I had a discussion with a pilot from another airline recently that leads me to believe that they have a potential flaw within their training system. If what I’m told is indeed correct, it suggests that the airline training department advocates a nonsensical and potential dangerous approach with regard to procedures associated with restarting an engine that has failed and continuance of flight.
Consider this scenario (performed in a simulator):
CAVOK (clear and no cloud) departure from AUK for SFO in a 2-engine wide-body jet. Very shortly after takeoff in visual conditions, and prior to top of climb, an engine ceases to produce power for no apparent reason. ENG Fail L/R checklist is performed, including a successful restart.
PF (Pilot Flying) wishes to continue to SFO. PM (Pilot Monitoring) raises concerns and objects. Sim Trainer supports PF and overrides PM suggesting that “… the engine has re-started with no indication of a fault, therefore continued flight is acceptable.”
I should make my disagreement known first and foremost. Given the inherent reliability of modern turbine engines, and the protections built into them, the possibility of a flameout without some underlying damage, be it software or hardware, is extremely unlikely. An engine will not fail without reason. Even if the failure was associated with known weather related phenomena I would still register my disagreement with what this other airline’s simulator instructor seemed to advocate.
Actions following a failure or shut-down of an engine due to fire, limit, surge, stall, severe damage separation, high oil temp or low oil pressure, is definitive with a QRH requirement to “land at the nearest suitable airport”. Other failures are covered by the NNC (Non Normal Checklist), Engine Fail L,R which allows for the possibility of a restart in the absence of apparent damage. An unsatisfactory restart re-imposes the “land at nearest suitable airport requirement”. In all cases CAO 82 and FAA AC 120 class any failure of an engine, whether restarted or not, as an In Flight Shut Down (IFSD). AC 120 makes an exception in the event of an automatic relight after a flame out.
The question of “to restart or not to restart?” is a vexed one that has plagued the industry for many years. Conventional wisdom suggests that if a relight will stop an abnormal situation progressing to an emergency situation – then it should be done. An example of this would be where it is necessary to garner whatever power is available to meet performance or terrain requirements. At any other time the inherent risks (damage and distraction) in restarting an engine that has, for unknown reasons, stopped producing power, outweigh the benefits of possibly getting back a bit of surplus power. It should be noted that Boeing, in typical litigation avoiding verbiage, states within the ENG L,R checklist “Choose one: Restart is needed.” They give no guidance on the criteria for contemplation of a restart, when is it needed or when is it not needed – leaving those discretionary decisions in the hands of individual airlines. Boeing’s FCTM (Flight Crew Training Manual) 8.2 states that “Trouble shooting is rarely helpful” and FCTM 8.3 states that “in all cases the PIC is expected to take a safe course of action.” All of which leave the PIC on a limb with no support if it all turns pear shaped.
If continuation into EDTO (Extended Diversion Time Operations) following an IFSD (In-Flight Shut Down) is this particular airline’s policy, I would not hesitate in registering my disagreement. I would also caution that it is my view that CASA/FAA may not be very approving should they stumble across it.
Arguably, an engine that has had an IFSD, whilst it may have been restarted and capable of producing power is, from a maintenance point of view, unserviceable. It requires, at the very least, an inspection prior to its next dispatch. Accordingly, it would surely fail the test of “status” at an EDTO entry point and should not be carried into that environment.
An IFSD is a serious incident which goes to the heart of EDTO operations, where engine reliability is often described as “the most vital aspect of EDTO”. Australia’s regulatory body, CASA, view the matter with such concern that all IFSD’s must be reported within 72 hours of the event.
It is my view that to carry on into an EDTO operation having had an IFSD and relight, would simply be negligent and potentially impact upon any EDTO approval any airline may hold.
Obviously, the impact on 4-engine aircraft may vary, but the same principle may apply.
References: CAO 82, FAA AC120 & CAO 20.6 (3.2)