Lucky13
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How do you see the difference between one with a single stage, and one with a double stage Merlin engine?
De Havilland Mosquito....?
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Lucky13
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kool kitty89
Senior Master Sergeant
What is the extra intake for?
Airframes
Benevolens Magister
Yup! That's right Lucky. As you can see, the double stage engine nacelle is longer, with the extra intake, rather like a Mustang, and normally drove a 'paddle blade' prop. (not to be taken as an identifying feature.) The top one is the Mk??? (forgotten!), a design branch from the FBVI, armed with the awesome Molins gun. bottom is a BXVI. Two-stage Merlins were introduced from the BIX/PRIX series, but not always in numerical-marque order!!
Exta intake is the ram-air supercharger intake.
Just remembered, the 57mm Molins gun was on the Mk.XVIII. Used for killing ships and U-boats. Somewhere, I've got some rare video of it in use. Frightening. The aircraft virtually stopped when the gun fired!
Exta intake is the ram-air supercharger intake.
Just remembered, the 57mm Molins gun was on the Mk.XVIII. Used for killing ships and U-boats. Somewhere, I've got some rare video of it in use. Frightening. The aircraft virtually stopped when the gun fired!
kool kitty89
Senior Master Sergeant
Sothere are two intakes going to the supercharger on the 2-stage merlins??? (or is the bottom intake for the intercooler?)
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Lucky13
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Airframes
Benevolens Magister
Hi 'Kitty. Yes, the bottom intake serves the intercooler, there are 'gills' just behind the intake on the cowling, serving a similar function as per the P51. I seem to remember that this intake also had a dual purpose in providing extra airflow for the supercharger at altitude but, as I've loaned the relevant book to a friend, I can't check the exact details. Still, at least Lucky has the answer now!
Marshall_Stack
Senior Airman
What was the difference in performance?
Airframes
Benevolens Magister
That would depend on operational role/requirements and altitude. Haven't got all the details to hand, but, as an example, the B.MkIV had a quoted max speed of 380mph at 17,000 feet, and 300mph at sea level. The BMkXVI (2 stage Merlins) was 415mph at 28,000 feet, some of which would be the effect of the 'paddle' blades in the thinner air at altitude.
Of course, mixture settings, payload etc would have a bearing on overall general performance, but the 2-stage Merlin gave more power, and therefor increased overall performance/speed, as a generalisation.
Of course, mixture settings, payload etc would have a bearing on overall general performance, but the 2-stage Merlin gave more power, and therefor increased overall performance/speed, as a generalisation.
No. The intake under the spinner (202 in the cutaway) is for the intercooler radiator (196 in the cutaway). The air exits through the duct on the side of the nacelle (195 in the cutaway) which is partially obscured by the man's head in the photograph. The intercooler itself is on top of the engine (187 in the cutaway). The attached pdf explains with diagrams how two-stage supercharging works and the what the intercooler does.
The other intake (194 in the cutaway) is the carburettor intake.
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Airframes
Benevolens Magister
Thanks Antoni! That's the data I was looking for, but had loaned out. Nice one!
Terry.
Terry.
Hi Marshall: Have a look at this site:
Mosquito Performance Trials
These charts show the difference in performance:
This is all the info I have, I know its not much sadly. In late 1943 the RAAF received an F.II Pattern aircraft to enable the establishment of local productions.
The Australian program suffered numerous organisational and engineering delays, which included problems with the wings structual integrity. Many of them were delivered post war.
174 were equivalent to the FB.VI but with Packard Merlins, there were also 6 PR.40's (unarmed photo recon)...there was also produced 11 T.43 trainers and a further 15 PR but Mk 41's.
The first Aussie Mosquito flew on July 23rd 1943 but as mentioned above the problems with the production meant that none of the FB versions saw combat, however the PR models were extensively used.
My source for this is Aircraft of WW2 by Stewart Wilson, a book that acts as a basic directory for basically all the combat planes of WW2.
Wildcat
Major
AFAIK the first operation flown by No1 (attack) sqn RAAF with FB Mosquitos was flown on 7 July 45 from Morotai. However it appears a Mosquito on deployment to the Phillipines made an attack earlier in May of 45.
RAAF PR Mossie's flew their first operational sorties in June 44 with No 1 PRU later redesignated as 87 sqn.
hmmm interesting, are you talking about locally manufactured Mosquitos? When the RAAF received the pattern aircraft they also received an order of FB Mossies.
