Justplanesmart From United States of America, joined Mar 2001, 726 posts, RR: 2 Posted (12 years 10 months 3 weeks 4 days 5 hours ago) and read 3589 times:
This might be more suited for the Technical Forum, but this forum gets more traffic, so my apologies in advance. The DC-10-10 was originally built with a metal plate in the engine exhaust. Later it was changed to a simple cone, with the existing fleet being retrofitted. Does anyone have info as to the story behind this? The pictures below give a good comparison:
(There was a change in the L-1011 engine exhaust structure also, but I am too tired to search for comparative photos at this time. If I get some good replies to this post, I will follow up with one for the TriStar.)
SAS23 From , joined Dec 1969, posts, RR:
Reply 3, posted (12 years 10 months 3 weeks 4 days 1 hour ago) and read 3523 times:
Rmm, that was certainly the case with the L1011 where you can see 'spikes' in the engine exhaust cones on some of the -22Bs where the hot stream reversers travelled. The costs of maintenance outweighed the benefits, and they were removed ... as was the case with the CF6-6.
Panman From Trinidad and Tobago, joined Aug 1999, 790 posts, RR: 0
Reply 4, posted (12 years 10 months 3 weeks 3 days 22 hours ago) and read 3488 times:
What benefits? Considering that only about 10% of the thrust is generated by the hot stream on a turbofan (it's main function being drive the compressors and fan) the effects of reversing the hot stream would be negligible. Hot stream reversers are more effect on turbojets (old 737s, 727s. 707 etc).
Broke From United States of America, joined Apr 2002, 1322 posts, RR: 3
Reply 6, posted (12 years 10 months 3 weeks 2 days 22 hours ago) and read 3366 times:
All of the early wide bodied airplanes had hot and cold stream reversers on their engines. The hot stream portion was removed from all of these airplanes in the early to mid '70's due to reliability problems. It became a regular event for an airplane to leave part of the hot stream reverser on the runway. On the RB211 on the L-1011, this was a little more complicated because the control sequence for the whole reverser was controlled by the hot stream portion of the reverser.
Braking tests and rejected take-off performance on all airplanes are predicated without the use of the thrust reversers.