VERTICAL REFERENCE FLIGHT (VRF) THE KAMAN K-1200 “K-MAX” HELICOPTER DESIGN

External lift helicopter pilots in the commercial utility market depend upon Vertical Reference Flight (VRF) techniques. VRF simply means the pilot sees the external load, the pick-up and the delivery point, and the surrounding environment directly from the cockpit (see Figure 1). Precision, speed, safety, and economy are the byproducts of using VRF techniques. The K-MAX helicopter is the only aircraft designed, built, tested, and certified for commercial external load operations with VRF as the principal design factor for operations. The cockpit is tailored inside and out for the pilot to see and fly the external load. The challenges of design, test, and operation with VRF have been overcome and the K-MAX has provided an efficient lifting platform that easily allows the pilot to directly view the external load operation.