Start sequence 2 then 1. why ??

[POT NOODLE HORN]

On 737-800 (ryr/fr) does the no2 engine get started first.... sequence 2-1 ??

[airseb]

well why shouldn't it? seriously it's the same on the airbus, on the 777 and it was the same on the Be58 I trained on. it's not unusual at all

seb

[hvogt]

Once a 737 driver told me it was because the more important hydraulic systems were powered by engine no. 2.

[airyana]

good question

I don't know however, I have thought about this before, and I noticed that the start sequence for starting with a ground air source is 1 and then 2, and external air should be disconnected and the no 2 engine started using crossbleed start, to minimize hazard to ground personnel. So possibly, the reason for starting 2 and then 1 under normal circumstances, is the same as starting 1 and then 2 when a ground air source is connected.

[A Very Civil Pilot]

As I see it....

For the first start of the day, the engine is ignited using the right igniters. These are powered from the AC standby bus, so it gives you a check that the bus is working. The AC standby bus is powered by the battery bus, which as well as being powered by the battery, is also powered from TR 3. TR 3 is in turn powered by AC bus 2, which is powered from Gen bus 2 and ultimately from Gen 2 on the No 2, right hand engine. Obviously you'tr not using gen 2 to start the engine, but at least it all follows through.

Hydraulically engine 2 will also give you normal brakes, which will be a benefit if you're not chocked or connected to a tug.

Ground personnel are on the right to check the engine starts correctly. A problem is more likely to occour on the first engine to be started.

Not that I have ever seen it recommended, but pax doors on the left can still be used if no. 2 is running!!!

[rogerg]

, standard Boeing procedures leave both electric hydraulic pumps off for start

All airlines that I know of turn the electric hydraulic pumps "on" during the pre-start checks, after getting the thumbs up from the ground engineer.
one of the checks is "all pumps on" during pre start.

[BOAC]

Covered before on PPrune and the reason I put forward was that it was 'traditional' and was supposed to have come about due to the location of the battery in early multi-pistons, which was, I was told, in the right wing and therefore had less cable current loss on start-up. As good as any.

Try this as well?

[tp555]

In my experience, the number 2, or right hand engine is started first traditionally because all airbridge / passenger servicing occurs on the left hand side of the aircraft.

The only time the number 1, or left hand engine is started first is when a crossbleed start is required. To accomplish this you first need to start one engine with ground pneumatic assistance as opposed to the APU and due to the location of the airbridge, the starter unit is parked on the right hand side of the aircraft.Therefore making starting the right engine first an unwise decision if you'd like to see your ground start unit returned. Once the left engine is running, the ground cart disconnects and the aircraft starts the remaining engine using pneumatic air bled from the previously started engine. This procedure is often reffered to on the type I fly at least as a Ground Air Start and then subsequently a Crossbleed Start.

[INLAK]

On the A330, the No. 1 engine is started first.

[cribble]

My company's 777s start both at once. Handy.

[fivegreenlight]

My company's 777s start both at once. Handy


777 eh,
do they shut both down together aswell, manually or automatically ?