Narrative:

In 1990 the maintenance chief of the FBO where we maintain our lear jet (an authorized service center for the lear) advised us that we needed a letter of authorization from general electric so we could exceed the time between overhaul (tbo) of 5000 hours on our ge cj-610-6 engines. The maintenance chief said he needed this letter in order to perform any inspections past 5000 hours. Our company is strictly a far part 91 operator. The letter of authorization from general electric arrived and okayed the extension of the tbo to XA53 hours. This factory service bulletin also stated we were to coordination this extension with the local FAA. I presented the letter to 2 maintenance inspectors at the local FAA FSDO. They said they had no problem with us going over the 5000 hour tbo limit because we operated under far part 91 rules. They said it would be a different story if we were a part 135 operator. They said a letter of authorization wouldn't be necessary since we were part 91. They did say however, that I should get an ok from our insurance company saying it was ok with them. We proceeded on the basis of the general electric factory service bulletin and the conversations with the FAA and insurance company. I resigned from the company around this same time (11/90) to accept a better paying job. I have occasionally returned to fly when I was available and this company needed a pilot. This was 3/92 and 11/92 to 4/93, approximately. The current chief pilot has dutifully kept up with requesting letters of extensions from ge, 300 additional hours at a time. The total time of the airplane is now approximately 5700 hours. On sep/xx/94 the chief pilot was advised by the FAA FSDO that the airplane had been flown illegally for the last 700 hours because the company did not have a letter of authorization from the FAA to exceed the tbo limit. This from the office of the FAA that 4 yrs ago said no letter of authorization was required. I learned of this on sep/xx/94. I called another FAA inspector from another district to get his input on the regulation. He confirmed exactly what the FAA FSDO said to me in 1990. He led me through all applicable regulations and explained why no letter of authorization is needed from the FAA for a tbo extension for a part 91 operator. I have learned 2 days ago that the FAA FSDO has graciously written a letter of authorization to extend the tbo by another 50 hours so the company has time to come up with options about the replacement of their engines. It appears to me that the FAA does not have the authority/authorized to establish engine times because that is the responsibility of the engine manufacturer. The engine manufacturer may amend, change, extend the tbo through the use of the factory service bulletin thereby changing the maintenance manual in this particular situation only. We, in effect, received a waiver from ge to exceed the tbo. We are still complying with far 91.409 in that the turbojet is being maintained in a legal and proper manner under the FARS. A letter may or may not be required from the local FAA but do they have the authority/authorized to deny an extension to an operator under far part 91? In our case we were given, in 1990, the 'go ahead' to exceed the 5000 hour tbo verbally by the local FAA because written authorization is not required. The maintenance chief has signed off the airplane at the completion of numerous inspections as being airworthy and inspected in accordance with the FARS and the applicable maintenance manuals. Pilots depend on the FAA inspectors and aircraft maintenance personnel for the proper interpretation of the regulations as they pertain to aircraft maintenance. But I think the question of being able to exceed tbo without an overhaul has not been addressed properly so that everyone is following the same set of rules. The only aircraft I care to fly are the ones that are completely legal. Callback conversation with reporter revealed the following information: reporter states he knows of no action by the FAA at this time. He wrote a very detailed letter to the company describing the procedures he followed informing the local FSDO and the resulting information of no problem since they operated under part 91 FARS. He hopes this letter will be helpful in working out the problem with the FAA. The company sent him a copy of a recent letter sent to the manufacturer and to the FAA requesting an additional 300 hours to bring the extended time up to 6000 hours. He just wishes the FAA would set a policy and stick by it. This is most confusing and frustrating. He has done a survey of pilots and mechanics and the split is about 50/50, so no one is sure.

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Original NASA ASRS Text

Title: EXTENSION OF TIME FOR TBO IN QUESTION.

Narrative: IN 1990 THE MAINT CHIEF OF THE FBO WHERE WE MAINTAIN OUR LEAR JET (AN AUTHORIZED SVC CTR FOR THE LEAR) ADVISED US THAT WE NEEDED A LETTER OF AUTHORIZATION FROM GENERAL ELECTRIC SO WE COULD EXCEED THE TIME BTWN OVERHAUL (TBO) OF 5000 HRS ON OUR GE CJ-610-6 ENGS. THE MAINT CHIEF SAID HE NEEDED THIS LETTER IN ORDER TO PERFORM ANY INSPECTIONS PAST 5000 HRS. OUR COMPANY IS STRICTLY A FAR PART 91 OPERATOR. THE LETTER OF AUTHORIZATION FROM GENERAL ELECTRIC ARRIVED AND OKAYED THE EXTENSION OF THE TBO TO XA53 HRS. THIS FACTORY SVC BULLETIN ALSO STATED WE WERE TO COORD THIS EXTENSION WITH THE LCL FAA. I PRESENTED THE LETTER TO 2 MAINT INSPECTORS AT THE LCL FAA FSDO. THEY SAID THEY HAD NO PROB WITH US GOING OVER THE 5000 HR TBO LIMIT BECAUSE WE OPERATED UNDER FAR PART 91 RULES. THEY SAID IT WOULD BE A DIFFERENT STORY IF WE WERE A PART 135 OPERATOR. THEY SAID A LETTER OF AUTHORIZATION WOULDN'T BE NECESSARY SINCE WE WERE PART 91. THEY DID SAY HOWEVER, THAT I SHOULD GET AN OK FROM OUR INSURANCE COMPANY SAYING IT WAS OK WITH THEM. WE PROCEEDED ON THE BASIS OF THE GENERAL ELECTRIC FACTORY SVC BULLETIN AND THE CONVERSATIONS WITH THE FAA AND INSURANCE COMPANY. I RESIGNED FROM THE COMPANY AROUND THIS SAME TIME (11/90) TO ACCEPT A BETTER PAYING JOB. I HAVE OCCASIONALLY RETURNED TO FLY WHEN I WAS AVAILABLE AND THIS COMPANY NEEDED A PLT. THIS WAS 3/92 AND 11/92 TO 4/93, APPROX. THE CURRENT CHIEF PLT HAS DUTIFULLY KEPT UP WITH REQUESTING LETTERS OF EXTENSIONS FROM GE, 300 ADDITIONAL HRS AT A TIME. THE TOTAL TIME OF THE AIRPLANE IS NOW APPROX 5700 HRS. ON SEP/XX/94 THE CHIEF PLT WAS ADVISED BY THE FAA FSDO THAT THE AIRPLANE HAD BEEN FLOWN ILLEGALLY FOR THE LAST 700 HRS BECAUSE THE COMPANY DID NOT HAVE A LETTER OF AUTHORIZATION FROM THE FAA TO EXCEED THE TBO LIMIT. THIS FROM THE OFFICE OF THE FAA THAT 4 YRS AGO SAID NO LETTER OF AUTHORIZATION WAS REQUIRED. I LEARNED OF THIS ON SEP/XX/94. I CALLED ANOTHER FAA INSPECTOR FROM ANOTHER DISTRICT TO GET HIS INPUT ON THE REG. HE CONFIRMED EXACTLY WHAT THE FAA FSDO SAID TO ME IN 1990. HE LED ME THROUGH ALL APPLICABLE REGS AND EXPLAINED WHY NO LETTER OF AUTHORIZATION IS NEEDED FROM THE FAA FOR A TBO EXTENSION FOR A PART 91 OPERATOR. I HAVE LEARNED 2 DAYS AGO THAT THE FAA FSDO HAS GRACIOUSLY WRITTEN A LETTER OF AUTHORIZATION TO EXTEND THE TBO BY ANOTHER 50 HRS SO THE COMPANY HAS TIME TO COME UP WITH OPTIONS ABOUT THE REPLACEMENT OF THEIR ENGS. IT APPEARS TO ME THAT THE FAA DOES NOT HAVE THE AUTH TO ESTABLISH ENG TIMES BECAUSE THAT IS THE RESPONSIBILITY OF THE ENG MANUFACTURER. THE ENG MANUFACTURER MAY AMEND, CHANGE, EXTEND THE TBO THROUGH THE USE OF THE FACTORY SVC BULLETIN THEREBY CHANGING THE MAINT MANUAL IN THIS PARTICULAR SIT ONLY. WE, IN EFFECT, RECEIVED A WAIVER FROM GE TO EXCEED THE TBO. WE ARE STILL COMPLYING WITH FAR 91.409 IN THAT THE TURBOJET IS BEING MAINTAINED IN A LEGAL AND PROPER MANNER UNDER THE FARS. A LETTER MAY OR MAY NOT BE REQUIRED FROM THE LCL FAA BUT DO THEY HAVE THE AUTH TO DENY AN EXTENSION TO AN OPERATOR UNDER FAR PART 91? IN OUR CASE WE WERE GIVEN, IN 1990, THE 'GO AHEAD' TO EXCEED THE 5000 HR TBO VERBALLY BY THE LCL FAA BECAUSE WRITTEN AUTHORIZATION IS NOT REQUIRED. THE MAINT CHIEF HAS SIGNED OFF THE AIRPLANE AT THE COMPLETION OF NUMEROUS INSPECTIONS AS BEING AIRWORTHY AND INSPECTED IN ACCORDANCE WITH THE FARS AND THE APPLICABLE MAINT MANUALS. PLTS DEPEND ON THE FAA INSPECTORS AND ACFT MAINT PERSONNEL FOR THE PROPER INTERP OF THE REGS AS THEY PERTAIN TO ACFT MAINT. BUT I THINK THE QUESTION OF BEING ABLE TO EXCEED TBO WITHOUT AN OVERHAUL HAS NOT BEEN ADDRESSED PROPERLY SO THAT EVERYONE IS FOLLOWING THE SAME SET OF RULES. THE ONLY ACFT I CARE TO FLY ARE THE ONES THAT ARE COMPLETELY LEGAL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATES HE KNOWS OF NO ACTION BY THE FAA AT THIS TIME. HE WROTE A VERY DETAILED LETTER TO THE COMPANY DESCRIBING THE PROCS HE FOLLOWED INFORMING THE LCL FSDO AND THE RESULTING INFO OF NO PROB SINCE THEY OPERATED UNDER PART 91 FARS. HE HOPES THIS LETTER WILL BE HELPFUL IN WORKING OUT THE PROB WITH THE FAA. THE COMPANY SENT HIM A COPY OF A RECENT LETTER SENT TO THE MANUFACTURER AND TO THE FAA REQUESTING AN ADDITIONAL 300 HRS TO BRING THE EXTENDED TIME UP TO 6000 HRS. HE JUST WISHES THE FAA WOULD SET A POLICY AND STICK BY IT. THIS IS MOST CONFUSING AND FRUSTRATING. HE HAS DONE A SURVEY OF PLTS AND MECHS AND THE SPLIT IS ABOUT 50/50, SO NO ONE IS SURE.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.