New versions of the Agusta Westland Merlin are being proposed to meet the UK's vital Support Amphibious Battlefield Rotorcraft (SABR) requirement.

Westland sources suggest that SABR could be as simple as a follow-on buy of the basic Merlin HC3, already in service with the RAF, or could incorporate some of the improvements proposed for the US101. It could even include higher powered engines, uprated transmissions, improved rotors, fly-by-wire controls and/or the rotor blade and tail folding already incorporated in other existing Merlin variants.


Italy's newest Merlin variant, which combines a rear loading ramp with a folding tailboom, is on show with Agusta Westland's static display, and could be very representative of a SABR-type Merlin.

A number of studies have been produced, using the designations Merlin 3+ and Merlin 4, though the exact SABR configuration will only be defined during the formal assessment phase. The SABR requirement emerged when the separate Royal Navy Future Amphibious Support Helicopter (FASH) and RAF Future Support Rotorcraf (FSR) programmes were merged.

The resulting requirement calls for a replacement for the RAF's ageing Eurocopter Puma Mk1 and Royal Navy Westland Sea King4 helicopters, augmenting existing Boeing Chinook HC2 and 2a and Merlin HC3 helicopters, and addressing the major shortfalls in battlefield and amphibious lift described in the recent National Audit Office report on UK battlefield helicopters.

The successful SABR contender is also likely to replace the RAF's search and rescue (SAR) Sea King3/3As.

The SABR helicopter will be required to deploy the Royal Marines 3 Commando Brigade in support of Littoral Manoeuvre operations, and will be optimised for sustained operations at sea. It will also contribute to 16 Air Assault Brigade's Air Manoeuvre capability, and will be capable of rapid deployment in support of national and NATO Rapid Reaction forces.

SABR's In-Service Date (ISD) is defined as being when six platforms can be fully deployed to an operational theatre by the Joint Helicopter Command, and is currently expected around the turn of the decade. The provisional definition of the ISD in the SAR role is defined as being when sufficient assets are available to equip the training unit and one operational unit.

Initial operational analysis suggested that about 100 aircraft would be required to fully provide the combined SABR Battlefield Support and SAR capability, though this was later rounded down to 70 aircraft. This number will be further refined during the SABR Assessment Phase, and the expectation now is that about 40 helicopters might be procured.


This assessment phase was due to begin in the autumn of 2004, when the estimated development and manufacturing cost of the SABR programme was estimated at £6.5 billion, and the 30-year life cycle cost was put at £14 billion.

The MoD is reportedly examining a variety of SABR options, including the procurement of a single aircraft type, and of separate 'Heavy' and 'Medium' SABR helicopters.

Some RAF sources have suggested that an all-Chinook SABR fleet offers the best way forward, and that operational analysis "showed that what was needed was lots of ship-optimised, powered blade fold Chinooks".

Others refute this, pointing out that an all-Chinook solution would be expensive and inflexible, and that developing a Chinook for the marine environment would result in a UK-unique solution.

Moreover, although many operational analysis models tend to favour large, high-capacity helicopters, this is often because they assume that commanders can and will wait to fill a helicopter before despatching it, whereas experience suggests that larger numbers of smaller helicopters may be more operationally useful.

The advantages of medium sized helicopters are "soft" and hard to quantify in operational analysis, but are nonetheless very real.

Recent reports that the NH90 may be under consideration to meet part of the SABR requirement would seem to indicate some slippage in the ISD, since the aircraft was originally judged not to "align with SABR timescale requirements".


Source: Flight Daily News