Hi,

I am trying to start a British Airways PMDG BAW 747-400 with Rolls Royce engines. I have the APU running; Pack 1 Normal, Pack 2 & 3 OFF; Duct Pressure of 29 PSI. However, if I pull the engine start switches, there is no airflow to the engines even though the Bleed Valves are OPEN and the duct pressure increases to 51PSI? Also the Engine Start Switches do NOT illuminate (see screenshots)

https://www.flickr.com/photos/141330124@N05/shares/J99y1q

If I do the same on a Lufthansa PMDG 747-400 with GE engines, the start up works properly; APU running; Pack 1 Normal, Pack 2 & 3 OFF; Engine Start switches Pulled (will illuminate) and I can see airflow from the duct to the open engine bleed valves (see screenshot.

Is there a different procedure to start Rolls Royce engines?

Thanks for help

 

One of your screenshots shows no Autostart fitted. Is this the GE?

When Autostart is available and selected ON, the engine will not begin starting until you have pulled the start switch and moved the fuel cutoff switch to RUN.

Actually, according to Boeing Wiring Schematic 80-11-02, you shouldn't have got a pressure rise in the bleed ducts without both actions. Can you confirm you had a pressure rise?

Cheers

JHW

one thing i noticed...in the first pic the 1-3 hydraulic pumps are set to off,..all 4 are off in the 3rd pic,maybe that is part of the issue? setting 1-3 to auto and 4 to aux is one of the steps listed in the tutorial before engine start..(page 102)... i don't know if it is actually a requirement as i haven't tried it without setting them.. 

also in the 1st pic the IRS is not aligned, although not sure if that matters either. the 3rd pic also shows most of the fuel pumps turned off which may be related..

good luck!

cheers,-andy crosby

 

Hi,

Picture with no Auto-Start feature is a Lufthansa fitted with GE engines and starts according to the manual.

The other 2 pictures are of a British Airways fitted with Rolls Royce engines. I tried with Hydraulic pumps ON, all Fuel Pumps On but NO engine start. I am not sure if the engine start switches are to illuminate once pulled?

I will try again and confirm settings and pressure rise.

Thanks

7 hours ago, Qavion2 said:

One of your screenshots shows no Autostart fitted. Is this the GE?

When Autostart is available and selected ON, the engine will not begin starting until you have pulled the start switch and moved the fuel cutoff switch to RUN.

Actually, according to Boeing Wiring Schematic 80-11-02, you shouldn't have got a pressure rise in the bleed ducts without both actions. Can you confirm you had a pressure rise?

Cheers

JHW

That's the way I discovered to start a BA R-R version as opposed to a GE-version yesterday. I was slightly perplexed when I first encountered the same as the OP.

As John says, you need to place the fuel control switches to RUN in order to initiate the start. The start switches will not illuminate, and the autostart sequence will not commence, until you select the fuel control switches to RUN.

For what it's worth, normal procedure at BA would be to select hydraulic demand pumps 1 and 4 to AUX, 2 and 3 to AUTO and turn all three packs off for the start -- the more air you have for the starter the less chance of start problems.

Hi,

I just tried the BA B747 with Rolls Royce engines again:

IRS set to NAV; Hydraulic pumps SET; Fuel pumps ON; Ignition CONTINUOUS; APU ON; Pack 1 Normal; Packs 2 & 3 OFF; duct pressure: 30psi;

Start switch engine # 4: PULLED (does NOT illuminate); duct pressure rises to 51 & 50 psi; engine # 4 bleed valve ON; NO airflow to engine # 4; APU running; continuous ignition ON.

EPR for engine # 4 shows a value of 0.8 (see screenshots)

https://www.flickr.com/photos/141330124@N05/shares/7h7wio

Any help would be appreciated

2 minutes ago, Juergen said:

 

Hi,

I just tried the BA B747 with Rolls Royce engines again:

IRS set to NAV; Hydraulic pumps SET; Fuel pumps ON; Ignition CONTINUOUS; APU ON; Pack 1 Normal; Packs 2 & 3 OFF; duct pressure: 30psi;

Start switch engine # 4: PULLED (does NOT illuminate); duct pressure rises to 51 & 50 psi; engine # 4 bleed valve ON; NO airflow to engine # 4; APU running; continuous ignition ON.

 

But have you placed the fuel control switch to RUN?

Why are you running Pack 1?

Hi Guys,

I saw the post late (post from skelsey).

Set the hydraulic pumps 1 & 4 to AUX; 2 & 3 to AUTO; fuel pumps ON; Pack 1 to 3 OFF; FUEL CONTROL SWITCH TO ON and the engines STARTED.

Thanks, I am good to go - problem solved

Hi Skelsey,

The pack situation I saw on a video, but can't remember why he had pack 1 set to normal. Your reason to set ALL packs to OFF makes absolute sense. I will change my procedure.

(same procedure for B737 NGX).

The blue is up again and thanks for help

4 hours ago, Juergen said:

Start switch engine # 4: PULLED (does NOT illuminate); duct pressure rises to 51 & 50 psi; engine # 4 bleed valve ON; NO airflow to engine # 4; APU running; continuous ignition ON.

It seems there is an issue with the sim. Is anyone else seeing a duct pressure rise before the fuel cutoff switch is put to run? (Autostart switch ON).

 

I did not have any of the 'Start' pull-switches illuminate and I did not see duct pressure before selecting the 'Run'

2 hours ago, vc10man said:

I did not have any of the 'Start' pull-switches illuminate and I did not see duct pressure before selecting the 'Run'

 

Do you mean you didn't see duct pressure rising, Rick? Or did you just not look at the duct pressure?

Thanks.

Anyone knows why Hydraulic 1 is set to AUX by BA SOP before engine start ?

 

Thanks

Michael Moe

It's an air-driven pump, so using the Aux electric pump takes load off the bleed system and provides pressure to Hydraulic System 1 for steering and alternate brakes.