Some boisterous turbulence turned into an emergency on Thursday for the crew of an SAS A330. The air was rough enough to shut down an engine on the widebody over Greenland as it went from Stockholm to Miami. The crew was able to relight the engine but the jolt was enough to mandate an inspection. They headed for the nearest maintenance base able to do that work in Copenhagen. The flight lasted more than 10 hours and landed a few hundred miles from its departure point.
It is possible in turbine engines although I have never experienced that. The Cessna Caravan manual specifically has a checklist item to turn on ignition when entering severe turbulence. I haven’t seen that in the jets I have flown but most of the time your in turbulence in a jet, it is at altitudes that require turning on ignition ( and anti-ice) due to possibly of ice.
Every airframe/engine combo is different. The mnemonic in the 737-200 was FLITTER. Turn on the continuous ignition during the following events, use of Fuel heat, Landing, Icing conditions, Takeoff, Turbulence greater than light, Emergency descent, and Rain. This was with the Pratt JT8-D.
No such requirment listed for the CE-500 with the Pratt JT15. Or any of the Lear 31, 35, 55 with the Honeywell TFE-731, or 60 with the Pratt 305.
In the King Air with the PT-6 being reverse flow, no need for it in rain, or in icing if you had the Inlet Vanes deployed. Only takeoff and landing. Same in the BE-99.
I’m not sure but it sure doesn’t seem like any of the world, outside of the usa, seems to understand the concept or the dangers of Jetstreems. I’m honestly really concerned about flying international and am really disappointed that they don’t seem to be considered. Mt winds are not really the issue as much as complete avoidance of the polar/ hadley currents.
Hitting a Jetstream perpendicular can drop a plane right out of the air. Similar to being hit by a train. There are going to be some serious, serious accidents if companies, pilots & fispatchers, don’t become more diligent. Where is the icao in this?
Could the engine stoppage have comes from a compressor stall? A severe abrupt change of angle of attack might cause the engine to flame out. My speculation.
One day riding in jumpseat of B737 during a post-maintenance test flight Captain Russ Revel stumped me and the FO by asking why fuel boost pumps should be turned on above a certain altitude.
I forget the answer, could be risk of cavitation at lower atmospheric pressures.
I wonder where the idea that hitting a jetstream could affect the aircraft to such an extent could have come from. Those of us fortunate enough to be flying in that environment effects of jet streams, and use them, or not. The only time that there is any great concern is at the boundaries of the jetstream, otherwise you take advantage of it if it is a tailwind or try to avoid it if a headwind. So long as this can be coordinated with ATC. we avoid the boundaries of a jetstream mostly out of consideration for the passengers.
It is not outside the realm of possibility. Engines and their installations (cowlings, placement) are tested for tolerance for flow disturbances through flow distortion tests. Usually they simulate conditions using screens to create a pressure distortion (as measured by pressure probe “rakes” across the fan inlet) but an extreme AoA could generate enough flow distortion to cause a surge. As others have mentioned igniter operation may be called for in turbulence checklists.