C-17 tactical descent
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C-17 tactical descent
A fairly interesting video for those of us used to more sedate descents.
https://youtu.be/khBioU1qFVY
https://youtu.be/khBioU1qFVY
Join Date: Apr 2010
Location: Sneaking up on the Runway and leaping out to grab it unawares
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I took some cadets for trip with 99 Sqn last year. The high rate descent was very impressive (especially for such a big aircraft) - all 4 engines into reverse thrust at FL190, RoD 20,000fpm. I even came off the floor as the aircraft was pitched nose down.
Flew a 'Da Nang' approach into Basrah one night in a B747 charter.
Company found out and were not pleased. If you do a lights out tactical approach that means it's a war zone and, if so, then your insurance is invalid
Company found out and were not pleased. If you do a lights out tactical approach that means it's a war zone and, if so, then your insurance is invalid
with reference to #2 above, the old saying about a landing being a crash you walk away from suddenly seemed very true as the Irish SLF 737 did its best to leave its main gear below sea level at MLA.
Reverse thrust in flight probably pioneered by the DC-8. Remember a rather rapid let down between thunderstorms at Houston January 1967 courtesy of Delta DC-8 with reverse deployed.
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Yes, all four engines can go into reverse thrust in flight. The C-17 also has speed brakes. In speed brake mode the flaps extend to dramatically increase drag, and the spoilers deploy to cancel out the increase in lift caused by the flaps and also further increase drag. This makes possible a tactical descent well in excess of 20,000 ft/min. The idea being to arrive directly over the destination airfield in a combat zone at high altitude and then very rapidly spiral down and land before an enemy outside the airport can drop mortars or other weapons on the runway. It works very well.
And incidentally, besides in flight reverse, the reversers are safe and effective at negative airspeed. Meaning the C-17 can back up on the ground under its own power at max weight, up a 2% slope, into a tail wind. On almost all aircraft you don't want to use the reversers below about 50 knots because of "re-ingestion," where the engines re-ingest exhaust air which can cause severe compressor stalls.
And incidentally, besides in flight reverse, the reversers are safe and effective at negative airspeed. Meaning the C-17 can back up on the ground under its own power at max weight, up a 2% slope, into a tail wind. On almost all aircraft you don't want to use the reversers below about 50 knots because of "re-ingestion," where the engines re-ingest exhaust air which can cause severe compressor stalls.
I got religion one night in a DC-8 headed towards Oz from Vietnam....when the Pilots needed to get down quick....with some silly explanation about a late clearance from ATC.
I am thinking they simply screwed up and were late starting down....which they made up for in a very dramatic fashion.
I am thinking they simply screwed up and were late starting down....which they made up for in a very dramatic fashion.
