Tuesday 15 December 2009

Vulcan B4


The AVRO Vulcan was the RAF's last heavy bomber. The last operational version was the B2, the last version proposed was the Vulcan B3 designed as a missile carrier. Given that the RAF now needs a long range bomber to act as a bomb truck and a stand off nuclear bomber as a cheaper alternative to Trident is it time for a new Vulcan?

To start from an existing design would seem to be sensible. A Vulcan update might seem to be a reasonable prospect, the aerodynamics of the form are already known and the Vulcan had a very low radar cross section from head on which could be improved by adding a V tail. In producing this specification we are not after a state of the art aircraft, but to specify an aircraft which is relative cheap and overall a conservative design which can be designed and built relatively quickly.


First let us consider the choice of engine. The last engine used in a Vulcan was the Olympus 301, in its day a very efficient engine, however the BR715, a larger version of the engine used in the Nimrod MR4A, will produce slightly more power for about 25% less fuel consumption and it is possible that the engines for the F-35 will be even more efficient and produce even more power. Either of these would provide off the shelf power with greater efficiency.

The F-35 uses Power by Wire to distribute power to control surfaces removing the need for a heavy and complicated hydraulic systems, while so far this has not been implement as the only control system for an aircraft it is sufficiently well developed to mean that it should be considered to be the primary candidate for use on this system.

For the Flight avionics again we can steal from the Nimrod again. The system for the Nimrod is based on the Airbus A340 aircraft. It is a full glass system, it may not be state of the art any more but it works and has been adapted for military use. A different system may be picked to take advantage of improvements in electronics and software but of all the problems with the MRA4 non have been reported with the Avionics suite. The original Vulcan system was one of the first analogue fly by wire systems.

For radar the Euroradar CAPTOR system for the Typhoon or the AN/APG-81 from the F-35 should be available, these are both capable state of the art radars design for operation in a single seater aircraft. The CAPTOR has been superseded by the CAESAR electronically scanned system.

The American B2 Spirit is the bench mark for long range bombers it range is given as 6,000 nm, the Vulcan B2 range is given as 3,995 nm various plans where made for the phase 6 Vulcans which had a larger wing span and greater full capacity extended range. The use of more efficient engines would increased this range further. Hopefully by at least 25% this at some 100mph faster the the B2 Spirit. This is assuming that the structure of the aircraft is the same as it was in the late 1960s, however modern design techniques would reduce the weight even if no advanced techniques were used. The Spirit has a crew of 2, 3 less than the Vulcan and with the updated avionics then a new Vulcan could be expected to have the same size crew. This would free up centre line space for a large fuel tank.

The phase 6 was designed to be able to carry up to 38 1000lb bombs with the extra attached to hard points on the wing.

The most important factor for this project to go ahead is cost as a result the aircraft should be acquired in a bare bones format capable only of use as a bomb truck in a non threatening environment. However the various spaces through out the airframe that where used for defensive counter measures should be provided with power and data bus connections. to allow the installation of any equipment needed to deal with a greater threat environment.

In addition the basic airframe can be used as the basis of a dedicated in-flight refuelling aircraft with the bomb bay replaced with tankage and the hard points used to carry the refuelling drogues and to provide the basis for a photo reconnaissance aircraft to replace the Canberra.

Cost should be in the range of £250 million per aircraft, this is considerably less than the MRA4 as the weapons and combat avionics fit will be far cheaper and construction techniques.

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