Different T.O & LNDG xwind components for H.S. Trident
l'aeroplanino
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Hi Discorde,
thank you very much (and my compliments) for having stored such important information (for us, "white-haired pilots" and "history and nostalgia" addicted).
I appreciate the fact that those limits apply for T.O. only and now comes the question: why not for landing too? Maybe, my guess brings to me a (stupid) conclusion: with that "geometry", would the xwind component (from the port side) affect less the landing roll due to a reducing speed in the landing roll, in a way that the lateral control could not be a problem? For sure my assumption can be wrong, but I put on the table as a topic for further discussions.
I saw in your following entry that you talk about the "skimmink technique".
After some reasearches on the net, I found an accident report (flight BA incident 1E, G-AVYD, happened at Bilbao airport (Spain) on 15 september 1975).
In short (the report is avalable on the net), the accident happened during a take off on a RWY covered with "puddles" and a momentary deceleration due to the drag of water puddles around V1 was misunderstood as an angine failure.
Following the "äbandon" take off order, the aircraft experienced some acquaplaning and the captain (who later stated: "marked deceleration compatible with a loss of engine power"),considering impossible to stop before the end of the RWY, decided to veer off to the port side. The happy result was that no one was injured.
Information reported on the company manual, regarding "T.O. from contaminated RWYs - PADDLES", required the use of "full thrust"and the "use of skimming technique"...maybe the meaning is "to skim the milk"...eehmm...sorry..."the water", to stay out of it?
Again, searching the net, some pilots report that the technique calls for a "weight off" of the nosewheel for T.O. and they say that it was introduced by RAF for early jet fighters.
A Vampire pilot reported, from his "Pilot's notes": äs soon as the aircraft reaches a speed of 60-70 knots IAS, lift the nosewheel just clear of the ground, then at 82-87 knots ease the aircraft off the ground".
The early De Havilland Comet airliners used the same technique: to lift the nosewheel just clear of the runway as soon as the elevators became effective.
It happened, unfortunately, that some pilots over-rotated early in the run in order to get the "nosewheel skimming" the runway and the aircraft failed to accelerate: there were two major accidents using this technique.
I don't know if I put more confusion on this issue, anyway it will be nice to talk further on this matter.
Happy New Year again.
thank you very much (and my compliments) for having stored such important information (for us, "white-haired pilots" and "history and nostalgia" addicted).
I appreciate the fact that those limits apply for T.O. only and now comes the question: why not for landing too? Maybe, my guess brings to me a (stupid) conclusion: with that "geometry", would the xwind component (from the port side) affect less the landing roll due to a reducing speed in the landing roll, in a way that the lateral control could not be a problem? For sure my assumption can be wrong, but I put on the table as a topic for further discussions.
I saw in your following entry that you talk about the "skimmink technique".
After some reasearches on the net, I found an accident report (flight BA incident 1E, G-AVYD, happened at Bilbao airport (Spain) on 15 september 1975).
In short (the report is avalable on the net), the accident happened during a take off on a RWY covered with "puddles" and a momentary deceleration due to the drag of water puddles around V1 was misunderstood as an angine failure.
Following the "äbandon" take off order, the aircraft experienced some acquaplaning and the captain (who later stated: "marked deceleration compatible with a loss of engine power"),considering impossible to stop before the end of the RWY, decided to veer off to the port side. The happy result was that no one was injured.
Information reported on the company manual, regarding "T.O. from contaminated RWYs - PADDLES", required the use of "full thrust"and the "use of skimming technique"...maybe the meaning is "to skim the milk"...eehmm...sorry..."the water", to stay out of it?
Again, searching the net, some pilots report that the technique calls for a "weight off" of the nosewheel for T.O. and they say that it was introduced by RAF for early jet fighters.
A Vampire pilot reported, from his "Pilot's notes": äs soon as the aircraft reaches a speed of 60-70 knots IAS, lift the nosewheel just clear of the ground, then at 82-87 knots ease the aircraft off the ground".
The early De Havilland Comet airliners used the same technique: to lift the nosewheel just clear of the runway as soon as the elevators became effective.
It happened, unfortunately, that some pilots over-rotated early in the run in order to get the "nosewheel skimming" the runway and the aircraft failed to accelerate: there were two major accidents using this technique.
I don't know if I put more confusion on this issue, anyway it will be nice to talk further on this matter.
Happy New Year again.
l'aeroplanino
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Thank you, Meikleour, I have that magnificent book somewhere buried at home...I'll start a search after these days of "drinking sessions"...
Happy New Year
Happy New Year
The investigation report criticises the Bilbao commander's failure to use the above measures, given that he was unaware of the depth and extent of standing water, although it draws no conclusion as to whether their use would have prevented the accident.
https://assets.digital.cabinet-offic...77_G-AVYD_.pdf
Thje skimming technique was intended for contaminated runways to avoid engine ingestion.
Basically the nose wheel could be lifted off the tarmac after 80 knots but care was needed to ensure the nose was not allowed to get too high. The technique could be practised on dry runways and possibly had the bonus effect of giving the first class passengers a slightly more comfortable ride on the runway.
However, God had already provided the HS121 with an offset nosewheel so that it didn't have to ride over the centre line lights -- although some pilots failed to take advantage of this.
Basically the nose wheel could be lifted off the tarmac after 80 knots but care was needed to ensure the nose was not allowed to get too high. The technique could be practised on dry runways and possibly had the bonus effect of giving the first class passengers a slightly more comfortable ride on the runway.
However, God had already provided the HS121 with an offset nosewheel so that it didn't have to ride over the centre line lights -- although some pilots failed to take advantage of this.
The skimming technique was intended for contaminated runways to avoid engine ingestion.
The other intent of the skimming technique was of course to reduce drag and thereby improve acceleration during the latter part of the takeoff run (a factor in the Bilbao accident).
However, God had already provided the HS121 with an offset nosewheel so that it didn't have to ride over the centre line lights -- although some pilots failed to take advantage of this.
However, God had already provided the HS121 with an offset nosewheel so that it didn't have to ride over the centre line lights
