sentences:  On 27 January 1961, a series of DOD actions resulted in an agreement where all of the military services would work on the "Tri-Service Assault Transport Program" under the Navy's Bureau of Naval Weapons (BuWeps) leadership.The original outline had been drawn up as a replacement for the Sikorsky HR2S, with a payload on the order of 10000 lb (4500 kg).BuWeps released a revised specification that specified the same payload, but extended the operational radius to and increased the cruising airspeed to and the maximum airspeed to .