Sikorsky has modified the S-92 utility rotorcraft to meet the requirements, particularly for search and rescue (SAR) missions, of the Nordic Standard Helicopter Programme (NSHP).
Denmark, Finland, Norway and Sweden are seeking a common helicopter to replace a range of types used for transport, anti-submarine warfare (ASW), SAR and shipborne roles.
Responses to a request for quotations were delivered by four of the five companies approached this month. Boeing did not reply as the CH-47 Chinook is too large, says a Swedish military source.
Sikorsky has given the S-92 a 400mm (16in) fuselage plug which allows the use of a smaller vertical tail to meet shipboard size limits. It also shifts the centre of gravity forward, improving hover performance. As a result, the cabin door size has been increased, to around 1.65m wide, giving better to the cabin for the SAR role.
Jack Carlson, head of Sikorsky's Stockholm office, says the company will modify the military S-92 prototype before it flies. He says the extension is placed in different locations on either side of the fuselage. On the port side, the plug is behind the gunner's door, maintaining the latter's position, while on the starboard side, the door, above which is the rescue hoist, has been widened. This provides better access to the cabin in SAR missions, particularly when a litter is in use. It also allows the hoist to be moved forwards, improving the clearance between the cable and the sponson. As a result of the stretch, the avionics bay is also lengthened, providing space for additional equipment.
Other NSHP bidders for the 50-90 helicopter order are Eurocopter, offering the Cougar MkII/MkII-Plus, EH Industries with the EH101 and NH Industries, offering the NH90. The Cougar MkII-Plus has higher power engines and a five-blade main rotor. It is in development for the French air force for the combat SAR role.
To meet the diverse requirements with a single type and raise fleet flexibility, EH Industries and Sikorsky have developed modular systems which allow helicopters to change roles rapidly.
Source: Flight International