The Hanker T-4 Instructor is a development of the T-1 Greenhand into an advanced/combat trainer. Powered by two 1000hp Rolls Royce water-cooled inline engines, the T-4 has much greater capabilities than the T-1. This includes the fitting of two .50 caliber M2 browning machine guns with 1000 rpg of training ammunition. This could also be swapped with live rounds if the need arises. The T-4 is also fitted with four underwing hardpoints for ordinance, but this is limited to two 250lbs training bombs and two 500lbs training bombs. The T-4 is not much larger than its single engined bretheren, and Hanker kept the same cockpit layout as in the T-1 for easy transition to the type.