The Airco D.H.9 was a fine airplane design held back by an underperforming engine. Designers were expecting 300hp out of the Siddeley Puma, but in practice it only delivered 230hp on a good day. This left the D.H.9 — a successor to the D.H.4 — with less power than the plane it was supposed to replace. While everyone, including high command, recognized that the D.H.9 wasn’t the two-seater they really wanted, there was no way to stop production or introduce a better engine (such as a Rolls-Royce), given the demand for high-performance engines on existing models.
A reprieve finally happened with the arrival of the 400hp Liberty V-12 from the USA. When installed in the D.H.9 airframe (modified for the larger engine), the D.H.9 gave excellent performance and was well-liked by its crews. Unfortunately the supply of Liberty engines never kept up with projections or schedules, so the supply of D.H.9As was limited as well.
Three paintable D.H.9/D.H.9A models are now available at Great War Planes as well as three full-color D.H.9s.
