[Graham Boak]

You're mixing different structural designs there. The engined mounted in pods on pylons would be likelier to break long before the more integrated designs such as the B-1, or even the 262/234. But it's an irrelevance on the later types, as failure would occur elsewhere first.

The main benefit of the engines on pod is the clean wing, with the pods providing bending relief so permitting a lighter design. But this is for low-g aircraft.

I'd like to step back to Franek's older posting about names. It has not always been a matter of politics, although that certainly was true at times in the US on the 40s and 50s. In the UK, aircraft names depended upon roles, so that the Vickers Vincent general-purpose type was the Vildebeeste torpedo bomber. The Fury went to sea as the Nimrod, the Hart as the Osprey. The bomber Hart became the army co-operation Audax, renamed Hartbees for export to South Africa. In both the US and the UK, it was normal to rename/renumber a type if the engine was changed, the Merlin engined P-51 becoming (initially) the P-78, the Allison-engined B-17 becoming the B-38. Something that was only reduced - not altogether forgotten - in the 40s. So having the Tornado/Typhoon with the same name is rational. The Tempest may have shared the engine and most of the fuselage with the Typhoon, but it had a very different wing. As one designer said, it is the wing that makes the aircraft, the fuselage being just a matter of packaging. (Not true since the need for area ruling, but true enough for the 30s and 40s.) Hence the suggestion that the 20-series Spitfires should have been renamed.

But I don't understand the reference to the Airacobra. There were no significant changes to the P-39 design throughout its life. There was a version for the USN as the Airabonita, but this had a tailwheel and other changes. The P-63 Kingcobra was a significantly different aircraft, with a two-stage engine and a "laminar" flow wing.