Maintenance Airframe; Maintenance Powerplant
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Aircraft; Company Policy; Human Factors
This [report] is to prompt investigation for Aircraft X which was returned to service without completing a [fault identification] procedure for high engine oil consumption in ZZZ. It includes modification of previous engine oil servicing records; failure to complete maintenance tasks; pressure from [Maintenance Control management] to return the aircraft to service; and failure to follow [the procedures manual] (and thus FAR) procedures. The attached timeline shows a summary of events regarding Aircraft X. On Day X an item was created with a 10 day limit to perform an inspection due to high oil pressure on the right engine.On Day X+4 it went out of service in ZZZZ after an oil service was performed in which the right engine required 18 pts - exceeding both the servicing quantity and spot consumption rate limits of GPM 8.08. An external leak was found at the starter gearbox pad and corrected in POP. The aircraft operated the following day; Day X+5; [on a multi-leg route]. During the day [an inspection order] was created to do a follow up leak inspection. This is not typical and the reason for the request is unknown to me. It then went out of service again the night of Day X+5 in ZZZ1 after oil servicing again showed high consumption on the right engine. This time due to spot rate only (3.191 pph) as quantity added was within limits (9.67 pts). [An inspection order] was created to accomplish [the fault isolation procedures] for the high oil consumption. The starter pad was reworked; this time by mechanics brought from [another hub's] engine shop on a field trip. A leak at the gearbox hand crank pad was also resealed. [Engineering Authorization] was issued to supplement the [maintenance manual] procedures involved. The aircraft was returned to service. On Day X+10 in ZZZ an oil service was performed in which both engines showed a spot consumption rate beyond allowable limits. An [inspection order] was created for each engine to be inspected prior to flight and the aircraft removed from service. The [procedures manual] flow chart led mechanics to return the left engine to service and the [inspection order] closed. The right engine followed a different path in the flow chart and required more inspection. The OTS (Out of Service) event lasted the remainder of our night shift; through the day shift; and through our night shift again.[Early morning] on Day X+12 the [Maintenance Control] asked [the engineering department] for approval to add time to the [inspection order] created for the high oil consumption so they could operate revenue and route to ZZZ2 for repair. [The engineering department] (when we were off-shift) replied that they would not agree to that - offering only concurrence for 1 flight cycle on a maintenance ferry flight. Day shift happened. When arriving for our night shift on Day X+12 we observed Aircraft X in [the system; logged as] OTS in [a different airport] for a pitot probe/heater failure. We reviewed the open items on the aircraft in [the system] and saw a new [inspection order] written to accomplish an inspection of the right engine for oil consumption and high oil pressure. (The original [inspection order] for oil pressure inspection was still open and had been extended multiple times). It was also noted that ZZZ had documented coking found in the engine during the incomplete inspection. The previous [inspection order] for the right engine high oil consumption had been signed off in reference to the newly opened item. No allowance exists in the [procedures manual] flowchart to discontinue or defer any corrective actions during the accomplishment of the [fault identification procedures]. An e-mail from [the engineering department] was sent that allowed another day for the high oil pressure inspection. Other e-mails may exist; but were not in the 737 tech services inbox at the time of our arrival on shift. We also found that the previous oil servicing in ZZZZ had been adjusted from 18 pts added down to 0 pts; with a note that the oil was not serviced; that it had been replenished due to the external leak. Review of the aircraft routing showed the aircraft scheduled to RON (Remain Overnight) in ZZZ1 during the current OTS for the pitot probe then operate revenue on Day X+13 with a RON in ZZZ3. The existing [inspection orders] would be out of time in ZZZ3 so a routing request was sent to [dispatch] to request the RON be changed to ZZZ2 only. [Maintenance Control] was contacted and told that we reviewed the new items on the aircraft since leaving it this morning; and that we do not feel the aircraft was signed off in an airworthy condition. The oil consumption [inspection procedure] had produced findings which were not addressed and had no authorizing document to allow for a deferral.I was not on shift at the time and may only assume that it was because; as we are always told by the [Maintenance Control]; that 'We need the airplane.' I can't believe that the [Maintenance Control manager; the engineering department; those on shift in Maintenance Control; and the AMT's] signing for these documents in ZZZ would cave to the pressure of management to 'give' them an airplane - knowing that a procedure had not been completed after inspection resulted in a finding. Also; how the determination was made that external leaks don't count as oil servicing is also a horrible precedent to set. External leaks often are the cause of a high oil consumption notification and subsequent inspections/corrective actions and is a part of the [fault identification procedures].It's bigger than me. I was not directly involved with the improper return to service; but I will say that I would not have created the new [inspection order] or changed the oil service history without some type of approved data. It appears that the persistence of management to move airplanes is starting to weigh on the operation.
Maintenance Technician reported that an aircraft returned to service without accomplishment of proper maintenance procedures.