Mosquito rear guns

[JohnL]

The Mossie avoided losses by outrunning the enemy . So why were streamlined pods not fitted to the rear fuselage say four in each quarter containing a small machine gun (the Browning .50 AN/M2 would be good ) that could fire tracer . Operated by the co pilot and sighted through enhanced rear facing wide and narrow mirrors .
How disconcerted an attacker would have been with four streams of tracer coming at him . So forcing him to evade or be shot down and reducing time could stay on Mossies tail .
In fact on firing this quad mount it would have given the mossie a speed boost . So good idea or ? .

 

[glennasher]

Weight is not your friend, four .50s weigh a considerable sum, add the ammo and the situation gets even worse. Not to mention the COG shift to the rear. The Mossie was pretty fast and hard to keep up with, as it was.
All in all, the penalties in weight would outweigh any minor benefit.

 

[pbehn]

A mosquito generally didn't outrun opposing aircraft it out cruised them, more fuel gives a higher cruising speed so its not a great idea exchanging fuel for guns.

 

[Glider]

Mosquito's often outran the opposing fighters and when they didn't they often reduced the closing speed significantly giving the Mosquito valuable time to find cover or for any escort to help out. One tactic I read was for the FBVI version. If spotted in time the rear most section would drop their bombs and execute a 180 degree turn, then attack the fighters head on and keep going for home. Normally the fighters would lose time speed and energy making a turn and the Mosquito's who had attacked would have a very healthy lead and be almost impossible to catch in a tail chase. Those still 'bombed up' would be well gone by the time the attacking fighters sorted themselves out.

 

[pbehn]

Mosquito's often outran the opposing fighters and when they didn't they often reduced the closing speed significantly giving the Mosquito valuable time to find cover or for any escort to help out. One tactic I read was for the FBVI version. If spotted in time the rear most section would drop their bombs and execute a 180 degree turn, then attack the fighters head on and keep going for home. Normally the fighters would lose time speed and energy making a turn and the Mosquito's who had attacked would have a very healthy lead and be almost impossible to catch in a tail chase. Those still 'bombed up' would be well gone by the time the attacking fighters sorted themselves out.

There were many versions of the Mosquito chiefly bomber, recon and fighter bomber, this was only an option for the fighter bomber version. Many were flying alone and duking it out with rear facing guns was not an option. For a lone aircraft 5 or 10MPH on maximum or cruising speed is huge. A single engine fighter climbing to 30,000 feet only has an advantage in speed (if at all) when it gets up to 30,000 ft and when it gets there it has maybe 30 minutes on full power.

 

[wuzak]

The Air Ministry did request that rear facing "scare" guns be investigated by de Havilland.

There was certainly a proposal for a single fixed rear faxing gun in the tail cone, can't recall what calibre but it is likely to have been 0.303".

There also may have been a proposal for a gun that could be moved either up/down or left/right, but I would have to check my references.

In any case, the conclusion was that such armament was not worth the effort.

And any aircraft attacking a Mosquito from behind and below would likely have not been detected anyway.

 

[nuuumannn]

Tail turrets were investigated for the DH.98 before the prototype was built; DH staff calculated the impact that various configurations of tail armament would have on it - a simple two gun tail turret would have added 500lb in weight and cost 20 to 30 mph in speed. A single traversing gun under the belly was considered also in conjunction with a tail turret. In November 1939, Arthur Tedder and William Sholto Douglas stated that the proposal would be of value if it had a tail turret, and instructed de Havilland to build two prototypes with a four-gun tail turret, although de Havilland was reluctant to relinquish the unarmed prototype and it was Freeman, that saviour of the type to gamble that the four-gun tail turreted prototype would be built some nine months after the unarmed prototype had been built, knowing the unarmed prototype's performance would be excellent and might dissuade supporters of the tail turret idea. Naturally, it was never built as the unarmed prototype's performance was. I've never found drawings of what a Mossie would have looked like with a tail turret. Probably ghastly. I don't think the company took a tail turreted Mosquito very seriously.

 

[Shortround6]

So why were streamlined pods not fitted to the rear fuselage say four in each quarter containing a small machine gun (the Browning .50 AN/M2 would be good ) that could fire tracer . Operated by the co pilot and sighted through enhanced rear facing wide and narrow mirrors .

Just from shear weight, the .50 AN/M2 was not a small gun, they went about 70-75lbs each in aircraft. .50 cal ammo is about 30lbs per hundred and 100 rounds lasts about 8 seconds. four guns with just 100rpg would be about 420 lbs without mounts and fairings, ammo boxes and chutes. Any movable mounting/s (not fixed guns) would add substantially to the weight.

Tracer is nowhere near as visible to the person being fired on as it is to the person doing the firing. Special rounds were developed for the purpose of 'scaring" attackers and were called 'headlight' rounds.

Carrying 400-500lbs more fuel (on the CG) would do more for the Mosquitoes ability to evade intercept (allow for more high speed spurts) that 400-500lbs worth of guns in the tail (well aft of the CG).

 

[swampyankee]

To add to the detrimental effects of these rear-facing guns, they would also reduce either warload or fuel, so there either be more aircraft to have the same effect on the target (fewer bombs) or fewer possible targets (less range).

To take the weight of the guns, the tail section would have to be reinforced, adding the the weight gain. The, something would need to be done to correct the center of gravity shift, adding more weight. Wing area would need to be increased to bring approach speed back to an acceptable value, then more power would be needed to bring performance back to the same level. The new airplane wouldn't be a Mosquito any more, so it would need a new name.

 

[GrauGeist]

The Ar234 was originally intended to have a pair of fixed, rearward firing MG151s, but were found to be ineffective and ommitted from the production models.

This reduced 182 pounds (not including the weight of ammunition) from the aircraft's overall weight.

 

[pbehn]

I like this talk of putting a turret in the tail of a Mosquito, the Mosquito doesn't really have a tail to put a turret in any more than a Spitfire or Hurricane has. It would be a completely different plane.

 

[Shortround6]

Even a remotely controlled tail barbette would require severe modifications.

and even four fixed .50 cal guns would add around 500lbs near the tail and quite a few feet from the CG.

 

[Denniss]

don't forget heating equipment so the guns won't freeze

 

[fastmongrel]

If you want to put an attacker off open the throttles.

 

[pirate_smee]

The British air ministry forced De Havilland to install a turret in a mock up, but the speed reduction was significant, so it was drooped.
And the Mosquito was first only accepted as recognition aircraft, not as bomber, because it was not armed.
The Germans made the same mistake with the Ju-88, it started with only 2 crew members, but was not accept without defensive armament.
Each crew member adds at least 100kg weight, without guns and ammunition and need space (drag). More weight results in more drag.
Remember the Bendix A-9 turret of the B-25 had a weight of nearly 500 Kg without crew, it had 2 turrets at the C and D model so roughly 1200Kg with the two crew members and had "only" 3000lbs ( ~1500Kg) bombload.
Some pictures of the mosquito turret installation.
De Havilland Mosquito

 

[Shortfinals]

Tail turrets were investigated for the DH.98 before the prototype was built; DH staff calculated the impact that various configurations of tail armament would have on it - a simple two gun tail turret would have added 500lb in weight and cost 20 to 30 mph in speed. A single traversing gun under the belly was considered also in conjunction with a tail turret. In November 1939, Arthur Tedder and William Sholto Douglas stated that the proposal would be of value if it had a tail turret, and instructed de Havilland to build two prototypes with a four-gun tail turret, although de Havilland was reluctant to relinquish the unarmed prototype and it was Freeman, that saviour of the type to gamble that the four-gun tail turreted prototype would be built some nine months after the unarmed prototype had been built, knowing the unarmed prototype's performance would be excellent and might dissuade supporters of the tail turret idea. Naturally, it was never built as the unarmed prototype's performance was. I've never found drawings of what a Mossie would have looked like with a tail turret. Probably ghastly. I don't think the company took a tail turreted Mosquito very seriously.

The People's Mosquito holds copies of outline sketches for both the proposed 4 x .303 rear turret (designed by Bristol) and the underlying turret ring and support structure. The whole assembly weighed closer to 1 ton than 500lbs. You are quite right in suggesting that the extra weight/drag would have cost the DH98 c. 20-30 mph. As an aside, you might want to know that Retrotec have begun construction of the first set of Mosquito fuselage moulds in the UK for over 70 years! TPM have already delivered over 6 tonnes of jigs and fixtures to Retrotec for the wing, flaps, elevators, tail planes, fin, tank bay doors, ailerons and bomb bay doors, and Retrotec have purchased over 1 ton of structural steel from the fuselage jig framework. The jigs and fixtures (which were shipped from Napier, NZ to Southampton) had been purchased in New Zealand, where they had been used to construct those components for PZ474, now flying with the Lewis Collection in Texas. More details here, www.peoplesmosquito.org.uk Our stand will be at Duxford, this weekend - if you are going, do drop by and have a chat with the Directors and staff!

 

[JohnL]

Lot s of interesting and informative comment .Their was a Aircraft version of the .50 which as cooled by the aircraft's slip-stream, the air-cooled 12.7 mm AN/M2 was fitted with a substantially lighter 36-inch (91 cm) length barrel, reducing the weight of the complete unit to 61 pounds from 83 pounds . So weight of 4 over 300 pounds plus ammo for fifteen seconds so one less 500 pound bomb or not . Using Headlight ammo for every 6th shell or whatever optimum . As read " If they were bounced from above, their saving grace lay in putting the nose down, maneuvering and hoping there were clouds in which to hide " an ideal position to fire a rear gun . As "Adolph Galland head of the German fighter arm states in his book. You get one chance at shooting down a Mosquito. You get above it you dive and you get one chance only, if you miss the mosquito has gone " . Though Mossie loss lowest at 1.7 could have been .5 .

 

[JohnL]

Follow on found this report by Lts. Richard M. Kenny/Arnold V. Kuehn (NS712) .I made another turn for a quick check of the rear, and to my surprise, there was an Me262 on my tail with his four nose guns flashing. So great if he could have fired back .

 

[JohnL]

Follow on to folow on . End of encounter this is what happened . "The Me262 then pulled along side on my right at a distance. The Luftwaffe pilot waved his hand, then turned around and headed for the Berlin area. "

 

[nuuumannn]

The People's Mosquito holds copies of outline sketches for both the proposed 4 x .303 rear turret (designed by Bristol) and the underlying turret ring and support structure.

That sounds very interesting and I'd like to see that. I have a copy of a drawing of the the third prototype, which was fitted with a Bristol B.11 turret, but it was behind the canopy, not in the tail. That was for a night fighter spec F.18/40 that DH didn't enter, but was asked to produce an aircraft for. Two turret fighter Mossies were produced, but both were converted to T.IIIs, the first became the T.III prototype. These were hardware, but were not the same as the proposals for a tail turret equipped bomber. The B.11 turret was a compact wee thing, but it was found that the hydraulics couldn't rotate it with the aircraft at speed.

The figures of 500lbs were a guesstimation made by the manufacturer before the first prototype, W4050 was completed, and I suspect you might have fittings for the Bristol B.11 turret fitted to the night fighter variant rather than the proposed tail turret equipped bomber? Nevertheless, I'd like to see them.

Sadly, Shortfinals, I'm in New Zealand, so won't be able to go to Duxford, as much as I'd dearly like to! Was in the UK in 2018 and dropped by the People's Mosquito stand at Shuttleworth and Legends.