A Brace of British Vigilantes

[MartG]

I've been on a Vigilante binge    - basically a 'whiff' history of the Vigilante in UK service. Group photo below, then more detailed sections on each variant below

1st pic, clockwise from top

GR.1, GR.1A, GR.2, S.1, F.1, F.2, F.3, F.4,  with the GR.1 Weapons Trials aircraft in the centre.

[MartG]

Vigilante GR.1

The fourth V-force bomber

In late 1961 it was recognised that the TSR.2 was unlikely to be in full squadron service before 1968, and Soviet air defences in Eastern Europe were improving rapidly and reducing the probability of a successful strike on certain high value targets by the existing subsonic strike aircraft operated by the RAF. A requirement was therefore drawn up for an interim supersonic nuclear strike aircraft, the requirement stating that an existing aircraft should be utilised if possible to meet an in service date in 1963, with multi-role capability also being sacrificed to meet the in-service date.

Coincidentally the requirement was issued at the same time as the US Navy reassigned its nuclear strike capability to its submarine fleet, leaving the recently developed A-5B Vigilante without a role whilst the USN and Congress wrangled over funding for the RA-5C programme. This funding hiatus had left North American with 18 partially completed A-5B airframes littering their shopfloor with no certainty about an order from the Navy, so the company was glad to be able to sell them to the UK.

To meet the in-service date the aircraft was initially taken virtually 'as is' with American avionics and engines, the only major modification being to fit conventional bomb bay doors to the forward section of the weapons bay, a modification originally offered to the USN but not taken up by that service. This change was carried out due to problems encountered with the linear weapons bay of the A-5A using the rearward ejection of stores, where the ejected store tended to be pulled along by the aircraft's slipstream to the detriment of delivery accuracy. The rearmost third of the weapons bay was converted to fuel tankage, and the arrestor hook was removed to reduce weight.

The Vigilante GR.1 proved a good match to the RAF requirement, with even its name falling in line with the other V-force aircraft and all 18 A-5B airframes originally ordered by the USN were purchased. Though its relatively large wing made for a bumpy ride at low level, especially in typical European weather conditions, this was not seen as an issue as it was envisaged that the aircraft would operate primarily at high altitude. Resplendent in their white anti-flash finish ( until a more muted colour scheme was applied in 1967 ) these aircraft became a familiar sight in their QRA shelters until replaced by the GR.2 in late 1969. Throughout its service only the Red Beard nuclear store was carried by the GR.1/GR.1A, it being felt that adapting the limited number of aircraft to carry other stores would not be cost effective given the intended short term of its service, and would affect its availability in its primary role of nuclear deterrent.

This GR.1 is the aircraft used for weapons release trials, ensuring that the Red Beard nuclear store could be successfully deployed from the modified weapons bay of the RAF aircraft. This particular aircraft was temporarily fitted with pod mounted cameras on the wings and under the fuselage to document events during weapons release, with high-viz markings to aid ground tracking.

Following successful completion of the trials the test equipment was removed and the aircraft was released for squadron service. It retained the high viz markings for most of its service career, being used by the OCU as one of its conversion trainers.

Built from the Airfix kit, with bomb bay and doors scratchbuilt from plasticard, nuclear store 'shape'  from the Airfix TSR.2, wing camera pods from a YF-12, underfuselage cameras from the TSR.2.

The second GR.1 represents an operational aircraft assigned to no. 617 'Dambusters' Squadron. ( also see here  http://www.whatifmodelers.com/forum//index...?showtopic=9907 )

[MartG]

[MartG]

Vigilante GR.1A

Earlier white anti-flash finish replaced in late 1967 by gray/green more suited to low level operations the aircraft now engaged in, though still with white underside with a high demarcation line. In an attempt to improve low level ride quality an experiment was carried out on a few aircraft, with the wingspan being reduced by the simple expedient of removing the outer section at the wing fold line. Although this mod created a slight change in trim it was deemed to be generally successful, and in time was extended to the rest of the fleet. A further mod was to attach launch rails for missiles to the truncated wingtips - these could accommodate either Red Top or Sidewinder missiles.

Built pretty much OOB from the Hasegawa kit with wingtips sawn off.

[MartG]

Vigilante GR.2

With the change to low level operations forced by the increasing capability of Soviet SAMs, the Vigilante GR.1 gave an unacceptably 'bumpy' ride due to the large size of its wing, though removing the wingtips to create the GR.1A provided a partial solution there were still concerns about the fatigue life of the wing and tail in these conditions. However, with the TSR.2 still over 18 months away from reaching operational status, it was decided to extend the usefulness of the Vigilante, and a number of GR.1As were refitted with a smaller wing and tail surfaces ( eventually most of the GR.1/GR.1As were converted to GR.2 standard, the sole exception being the airframe used as the F.1 prototype ). To reduce development costs the wing was based very closely on that already in production for the TSR.2 .

Modifications were also made to the weapons bay to allow carriage of WE.177 nuclear weapons as well as the Red Beard store.

With its small wings, the GR.2 echoed the experience with the B-26 Marauder, with comments being made that it had no visible means of support.

This was the final RAF strike version of the Vigilante as its role was increasingly taken over by the Eagle. However the GR.2 proved to have such outstanding performance at low level that it was retained in service in various roles much longer than planned, with 23 additional ex-USN RA-5Cs also being purchased and converted, and some even saw service in Operation Desert Storm carrying laser target designators before being finally retired in 1995.

Yes, I really did cut up an Airfix TSR.2 to make this ! Don't worry though, the TSR.2 will appear in due course with new wings.

Horizontal tail from a Tornado, as the originals were way too big for the new wing - their span was actually greater than the new wingspan ! Fin is from the TSR.2.

Looks like a baby TSR.2 doesn't it  

[MartG]

Vigilante S.1

Although inter-service rivalry normally created a reluctance to use an aircraft operating with the RAF, as the Vigilante was originally a Navy plane ( albeit USN ) the Fleet Air Arm was happy to buy it for the land based maritime strike role. As there was no intention to ever operate it from a carrier, the airframes were like the RAF ones in that all the weighty arrestor gear etc. was removed. They also had the same weapons bay modification as the RAF strike variants, and had the same ability to tote nuclear stores, though it was more common to see them with Martel ( later Sea Eagle ) missiles loaded. The FAA aircraft also had modified weapons bay doors to allow the carriage of external stores on a centreline pylon, the usual load being a fuel tank.

Two operational squadrons were formed, one based at RNAS Culdrose covering the Southern approaches to the UK, and one at RNAS Fulmar at Lossiemouth operating in the GIUK gap, plus a training wing at RNAS Yeovilton.

Hasegawa kit, Martels from an old Airfix MRCA kit, centreline tank from an Airfix Phantom

[MartG]

Vigilante F.1



With the increasing threat from air launched stand-off missiles in the mid 70s, the RAF needed more aircraft capable of neutralising the launch aircraft at distances beyond the effective range of the missiles. The existing Arrows were upgraded with the AWG-9 weapon system, and a number of F-111K interceptors with the same weapon system were also procured. However the RAF identified a need for yet more long range interceptor aircraft, at a lower cost than the refurbished/new-build Arrows and F-111Ks with the AWG-9,  accepting that such an aircraft would also have a slightly less capable weapon system. The solution was found by firstly modifying a Vigilante GR.1A as a prototype, then with additional USN surplus RA-5C airframes being purchased and modified.

Modifications involved reprofiling of the nose to house the Ferranti AN/AWG-11 fire control system with its larger radar scanner ( conferring Sparrow/Skyflash capability ), with three missiles semi-submerged under the fuselage. To offset some of the additional weight the wing and fin folding mechanisms were deleted, and fuel tanks semi-permanently fitted in the weapons bay. The wing pylons were also wired for both the SARH missiles, and the outer two also had Sidewinder capability.

Built from the Revell kit, using a Phantom nosecone.

[MartG]

Vigilante F.2

Developed from the F.1, the Vigilante F.2 had incredible performance thanks to the installation of a DeHavilland Stentor rocket engine in the rear of the weapons bay, nearly doubling the total available thrust. The attendant HTP oxidiser tank was  housed immediately ahead of the motor ( two sizes of HTP tank were produced, the smaller of which allowed the forward third of the weapons bay to be retained for either a fuel tank or weapons ), with kerosene fuel being drawn from the aircrafts normal tankage

In operational service a typical load for the extreme range interception role would be a full size HTP tank internally, occupying the full length of the weapons bay, three underfuselage AIM-7 Sparrow or Skyflash missiles, fuel tanks on each of the inner four wing pylons, and AIM-9 Sidewinders on the outer two pylons. For shorter range missions two of the fuel tanks were often traded for an additional pair of Sparrows.

The rocket engine conferred the ability to gain altitude extremely rapidly, as with an aggregate thrust to weight ratio in excess of 0.8 even at maximum takeoff weight the aircraft could climb almost vertically straight off the runway - a spectacular manoeuvre which rapidly became a crowd favourite at airshows !  It also allowed the aircraft to operate at altitudes in excess of 80,000ft, even after the jet engines had flamed out due to insufficient oxygen, though due to the rarified air at these altitudes the aerodynamic control of the aircraft was considered sluggish. One mission profile demonstrated was essentially a ballistic trajectory which sent the aircraft to over 110,000ft. Whilst this allowed a distant target area to be reached very quickly the dangerous nature of the profile meant it was reserved for the direst emergencies only - most Vigilante pilots only ever carried it out in the simulator. Fortunately no aircrew needed to eject at these altitudes, as the odds of surviving were considered to be minimal.

The F.2 also had the distinction of being the only aircraft to successfully intercept an SR-71 Blackbird, a feat which it managed on a number of occasions during various joint US/UK exercises - the first time it happened the Blackbird crew were very surprised indeed to have an attacker coming in from above them !

Despite the risks entailed by the use of the rocket, competition amongst Vigilante crews to be assigned to an F.2 squadron was intense, thanks to it being a true 'rocket ship' in more sense than one.

Built from the Airfix kit, the rear fuselage Stentor rocket motor is from the Blue Steel missile supplied with the Airfix Vulcan, new pylons from the spares box ( not sure of their source ), nose from a Phantom, IRST pod from a Tornado.

The Stentor was a dual chamber motor - the large chamber produced 25,200lbs thrust and the smaller was throttleable between 1,000 and 6,200lbs thrust ( both figures at 45,000ft altitude- rocket thrust increases as atmospheric pressure decreases so thrust at higher altitude would be slightly greater ). Being a 'hot' HTP engine it burned kerosene in addition to the HTP, the fuel being ignited by the temperature of the HTP which had been decomposed by passing over a catalyst - 'cold' HTP engines just relied on the expansion of the decomposed HTP for thrust.

[MartG]

Vigilante F.3

Although the earlier F.2 variant performed its role well, continuing safety fears regarding the use of HTP on a day-to-day basis prompted the RAF to investigate alternatives. Based on an old NAA proposal ( the NA-349 ), the F.3 replaced the Stentor rocket motor with a third J-79 engine, fed by a pair of intakes located above and behind the original ones. The new engine was located between and above the original engines, creating a dorsal hump which also blended in to the new intakes. The high engine location left sufficient space in what remained of the original weapons bay for sufficient additional fuel tankage to allow the aircraft to retain a reasonable range with internal fuel only, though it was rare to see the F.3 without external tanks fitted as the third engine made the F.3 quite a thirsty bird.

The location of the new engine meant that the original single all-moving fin could not be retained in its original position, as there was no space above the engine for the required actuators and support structure, and servicing access to the engine would also have been compromised ( hanger height was also a factor ). Instead the decision was made to revert to the layout proposed by NAA for the original A3J, with twin outward canted fins located near the edges of the rear fuselage. After the initial test flights the wingtips were drooped to counter lateral instability at high speed. The canopies were also altered to a single clamshell design to provide better visibility for both pilot and WSO, and a 30mm Aden cannon was added under the forward fuselage, though this last feature involved deleting the IRST system.

Whilst the third engine conferred excellent performance the F.3 was also capable of carrying out extended patrols at low speed, and the prototypes demonstrated the ability to loiter with two engines shut down to save fuel ( in-flight engine start up took less than 2 minutes under combat conditions ). Unfortunately the cost of the extensive conversion meant that only 34 were completed before production switched to the F.4

Built from an Airfix kit, dorsal hump is actually a Tornado lower front fuselage, new intakes cut down from  Tornado ones, lots of filler, fins are tailplanes from another Vigilante, canopy and cockpit from a Tornado, tailcone is an old Mirage nosecone.

[MartG]

Vigilante F.4

When it became apparent that the conversion to F.3 standard was costing nearly as much as a complete new build aircraft, the RAF asked for alternatives which would give similar performance but an affordable cost. After a 'paper based' competition, the F.4 configuration proposed by BAe Warton was selected. The F.4 modifications included replacing the original 17,000lb thrust J79 engines with RR Spey 205 engines delivering 25,000lb thrust each in reheat, giving similar total thrust to the F.3 but with significantly lower weight, cost, and fuel consumption. The combined dry thrust of over 25,000lbs also conferred the ability to cruise at supersonic speeds without the use of afterburner.

Apart from the revisions to the tail to accommodate the larger exhausts, the Spey installation also required larger intakes and revised internal ducting to cater for the greater mass airflow. The F.4 also included many of the features developed for the F.3, including the drooped wingtips, and revised cockpit, though the Aden cannon was moved further aft and offset to starboard to avoid shooting off the IRST , with ammunition stored in the lower electronics bay in space made available thanks to advances in electronic miniaturisation reducing the volume occupied by the avionics fit. A proposal to fit two cannon on the sides of the forward fuselage were abandoned due to concerns over engine ingestion of gun gases. The F.4 also received small leading edge root extensions.

The major increase in the combat capability of the F.4 however came with a new weapon system. The advent of the digital AN/APG-71 radar in the late 1980s finally provided the Vigilante with the AIM-54 Phoenix capability previously impossible due to there being insufficient space in the airframe for the AN/AWG-9. Two Phoenix could be carried in tandem under the fuselage centreline ( conversion to/from Skyflash/AMRAAM configuration took around 1 1/2 hours ), and four of the wing pylons could also carry the big missile.

Built from the Airfix kit, nose from a Phantom, tailcone is actually an F-15 nose, exhausts also from an F-15 ( couldn't find any Spey ones ). Intakes widened by fitting std ones a bit further out and filling the gap with putty, canopy and cockpit from a Tornado. Cannon is cut down from an Airfix Hawk item.

[MerlinJones]

Beautiful...just beautiful.

And a great back story to go with them.

Regards.
Bruce

[Archibald]

[SIZE=14]Its the thread and model of the year!!!! CONGRATULATIONS FOR THIS IMPRESSIVE WORK? I'M STUNNED!!!!!!!!!!!![SIZE=14]

[Radish]

Really, really, REALLY impressive

Very IMPRESSIVE

Hey, I'm IMPRESSED          

[Radish]

Not only am I IMPRESSED, I like the big base too  

[Archibald]

I'm impressed, too... so many work...