Country of origin:

United States of America

Description:

Commercial transport helicopter

Power Plant:

[S-76]

Two 485 kw (650 shp) Allison 250-C30 turboshafts

Specifications:

History:

The S-76 was developed solely as a medium-lift helicopter for the commercial market, in particular the oil-drilling industry.  The first of four prototypes was flown on 13 March 1977.  It was unique amongst Sikorsky designs in that it was not developed from a helicopter designed for military use, although since deliveries began in 1978 a number of military customers purchased the type, including the Philippine Air Force, Jordan, Iraq, Guatemala, Chile, Dubai Air Wing, Honduras, the Royal Hong Kong Auxiliary Air Force, Spain, Japan and South Korea.

Announced in 1975, the design of the S-76 underwent some refinement, including an increase in rotor diameter, fuselage length, and tail height; changes in the shape of the engine inlets, main rotor pylon, and engine fairings, and a modification to the main rotor blade tips.  The main objective of the design was to satisfy requirements of the off-shore oil transportation industry, and general business aviation markets during the 1980s and 1990s.

Among the features of the type were a composite bearingless tail rotor, and a fully-retractable tricycle undercarriage.  The main rotor blades had titanium spars, fibreglass skin, and swept-back tips.  Optional equipment included long-range fuel tanks, air-conditioning equipment, rescue hook, emergency flotation gear, etc.  Provision was made for the installation of IFR equipment, and communication and navigation aids for all-weather operation.  The Allison 250-C3 turboshafts were rated at 485 kw (650 shp) for take-off, 416 kw (557 shp) for maximum cruising speed, and a maximum of 522 kw (700 shp) for 1½ minutes in an emergency if one engine failed. Accommodation for a crew of two and up to 13 passengers was available. Cabin volume was 5.78 m³ (205 cub ft) and baggage compartment volume was 1.19 m³ (42 cub ft).

Quite a number of S-76s have operated in this region, first operator being Okanagan Helicopters, a Canadian operator which operated two S-76As VH-WXE (c/n 76-0005) and VH-WXF (c/n 76-0006) from Exmouth in Western Australia on off-shore oil-rig support work; and two VH-IMI (c/n 76-0016) and VH-IMZ (c/n 76-0017) from Longford, VIC. Other operators have included Esso-BHP operating from Longford, VIC.

S-76As have included VH-EML (c/n 76-0045), VH-EMM (c/n 76-0051), VH-EMN (c/n 76-0067), VH-EMX (c/n 76-0109), VH-ECR (c/n 76-0075), and VH-ECS (c/n 76-0132) and S-76Cs have included VH-EXK (c/n 76-0422), VH-EXN (c/n 76-0423), VH-EXQ (c/n 76-0424), VH-EXU (c/n 76-0432), VH-EXW (c/n 76-0434) and VH-EXX (c/n 76-0435).

More than 30 examples have been operated in Australasia.

Sydney businessman, Dick Smith , who has made many long-distance flights in a Bell 206 Jet Ranger, obtained an S-76A VH-SHW (c/n 76-0012 – ‘World Explorer’) and also made a number of flights in it.  In 1994 he flew from Sydney to Kathmandu in Nepal, this being the first stage of a trip around the world involving visiting over 150 countries during a period of five years compiling a data base of photos.  On completion he published a book “Solo Around the World”. The aircraft covered 73,000 km (45,360 miles) and visited 41 countries.  The aircraft had previously been owned by the King of Jordan. Eventually Mr Smith sold the aircraft and it was flown to New Zealand where it became ZK-ISJ (c/n 76-0012 Helimed I) operated by the Northland Emergency Service Trust out of Whangarei, being retired in early 2020.

Two S-76As, VH-BJR (c/n 76-0078) and VH-BJS (c/n 76-0224), were used in support of a three-year Australian Antarctic Research Expedition contract based at Davis Station, Antarctica from 1995.  S-76s have also been used by Lloyds Helicopters in the search and rescue support role from a number of RAAF bases.

In 1985 Sikorsky offered the French Turbomeca Arriel I engine as an option in the S-76A.  Further up-dating modifications continued, and early production aircraft were modified to become known as the S-76 Mk II.  At the end of 1986 new examples were offered with 548 kw (735 shp) Allison 250-C34 turboshafts, this being aimed at customers requiring improved performance in hot and high conditions, this engine being available in two models, one with an electronic fuel control system (C-34) and one without (C-34A).

A military general-purpose utility variant was also made available, known as the AUH-76.  This could be fitted with either 522 kw (700 shp) Allison 250-C30S or 716 kw (960 shp) Pratt & Whitney PT6B-36 engines.  This model was intended for use as a gunship and utility transport accommodating 12 troops, or as a scouting and reconnaissance machine.  Podded 7.62 mm (0.3 in) or 12.7 mm (0.5 in) machine guns or various 7.62 mm (0.3 in) mini-guns could be installed on outrigger type pylons; and various pods for folding-fin rockets or anti-armour missiles could be carried.  This model, the prototype of which was flown on 22 June 1984, in civil guise was known as the S-76B.

Further development continued over the years.  The S-76C was introduced to the line with Arriel 1S1 engines.  The S-76A+ designation was attached to examples of the S-76A which were fitted with Arriel engines.  The S-76C+ had more powerful Arriel 2S1 engines, this model becoming available in 1996.  Further improvements led to composite blades, a quieter tail rotor with curved blades, three LCD screens integrating the instrument display for engine rotor information, and four screens for the Honeywell EFIS suite.  Production of the series exceeded 500 aircraft, this including 284 S-76As, 101 S-76Bs, 17 S-76A+s, 43 S-76Cs and 35 S-76C+s.  By early 2016 800 examples had been completed, with a total fleet time reaching 6.7 million flight hours.