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Effects of tailwind

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Effects of tailwind

Old 24th Mar 2014, 02:25
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Effects of tailwind

Hi guys,

I seem to remember in the dim and distant past being shown an American video demonstrating the effects of various wind conditions on takeoff and landing, possibly using a B707. I think the video may have been initially made from NASA experiments-it was pretty old. However, it would be perfect to use during a lesson I'm preparing. I've looked online and can't find it anywhere. Does anyone have a copy they could point me to or a link to it?

Many thanks for any help offered.
FJ2ME is offline  
Old 24th Mar 2014, 08:06
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Delta Air Lines Flight 191 - Wikipedia, the free encyclopedia

The NTSB attributed the accident to lack of the ability to detect microbursts aboard aircraft the radar equipment aboard aircraft at the time was unable to detect wind changes, only thunderstorms. After the investigation, NASA researchers at Langley Research Center modified a Boeing 737-200 as a testbed for an on-board Doppler weather radar. The resultant airborne wind shear detection and alert system was installed on many commercial airliners in the United States after the FAA mandated that all commercial aircraft must have on-board windshear detection systems.[4]
Was it developed after this accident as above - may be easier to source the video?
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Old 25th Mar 2014, 01:21
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Its not the one you were looking for, but here is a vid of 3 high-crosswind landings by B777s (Boeing test flights, not in-service):

There are links to lots more vids there.
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Old 25th Mar 2014, 02:15
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I'm struggling to see just what those crosswind testing videos, nice as they are, have anything to do with the OP's thread
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Old 25th Mar 2014, 10:37
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It's all part of life's rich pageantry, g-r.
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Old 25th Mar 2014, 11:45
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GreenKnight - That's steady old stuff - takes ba**s of steel. ISTR it was done at Moses Lake. BTW the Speckled Trout was allegedly capable of autoland with 38kts across.

glad rag - you're quite right - we should get back to the thread. More discipline required here.

FJ2ME - for clarification - are you talking about routine runway performance calculations, or about aircraft behaviour close to the ground in abnormal situations such as windshear/downburst etc ?

Lordflasheart is offline  
Old 25th Mar 2014, 12:25
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Remember doing wet Xwind trials with short landings at BD prior to the Nimrods going down to Stanley after we had kicked their a--es. The max Xwind we tried was 40kts and, using the wing down technique, it was not a problem. The test plan required the final landing to be stopped using max anti skid. Interestingly, this caused all the upwind tyres on both bogies to burst. It was quite exciting. It was concluded that this was because the Xwind component was causing the undercarriage legs to slightly "lean over" which, effectively, gave the upwind wheels less purchase on the runway. It was the only time I have heard multiple tyre bursts. It was nice to have had a cast iron excuse!
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Old 25th Mar 2014, 21:24
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Still off topic, but on crosswind landings. I used to be a member of the Crusaders Gliding Club in Cyprus back in the early 80s. Due to the sea breeze we generally operated with a fairly stiff 45-90 deg crosswind. Not a problem, we were used to it.

We had the gliding members of more than one APC Sqn turn up(and try and take the place over!) and declare the conditions too dangerous to fly in.
MightyGem is offline  
Old 27th Mar 2014, 01:51
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Thanks guys for the replies. I seem to remember that it was shown to us in some sort of performance Groundschool, to visually hammer home the effect of tailwind on takeoff and landing distances required. It may have been as a result I that Delta incident above but I thought it pre-dated that...

So more performance planning than dealing with an unexpected weather change.

And I'm all good for exciting crosswind videos thanks 👍
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Old 27th Mar 2014, 02:01
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It was quite exciting. It was concluded that this was because the Xwind component was causing the undercarriage legs to slightly "lean over"
Surely it would have been the into wind aileron I assume you were applying that would have caused the extra pumpy bit on the into wind tyres?

Reminds me of the General's son who was an RFC recruit during the Great War. He pranged during training and the enquiry concluded that 'there was insufficient lift in the air'.
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