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Post by louross on Mar 21, 2017 21:40:10 GMT
I believe that crews used to extend the ejectors on Nos. 2 and 3 in order to help slow down the a/c on descent. Assuming that's true, wouldn't it be possible to select engines 2 and 3 and extend the ejectors, or even reverse the 2 inboard engines in order to slow dow??
Thanks-
me, lr.
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Post by aerofoto - HJG Admin on Mar 22, 2017 2:01:23 GMT
"TECHNICALLY SPEAKING"  .... Ejectors (also known as T or Translation-Rings) apply from DC-8-11/12 through DC-8-40 series aircraft only, but, not to DC-8 SHIP ONE though (in its earliest configuration) .... or any of the later series DC-8's. Since the wing Spoilers on DC-8 should never be deployed inflight (they can be, but, with potentially disastrous/fatal results) the use of inflight "reverse idle" .... on engines # 2 and # 3 "ONLY" was an approved DC-8 procedure when going down .... though this too was "banned" from the late 1990's after a few DC-8-70's shed engine nacelle covers due to the vibration inflight reverse idle actually inflicted. To respond to your query though in regard to DC-8-11/12 through -40 series aircraft .... "IF" inflight reverse is used on these aircraft version .... then that not only implies engines # 2 and # 3 .... but .... also implies the Ejectors/Translation Rings on these 2 engines are extended also since these house part of the external reverser bucket feature . And "IF" I'm understanding you correctly also .... Extending the Ejectors/Translation Rings only .... as means of inducing drag in order to slow down, but, not using reverse idle .... it probably wouldn't be all that effective as a means of deceleration (use of the Ejectors/Translation rings was restricted to within the flap airspeed range and below 10,000 FT). It's also my understanding that inflight reverse idle was used on DC-8's to assist "going down" .... when circumstances warranted its use .... rather than actually slowing down. And for the sake of anyone wondering about all this in regard to animations the HJG DC-8 simulations .... The Ejectors/Translation Rings are included/animated among these models, and "DO" work, but, it "IS NOT" possible for us to replicate inflight reverse idle among any of our DC-8 simulations  Mark C AKL/NZ |
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Post by louross on Mar 22, 2017 15:25:31 GMT
Thanks for that!
lr
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Post by deeman69 - HJG on Mar 26, 2017 19:32:10 GMT
Also, at the time our DC-8 models were built, the animation code only allowed all 4 engine t-rings to animate at the same time. It was not possible to code each engine t-ring animation individually. I think that has changed in the newest model building xml technique, but that will be up to a new model builder. If... Dee |
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