to hold the rod axis horizontal, but not interfering with its ability to move horizontally a few thousandths of a inch. Place indicating point on the bottom of the connecting rod cap, and adjust to approximate middle of indicating range, Without rotating crankshaft, use hand force only to move connecting rod from side to side a few times. Force applied to connecting rod should not exceed five pounds, and small end (wrist pin end) of connecting rod should remain in contact with its support.

Move connecting rod toward Top Dead Center direction perpendicular to crankpin, hold at that position with about five pounds of force, and note reading (1) on dial indicator. Move connecting rod toward Bottom Dead Center direction, hold with about five pounds of force, and note reading (2) on dial indicator. Reverse procedure and return connecting rod toward Top Dead Center direction, hold, and note reading (3). Third reading should be within 0.0005" of first reading. If not, repeat measurement. Record raw data and computed clearance for each rod as it is measured,

Repeat procedure for each of the remaining connecting rods, rotate crankshaft to bring each to Bottom Dead Center for measurement.

Value recorded for test is absolute difference between first and second readings.

One or more readings in excess of TCM Service Limits require confirmation by Mobil representative, and, if accurate, will require removal of connecting rods from crankshaft for diagnosis of source of excessive clearance, and appropriate action.

Three or more readings in excess of TCM Service Limits require confirmation by Mobil representative, and, if accurate, will require the engine to undergo the Engine Teardown/Case Inspection Protocol described in Section VII below. If the engine satisfies the requirements of the Connecting Rod Bearings Protocol, it shall then undergo the S.O.A.P. Protocol described in Section X.


VII. Engine Teardown/Case Inspection Protocol

On the basis of the Propeller Operation Protocol described in Section II; the Axial Crankshaft Protocol described in Section III; or the Connecting Rod Bearings Protocol described in Section VI, certain engines shall undergo the Engine Teardown/Case Inspection Protocol described in this section. While having agreed to the disassembly of certain engines where the protocol results require it, Mobil is doing this for the comfort and assurance of the engine owners and without any admission that such bottom end inspection is or ever has been necessary on the basis of reasonably applied engineering criteria.

The Engine Teardown/Case Inspection Protocol shall consist of the following:

Mobil shall pay for the reasonable labor costs of removal, disassembly, inspection, reassembly and re-installation of the engine. The examination will include any turbo super charger. Regardless of the condition or cause of problem, Mobil shall pay for those crankcase parts which are normally replaced at the time of engine reassembly after complete teardown: all rubber goods, diaphragms, o-rings, packings, hoses, and seals, gaskets, circlips, lock plates & retaining rings, bushings, bearings, thrust washers, counter-weights, pins and springs, snap rings, nuts, oil suction screens, spark plugs, counterweight hangar bushings, primer diverter valve, clamps, and washers. Mobil will pay, up to a maxhnum of $2.200, for the replacement of a non-V.A.R. crankshaft with a V.A.R. crankshaft, where such replacement is required by T.C.M. Service Bulletin M92-16. Mobil will not pay for compliance with any other Service Bulletins or Advisory Directives. Mobil will not pay for the replacement or repair of any other crankcase parts including, but not limited to, V.A.R. crankshafts, camshafts or lifters, unless the Special Master finds that AV-1 caused damage to the part. Mobil will not pay for the replacement, overhaul or repair of any engine accessories. If, after consultation with the designated Mobil representative, there remains a disagreement as to the causation of any damage to the part in question, the Special Master shall determine if AV-1 was responsible for the damage. The Special Master shall be able to apportion fmancial responsibility between Mobil and the owner, when appropriate.

Once an engine has received both a Top End Overhaul and the Engine Teardown/Case Inspection, it shall no longer be included in the Inspection Program.


VIII. Mechanic's Written Recommendation For Out of Protocol Inspection or Repair.

If at any stage in the inspection protocol, except for post-protocol S-O.A.P. Analysis, a particular protocol stage has been satisfied, so that further inspection after that stage is not necessary under the protocol, but the inspecting mechanic, despite such protocol compliance, recommends further inspection or repair then Mobil will provide a representative who may meet with the mechanic, inspect the engine, and adjust the situation by consensus if possible. Any recommendation for additional inspection or repair must be submitted in writing by a licensed A&P mechanic to the designated Mobil representative within two weeks of completion of that portion of the inspection protocol. If, after such divergence from the protocol, and after such review by Mobil's representative consensus has not been achieved, then the claimants based on the inspecting mechanic's written recommendation, may make application to the Special Master for review of the requested out-of-protocol inspection or repair. If the Special Master finds that AV-1 caused damage which required the repair, then the repair or inspection shall be made at Mobil's expense. If the Special Master finds that AV-1 did not cause the damage, then the inspection or repair shall be paid for by the Clairnant. In all such circumstances the Special Master shall have the ability to apportion the cost of the repair or inspection. The Special Master shall also have the ability to apportion the Special Masters' own charges and expenses, for applications under this Section.


IX. Oil Pan Cleaning Protocol

If an engine qualifies for the Propeller Operation Protocol due to excess sludge, as described in Section II above, or for the Top End Overhaul Protocol described in Section V above, the owner may request that the oil pan be cleaned of sludge. If the oil pan can be separated from the engine case without removing the engine from the aircraft, the pan shall be so separated from the case and manually cleaned, using standard tools, and an appropriate F.A.A. approved solvent for the purpose, and the interior pan surface shall be wiped dry prior to re-attachment to the engine. Should a rare instance occur in which sufficient separation between the oil pan and the case to allow manual cleaning cannot be obtained without renioval of the engine from the airframe, then the pan may be cleaned with an appropriate solvent which is F.A.A. approved for this purpose. Any dispute over this procedure shall be resolved by the Special Master, who shall have the authority to order an engine from the airframe for oil pan cleaning only if such cleaning cannot be safely accomplished without such removal.


X. S.O.A.P. Analysis Protocol

1. Every "Qualified AV-1 Engine" as described in Section I which has not undergone the Engine Teardowi/Case Inspection Protocol described in Section VII may undcrgo the S.O.A.P. (Spectrographic Oil Analysis Program) Protocol described here at Mobil's expense. Oil samples may be taken at 25-hour oil &ain intervals. The sampling may, at the discretion of the Qualified AV-1 User, continue for 150 hours of use or for two years from the date the settlement notice is sent to the class, whichever occurs first.

Samples should be taken hot, as soon as possible following shut down of the engine. Approximately one quart of oil should be allowed to flow before samples are taken.

The filter shall be removed; the can shall be cut; and the filter material shall be inspected. If excessive metal is found, the filter material shall also be sent to the lab for analysis.

2. All samples shall be labelled completely including, but not limited to:
owner's name
aircraft number
engine model
engine serial number
date sampled
hours since major overhaul
hours since last oil change
cylinder material: chrome/steel

3. Copies of the completed analysis shall be sent to the owner of the engine and to the designated Mobil representative.

4. If the owner wishes to request action based upon conclusions or recommendations provided by ttle laboratory conducting the S.O.A.P. analysis, which in turn shall be based upon or practices, procedures and guidelines established by the approved laboratory, the owner may submit a written claim to the designated Mobil representative. The owner may request action whether or not the laboratory has recommended any particular action. If the owner and the designated Mobil representative disagree on the owner's claim, the Special Master shall evaluate the analysis and the request for action made by the owner. If damage is found, the Special Master shall determine the appropriate action to be taken and shall establish who will bear financial responsibility for such action and in what percentage. The Special Master may consult with whatever experts she/he wishes. The cost of such expert consultations shall be paid by Mobil. Telephone consultations and other cost-effective inethods of communication are preferred. The laboratory or laboratories which shall accomplish the S.O.A.P. tests called for in this Section shall be identified through agreement between class counsel and counsel for Mobil within 15 days of the Court's Preliminary Approval of this Settlement. If not so identified by consensus within 15 days, the laboratory shall be selected by the Special Master(s) within 35 days of said Preliminary Approval, under Court supervision.


IX. Miscellaneous

A. All disputes which may arise concerning the implementation, interpretation, construction and administration of this Protocol shall be determined by the Special Master, whose decision shall be binding and final between the Settling Parties. There shall be an appropriate number of persons agreed upon by the parties to serve as Special Masters. The number and identities of these persons shall be agreed upon by the parties within 15 days of this Court's preliminary approval of this settlement, and if there is no such agreement between the parties within those 15 days, then the Court shall appoint such persons to so serve within 30 days of the Court's preliminary approval of this settlement. Except as provided in Section VIII, all of the fees and expenses of the Special Masters shall be borne by Mobil, through the establishment and replenishment of a fund in such amount and at such times as the Court may direct.

B. Mobil expressly reserves the right to independently examine, inspect, measure and test any and all engines, and component parts therein, which participate in this Protocol, and each claimant shall have the same right.

C. All inspections and service to be performed pursuant to this Protocol shall be performed by an appropriately certified inspection and repair facility ("facility"). This inspection and all other inspections described hereafter must be done by an A&P mechanic or an inspector holding an Inspection Authorization from the FAA, or at an F.A.A. certified engine repair station. Subject to these limitations, inspections and service shall be performed at the facility which is routinely utilized by the engine owner or at another facility which is mutually agreed upon by the engine owner and the designated Mobil representative, which agreement will not be unreasonably withheld, and in the instance of any dispute the dispute shall go to the Special Master.

D. Expert Consultations

The Special Master(s) may consult with any experts he/she wishes in relation to any aspect of this protocol.

E. Parts and Labor Rates

Parts and labor shall be paid at the reasonable prevailing rates in the region.

F. Loss of Use

Loss of use related to the past use of AV-1 and associated with future participation in the Settlement Protocol shall be paid on the basis of actual days of down time, commencing from the date on which inspection pursuant to this protocol actually begins and ending when the engine has been certified to be in airworthy condition by a licensed A&P mechanic and reinstalled in the aircraft. Mobil will not pay for loss of use for the period of time which passes during the Mechanic's Written Recommendation for out of Protocol Inspection or Repair, as described in Section VIII, unless it is determined, whether by consensus or by the Special Master, that the engine condition complained of was attributable to AV-1. Loss of use shall be calculated on the basis of the historical daily use of the claimant's aircraft during the one year prior to September 28, 1995 or the date upon which the aircraft was taken out of service due to alleged AV-1 related problems, whichever comes first. Loss of use shall be calculated on the basis of one hundred and seventy five dollars ($175.00) per hour for airplanes containing 520 or 550 Series engines and one hundred dollars ($100.00) per hour for airplanes containing 360 and 470 engines. The number of hours of loss of use shall be based on the claimant's logged average daily use of the aircraft during the year prior to September 28, 1995 as evidenced by the original aircraft log books for the aircraft equipped with the "Qualified AV-1 Engine," pursuant to Section I.

Claimants with past repairs that satisfy the Past Repairs Protocol shall be allowed compensation in the amount of actual loss of use, based on the average daily usage for one year prior to September 28, 1995, exclusive of any period during which the aircraft was grounded on the basis of AV-1 related repairs.

G. Past Repairs Protocol

In some instances, members of the Plaintiffs Class may have paid for engine repairs prior to this Settlement, for a type of damage, such as top end damage, of the sort which Plaintiffs have claimed may result from the use of AV-1 under certain operating conditions.

This Protocol provides for compensation for past repairs where AV-1 has been used, but only if certain express criteria for such compensation are met. The provision of this compensation shall not be deemed as an admission that such past repairs were necessary, or that AV-1 was a factor leading to such repairs.

For a past user of AV-1 to qualify for repair costs incurred prior to September 9, 1995, the engine must have been operated for a minimum of 150 hours on AV-1, as evidenced by the original engine log book, and there must have been a loss of compression, propeller sluggishness as defined in Section II, or increase of consumption as defined in Section IV(1), or logged entries showing stuck oil control rings.

Loss of compression, for purposes of the Past Repair Protocol only, shall mean a review of historical differential compression test data that shows an abnormally large (15%) and sudden decrease in the compression readings over 150 or fewer hours in service. This sudden change in readings must have occurred using the same compression test equipment . If an abnormally large and sudden decrease appears in two or more cylinders, the engine shall qualify for compensation pursuant to the Past Repairs Protocol.

Past problems must be evidenced by original engine log book entries, invoices, receipts, inspection reports, affidavits or other original, maintenance records. Where these criteria are met, the claimant shall be reimbursed for out-of-pocket expenses actually incurred for top end or propeller damages. The sum of such damages must be proven through original receipts or invoices.

Where there has been a past total rebuild, Mobil will pay the more expensive of: a Top End Overbaul or a prorated total rebuild based on engine hours as against the published T.B.O. if: (1) the top end criteria described above are met and (2) the owner can provide a letter or other proof from the mechanic stating that he had recommended a full engine rebuild and why he had made such a recommendation, and whichever amount is paid, Mobil will pay for the reasonable labor costs incurred for such past engine removal and replacement. If there is any disagreement as to what level of reimbursements is proper, the Special Master shall review the information and determine whether Mobil must pay for the past repairs, and what amount, if any, Mobil must pay. The Special Master shall be able to apportion financial responsibility between Mobil and the owner, when appropriate.

In those instances where the criteria above stated for repair were met, and a rebuild took place after more than two thirds of the manufacturer's reconunended TBO interval, then the claimant shall be paid on a pro-rata basis, at $17.50 per hour, for the difference in hours between the actual time on engine at the time of repair and the TBO for that engine.

H. All amounts to be paid by Mobil shall be paid within a reasonable time not to exceed 45 days of the date they are incurred, or if challenged, ordered by the Special Master,

I. No work is to commence on any engine pursuant to this Inspection Protocol without prior authorization by the Designated Mobil Representative or the Special Master. Such authorization shall be given promptly upon qualification pursuant to the terms and conditions of this Inspection Protocol. It is the intention of all parties that the inspections called for by these protocols, and any repairs found through these protocols to be necessary, shall proceed with all deliberate speed.