DH98 Mosquito external fuselage strake/reinforcement?

[MrSmoothie]

Since I apparently don't know the correct terminology, I've been unable to find out what the purpose is for the external strake on the Mosquito's side, and why only on the starboard side? I suspect the answer to the latter is that both props turn clockwise (from pilot's perspective), so the pull (torque, P-factor) would be to the left. Why was it added externally and not built into the fuselage's basic shell?

 

[ww2restorer]

Probably there for reinforcement, there is an aft access door in that exact area.

 

[MrSmoothie]

There sure was -- great hypothesis. Can anybody confirm this as the reason?

 

[wuzak]

Probably there for reinforcement, there is an aft access door in that exact area.

Yes, I believe that is correct.

The prototype did not have that strake. The prototype's fuselage was damaged in that area when there was a problem with the tail wheel while taxiing on rough ground. The fuselage was replaced by the first production fuselage, which was modified to add the strake.

The strake was then added to production.

 

[Wurger]

Also I agree with that above. According to a couple of a cutaway that's the external stiffening longeron or the external guttering strake.

Anyway ...

the source: DH Mosquito Design Analysis

 

[EwenS]

Further external stiffening was added on the port side when the Mosquito went to sea. First with the prototype LR387, then the Highball Mk.IV in late 1944 and finally the full blown Sea Mosquito TR.33 & TR.37 from 1946.

This was required to further strengthen the fuselage for the arrester hook seen just aft of the strake on the bottom of the fuselage and the strains of arrested carrier landings.

 

[MrSmoothie]

Thanks everybody for the great information! I'm almost done with a 63" RC model and I add this and many other details -- inevitably somebody will ask me what something was for, and I like to have an answer. I also posted my question about why the yellow dots in several locations in the cockpit and got some interesting answers, although it looks like nobody really knows for sure! Evidently they were applied to armor panels -- but the reason is unclear.

 

[Airframes]

Gas detection patches.

 

[ThomasP]

I remember reading that the yellow circles painted on the armour plate in RAF aircraft was to indicate the type of armour plate and differentiate it from another type. But I do not remember what the difference was.

There are a couple of photos out there that show the yellow circle painted on both the upper and lower sections of the navigator's seat armour in the Mosquito, along with the yellow circle on the pilot's seat. Plus there are photos of the Lancaster and Stirling pilot's seat armour with the yellow circle(s).

 

[MiTasol]

I am not familiar with the Mosquito armour but many other aircraft had armour with one hard and one soft face and that armour was usually identified with paint if there was any possibility of fitting it in reverse.

 

[ThomasP]

Some one either does not like the Lancaster pilot, or else they do not like the Mosquito navigator.

Lancaster

Mosquito

Somewhere on the internet . . . there is also a photo of the back of the Mosquito pilot's armour plate with a yellow circle on it.

 

[Crimea_River]

I am not familiar with the Mosquito armour but many other aircraft had armour with one hard and one soft face and that armour was usually identified with paint if there was any possibility of fitting it in reverse.

Cockpit armour on the Mosquito bomber versions consisted of steel plates for the Observer and Pilot back rests as well as on the half bulkhead (#2) that formed the front of the bomb bay. There is no possibility of installing these in reverse as they are not "handed".

More discussion on this topic here: Yellow Dots in DH98 Mosquito Cockpit?

 

[MrSmoothie]

Since we're on a roll here, refer to the nose of recently restored PZ474. I believe the larger port above and to the side of the .303's is the gun camera.

But what is the round part right in the middle between the two innermost .303's?

 

[Crimea_River]

Forward nav light.

 

[MiTasol]

Some one either does not like the Lancaster pilot, or else they do not like the Mosquito navigator.

View attachment 666699Lancaster

View attachment 666700Mosquito

Somewhere on the internet . . . there is also a photo of the back of the Mosquito pilot's armour plate with a yellow circle on it.

I am 90% sure that round thing top left on the mosquito navs armour is a window - laminated to provide some protection

 

[ThomasP]

It is, but that is not what I was referring to. If the yellow circle indicates 'face-hardened, this side toward enemy', then the plate with the yellow circle in the Lancaster is toward the rear where it would protect the pilot agains MG fire. But the armour plate for the Mosquito navigator would be protecting the electronic equipment from the front. Or it could be vice-versa. Plus there is a vintage photo somewhere that shows the same yellow circle on the rear of the Mosquito pilot's seat armour. Since the crew's seat armour is not intended to protect the pilot and navigator from the front, the yellow circle should not be an indicator of 'this side toward enemy'.

Magnetic vs non-magnetic (as suggested elsewhere )plate might make sense.

 

[MrSmoothie]

I am 90% sure that round thing top left on the mosquito navs armour is a window - laminated to provide some protection

I'm also pretty sure that the window was "armored glass".

 

[MrSmoothie]

Forward nav light.

I guess that seems pretty obvious, now that you say it -- but offhand, I'm not recalling any twins (that I've modelled) having a front light -- very interesting. Thank you!

 

[Crimea_River]

I am not familiar with the Mosquito armour but many other aircraft had armour with one hard and one soft face and that armour was usually identified with paint if there was any possibility of fitting it in reverse.

I'm not sold on the idea that the dots represent the face hardened side given the apparent inconsistencies in placement. The dot is on the BACK of the Lancaster seat armour and on the FRONT of the Mosquito seat armour. More here: Yellow Dots in DH98 Mosquito Cockpit?

 

[MiTasol]

I now think in the case of the British aircraft it indicates steel, or, far less likely, magnetic steel. That way it will be a warning to the Nav not to use his hand held compass near it. I say less likely magnetic steel because degaussing was a very common knowledge before WW2 so there should not have been any magnetic steel in any location where the hand held compass was used.

Given that the yellow dots appear in so many aircraft there must be an AP that covers the subject. There were Standard Notes for fitters, riggers, armourers etc so surely there was one for painting and doping. The question is whether any copies remain. Hopefully someone with physical access to the PRO or Duxford or other archive can find one.