Avro Vulcan B.2 XM597, although an in-service Vulcan was a testbed for different weapon systems (the following is cut and pasted from an article I wrote about XM597 and its varied career years ago).
Completed in 1963 as the sixty-first Vulcan built, XM597 was the first to be modified on the production line for carrying the cancelled Douglas GAM-87A Skybolt Air Launched Ballistic Missile, and the last to be fitted out for carrying the Avro Blue Steel stand-off nuclear missile, thereby making it the only Vulcan that was potentially capable of carrying both (although not at the same time, I'd imagine...)
During the Falklands War, throughout April and May 1982, XM597 carried out weapons trials for the possible carriage of laser guided bombs and AS.37 Martel TV guided missiles on makeshift pylons constructed from metal girders discovered lying about at Waddington. The pylons were fitted to hardpoints initially incorporated into the Vulcan’s wings for the carriage of the Douglas GAM-87A Skybolt missile. The plumbing for the cooling and electronic systems for the canceled American weapon housed the cabling for the carriage of stores under the wings.
Hastily designed by Squadron Leader Chris Pye, Waddington’s mechanical and engineering officer, the under wing pylons subsequently became known as “Pye pylons”. These were fitted to the Vulcans after refinement at RAF St Athan for operations, although based on Sqn Ldr Pye’s designs.
During trials, both laser guided bombs and Martels were dropped from the aircraft; three 1,000 lb High Explosive laser guided bombs were carried internally or a single Martel was carried externally. On 4 May the first flight carrying a single Martel round and a AN/ALQ-101 E-10 ECM pod, the Dash Ten as it was known, was made. The next day, XM597 carried out the first live firing trial with a Martel (sans warhead) at the Aberporth Firing Range in Wales.
XM597 was also the platform for Black Buck's 4, 5 and 6, although BB4 was canned owing to problems with one of the Victor tanker's Hose Drum Units and on these raids, XM597 carried AGM-45A Shrike anti-radar missiles. It was during BB6 that XM597's refuelling probe failed and the aircraft infamously diverted to Rio de Janeiro, Brazil, hence the Brazilian flag on its nose. XM597 is outside at Scotland's National Museum of Flight at East Fortune.
The Douglas Skybolt missile was to be Britain's airborne strategic nuclear deterrent after the Blue Steel. The Skybolt test bed Vulcan was B.2 XH537. This missile casing can be seen at the RAF Museum Cosford under the wing of XM598, which is fitted with Pye pylons owing to its use in the Black Buck raids as the back up to XM597. Note that the pylon is smaller than XM597's left hand one, this is because the Dash Ten was to be carried on the right hand pylon, with the Shrikes on the left, although on BB6, XM597 carried two twin Shrike launchers and no Dash Ten.