747 autostart

[cowpatz]

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?

[Avtrician]

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:E:E

[gengis]

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 ;)

[spannersatcx]

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.

[cowpatz]

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?

[vapilot2004]

My question is are there any operators out there that put the fuel control switches on prior to pulling the start switches?

Boeing-approved autostart sequence on several
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. :8

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 :)

[spannersatcx]

What do Cathay or Qantas do for example?

Don't know about Qantas, but CX 744 don't have autostart. (Don't know about the PW4000) as I haven't done the course yet.

[Mister approach]

I believe this was an error in the manual that the developers have acknowledged, it is indeed a great piece of software that certainly rivals
Ps1.

Jason.

[Rudder Pedals]

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 ;)
I believe it's called the PMDG B747-400. Looks quite interesting actually.

Just done a quick search and managed to find abit of info about it here -

http://www.precisionmanuals.com/html/747400.htm

[HotDog]

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.

[Swedish Steve]

[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!

[Joetom]

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.:)

[Feather #3]

For the record, QF autostart as per vapilot's words above.

And...for the third time....make sure the AUTOSTART s/w os ON before you do!! It's worth repeating.:eek:

G'day ;)

[Charles Darwin]

How many engines can the 744 start simultaneously?
Just curious of how powerful the APU might be.

[Feather #3]

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 ;)

[Swedish Steve]

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.

[Rainboe]

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.

[Bumpfoh]

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. :ok:

[gengis]

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)?

[JD8520]

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

[Mister approach]

Gengis,

This was a shot taken whilst the product was still in testing , you will find that the FD bars operate properly in the final version.

Jason.

[cowpatz]

The FD is now correct. Further more, like the real aircraft, you can change the style of FD.
We have a mix of RR and GE aircraft. The GE's have autostart and the RR's dont. Big potential for a screw up. At least pulling the start switch out first the Fuel control lever to run keeps things conventional. We start 3&4 and then 2&1 (2 packs off but will start well with all 3 going).

[AeroTech]

Hi,

originally posted by Rainboe
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.

-What are the limitations of autostart at high altitude airport?

-Why there are such limitations?

- Are there such limitations for a manual start?

- Can a high temperature affect a normal start and autostart?

- Are there special procedures for engine start (normal and autostart) at high/hot (or cold) airport? (can APU start be affected in such airport).

Feedback appreciated.
Thank you.