Updated: Oct 14, 2021
It was on this day in aviation history the Sikorsky YCH-53A made its first flight.
The Sikorsky YCH-53A Sea Stallion on its maiden flight, 14th of October 1964, Stratford, Connecticut, USA.
The fuselage of the YC-53A was based on the smaller CH-3C (Skorsky S-61R) while some dynamic parts were sourced from the CH-37 Mojave (Sikorsky S-56) and the CH-54A Tarhe (Sikorsky S-64). It was de first aircraft in family of heavylift helicopters based on this design. Allready in 1960 yje US Marine Corps was looking for a replacement for their piston powered helicopters. After several research projects the US Navy (on behalve of the US Marine Corps) issued an request for a "Heavy Helicopter Experimental". The main specifications in the request were:
Load capability: 8000 lbs (3600 kg)
Operational radius 100 nm (190 km)
Speed 150 knots (280 kph)
As a result Boeing tendered the CH-47 Chinook, Kaman Aircraft tendered a version of the Fairey Rotodyne Compound helicopter while Sikorsky tendered a large version of the S-61R, the S-65. In July 1962 it was announced that Sikorsky had won the contract, After further negotiations it was agreed that 2 flying prototypes would be built by Sikorksy, together with a mock-up and a ground test airframe. Sikorsky received $ 9.965.635,-- for this contract. The first flight was actually 4 months behind schedule. This didn't stop the US Marines from ordering 16 helicopters before the first flight! The test program progressed smoothly and Sikorsky managed to make up some lost time, In November 1964 the aircraft was introduced to the general public. at the same time it also received it designation and name, CH-53A Sea Stallion.
The CH53A family would grow considerably over the years to come, an overview of the different variants;
YCH-53A, 2 built Prototypes with T64-Ge_3 engines (2850 shp)
CH-53A, 139 built Initial production variant for US Marines
RH-53A, 15 CH-53A converted Airborne Mine Counter measure aircraft, powered by 3925 shp T64-GE-413 engines
TH-53A CH-53A adapted for training by the US Air Force
CH-53D, 126 built Improved transmission, larger cabin for US Marine Corps
RH-53D, 30 built for US Navy 25.000 lbs (11340 kg) external load capable, Armed with machine guns and capable of aerial refueling
VH-53D, 2 built VIP transport helicopter for US Marines
VH-53F, 6 planned, not built VIP transport helicopter for US Marines
CH-53G, 112 built CH-53D version for German Army. Powered by T64-100 engines
CH-53GS, 20 converted from CH-53G Updated version of the CH-53G
CH-53GA, 40 converted from CH-53G Further update of the CH-53GS for Combat Search and Rescue. Increased fuel capacity, modernised electronics.
CH-65C-r Yas'ur Export version for the Israeli Air Force.
S-65Ö Export version for Austrian Air Force
Other helicopters that are based on the CH-53 are the HH-53 "Super Green Giant, the MH-53 Pave Low and the CH-53E Super Stallion.
Specifications for the CH-53D variant:
Crew: 2 pilots, 1 or more loadmasters / crewmen
Capacity: 38 troops (55 in alternate configuration) or 24 stretchers / 8,000 lb (3,600 kg) payload
Width: 28 ft 4 in (8.64 m) over stub wings, 15 ft 6 in (5 m) across fuselage
Empty weight: 23,628 lb (10,717 kg)
Gross weight: 33,500 lb (15,195 kg)
Max takeoff weight: 42,000 lb (19,051 kg)
Powerplant: 2 × General Electric T64-GE-413 turboshaft engines, 3,925 shp (2,927 kW) each
Main rotor diameter: 72 ft 2.8 in (22.017 m)
Main rotor area: 4,098.1 sq ft (380.73 m2) 6-bladed main rotor
Maximum speed: 170 kn (200 mph, 310 km/h)
Cruise speed: 150 kn (170 mph, 280 km/h)
Range: 540 nmi (620 mi, 1,000 km)
Combat range: 95 nmi (109 mi, 176 km)
Ferry range: 886 nmi (1,020 mi, 1,641 km)
Service ceiling: 16,750 ft (5,110 m)
Rate of climb: 2,460 ft/min (12.5 m/s)
Disk loading: 8.95 lb/sq ft (43.7 kg/m2)
Two door mounted .50 BMG GAU-15/A machine guns. Some have a ramp mounted .50 BMG GAU-21 machine gun.
German CH-53Gs can mount two 7.62×51mm MG3 machine guns in the side doors, which are to be replaced by two .50 BMG M3M/GAU-21 machines guns in the doors and one on the ramp.