[Cross-posted at Revise and Dissent.]
This is the front cover of a book by J. M. Spaight on British airpower, called The Sky's the Limit. It was published in 1940, a not-insignificant year for the RAF. In fact, this 'New and up-to-date' edition was published in August, right in the middle of the Battle of Britain. (The first edition was published prior to the fall of France, judging from the number of references to the Armée de l'Air, now in the past tense.) It's a familar image -- the young fighter pilots sitting in their Spitfires on a glorious summer's day, standing by for the word from Ops to hurl themselves into the sky to repel the hordes of Nazi invaders. In fact, it's almost iconic. But hang on -- something's not quite right here. Take a closer look at the aeroplane in the background:
It's got a turret on it! That's no Spitfire. It's not even a Hurricane. It is, in fact, a Defiant (from 264 Squadron, judging from the markings). The Defiant was an oddity -- unlike most fighters, it had no fixed, forward-firing guns, but instead had four machine-guns in a power turret. The idea was that they would fly alongside or below a bomber and pour fire into it. A 1938 Air Staff memorandum explains:
The speed of modern bombers is so great that it is only worthwhile to attack them under conditions which allow no relative motion between the fighter and its target. The fixed-gun fighter with with guns firing ahead can only realise these conditions by attacking the bomber from dead astern. The duties of a fighter engaged in 'air superiority' fighting will be the destruction of opposing fighters ... For these purposes, it requires an armament that can be used defensively as well as offensively in order to enable it to penetrate into enemy territory and withdraw at will. The fixed-gun fighter cannot do this.1
But because of the extra weight of the turret and the gunner, and because the shape of the turret impaired streamlining, it was slower and less maneuverable than its more conventional counterparts, which turned out to be a fatal flaw.
Defiants did take part in the Battle, but in very small numbers -- two squadrons only. They can hardly be considered emblematic of Fighter Command as a whole. So how did they come to grace the cover of The Sky's the Limit? The answer is to be found in Spaight's account of the last days of the air campaign in France. He describes the Defiant's combat debut:
On 29th May  our fighters destroyed at least seventy-seven German aircraft and seriously damaged a number of others. Of the seventy-seven no less than thirty-eight were brought down by a squadron of twelve Defiants without loss to themselves. The success of this new two-seat fighter, equipped with a gun-turret, was the outstanding feature of a wonderful day ... sixteen of their thirty-eight victims were Me 110's, the others being an Me 109 and twenty-one bombers. It was almost a battue. No single squadron had ever had such a day's hunting, nor had the total bag for the day ever been surpassed.2
This is a well-known story. The Defiants had an initial advantage, because of their resemblance to Spitfires, so German pilots thought they were safe attacking from the rear, which of course was exactly the wrong thing to do. But once this was realised, Defiants were terribly vulnerable: 141 Squadron lost 7 aircraft and 12 men in the space of half an hour, after being bounced by Me 109s on 19 July. They had to be rescued by a squadron of Hurricanes. Spaight obviously hadn't heard of this, and was still lauding the Defiant as a powerful new air superiority fighter. He clearly expected it to play a important role in the Battle of Britain then raging over his head. Instead it was soon relegated to night fighter duties, where it did it fact do good work during the Blitz.
As a final example of Spaight's promotion of the Defiant, here's a glamour shot from his book:
'DEFIANTS ON THE WING. The Boulton-Paul Defiant Fighter is a two-seater monoplane with a Rolls-Royce Merlin engine and a multiple gun-turret amidships. It is the fastest plane of its class in service and the only land fighter in the world with a revolving turret. (Official photograph.)'3
So the Battle of Britain Spaight expected was different to the one that was actually unfolding as he wrote. And that's just for the British side of things -- his thoughts on the German aircraft were even more 'alternative'. I'll discuss them in the second part of the post.