Actually, I meant to say at night is when I noticed this the most. Makes sense. Best regards, Jeff Moss

UK - Stobes on from second you enter a runway - left on at all times in flight and not off again until landing - Beacon on from moment engines are to be started(it helps personnel see the aircraft is starting or engines are running) until engines are shut down. Nav lights(steady) on all time there is power to the aircraft so even on stand will be on. Aircraft in UK will use taxilight on ground in day also, as it indicates the aircraft is about or is moving. Some pilots will switch it off if they are giving way to another aircraft, one so as not to dazzle, but also to help show that they are holding for it.and turn it on again once they start moving. Landing lights turned on for takeoff and switched off around 10k and back on again around 10K - some will turn wing and turn off lights on once cleared to land as a visual reminder to themselves that they have been given landing clearance. Use of lights is governed by law - and whole set of procs on what is allowed to be unserviceable etc and used - but some of the descriptions I have given are also a "best practice" adopted by many pilots.

UK - Stobes on from second you enter a runway - left on at all times in flight and not off again until landing - Beacon on from moment engines are to be started(it helps personnel see the aircraft is starting or engines are running) until engines are shut down. Nav lights(steady) on all time there is power to the aircraft so even on stand will be on. Aircraft in UK will use taxilight on ground in day also, as it indicates the aircraft is about or is moving. Some pilots will switch it off if they are giving way to another aircraft, one so as not to dazzle, but also to help show that they are holding for it.and turn it on again once they start moving. Landing lights turned on for takeoff and switched off around 10k and back on again around 10K - some will turn wing and turn off lights on once cleared to land as a visual reminder to themselves that they have been given landing clearance. Use of lights is governed by law - and whole set of procs on what is allowed to be unserviceable etc and used - but some of the descriptions I have given are also a "best practice" adopted by many pilots.

True. Also, I think some airline's SOPs are to turn the beacon on when they pressurize. You don't want an elevator to hit somebody (a giant passing by for instance). On the 737 you presurize B first (A controls the nose wheel, which wouldn't let the tow-truck to pivot). What i've seen where I've flown is that they turn on the beacon and then turn off both hyd pumps (elec and engin driven) for A, and turn both pumps for HYD B on. After pushback, then they pressurize A. So, it is safe to say that good operating practice is to turn on the beacon whenever standing near the airplane is going to get more dangerous than normal.

I thought beacon was switched on when the aircraft is running off of APU, ie, the ground power has been disconnected.

...some airlines won't pay for ground power and some fields don't even have GPUs. They do it all on APU yet the beacon isn't on all the time. The law says, you turn it on when engines are on. Good operating procedures are to turn them on when control surfaces become movable (Hydraulic pressure).

Ahhh. I see. I've noticed BA and Virgin turn on beacon when changing to APU from ground power but for the airlines who don't use Ground power it must be that.

Ahhh. I see. I've noticed BA and Virgin turn on beacon when changing to APU from ground power but for the airlines who don't use Ground power it must be that.

Are you sure about that? Where is that exactly? I remember when getting to the airplane, APU would be turned on long time before passengers arrived. On most fields non hub fields, it was not only for electrical, but also for air conditioning. The beacon is one of the last things you turn on before pushback and is really when it all starts, when the airplane is about to act as one. Usually APU has been running long before that moment.

With regards to the Virgin captain, I got a jumpseat ride in a A340-600 from EGLL-KJFK. And I saw the switchover from ground to APU and that was when the beacon went on.

Makes sense only if he pressurized right after that. Why would he turn on the beacon when putting the APU online say, 20 minutes before pushback, with no pressure and engines off. It would also freak out the ground staff.

I don't think he pressurized. I can't really remember. It was a while ago and I just remember him turning on the beacon then because I though ohhh! So that's when you turn it on.

UK - Stobes on from second you enter a runway - left on at all times in flight and not off again until landing - Beacon on from moment engines are to be started(it helps personnel see the aircraft is starting or engines are running) until engines are shut down. Nav lights(steady) on all time there is power to the aircraft so even on stand will be on. Aircraft in UK will use taxilight on ground in day also, as it indicates the aircraft is about or is moving. Some pilots will switch it off if they are giving way to another aircraft, one so as not to dazzle, but also to help show that they are holding for it.and turn it on again once they start moving. Landing lights turned on for takeoff and switched off around 10k and back on again around 10K - some will turn wing and turn off lights on once cleared to land as a visual reminder to themselves that they have been given landing clearance. Use of lights is governed by law - and whole set of procs on what is allowed to be unserviceable etc and used - but some of the descriptions I have given are also a "best practice" adopted by many pilots.

I think this would be the most accurate post on the subject.

From my experience at CO, FX, and AA the beacon was on when pressurized and jet way removed.Also the ramp personnel were told to never approach a plane with a beacon on. (I've heard pilots get annoyed no one was coming to connect power/jetway when they inadverdantly left the beacon on.)

From my experience at CO, FX, and AA the beacon was on when pressurized and jet way removed.Also the ramp personnel were told to never approach a plane with a beacon on. (I've heard pilots get annoyed no one was coming to connect power/jetway when they inadverdantly left the beacon on.)

The cabin is pressurized as the aircraft climbs, not on the ground,cabin pressure has nothing to do with it. Read JC75 post, it is correct.

The cabin is pressurized as the aircraft climbs, not on the ground,cabin pressure has nothing to do with it. Read JC75 post, it is correct.

I'm sure SKEWR meant hydraulic pressure, check FCOM vol. 1, NP.21.31

From my experience at CO, FX, and AA the beacon was on when pressurized and jet way removed.Also the ramp personnel were told to never approach a plane with a beacon on. (I've heard pilots get annoyed no one was coming to connect power/jetway when they inadverdantly left the beacon on.)

Exactly. When ready to push, on the 737 the flow is normally:-Beacon light on.-Hydraulics A OFF (push back guy will appreciate it).-Hydraulics B ON.-Fuel pumps ON.-Packs OFF And yes, when on the ground you say pressurize, you normally mean hydraulics.