Please note that the "R" in RH-53 doesn't mean recon.
The RH-53D mission was anti-mine sweeping. After the CH/RH-53E helicopters were introduced to the fleet the Marine Corps was able to retire some of it's olderCH-53D helicopters and replace with the slightly younger airframe RH-53 helicopters which utilized the stronger t64-ge-415 engines. 05/19/2005 @ 01:33 [ref: 10261]