Flight 370 question

[william watts]

While watching tv news the announcers report that the plane suddenly lost altitude from 39000 ft to 4000 ft. ,but no one seems to know why the sudden decent. I am not a pilot and know nothing about aviation, but I recall from news of another aviation incident that a steep dive is a maneuver to restart the engines. None of the announcers say anything about that possibility. Any pilots here that know about that?

I apologize if this question is to far off topic or is considered ridiculous. Just thinking talented people hang out here and this is the only form I post on.

[David Dockstader]

More likely scenario - Rapid decompression (sudden loss of cabin pressurization - think Gert Fröbe going out the fuselage hole in "Gold Finger." ) It's generally not that much fun, but no one can breathe for long above about 20,000 feet so you have to dive down pretty quickly to keep folks from passing out. The only other time I can think of is if you get jumped by 2 Libyan Mirages over the middle of the Mediterranean and they engage their heat-seeking missiles, but DAMHIKT. Jet engines can be started if they are windmilling as you lose altitude, but the dive doesn't have to be that steep. Usually you maintain the power-out best glide speed. That will keep the engines windmilling and give you the longest possible time in the air to figure things out. No use doing a steep dive - that only cuts your expected life expectancy.

[Randy Rizzo]

In the case of a flameout N2 needs to be rotating at 10-15% for a restart and it needs to be within the restart envelope (range of altitude specified by airframe/engine manufacturer) Speeds necessary to keep the N2 rotating at this RPM are probably in the 250-300KT range, higher than speed necessary for "stretching the glide". In the case of a rapid decompression or explosive decompression the target altitude is 10,000-14,000', depends on terrain.

[william watts]

Thanks for the replies. Just had intense curiosity about the accident. Not only did I receive good aviation knowledge but Gold Finger knowledge as well :)