Prototype Mosquito.

The Bf 109 could have been designed with washout instead, but this would have increased its landing speed and hence distance. Also washout makes production more difficult. There’s always trade-offs.

The bf109 seemed to work well with leading edge slats.

They were however a pain occasionally for gun aiming – however the 109 really did need them – whereas the mossie obviously could fly safely without them : )

Also has the advantage of not having to pay licensing fees to Handley-Page who owned the patent on slats.

They would seem to be a useful concept but not widely adopted.

However, the Tiger Moth used them and there were rather a lot of them. I remember my first solo (on the Tiger Moth) when I forgot to unlock them, and had to go round. Shameful.

Southern Air has it – the low speed handling was considered to be good enough, so no other aircraft was so fitted. They were locked closed after completion of initial test flights.

I have slots (fixed) on my a/c and wouldn’t be without them.

The bf109 seemed to work well with leading edge slats.

They were also draggy. They were quite widely used on 1930s aircraft, under a Handley Page patent. They weren’t all that common on German aircraft – Heinkel, Junkers and FW did without. Apart from the low-speed role, which became less important with the building of many long runways, on a fighter they could prevent tip stall due to wing twist under high g. A better solution was to add washout – locally reduce the angle of attack at and near the tips – and this was more widely adopted in the 40s.

Slats could also be a nuisance on combat a/c,they were not usually interconnected and could interfere with gun aiming etc !

Wasn’t it because it was decided it had sufficient low speed handling, so they just weren’t needed, strapped back and omitted on production aircraft?

Prototype Mosquito.

Ed playing at a being a skipper.