Start sequence B737
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Start sequence B737
I am trying to figure out what the reason is for starting engine #2 before starting #1 engine ?
Can somebody help me figure it out? Thanks. /pt
Can somebody help me figure it out? Thanks. /pt
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Official Boeing procedures on the NG actually calls for no 1 then no 2.
Most operators start no 2 first so that they can keep the cabin air flowing by operating the right pack whilst starting no 1.
Most operators start no 2 first so that they can keep the cabin air flowing by operating the right pack whilst starting no 1.
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My SOP , with APU , eng 2 then eng 1.
I was told , it has to do with Tank 1 which has decreased by APU use and other thing at the LEFT side of airplane while preparing to depart.
I was told , it has to do with Tank 1 which has decreased by APU use and other thing at the LEFT side of airplane while preparing to depart.
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I thought it was more basic reason than that... for all aircraft. Just logic of starting engine/s away from pax doors allowed them to be used in emergency. One of those habits from yesteryear, that has just carried on. And perhaps from days when they may have started #2 before doors closed.
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If fuel balance (per Arba re:APU) or cabin comfort (as I suggest) are not at issue, the choice can also be at the captain's discretion for many operators.
Above examples not withstanding, this seems to be not unlike the switching off on igniter usage - some will go by even-odd days, others eastbound or westbound flights, while many will have the crew alternate on segments using L then R igniters. (or vv)
Cheers !
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the start sequence is a throw back to days when apu's were less reliable or didn't exist on some a/c. the air start goes on the left hand side of the a/c so you have to start the engine(s) on the right hand first and when running remove the airstart and then start the left hand side.
Green Deisel,
On the 300 onwards (dont know about the 1/200) you must start the #1 engine first if using ground air start because it attaches on the stbd side of the aircraft.
No idea why we start #2 first in normal ops, I think outofsynch's reason is most plausable.
S&L
On the 300 onwards (dont know about the 1/200) you must start the #1 engine first if using ground air start because it attaches on the stbd side of the aircraft.
No idea why we start #2 first in normal ops, I think outofsynch's reason is most plausable.
S&L
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the start sequence is a throw back to days when apu's were less reliable or didn't exist on some a/c. the air start goes on the left hand side of the a/c so you have to start the engine(s) on the right hand first and when running remove the airstart and then start the left hand side.
Hot days aside and with no cart, does anyone have a start 1, 2 SOP on the NG ?
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number 2, number 1?
whilst flying in the states on the 737-2/3/400's our defunct airline started number 1 first, which did seem to make good sense. no change for the air start procedure and from time to time during pushback, they would come with last minute bags and be able to load since we hadn't started number 2 yet. (we could leave with bags missing). might have been a factor as to why they are defunct. it was quite an ordeal when the APU was inop and flying in alaska in the winters to remote airports. shut number 1 down. off load pax.close up, start 1, shut down 2, off load bags and takeon fuel, start 2, shut down 1, load pax and then restart 1. ground staff would do the walk-around check.
only when i came over here did i see the number two first. but then again, which side of the road do they drive on??? HAH!
i have always thought it odd that N2 is always the first call as well. and every checklist i have seen, "engine start levers---idle detent" --we just started the engines, where else would they be. and if not in proper position, you will see it when you try taxiing!
only when i came over here did i see the number two first. but then again, which side of the road do they drive on??? HAH!
i have always thought it odd that N2 is always the first call as well. and every checklist i have seen, "engine start levers---idle detent" --we just started the engines, where else would they be. and if not in proper position, you will see it when you try taxiing!
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XPMorten:
what edition is your 'old manual classic and NG
" ?
On my 'old manual ',at page 02.02.12 ,from May 24/91 ,I have the engine start procedure where it says 'Captain :Announce engine start sequence.Normal starting sequence is 2,1. ....."
I'm sorry I don't know how to insert a image,so I could've put here a scan of that page.
In the new manuals the reference of the start sequence has disapeared.
Also,when we do the pushback with a power-push it is attached to the left wheel,allowing us to start only the nr 2 eng.
The only time when we start first the nr1 eng is when we use the ground air-starter.
what edition is your 'old manual classic and NG
" ?On my 'old manual ',at page 02.02.12 ,from May 24/91 ,I have the engine start procedure where it says 'Captain :Announce engine start sequence.Normal starting sequence is 2,1. ....."
I'm sorry I don't know how to insert a image,so I could've put here a scan of that page.
In the new manuals the reference of the start sequence has disapeared.
Also,when we do the pushback with a power-push it is attached to the left wheel,allowing us to start only the nr 2 eng.
The only time when we start first the nr1 eng is when we use the ground air-starter.
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Our company starts 2 then 1 because of earlier fuel balance issues, and the possibility to use RH pack after starting no 2. engine in case of hot weather.
It is also company standard. (We have smaller types where the LH doors are by far preferable for rapid disembarkation)
Of course without APU the sequence is 1 then 2 for protection of ground crew.
Spuis
It is also company standard. (We have smaller types where the LH doors are by far preferable for rapid disembarkation)
Of course without APU the sequence is 1 then 2 for protection of ground crew.
Spuis
Traditionally (in the old days), with a twin engine aircraft the No 2 engine was started first. It may have started with the DC3 where the loading doors were on the left side of the fuselage as with most British and American types.
Again, traditionally in a four engine aircraft, No 3 was started first, followed by No 4 then No 2 then No 1. I have not heard of any specific reason why in the 737 No 2 is started first except it follows tradition.
Again, traditionally in a four engine aircraft, No 3 was started first, followed by No 4 then No 2 then No 1. I have not heard of any specific reason why in the 737 No 2 is started first except it follows tradition.
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Some airlines retained the start sequence on all of their 737s from the 100 series to the 900. You would start engine number two, then close the isolation valve and turn on the right pack to minimize the climate in the cabin.
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My company has quite a practical (safety driven) view on engine start sequence on our B732/3/4 fleet. When a push back is required, the engine on the "outside" of the turn is started first. The first engine is thus started while the aircraft is still moving straight backwards. This allows the ground engineer to walk "inside" the turn while the second engine start is in progress, preventing possible injuries in case of tow bar shear antics. Generally, at most airports, this makes for the downwind engine to be started first (provided the ramp is parallel to the runway).
Where no push back is required, we start the downwind engine first, minimizing static time with an engine running upwind of the fuselage (think fire).
Ground cart starts are done turning number one first (for reasons stated in an earlier post), disconnecting the cart, pushing back, then starting number 2 using crossbleed.
No wind, no pushback, we start number 2, then 1, just because it feels right.
My five cents' worth.
Cheers
Where no push back is required, we start the downwind engine first, minimizing static time with an engine running upwind of the fuselage (think fire).
Ground cart starts are done turning number one first (for reasons stated in an earlier post), disconnecting the cart, pushing back, then starting number 2 using crossbleed.
No wind, no pushback, we start number 2, then 1, just because it feels right.
My five cents' worth.
Cheers
