Unleash the mossie

[GScholz]

When did the Mossies get 150 octane fuel? Certainly not in 1943? A Mossie on 100 octane fuel would be slower than every single engined LW fighter type in service in 1943.

And I think the problem here is not that people are saying the Mossie could not run, but that the LW could not catch it. Both sentiments are of course wrong.

[Karnak]

Originally posted by GScholz
When did the Mossies get 150 octane fuel? Certainly not in 1943? A Mossie on 100 octane fuel would be slower than every single engined LW fighter type in service in 1943.

~350mph at SL is slower than the Bf109G-6 and Fw190A-5?  Since when?

[GRUNHERZ]

"Unshroud it so it can run away faster!!!"

[GScholz]

350 mph is slower than a 109G-6 and 190A-5 at 2k. So the LW fighters would need 2000 feet of alt to be faster up to about 7k when the LW fighters start getting a speed advantage at equal alt. Since the FB mark Mossie was a low alt intruder, the LW fighter would almost certainly have an altitude advantage whenever they managed to effect an interception. But that was not easy since the Mossie was so fast, and therein lays its strength, to avoid interception. If caught however they had little chance of escape.

[Karnak]

If the LW fighter is diving of course it has the speed to overtake if it is reasonably in position.  However that was usually not the case because there was no warning of the Mossies being there due to their low alt, high speed approach.

I have several accounts of FB.VIs being pursued at low alt that simply ran away from the pursuing 109 or 190.

If co-alt the Mossie FB.VI in 1943 was faster from probably ~5,000ft on down to SL.

[GScholz]

With a 2k alt advantage the LW fighters are faster in level flight than the Mossie. Above 7k they are faster in level flight at the same alt, or even with a slight alt disadvantage. Like I said, the Mossie's strength was its ability to avoid interception by staying low, fast and unpredictable. It was a WWII stealth plane if you will. However if intercepted by a LW patrol they were in deep trouble.

[Replicant]

Originally posted by Karnak

Removing the dampers would raise the survivability of the Mossie in AH as any additional speed helps, but there are still many fighters that could run one down and those fighters tend to be the most popular.

Is the Mosquito faster without the flame dampers?  I honestly don't know but I asked an engineer with over 40 years experience of working for/with De Havilland (at DH museum, London Colney) and he seemed to think that the dampers actually assisted the Mossie as it helped like a ramjet.  I don't know if that was true or not?  I always thought the dampers would interupt the exhaust flow.

[Karnak]

Dampers reduce the top speed by 10 to 15mph.  They remove the thrust from the exhaust stubs.

For an example of exhaust thrust look at the A6M3 and A6M5.  Same exact engine but the A6M5 has exhaust stubs to produce thrust and the A6M3 does not.

A6M3: 332mph
A6M5: 355mph

[Nashwan]

From an RAF test report posted by Neil Sterling on another board:

In tests reported in the 12th part of report No A&AEE 767,c, it wa shown that the use of ducted saxophone type exhausts in the place of single ejector type reduced the top speed at 9 lbs sq in of Mosquito IV DK 290 by 13 to 16 mph.

[Angus]

A Spitfire pilot told me he always admired (with a grain of envy) the Mossie boys. They could run away from the LW he said, they couldn't even catch them in a tail case.
Looking at the mozzie data, this always baffled me a bit.
Would be nice to see a breakdown of mossies in service within given timeframes and their German adversaries.

[MiloMorai]

Angus, when 2 small raids on Berlin at the end of Jan '43 that interupted 2 large Party functions Herr Meyer (Goering) had 2 special units formed, JG25 and 50 with special 109G-6s. They were disbanded in less than 6 months due to their inablity to stop the Mosquitos. Might have had 1 'kill'.

[Scherf]

Alas, my favourite subject.

The sad fact is, the only FB.VI which the A&AEE ever tested with Merlin 25s and ejector exhausts (which, as noted above, did have a "jet" effect) was an aircraft which the testers themselves acknowledged was "unrepresentative of the type." So, the published numbers you see are also unrepresentative.

I've had the Boscombe test files in my hand, at the PRO, and am sad to report that no further test was made, for example on HX809, with the ejector exhausts, by the testing authorities. (Karnak, I owe you an email on this subject - I have your pvt addy somewhere around here, will try to do it this weekend, however I don't have access to a scanner.)

The 354 mph quoted above (for 150 octane) was with both saxophone / shrouded exhausts fitted, as well as wing tanks. The latter reduced speed by a further 5 mph or so.

Plenty of anecdotes on both sides, enough to fill several books ( ). The fact remains though, the current Mossie's performance reflects an aircraft setup for night ops, and we don't have night. The Day Ranger ops were meant to be run on days where low cloud would afford some cover (though some pilots ignored this - including the man whose name I have adopted, groupie-like, for AH purposes), and we don't have cloud cover. Waaaaa.

Thrila, btw, is my new hero ...  

Cheers,

Scherf

PS - The file Milo refers to above has some "issues" here and there, especially the lack of detail whether, for example, "November 6, 1944" is November 6 during daylight hours, the night of the 5/6 or the night of the 6/7, however it is nonethless an excellent resource. I've a mate or two working on private databases, but, as they are to some extent "a life's work", they are never quite finished, and they never quite send them to me...

[MiloMorai]

This site has a loooonng list of Mosquito books

http://www.mossie.org/books/Mosquito_books.php

I found this technical book very interesting

The Mosquito Manual (RAF Museum Series #6)
Author(s):    Unknown
Publisher(s):    Arms and Armour Press (UK), Hippocrene Books Inc. (USA)
ISBN:    0853683913 (UK), 0882544462 (USA)
Date Published:    1977
Format:    Hardback, 351 pages.
Notes:    Technical specs, no narrative. Reprinted in 1988 by Aston Publications, ISBN 0946627320.

[MiloMorai]

Part of a report of 2 Mossies of #418 attacked by Fw190s, April 14 1944

[Scherf]

Strange how things like that ^ always seem to come full circle.

I wonder if Rheinhard or his Danish contact have seen this board.

Rheinhard's uncle was the pilot of one of the Luftwaffe aircraft which appear on page 1 of that report. The Danish fellow is a researcher, I believe of aviation archaeology, who originally retrieved the report from the archives in Kew.

The whole incident is depicted on the cover of the Osprey Mosquito Fighter-Bomber book - the one with the Mosquito zooming past a blazing Ju 52 minesweeper. It's also mentioned in Dave McIntosh's wonderful book, Terror in the Starboard Seat. Without mentioning Caine by name, McIntosh describes another pilot telling Caine; "that makes up for what you did in the Baltic."

"What [Caine] did in the Baltic" was to force one of the Junkers to ditch, the 5 or 6 members of the crew surviving and clambering out onto the fuselage. Caine then fired a four-second burst of cannon and mgs at them, closing to point-blank range. Rheinhard's uncle was one of those killed.

Scherf