747 autostart
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747 autostart
As if I dont spend too much time flying I am mucking around with a computer flight Sim package called 747 Queen of the skies. It is the most accurate 747 flt sim yet developed and includes a fully functional on screen FMC. In the manuals that are included (which are better than my airlines ones and the creators pride themselves on accuracy) it says that the autostart procedure is to select the fuel control on and then pull the start switch. This is the opposite of what we do.
My question is are there any operators out there that put the fuel control switches on prior to pulling the start switches? Seems to me to be a bad habit to get in to if one ever had to do a manual start. What would be the advantage?
My question is are there any operators out there that put the fuel control switches on prior to pulling the start switches? Seems to me to be a bad habit to get in to if one ever had to do a manual start. What would be the advantage?
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Not familiar with 747 engines, but with all the Mil jets/turbines that I have worked on, the engines crank to get airflow and spark first, then add fuel. Having fuel before start seems like a good way to get a hot start to me ( Tho the flames from the tail pipe look kinda cool
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Cowpatz: "My question is are there any operators out there that put the fuel control switches on prior to pulling the start switches?"
Not in my outfit.
By the way, where can one pick up a copy of this sim programe? I am curious to see how it fares against Precision Sim - another 744 one which i was suitably impressed with
Not in my outfit.
By the way, where can one pick up a copy of this sim programe? I am curious to see how it fares against Precision Sim - another 744 one which i was suitably impressed with
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Avtrician, with autostart no fuel is put in until certain parameters are met, no matter when you put the cut off lever to run, parameters would be something like EGT below xxxC N2 or N3 above a certain % etc.
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Thanks for the replies.
Just to clear up one point. We are talking about autostart and not a normal manual start. During an autostart sequence pulling the start switch does nothing until the fuel lever is selected to run then the start valve opens etc. Doing either first sems to work (at least it does in the sim package and the docs indicate clearly that the fuel lever is selected to run prior to pulling the start switch). To me this seems a recipe for potential disaster especially if you run a mix of autostart and manual start engines. It may also cause different EICAS messages to appear during the start...I dont know. What do Cathay or Qantas do for example?
Just to clear up one point. We are talking about autostart and not a normal manual start. During an autostart sequence pulling the start switch does nothing until the fuel lever is selected to run then the start valve opens etc. Doing either first sems to work (at least it does in the sim package and the docs indicate clearly that the fuel lever is selected to run prior to pulling the start switch). To me this seems a recipe for potential disaster especially if you run a mix of autostart and manual start engines. It may also cause different EICAS messages to appear during the start...I dont know. What do Cathay or Qantas do for example?
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My question is are there any operators out there that put the fuel control switches on prior to pulling the start switches?
American operators of the 744:
Pull Engine Start Switch
Position Fuel Control to Run
Monitor EGT rise
Monitor N1 and Oil Pressure
Manual Start Seq:
Autostart Switch OFF
Pull Engine Start Switch
Observe N2 rise
Position Fuel Control to Run at Fuel On Msg
Monitor EGT rise
Monitor N1 and Oil Pressure
With both sequences we have FADEC assistance
either with auto fuel control or with the Fuel On
message - enough of a reminder perhaps not to
throw the Fuel control mindlessly into Run.
Just for fun, manual start procedures on a moldy-oldie:
(FE's job almost the same)
Boeing-approved start sequence: 742
Push GND Start Switch
Check Start VALVE OPEN Light on
Observe N2 rotation within 10 seconds
FE Calls N2 rotation, 20% and 45 % N2
FE monitors:
duct press and bleed valve closed light
Hyd press and Oil press increase
CSD low press light out
At 20% N2 with N1 rotation, EGT below 100C
Start Lever to Idle*
Observe FF indicator
*Below 0C or cold-soaked engine Start lever to
Rich at 20% (or max motoring at or above 15%)
FE monitors:
Fuel valve opens
Calls initial stable FF
At 45% N2 check GND Start switch trips off and start Valve Open light goes out. If not automatically tripped, press Off
After cutout FE monitors:
Duct press rises to Norm
Bleed valve closes
HP valve opens
At stable idle FE monitors:
All engine instruments for norm
Low oil press and filter bypass lights out
Pilot starting keeps hand on Start lever until EGT stabilzes
All 3 crew must monitor N2, EGT
Now on to 2 and 4 with 3 started during taxi
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Originally Posted by gengis
By the way, where can one pick up a copy of this sim programe? I am curious to see how it fares against Precision Sim - another 744 one which i was suitably impressed with
Just done a quick search and managed to find abit of info about it here -
http://www.precisionmanuals.com/html/747400.htm
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We have always used max motoring N2 speed before activating the start lever to idle or rich on the classic. Motoring the engine cools the rear stages of the HP compressor and restores the correct temperature profile and therefore the surge margin. This is standard starting procedure with RR and P&W engines. GE on the CF-6 recommends a min N2 of 15% before fuel is turned on but we adopted the max motoring procedure on those engines as well.
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[QUOTE=vapilot2004]Boeing-approved autostart sequence on several
American operators of the 744:
Pull Engine Start Switch
Can I add as item 1, Check that an autostart system is fitted!
Heard the story about a crew picking up a B747 delivery flight in CDG.
They had been training on a simulator with autostart.
Unfortunately their brand new aircraft did not.
Started 3 and 4 together on autostart and overtempted them both.
Two engine changes required.
So pulling the start switch before putting on the fuel and ign switch is a very good idea. If the engines start going round then that is a good clue that autostart is not fitted!
American operators of the 744:
Pull Engine Start Switch
Can I add as item 1, Check that an autostart system is fitted!
Heard the story about a crew picking up a B747 delivery flight in CDG.
They had been training on a simulator with autostart.
Unfortunately their brand new aircraft did not.
Started 3 and 4 together on autostart and overtempted them both.
Two engine changes required.
So pulling the start switch before putting on the fuel and ign switch is a very good idea. If the engines start going round then that is a good clue that autostart is not fitted!
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Tip......make sure the autostart button is in correct position for what you doing.
About 7 years ago, an engineer started all 4 on a 400,thinking autostart was on, it was't.
3 engines were replaced before next flt.
A very easy mistake to make.
About 7 years ago, an engineer started all 4 on a 400,thinking autostart was on, it was't.
3 engines were replaced before next flt.
A very easy mistake to make.
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Turn OFF two a/c packs, leave one ON.
Start #4 & #3 individually, then #2 & #1 together.
No altitude or environmental limts, but not a bad idea to knock all packs off if the temp's above 30C?
G'day
Start #4 & #3 individually, then #2 & #1 together.
No altitude or environmental limts, but not a bad idea to knock all packs off if the temp's above 30C?
G'day
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Haven't seen a B744 since October, but here in the cool north I am sure MH used to start them in pairs. 3 and 4 together followed by 1 and 2.
Also on the B777 with trents, we always start both together and it works well.
Its not new. In the winter even a Tristar could get two engines up to motoring speed together. I never tryed starting them though. Without autostart its so easy to go wrong.
Also on the B777 with trents, we always start both together and it works well.
Its not new. In the winter even a Tristar could get two engines up to motoring speed together. I never tryed starting them though. Without autostart its so easy to go wrong.
Warning Toxic!
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With BA's 747s, all packs off, start in pairs. Works extremely well, hot starts rare, and handled automatically. Fuel will be cut, motored and restarted. Even if one of the two ignition systems on an engine fails, it will cut fuel, motor and restart with the other. Starting could be a problem at Bogota when you were outside the autostart envelope and above the altitude restriction for autostarting.
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I believe not all 744's are fitted with autostart, was retro fitted to QF 744's pre factory fit delivery (RR powered).
SQ do not have it fitted to theirs, at least the ones I have come across but MH do (PW powered).
Think it is standard fit to GE powered aircraft.
SQ do not have it fitted to theirs, at least the ones I have come across but MH do (PW powered).
Think it is standard fit to GE powered aircraft.
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I'd hate to sound overly pedantic, but with respect to the "Queen of the Skies" homepage, while it all looks impressive, has anyone observed that the PFD pics on ground before start have got the F/D pitch bars the wrong way around..... pitching down instead of up (at least in the "Weekend Updates Screenshots" section)?
Last edited by gengis; 25th Apr 2006 at 12:44.
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Hi Gengis,
I use this software at home, I dont know why the bars are at the bottom but i do know when i use it once ive finished programming the FMC and turn my FD switch on the pitch bar works its way up for the appropriate pitch on T/O.
Regards
I use this software at home, I dont know why the bars are at the bottom but i do know when i use it once ive finished programming the FMC and turn my FD switch on the pitch bar works its way up for the appropriate pitch on T/O.
Regards