Original sentence: Army production aircraft with redesigned vertical tail and powered by a 435hp Wright IV-1460-1 engine, 15 built.OA-1A with a water-cooled V-1650-1 engine, 9 built
Edited sentence: Army production aircraft with redesigned vertical tail and powered by a 420-horsepower, water-cooled Liberty V-12 engine that was mounted inverted, 15 built