Patuxent River Naval Air Museum on November 23 accepted a recently retired test helicopter from the Patuxent River based Air Test and Evaluation Squadron TWO ONE (HX-21) “Blackjack.”

The CH-46 Sea Knight is the Marine Corps’ primary medium lift helicopter. The tandem-rotor helicopter was built by Boeing Vertol to replace the venerable UH-34 Sea Horse medium transport helicopter and has been involved in every conflict and Humanitarian mission since the type entered Navy and Marine Corps service in November 1964.

One of the more noteworthy Sea Knights was the HMM-165 Sea Knight currently on exhibit with the Flying Leatherneck Aviation Museum in San Diego, California. Lady Ace 09 flown by then Major Gerry Berry and his crew evacuated Ambassador Graham Martin, the last United States Ambassador to South Vietnam from the United States Embassy, Saigon on April 30, 1975.

The Marine Corps currently has 95 CH-46Es and four HH-46Es in service. According to Navy and Marine Corps officials the CH-46 will be retired in fiscal year 2016. The last of those to retire will be the Search and Rescue (SAR) helicopters of MCAS Cherry Point based VMR-1. The SAR HH-46E will be replaced by UH-1Y helicopters.

The Pax River Naval Air Museum helicopter was used to test the CH-46E Infrared Suppression System (IRSS). According a Navy 2009 budget document, the IRSS “reduces the risk of engagement by battlefield IR missile systems… In performing the missions assigned, the CH-46E is increasingly exposed to an IR missile threat and does not have an IRSS for its engines to help mitigate this threat…”

The Sea Knights transfer to the museum closes the door on a long history of the “Phrog” aboard Pax River where the helicopter has been used by the Navy Test Pilot School, Search and Rescue and flight testing.