Engine Start-Up on 4-Engine Aircraft

#1

Feel free to switch the category. I don’t know where this should belong in, so I’ll just leave it in general for now.

Hey IFC,

I may be a noob for saying this, but how do you start engines on a 4-engine aircraft like the B747, A380, and A340. I know for a two-engine aircraft, you have to start one engine either before or during pushback and then the other after pushback, not at the same time. How do I start 4-engine aircrafts properly?

Thanks!

Btw, if this is a duplicate, you may close it (but leave the link to that topic, so I can go check it out), but I have used the search bar and haven’t seen any topics relating to starting a 4-engine aircraft.

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#2

I mean you could do a two engine taxi in order to conserve fuel. I would recommend turning on the inner engines (2 and 3) then 1 and 4 later on. So I would say start up the two inner engines

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#4

Well,
I normally start number two first, is in real life the inboard #2 engine supplies the air for the cabin. I then start #3 the other inboard engine before taxing.
If the takeoff line is very long, I will not start the other two until second or third in line, at that point you can start both at the same time if you want.
If the takeoff line is not very long I will start the other two when I am taxing.

Remember, this isn’t 100% accurate or should be used in every situation, for instance, if you are right on the MTOW you might need three engines to taxi.

In the MD-11 I normally start 1 and 3 and start the second when taxing or in line for takeoff.

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#5

I thought it depends for aircraft type? This is an example of an accident in whichever a leading factor was the captain thinking one engine supplied cabin air, when it was actually both that supplied it. This example is just between two models of the 737 having different systems, so between completely different aircraft Imwould expect it to vary.

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#6

We are talking about how to start a 4-engine aircraft. The 737 is a 2-engine aircraft. Yes, I know that both engines on the 737 supply air to the aircraft.

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#7

I know an Atlas 747 pilot. There start procedure is 1 and 4 at the same time and then 2,3 at the same time.

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#8

Yes but I’m just using the 737 as an example.

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#9

I have never seen or been on a flight when the engines are started at the gate or early in pushback (Pushing out of gate). Usually engine (2) is started near the end of pushback (along the taxiway) and then engine 1 is started after pushback is finished. After this, flaps are set.

#10

My procedure for 2 engine A320 is start engine just after pushback start second once pushback finished pre taxi.

I’m not sure 4 engine aircraft.

#11

I’ve been asked this many many times and it seems folk don’t know the answer I give either. So here goes.

The order for a standard 4 engine startup (depending on company standard procedures) is 3, 4, 2, then 1. It means you start both engines on one side before moving on to the other, in-board then outboard.

The reason is because when you have one side running or still starting, you will have a “green zone” or safe side that passengers and crews can escape to.

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#12

From watching Pilots Eye TV and simular I would say that this is the correct procedure. 3&4 first and then 1&2.

I have heard of TP aircraft taxing on single engines, but not seen that on any Jet aircraft I have been on, either twin or 4 engine aircraft including where is long taxis such as at JFK or LHR.

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#13

Depends on the aircraft. The A340 and A380 start with Engine 1 and 2, then 3 and 4. Here is an example from one of the most famous A380-pilots in the world.

The 747 starts with Engine 4 and 3, then 2 and 1, as you can see in this video.

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#14

When starting the engines should i start 2 at the same time ag 1 and 2 then 3 and 4 or all separately

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#15

On the C-130 it’s 3,4,2,1 Three is aircraft right inboard, 4 is aircraft right outboard, 2 is aircraft left inboard, 1 is aircraft left outboard.

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#16

I always turn on the engines one by one, and don’t start taxiing until all of the are running. In two engine aircraft, I start number 2 and then 1. In three engine aircraft, I start 3, then 2 then 1. In four engine aircraft, 4, then 3, then 2, then 1.

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#17

In order to check they are working before takeoff, you have to have all your engines running during taxi. On the inbound taxi, 2 engines can be used then.

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#18

On a twin ‘right’ then ‘left’, on a 747, ‘right 2’ then ‘left 2’.

We don’t do engine out taxi on heavies as the cost of wear to the engine applying full take off thrust without an adequate ‘warm up’ period is greater than the cost of the fuel consumed during taxy.

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#19

I do a 2 4 on push then 1,3. The way I do a two is 2 then 1. (2 on pushback) .

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#20

I find this a really good question: ‘how to do this properly’. Too bad many responders didn’t read your question properly.

Luckily, in between the many “well, this is how I do it” answers, I believe you got one or two answers that describe how it should be done.

I think the YouTube clips from @Starley contain good info.

Apart from this I found two links that are worth a read:
https://www.quora.com/In-which-order-are-plane-engines-started-and-why
http://www.airliners.net/forum/viewtopic.php?t=738851

The pilot in the last link says: 4-3-2-1. This is a 747. Could not work out if this applies to all 4-engine aircrafts. I suggest @Aernout can tell us about the A380?

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#21

This is one of the best answers I have received so far. Thank you!

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