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Thread: Planned descents of 12-13,000/minute by four engine a/c?

  1. #11
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    Quote Originally Posted by bvs View Post
    JD

    IAS = Indicated Air Speed
    So in this case it will be 190 mph indicated air speed which simply means that 190 will be displayed on the Air Speed Indicators in the aircraft.
    Yes. For November, 1944. But...my point was you need to be sure of the units that different squadrons were using because Bomber Command was shifting over to knots in the latter months of the war. Some squadrons were using updated ASI units with scales in knots and others were still in MPH.

    Jim

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    Apologies Jim - I realised after I turned my PC off that you probably knew exactly what IAS meant.

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    It looks like an evasive manouevre, indeed. By the time radar ranging was automatic, so radar crew had to readjust settings to provide Flak with new position, and those had to set fuses. By the time the aircraft should be out of range of the Flak. 1,300 ftpmin seems too shallow to make any effect.
    https://www.facebook.com/Franciszek-Grabowski-241360809684411/

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    Hello All,
    OK, we now know (regardless of units used by different Groups) that this procedure was probably a valid manoeuvre for a/c involved. We now know where/when/how. Nobody has come up with ‘why’. I worked from basic (known?) principles (and some FSX) to provide a possible reason. Franek seems to be on my side? How widespread was this procedure? You couldn’t do it every time (German radar/flak would soon pick the procedure up, and be ready for it?).
    Is there any Ops Research paper indicating fewer casualties (immediately post-bomb release) where this procedure was used, as against those where the procedure was not used?
    The ‘why’ is usually far more interesting than mere facts/figures?
    HTH
    Peter Davies
    Meteorology is a science; good meteorology is an art!
    We might not know - but we might know who does!

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    Peter: It is identified on the two consecutive ops I have mentioned: Oberhausen on Nov 1, 44 and again the next night to Dusseldorf, which was "almost" a 1,000 bomber raid. On the raid to Bochum, November 4, 1944, crews were instructed to loose 200'/minute after bombing. In any event, it could have the potential to confuse the fighters and flak crews. The moon was nearly full on both nights and the conditions were cloudless on the operation to Dusseldorf. Boiten and MacKenzie show a particularly striking photo of aircraft during this raid. I suspect this manoeuvre may have been chosen specifically for these conditions. I have quickly scanned Wakelam's book (Science of Bombing) for information on flight plans, but as yet have not been able to find any information.

    Richard raises a valid concern regarding the equalization of the ears during such a descent.

    I think the best validation of this would be to view the "Form B's" which would be an independent verification of the flight plan. I do not, as yet, have these documents.

    Jim
    Last edited by JDCAVE; 25th February 2020 at 18:07.

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    Took a look at a Lancaster instrument panel. the climb/descend instrument only goes to 4,000 feet per minute.
    Richard

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    Quote Originally Posted by Richard.K View Post
    Took a look at a Lancaster instrument panel. the climb/descend instrument only goes to 4,000 feet per minute.
    Richard
    Interesting! That is why I want to see the Form "B's" that were sent to the stations. While the op to Oberhausen was a 6 and 8 Group affair, the one to Dusseldorf would have included other groups so if anyone of the RAF researchers has any Form "B's" for operations on the night of November 2-3, 1944, it may reveal what actually was the flight plan.

    Jim

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    Well done, Richard! An unarguable instrument observation.
    Further examples: the Blenheim I and Blenheim IV instrument each read only to 2 '000/min (AP 1530A, 1530B) - while the current "Mark I" restoration has the 4 '000/min instrument (Haynes Owners Workshop Manual).

    There's no substitute for access to sufficient originals (incl paper or image of) sources - errors thus better detectable, although successive errors are less than usual.

    Still, so much for my "far from improbable"
    [Shuffles off red-faced]

    Don Clark
    www.211squadron.org
    Last edited by Don Clark; 25th February 2020 at 21:15.
    Toujours propos

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    Has anyone checked the location of that co-ordinate given in the raid instructions to see where that is and how far from the target? It might (rpt 'might') indicate whether the descent was rapid or gradual.
    Just a thought.
    Ian

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    Offered as a penance...

    Approximately 60 miles SW of Dusseldorf, in Belgium, between Belle Croix and Solwaster. Approximately 15 mins flying time.
    By quick map check then recheck per Map & Distance tool https://www.acscdg.com/

    The terrain rises to the East, up to 2300 feet (to Signal de Botrange, being the highest point in Belgium, on the plateau that is the Hautes Fagnes nature reserve ("High Fens")).

    May help?

    Don Clark
    www.211squadron.org
    Last edited by Don Clark; 26th February 2020 at 08:08.
    Toujours propos

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