X-Plane 9.50+ Douglas A2D Skyshark. This rendition of the A2D-1 Skyshark is actually a "what if" portrayal of the ill-fated original A2D-1. The original Allison XT-40-A-2, which was was trouble-prone and eventually lead to the program's cancellation, is replaced with a modern, reliable engine of slightly greater power--the Allison Roles Royce T406-AD-400 of 6150 hp. Please read and follow the advice in the Flying Notes file included in the package. By Ron Norvelle.