20mm Cannon Fitted to Spad XIII

[Desdichado]

A friend of mine swears that the French Air Force fitted a Spad XIII with a 20mm cannon that fired through the propeller boss. I'm not sure if he is pulling my leg or not so I thought I'd raise the question here. I was always under the impression that such a weapon was not used until the 1930s when it was fitted to newly-designed German fighter aircraft.

If the Spad was equipped thus, how was the cannon fed? I assume it would be by means of a drum but how would the pilot change this after one was empty?

Over to you (Gareth?) as ten quid is riding on this.

Cheers - Des

[Dolphin]

Des

Your mate is incorrect, as it was the SPAD XII Ca.1 that was the cannon-armed fighter. A short-barrelled 37mm Hotchkiss cannon was fitted between the engine cylinder banks, with the rounds being fired through the propeller hub - see the photo below. Twelve shells were carried for the cannon, and the machine was also fitted with a 7.7mm Vickers gun (often used as a sighting device for the cannon).

The French ace Georges Guynemer used the S.XII quite a bit, and liked it, but it wasn't popular with many other fliers, as it was difficult to fly and the recoil and fumes from the cannon made the cockpit most uncomfortable. In addition, reloading the cannon, which was a single shot weapon, was difficult, especially in combat.

300 SPAD XIIs were ordered, but production probably didn't get near that number. They were farmed out among the French Escadrilles de Chasse with the suggestion that the better pilots could use them. Rene Fonck was credited with 11 of his 75 victories while flying an S.XII. The RFC evaluated one, and the USAS also had one.

I hope that this helps you, if you can persuade your mate that it wasn't a SPAD XIII, and it wasn't a 20mm cannon.

Cheers

Gareth

[Desdichado]

Thanks Gareth, I thought that you would have the correct answer. It must have been damned hard to re-load the cannon in flight, especially if the pilot was engaged in a dogfight. I would have thought that the lighter-armed German scouts would have a distinct advantage here.

[centurion]

. It must have been damned hard to re-load the cannon in flight, especially if the pilot was engaged in a dogfight.

It wasn't used in dog fights (unless its pilot got caught napping). The technique was to pick one's victim from afar and attack in a shallow dive, fire the cannon when sighted on the target and then beat it away out of any action so that the pilot could reload (and come in for another attack if necesary). A hit on any structural part of the aircraft, the engine or the pilot signified the end for the target. However I have seen somewhere that a hit on say the fuselage between longerons and any vertical fuselage members would just leave a hole in the linen on either side of the aircraft.

It was essentially an assassin's weapon, the target would know nothing about it until it was too late. The aircraft was issued to various French squadrons in small numbers for use only by the most skilled and expereinced pilots.