Het is wat te gemakkelijk om 71 jaar na dato lacherig te doen over De Seversky's voorspelling hoe toekomstige vliegtuigen er uit zouden zien, maar het blijft merkwaardig de volgende regels n.a.v. de Bell P-39 "Airacobra" in zijn boek "Victory Through Air Power" te lezen: "From the point of view of design and workmanship the Airacobra is a plane of which American engineers and manufacturers can be proud. Its performance, however cut down by a pititfully underpowered engine - a fact that can be traced to our procurement policy. The engine situation could have been corrected, once the Allison engine had failed to serve as expected, by frankly adopting the best available substitute. The British Napier Sabre, a 2000- horsepower engine, eminently successful in the Spitfire and Hurricane, was at hand for immediate use. Unfortunately the Army steered around this and adopted instead the Rolls Royce Merlin, with horsepower similiar to the Allison's." Noch de Spitfire noch de Hurricane hadden echter Napier Sabre-motoren, ze hadden Rolls-Royce Merlins, de Napier Sabres zaten in de Hawker Typhoon en Tempest en zover ik heb kunnen nagaan is de Merlin nooit geinstalleerd in de Airacobra.
