Page 2 of 2

Re: Reduced thrust takeoff

Posted: 27 Sep 2007, 21:13
by forthbridge
Tonks, thanks for that expansion on the info on this. I suppose it slipped from the grey matter a bit, after all You can't even over-rev a car these days with the engine management - it all makes sense ;-)

Techy, I'm not sure on whether Freddy and co were the first..

I also read that the 'got talking' with other A/C over the radio flying the same routes (rival airlines) to find out what height and speeds etc they were using - exactly why this was instructed I have absolutely no idea!!

(Of course were they fitted with a refuelling nozzle it would make perfect sense to find out Tonks' Speed, heading and altitide, but goodness knows how you'd get the fuelcard into the slot..... :-# ;-) )

Re: Reduced thrust takeoff

Posted: 27 Sep 2007, 21:38
by DaveB
Neither the VC10 or One-Eleven preceeded Sir Freddie but they did preceed Laker and Skytrain so I doubt it was the Laker-Skytrain team that initiated it. Been wrong before though.. many times! :)

ATB

DaveB :tab:

Re: Reduced thrust takeoff

Posted: 27 Sep 2007, 21:40
by Techy111
Hang on i'll get the piece i read it from (might be wrong LOL)

http://executivetraveller.net/images/ar ... dition.pdf

On page 4 Tribute to Sir Freddie Laker just above pilot ,sir Freddie and DC10.. Bit of a large D/L (7.74Mb)

Techy

Re: Reduced thrust takeoff

Posted: 27 Sep 2007, 21:50
by DaveB
Go one then Techy :lol:

I'm not saying that Sir Fred didn't initiate it as he was a ground-breaker and innovator in may areas of aviation.. just that I find it unlikely as two of the aircraft he used (first as BUA - VC10/1-11 - and second as Laker - 1-11) were available and these things were already (or so I'd guess) written into the Flight Manuals. That said.. Flight Manuals get updated on a regular basis and it's inclusion must have been instigated by someone ;-)

EDIT.. Ah.. rat bag, you edited that in while I was typing the above! :lol: Unfortunately, I lost the will to live waiting for the pdf to load so I'll take your word for it ;-)
ATB

DaveB :tab:

Re: Reduced thrust takeoff

Posted: 27 Sep 2007, 21:54
by Garry Russell
Laker operated their One-Elevens different to the norm to preserve engine life and fuel.

There was a special climb out procedure as well.

As I mentioned above they reduced pax and could fly direct missing out tech stop and as a result their aircraft could operated more rotations.

This was Laker thing rather than a BAC thing.......run them gentle and light.

This was from their introduction of the One-Eleven......it had nothing to do with Skytrain which came much later.

Laker was said to have initated low cost operations more wideley adopted later.

Garry

Re: Reduced thrust takeoff

Posted: 27 Sep 2007, 21:57
by Techy111
:kissu: LMAO (at Dave....!)

Techy

Re: Reduced thrust takeoff

Posted: 27 Sep 2007, 21:58
by DispatchDragon
Nice thread -

Chris nice explanation :) , I couldn't have put it more succinctly - Flex power is the norm and has been since I started in the industry.

The one anonmaly in all this were the original IAE V2500s (A1's) which had a max continous thrust of 22,200lbs
but could be over ridden and exceeded to 25000lbs of 5 mins on take off - this was refered to as a "Bump" takoff
and as such the cycles on engine would be reduced by a factor of two for every "bump" (effectivly shortening the
TBOh) IAE countered this by beefing up the V2500s hot section and upping the max cont thrust to 24,800lbs.

Oh yes and Laker wasnt the pioneer to use Reduced Take Off power - Boeing was teaching Britannia Airways crews
the technique for the first 737s in the UK in 1967 When Laker was still trying to get off the ground in Britannias.
So Im assuming that if Boeing was teaching Britannia then the technique had been around for awhile.

Edit - Chatting with BrianH (Horse) on Skype this evening he confirmed that Quantas was using Reduced Power
takeoffs when he was an engineer with them - and that sort of blows the Laker theory out of the water - sorry :$

Leif

Re: Reduced thrust takeoff

Posted: 28 Sep 2007, 00:54
by Sl4yer
cstorey wrote:Incidentally, the Speys in the 1-11 had a 5 minute limitation which allowed higher than normal jet pipe temperature to be sustained to cater for hot and high/max gross weight operations. I do not know whether this also applied to the Trident.
Just for interest, from ZK:

Image

James

Re: Reduced thrust takeoff

Posted: 28 Sep 2007, 01:04
by DaveB
Hi James,

I have the same shot here off ZK and had forgotten about it :lol: That shot illustrates that Max Pwr is 5mins but at 600c which is the max takeoff pwr limit anyway. Although you are allowed to overspeed, this is limited to 20secs as is the limit of the jetpipes above 600c :) 5mins above 12800HPrpm or 600c and you've killed the engine though LPrpm also plays a part ;-)

ATB

DaveB :tab:

Re: Reduced thrust takeoff

Posted: 28 Sep 2007, 20:51
by forthbridge
:o
Amazing!

Thanks for all the info on this - very enlightening :)