United States Department of Defense - CH-53 Sea Stallion

The CH-53 Sea Stallion is the most common name for the Sikorsky S-65 family of heavy-lift transport helicopters. Originally developed for use by the United States Marine Corps, it is also in service with Germany, Mexico, Iran, Israel, and as the MH-53 Pave Low with the United States Air Force. The USAF also operated the HH-53 "Super Jolly Green Giant" during the late- and post-Viet Nam War era.

The dimensionally-similar CH-53E Super Stallion is a heavier-lifting, improved version designated S-80E by Sikorsky. Its third engine makes it more powerful than the Sea Stallion, which it has replaced in the heavy-lift mission.

The Sea Stallion has a fuselage design similar to the Sikorsky S-61R/Jolly Green Giant series. It has a passenger door on the right side of the fuselage behind the cockpit and a power-operated rear loading ramp. The fuselage was watertight, though not intended for amphibious use, and only landed on water in emergencies. The Stallion has mechanical flight controls which are backed by two independent hydraulic systems. Armor protects crew and vital systems.

The CH-53A carries a crew of four; pilot, copilot, crew chief, and "aerial observer", a load of 38 troops, 24 litters with medical attendants, an internal cargo load of 8,000 pounds (3,630 kg) or an external load of 13,000 lb (5,900 kg) on the single-point sling hook. The CH-53A is equipped with a pair of M60 0.308 in (7.62 mm) machine guns that point out to each side of the fuselage.

The CH-53A features the six-bladed main rotor and four-bladed tail rotor proven on the S-64. To save space on board naval vessels, the tail boom and the rotors folded. The rotor system was initially driven by twin GE T64-GE-6 turboshafts providing 2,850 shp (2,125 kW) each, with an engine on each side of the forward fuselage. It was later produced with the T64-GE-1 with 3,080 shp (2,300 kW) and then the T64-GE-16 with 3,485 shp (2,600 kW).The HH-53B featured T64-GE-3 engines producing 3,080 shp (2,297 kW).

The CH-53D features uprated engines, initially T64-GE-412 with 3,695 shp (2,755 kW) then the T64-GE-413 with 3,925 shp (2,930 kW) with an uprated transmission. Its interior added seats to allow for 55 troops. CH-53Ds are generally armed with twin 0.50 in (12.7 mm) M2/XM218 machine guns. In later years, CH-53Ds have been fitted with defensive countermeasures including an AN/ALE-39 chaff dispenser and an AN/ALQ-157 infrared set.

Later production CH-53Ds featured a Blade Inspection Method (BIM) scheme to detect cracks in its metal rotors. BIM involved pressurizing the interior of the rotor blades. If a crack is present pressure is lost and a red indicator on the rotor blade tip was tripped. Later, the BIM system was connected to a cockpit display. BIM reduced the need to swap out rotor blades on a routine basis.