According to the Museum’s website (which also provides technical specifications):

The HH-43 was developed from the earlier HOK-1 for the U.S. Navy and Marine Corps. The first prototype flew in 1953. The intermeshing rotor configuration eliminated the need for a tail rotor. Also, by substituting a gas turbine engine for the reciprocating engine of the earlier model, and mounting it above the cabin, it was possible to carry up to 10 passengers in the space previously occupied by the engine.

The Navy had used helicopters for “Plane Guard” duties during carrier operations to pick up flyers who ditched or crashed. The “Huskie,” however, was the first helicopter to be used by the U.S. Air Force for that purpose. The HH-43 saw use in Vietnam, known informally as “Pedros” because of their radio call signals, with Air Rescue and Recovery Squadrons. From 1966 to 1970, the Huskies saved more lives in combat, 888, than any other USAF helicopter.

Equipped with a fire suppression kit, Huskies on rescue alert could be airborne in about a minute and could reach crash sites before ground vehicles arrived. By spreading foam and by using its powerful downdraft it could open a path for rescuers to reach crash victims.

The HH-43 was retired from active service in the early 1970’s, replaced by the Sikorsky HH-3 Jolly Green Giant.

Taken with a Sony RX-100 M3.