This should be an interesting story.......
This should be an interesting story.... https://www.seattletimes.com/seattle-news/delta-flight-from-beijing-to-seattle-lands-on-alaskan-island-due-to-engine-issue-alaska-public-media-reports/ A Delta Airlines flight from Beijing to Seattle was forced to land on a remote Alaskan island Monday after pilots were alerted to a “potential engine issue,” leaving almost 200 hundred on board stranded for more than 12 hours. The carrier sent another aircraft to pick up the 194 passengers, Delta spokeswoman Savannah Huddleston said in an emailed statement. She didn’t have more information on the engine problem. The diverted plane, flight DL 128, was a Boeing 767-300ER. The plane sent from Seattle to pick up the passengers landed at Eareckson Air Station at 1:10 p.m. Seattle time, about 11 hours after their arrival, according to data from FlightAware, a flight-tracking website. It was scheduled to turn around and come back after spending about three hours on the ground, arriving in Seattle at about 9 p.m. The flight was diverted to Shemya Island, which is part of the Aleutian chain off the coast of Alaska. The airline has sent maintenance technicians, customer service agents and a new crew to work on the flight back to Seattle,
Cold, this time of year. They've also had to do diverts into the islands in the mid-Atlantic... I can't remember the name.
Depending on route, a 4 engine might have diverted, too. They have similar rules. ETOPS now means extended ops and applies to 4 engine aircraft, as well.
Except when you lose an engine on TO, which apparently doesn't count, so you continue for 10hrs on 3 and then divert at the very end after running low on fuel. https://en.wikipedia.org/wiki/British_Airways_Flight_268
That's a bit surprising, considering they were only burning fuel in three engines; one would think that would have increased their fuel reserve. Or did the drag of the dead engine cancel out the advantage of not burning fuel in it?
Lots of stuff. With one engine down, you have asymmetric thrust and are flying sideways to a certain extent. Plus, you have to carry more power on the other three engines to maintain a useful airspeed and altitude. In many cases, you cannot reach a more fuel efficient flight level with one engine down.
In the article, they also said that over the Atlantic, they "encountered less favorable conditions than predicted". So maybe a smaller tailwind component?
BA did that a number of times before it made the press-- and in that case, as you mention, it was only because they had to divert at the end of the trip. It would be interesting to know if a four-engine airplane (747 or A340) would have had to divert in this specific case. I'm guessing no, butI really don't know.
It may be that the BA 747 couldn't climb high enough on three. In the CL 44 when we had to shut down an engine in fight it we would usually descend about 2,000 feet and kept on going toour destination at a slightly reduced (about 15 knots) airspeed. Remember also that the Navy P3s usually patroll on three engines-normal procedure. Still, for a 747 to cross the entire USA and then the Atlantic ocean on three is very impressive.
Wiz- I think you mean the P-3s cruise on two engines, not three, and that is at low altitude and low airspeed.
And props are different in that you can feather the blades, thereby greatly reducing drag. Not so on a turbofan.
