Among its many virtues, the de Havilland Mosquito seems to have been able to deliver its payload with impressive precision. During WWII, most aircraft-delivered bombs fell far from their targets, with an overall circular error probability greater than a kilometer. The Mosquito, on the other hand, could hit specific buildings!
Famous examples of single-building targets successfully hit by Mosquitos include the Copenhagen Gestapo Headquarters(in Operation Carthage) and the Amiens prison raid (in Operation Jericho). Less spectacular, but of more significant and sustained impact for the Allies, was the use of Mosquitos as ‘pathfinders’ in air raids (where their pilots would identify and then specifically “label” the target (by, say, dropping incendiaries on it)).
I know the Mosquito was very fast and quite light (weighing less than half of any of the ‘famous’ B-series bombers). In fact, compared to the B-series planes, it was also shorter (by one third or more) and a had a reduced wing span (by 30 to 50 percent). Obviously, these features would have contributed to its accuracy in payload delivery. Still, I ask: Are these differences in scale sufficient to account for the Mosquito’s order(s) of magnitude improvement in bombing precision? Or, did it have other characteristics or features that also contributed substantially to its “pinpoint” precision?
It was the mode of operation, and the training of the crew. In the raid on the Gestapo HQ and on the prison, they came in very low, it is simply harder to miss when you are closer to the target.
Secondly these were the elite crews of the RAF, and were specifically trained as pathfinders for the main bomber force. Their job was to drop a few bombs (incendiaries) very very accurately, so the main force had something bright to aim at. That job was very similar to those raids.
Oops, hit Send too soon. The point is that normal bombers drop from way high so it’s a lot easier to miss. Also, pinpoint accuracy is not required when you are only aiming at a suburb, city, or large factory complex.
Take a look at the Pathe newsreelof Operation Jericho to see Askance’s point. At 1:30 you see the Mosquitos crossing the channel at wavetop height. From 2:00 there’s footage from a plane in one of the later waves, taken from maybe 500’ or so.
So, for air crews of equal skill, what you are saying is that the Mosquito came in low and close. Fair enough; clearly that is going to assist, or permit, accuracy.
But, to belabour the point and my question a bit more, what enabled the Mosquito to go low and close when other, not terribly dissimilar, planes could not?
The wooden construction partly gave it better maneuverability and higher power:weight ratio so low speed, low altitude flight was natural for it. All-metal planes with heavy armaments and armor require stronger engines and result in a very heavy aircraft. Even if you maintain constant power:weight, the overall lighter airplane will perform better at low speed and low altitude. The aircraft that best exemplified this in WW2 was the Japanese zero.
Going in that low is very very dangerous. Just as it’s easier for you to hit your target, it’s easier for the AA defences to hit their target - you. And more guns come into play - a guy with a pistol could hit you.
The higher the heavy bombers flew the harder it was for AA to hit them, the Allies just put enough planes in the air so that their increased inaccuracy didn’t matter so much. In fact the Superfortresses flew so high enemy fighters couldn’t reach them, let alone AA guns.
You are really comparing two very different classes of plane doing two very different jobs, it’s like comparing a sniper to a heavy artillery battery. The Mosquito could carry 4,000lb of bombs, the Lancaster up to 22,000lb.
I guess it’s not clear to me what planes you are including in the “not terribly dissimilar” class.
You’re absolutely right and, frankly, I’m not sure that I know what “not terribly dissimilar” means.
When I wrote the OP, I was thinking specifically of the B26 Marauder and (but less so) the B24 Liberator. Still, and as you imply, even the lighter and shorter of those two are not very much like a Mosquito.
FWIW, my “intuition” was more along the lines of what the_diego notes, i.e. that its wooden construction somehow came into play (via the light weight that results for any given dimensions)
IIRC, they are very fast, At low altitudes and at speed with less time to recognize, and set firing solutions, they were gone before much could be done. They could do photo runs the same way.
They could push 400 MPH on the deck, hard to get a shot unless you were right in the flight path & very fast & lucky with your guns.
B 26 was much bigger.
B-24 was a 4 engine high altitude bomber.
A- 20 Havoc & A- 26 Douglas attack bomber were much more in the same class as the Mosquito.
Much later, the P-61 was sort of the same as well as the P-38.
Pure speed and low reflection on the early RADAR systems, engine sounds & they way the flew made the Mosquito unequaled in its class / job…
Googling mosquito bomber accuracy comes up with a google book result where it says they developed a technique larger bombers probably couldnt copy.
They would enter a shallow dive and then release the bombs at about 1500 feet.
This isnt something a large fleet of bombers could safely do, so part of the difference is the aircraft, and part of it is the intended role - 500 aircraft bombing a target vs 20. Larger aircraft carried more bombs, but were slower, less manouverable, and larger, so easier targets at lower altitudes. Also pulling out of a long shallow highspeed dive probably wouldnt have been much fun either, they werent really designed for it.
Leonard Cheshire (who led the Dambusters for a time) was a pioneer of using a Mosquito to mark targets at low level (he started out dive-marking targets in a Lancaster). He eventually moved to a P-51, for speed and maneuverability (and a smaller target).
He is noted for a mad dive in a mosquito through flak over Berlin to lay markers (possibly fatally stressing the wing spar on the mosquito, which later crashed in England killing some of his squadron mates), and also for flying a slow figure-8 above low cloud above the target to act as a living bombing marker on another raid.
He justifiably deserved his VC, OM, DSO and Two Bars and DFC.
My speculation, expanding on the_diego’s point: the fact that they were made of (balsa?) wood meant they weren’t picked up by German radar. So, they could make their trip, and bombing run, without getting sighted & harassed by the German fighters and/or flak crews. This fact, combined with their speed, meant they could sneak up on their targets, and without having to take evasive action til the last second, had more time to aim & do the approach run.
1 thing to be checked: did they bomb at night? I know the strategic campaign was divided with the Americans, who bombed by day while the Brits did at nite. If so, it would be even more of a case for lack of radar profiling, and easier for them to hit a known and lit target.
The Mosquito was made of wood - balsa was the inner layer of the laminate with strength from birch and spruce - and it did have a low radar cross section, partly from the wooded construction and partly from just being a hell of a lot smaller than a Lancaster or a B17, but this was not why it was known for its precision bombing. This was entirely down to dropping the bombs from a low height. Inevitably a dumb bomb dropped from 200ft is more likely to hit its target than one dropped from 20000ft.
All the precision bombing raids were done in daylight (see the full accountand pictures of Operation Jericho hereand here) with the planes coming in fast and low. Quite apart from the low radar cross section flying low almost eliminates the chance of being tracked by ground based radar. True in 1944 and true in 1982 in the Falklands! Of course as **Askance **says you are vulnerable to ground fire but if your going fast enough they have to react very quickly to identify you, aim, and shoot before you are over and away. Of course this advantage goes if you linger any time over the target and two of the attacking Mosquitoes were lost on the Amiens raid.
Pathfinders also carried special radar and radio gear that most bombers didn’t; or were guided by “Oboe”, which could track one aircraft via transponder extremely accurately and allow it to get within about a hundred yards of the target 250 miles away. This wasn’t necessarily low-level as the plane had to be “visible” over the curve of the Earth, but it did mean that flares or incendiaries could be dropped to mark the target for the ordinary joes in the heavies to stoke up.
I had thought (from some serious arm chair generalling with Wikipedia and cable TV) that the goal should have been trying for more appropriate targets with any sort of bomber, such as refineries and ball bearing plants.
I frequently hear the latter mentioned as important targets. Were they some sort of technology that was seriously under valued until war broke out and a drive was made for increased mechanisation?
The Mosquito was fast mostly due to the fact that it was powered by two Rolls-Royce Merlin engines, the same power plant that (in various versions) powered the Spitfire and the P-51 Mustang, two of the hottest piston-engined fighters ever developed. Sure, the wooden construction might have helped some, but don’t over-attribute the performance to that.
Probably the main reason the Mosquitoes achieved such accuracy is a combination of the low-level tactics, and, significantly, that the crews were carefully selected and intensively trained for special mission and to serve as Pathfinders. Incidentally, Bomber Command leadership took a dim view of this, based on the belief that assignment to specialist Pathfinder squadrons took the best flight crews and the natural leaders out of the heavy bomber formations, draining them of quality.
My impression is that ball bearing manufacturing sites were perceived as a “bottleneck,” something that was vital to war production, but not plentiful nor widely dispersed, and thus vulnerable to being eliminated in a few heavy strikes. My guess would be that it’s not the nature of ball bearings per se, but that there wasn’t much need to have many different ball bearing suppliers before the war, and only a few sources could meet industrial needs and turn a profit. I don’t think anyone thought ball bearing manufacture couldn’t eventually be dispersed to many small secret locations; just that it had not yet been so protected, and thus an immediate industrial crisis could be caused by disrupting production in a few places.
Not really. Bombing specific factories intended to have a disproportionate impact on war production was pre-war RAF doctrine. The trouble was the RAF couldn’t actually hit individual factories. Up till 1943 they could barely hit a specific town… Hence the area bombing to “de-house” the industrial workforce.
The USAAF tried for the destruction of point failures in the German industrial economy - like the ball bearing factories - but, quite apart from the unsustainable losses they took prior to the introduction of effective long range escorts, stopping production proved to be incredibly difficult. Machine tools are very hard to destroy - you can knock down the factory but the tools are ready to go again within days. Destroying oil production was more effective but did not really have much of an impact until Germany had lost its external sources of supply.
