V-Force, 4-engine starts

[PAXboy]

This was discussed here a while back. There is a thread running in Questions about this. Although it started from multi-engine starts on modern commercial machines, the thread has drifted to the V-Force. Might someone with a memory be able to step over there and clear up a question or two? Cheers. :ok:

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"I tell you, we are here on Earth to fart around, and don't let anybody tell you any different." Kurt Vonnegut, Jr.

[BEagle]

Not quite. The 'Mass Rapid' was rather more than simultaneous rapid start as it also put the alternators on line and started all the PFCUs. It put a lot of strain on the aircraft systems and was very hazardous. I believe it went out of service when nuclear QRA responsibility was handed over to the RN's Polaris submarines.

Any Vulcan with charged air bottles could carry out a 'combustor' rapid start of the associated engines; however, it was often easier to start one using the rapid start, then crossbleed via the 'Engine Airs' to the others, either individually at 70% or simultaneously at 93%, for 'normal' starts.

A 4 engine 'ripple rapid' was rarely needed - and towards the end of their lives, most Vulcans didn't have fully serviceable rapid start systems.

The normal, safer way to start the Vulcan was to carry out individual starts using external air, not the rapid start system.

[RFCC]

"I seem to recall that the engine start airbottles needed to be charged to 6000psi. Quite how that was done (extenal bottles or internal a/c charging):
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The airbottles were re-charged from external bottles, there was no facility for a/c charging.

[FJJP]

Each bottle of four was charged to 3300psi, externally charged - there was no on-board replenishment system. It was PRV'd to 300psi for combustion - hence you could get several starts out of a bottle, although normally the bottles would be recharged routinely during AF servicing.

[DOC.400]

They used to show a video in the belly of the Vulcan at Hendon of a mass start -lots of cables attached to the rear of the planes that automatically unplugged, so I always assumed that this was where the power came from.

But by the time the last plane was airborne, he must have been IMC due to the smoke!!

DOC

[The Rocket]

There was the capacity for 6 individual engine starts, 3 on each side, using the compressed air system.

[Dan Winterland]

The Victor Bomber had bottles in both wings so all 4 could be started simultaneously. The left hand bottles were removed from the tanker, so you could only start 3 and 4 by combusting. 1 and 2 could be crossfed with the running engines at 75%. An air charge of 2800psi would give you 2 engine satrts, 1500psi one. The Victor could combust start with just LV power, i.e. the 28V batteries only. On the tanker, it was handy for starting on remote stands with little support. I tried it on more than one occasion.

[PAXboy]

DW: When you use the term: " tried it on more than one occasion." it almost sounds like you were testing it for other than operational reasons. And, surely, that can't be true? ;)

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"I tell you, we are here on Earth to fart around, and don't let anybody tell you any different." Kurt Vonnegut, Jr.

[Dan Winterland]

Using a lot systems on the Victor seemed to be an attempt at the intended! But seriously, what I should have said was 'I used it on more than one occasion'. We had no limitations on using the combust sytem in peacetime. In fact, we had a policy of using every now and again just to see if it worked - which it usually did.

[Stan Evil]

2 stories:

While on the OCU as a studnet I was a guard commander on a dispersal at Scampton during a TACEVAL. One night the order to scramble came and the captain of the nearest Vulcan to us hit the rapid start - instead of the usual 'whee - whoosh - roar' noise there was a 'whee - phut' repeated at least 4 times and then silence. It seems the groundcrew had managed to fill the system with nitrogen - not very good for supporting combustion.

Later in life I was involved in 4-ship scrambles where we used a ripple-rapid start. The captain pressed the 4 buttons in turn and then he monitored engines one and 2 and the co monitored 3 and 4. This was used rather than the mass rapid button to both avoid starting all of the PFCUs simultaneously and to give more chance to monitor the individual engines. Prior to start we had the AAPP (APU these days) running to give us 200 volts ac; we used to start the PFCUs using this which was not approved but it gave us less to do after engine start. The throttles would be set to half open and so, when it was time to move we just took the brakes off, started to roll, briefly brought the throttles back to close the bleed valves and then opened them up fully; 4 aircraft airborne 90 seconds after the scramble call leaving behind an IMC airfield - always impressive. For the public displays we were allowed to take-off as long as we'd managed to start 3 of the 4 engines - we'd sort the other one out once airborne!