The U.S. Coast Guard (USCG) has signed a $260,000 contract with Boundary Layer Research (BLR) to adapt a NASA-patented technology for use on the Coast Guard’s fleet of HH-65 Dolphin helicopters.

BLR’s tailboom strake modification is essentially a vortex-producing surface attached to, protruding perpendicular from and extending for much of the length of a helicopter tailboom. The drag-producing vortices created by the surface lessen loads on the tail rotor during hover and expand yaw control safety margins. Adapting the strake mod to the HH-65 (the Coast Guard version of Eurocopter’s AS 365N2 Dauphin 2) will take place in three phases over the next 12 months, with flight test beginning at the USCG aircraft repair and supply center in Elizabeth City, N.C., within weeks. Aboard the Dolphin, the BLR strake weighs 3.5 lb and tapers from a 3.8-in. protrusion at the aft end of the tailboom to 1.8 in. at the tailboom base. USCG approval could mean an order of 110 kits for its fleet of 96 Dolphins.