Which engines are started first on which aircraft?

Question

I have heard that when starting starting up an Airbus you begin with engine #2, with Boeings its #1 first, and then I've also heard alternative stories such as a 757's engines are started with #2 first, on 737s it's #1 first and some Airbuses are #1 first, etc. I would just like someone to clarify what the correct sequence is depending on the plane type. Thanks.

Answer 1

i don't think it matters much, but pilots mostly start the engines from the outboard ones on the left(#1) but i've heard that on four engines aircrafts like the 747, you can start engines in pairs.

Answer 2

Whichever one that you choose will be the one that you'll start first. There's really no requirement to favor any engine over the others. Of course if there are any late bags on their way, you'll be well advised to start the #1 engine first. The cargo doors are on the right side of the airplane. Sucking rampers and late bags into the engines is considered bad form.

Same goes when you're doing an external start at the gate. Start the engine that the guys pulling the air and electrickery WON'T be on.

The 757, however, has its engines labeled Left and Right, not 1 and 2 as the 737 and all of the rest do. Anyone know why?

Answer 3

It does depend on the aircraft, especially where one specific engine provides hydraulic power for instance. That isn't often the case these days and, all things being equal it depends either on the company policy or how the aircraft is parked. If there is equipment or personnel nearby on the ground it's usually the engine farthest from that which is started first.

Otherwise, it's down to the captain's preference and lots just start in the order 1-2-3-4 for simplicity's sake.  They count from the left outer in that order and that's what the bloke on the ground is normally expecting.

On our piston twin we always start No 1 (the left engine)  first simply because that's the one nearest the captain and it's easier to see and hear what's happening.

Answer 4

On the P-3, we start 2-1-3-4 due to the fact that there is no generator on #1, and you want a generator running after the first start.  Also, there is no air conditioning on 1 and 4.  #2 is also on the side of the pilot (left) commanding the start, so it's natural to start on the side you can see first.

Answer 5

i like to start both at a time because the APU is able to supply sufficient duct pressure to both engines simultaneously, otherwise start the left ones followed by the right ones. if starting at the gate then start the right one first because of the aerobridge.

Answer 6

There is no set procedure, and captains have their own rationales.  On the 727 we used to start the center engine (#2) first and then either outboard engine next.

On piston engine airplanes it depends on the preferences of the captain and whether or not you have an observer/fireman on the ground.  If I had a person on the ground, I preferred to start the old DC-6 in 2-3-4-1 order, because it always made more sense to me to start the inboard engines first to make the airplane easier to control if a brake gave way.  It's a small matter.

If you don't have a ground crew, it makes more sense to start them 1-4-3-2  so you can see and hear the first two engines more easily, as mentioned by a previous answerer.

On jets it really doesn't matter.  We used to start the 747s 1-2-3-4 because it is easier to keep track of what you are doing.

Answer 7

In the Metroliner it depends on what type of start I'm doing as to what engine I start first.  If I have a GPU to start me I'll start the left engine first.  My view of the left engine is much better than the right so I can see if anybody could be in a potentially hazardous area.  If I'm doing a battery start, however, the book recommends starting the right engine first due to shorter wiring from the batteries to the engine-- so I do what the book says.

Answer 8

In the past, on four- engined piston aircraft, the inboard engines (i.e. numbers 2 and 3) were started first so that if there was an engine fire the fire crew did not have to pass a running propellor.

Answer 9

There's no simple answer.

On the Boeing 767 (and I imagine the 757 because they're very similar as far as cockpits and procedures go), the right (#2) engine is started first. However there is nothing to stop you starting the left engine first except the fact that it's not written that way. It has no noticeable effect on the starting process.

On the Boeing 747-400, we started the right engines (#3 and 4) before the left ones. They were started in pairs, but even this procedure changed under some circumstances to start them individually.

On some older aircraft there were reasons to do it in a particular order. This was to do with which electrical or pneumatic or hydraulic items you needed to get online first, and which engine powered them. An example is where wheel brake systems are powered by the right hydraulic system.

This is not usually a problem nowadays with modern systems that can often be tied together or get power from another source (like electric demand pumps in the case of hydraulics), and APUs which can power any electrics needed until all engines are running.

I fly the 767 and the engines are referred to as "left" and "right" and everything is labelled that way (as opposed to #1 or #2). I have absolutely no idea why. For all I know it could've been the personal preference of the design engineer at the time!

Answer 10

It is always left to whether Airbus or Boeing for the simple reason that the APU which powers the aircraft  and starts the engine fuel line is in the left side. Starting with the right you have to open cross bleeds valve for the pneumatic and fuel lines  to get from left to right side.

Usually when they start right to left it is because  the electrical supplied by the right main buses connects the aircraft right away to its ground service buses and battery charging taking the load from APU.

Answer 11

Could be the closest one to the battery (King Air), could be which ever the operating handbook says to.  Could be Company policy worked out with the FAA, etc., etc.

It, however, is not done willynilly; the Feds and the engineers decided how it's done.

Answer 12

For safety issues, they start engines on the right side first, then the left. The reason, you don't want someone on the ground walking in front of  a running engine. This, of course, assumes the aircraft is parked with the right side away from the terminal.

Answer 13

usually on prop aircrafts, its the farthest one from the person starting the a/c, because its hard to hear if there is any problems if you start that one second because of the noise from the inside engine.

Answer 14

I don't know about the Boeings. On the Airbus A320, engine 2 is started first because it powers the yellow hydraulic system, and the yellow system pressurises the parking brake.

On the A330, engine 1 is started first because it powers the hydraulic system for the parking brake.