Author Topic: Coventry Question 2 ...  (Read 15499 times)

0 Members and 2 Guests are viewing this topic.

Offline eagle770

  • Club Member
  • Serious User
  • *****
  • Posts: 477
  • Gender: Male
    • View Profile
Re: Coventry Question 2 ...
« Reply #15 on: September 30, 2010, 12:21:09 PM »
I seem to remember that some of the Crew Chiefs used to stand close to the Rover exhaust on cold days during start-up, but not too close after one of them shed its turbine blades onto the concrete! :o
« Last Edit: January 01, 1970, 01:00:00 AM by Guest »
Consulting : If you are not part of the solution, there's good money to be made prolonging the problem!

Offline Gully

  • Global Moderator
  • Serious User
  • *****
  • Posts: 846
    • View Profile
Re: Coventry Question 2 ...
« Reply #16 on: September 30, 2010, 01:20:23 PM »
One of my many books on Vulcans indicates that the original B2 design allowed for engines to be air started from the Rover, but the process was putting too much of a strain on the AAPU so the facility was deleted not long after they entered service.

As for cross-feeding air from a started engine to start the remaining 3, I seem to recall that this was done quite recently after the STAD failed at Brize? According to my aforementioned books, one needed to run the cross-feed source engine at 60-70% RPM.

Gully
« Last Edit: January 01, 1970, 01:00:00 AM by Guest »
Vulcan To The Sky Club Secretary

Offline Ravin&Droolin

  • phpBB Newbie
  • *****
  • Posts: 45
    • View Profile
    • http://www.topmarksit.co.uk
Re: Coventry Question 2 ...
« Reply #17 on: September 30, 2010, 02:09:46 PM »
Sorry - More Questions...

1 - How is the air that is used to cross feed other engines generated. Is it bled off as 'surplus pressure' or is there a dedicated engine driven compressor?

2 -  How is/are the 'Air Starter(s)' mechanically connected to the main engine(s)?

Yours, Perpetually fascinated by the nuts & bolts - or just a closset anorak  :oops:
« Last Edit: January 01, 1970, 01:00:00 AM by Guest »
Us and Them: The most concise summation of the Human Condition...

Offline StAthan lecky

  • Club Member
  • Expert User
  • *****
  • Posts: 1975
    • View Profile
Re: Coventry Question 2 ...
« Reply #18 on: September 30, 2010, 02:51:50 PM »
Quote from: "Zero One"
Quote from: "StAthan lecky"
I think I can recall instances of the Rover being used to start an engine whilst I was at St Athan and then as Denis says crossfeed being used to start the other engines ,I was at "Saints" in 1970 so I am unsure when the facility was removed from the Rover AAPU,we did test both start methods during the Major servicing (of the Rover) but the normal method was the elecrical start.

 :D
Mike

Mike.......

Engine cross feed air was not needed, as stad/palouste is connected to a piped air system which is connected to all engines controlled by electrically controlled air valves one per engine, selected by the co-pilot, switches mounted on the starboard side console.



Are you saying that you started the main engines electrically?

if so then you were working on BMK1s and they didn't have a Rover only fitted to  BMK2s?.[ ready to be shot down on this point] ..which were air started..

Bovrill...

Thanks for correction couldn't quite picture where it connected... haven't touched a Vulcan for 2-3yrs

 :D

Hi Denis,
I only ever worked on the B Mk 2 Vulcan,to clarify the point regarding the Rover Gas Turbine (AAPU),we used to test both methods of starting it after the Major Servicing had been completed and during the functional phase ie-: Electrical and Cartridge.During the ECU functional tests we also checked the various options for starting them ie-:

1.Palouste Air Start
2.Mass Rapid Start
3.Cross Feed from a running ECU (can't remember which one was used to cross feed from)
4.AAPU Start of one ECU using bleed air and then as above cross feed from the running ECU to start the others.

That is how I remember it,the highlight of the ECU functionals being of course the Mass Rapid Start which has been deleted from 558's start options I believe.

Mike
« Last Edit: January 01, 1970, 01:00:00 AM by Guest »
1000+ Posts and not a Newbie

Freddie Mercury and Queen Will Live Forever

Another "Kind Of Magic"

Offline bovril

  • Serious User
  • *****
  • Posts: 272
    • View Profile
    • http://xm655.com
Re: Coventry Question 2 ...
« Reply #19 on: September 30, 2010, 05:16:13 PM »
we tipically start No.4 from the Palouste and then 3,2,1 all from the Palouste, this allows the ECU's to run at idle as we get them all runing..

to cross feed from a running ECU would mean we have to run it at approx 75% (can't remember the exact figure) to cross feed to start each of the other 3 in turn..

if you want to start the other 3 ECU's together after starting the first ECU, we would have to run the first at around 90%..

so we keep it simple and bring each ECU to idle from the palouste
« Last Edit: January 01, 1970, 01:00:00 AM by Guest »
XM655 - the most powerful vulcan in the world
[Alive and Kicking]

Offline Gareth

  • Regular User
  • *****
  • Posts: 133
  • Gender: Male
    • View Profile
Re: Coventry Question 2 ...
« Reply #20 on: September 30, 2010, 06:00:48 PM »
So, we know that 558 has her rapid start system disabled, but what about XM655?
« Last Edit: January 01, 1970, 01:00:00 AM by Guest »

Offline Gully

  • Global Moderator
  • Serious User
  • *****
  • Posts: 846
    • View Profile
Re: Coventry Question 2 ...
« Reply #21 on: September 30, 2010, 10:26:47 PM »
Quote from: "Gareth"
So, we know that 558 has her rapid start system disabled, but what about XM655?

No reason for it to have been deleted that I'm aware of, but I would guess it's inoperable solely down to the challenges of keeping a high-pressure system functional. Bovril?

Interesting point of note for the anoraks - '558's last engine start in RAF hands was internal, albeit one by one, not the mass rapid start.

Gully
« Last Edit: January 01, 1970, 01:00:00 AM by Guest »
Vulcan To The Sky Club Secretary

Offline Wizz Kid

  • Regular User
  • *****
  • Posts: 72
    • View Profile
Re: Coventry Question 2 ...
« Reply #22 on: October 01, 2010, 12:47:25 PM »
Typically, a standard engine start procedure if an air start trolly was available was 1,2,3,4 in turn, each from the air start trolly.  If there was no air start trolly available then a rapid start was effected on either 1,2 or 3 engine and then a 70% cross feed to the other three in turn was carried out or, if the captain was in a hurry, a 90% cross feed to the other three simultainiously.  Remebering that No 4 ECU did not have a hydraulic pump fitted,  it was not desireable to run up to 70% with only residual break pressure in the brake accumulaters from the EHPP (emergency hydraulic power pack).
« Last Edit: January 01, 1970, 01:00:00 AM by Guest »

Offline Gully

  • Global Moderator
  • Serious User
  • *****
  • Posts: 846
    • View Profile
Re: Coventry Question 2 ...
« Reply #23 on: October 03, 2010, 09:03:07 PM »
Sooty655 from 655 MaPS confirmed I could post the following in respect of XM655's rapid start system:

"655's rapid start ... system is complete, but the bottles are not pressurised. We have no intention of using it because it puts a higher stress on the starter motor compared to an air trolley start, and spare starters we ain't got!"

Thanks!

Gully
« Last Edit: January 01, 1970, 01:00:00 AM by Guest »
Vulcan To The Sky Club Secretary