Use of Position and Strobes
 

I am wonder what the normal use of position lights (nav) and strobes are. I often see aircraft with the red and green position lights on for hours before departure, do these go on when the APU is fired up and strobes when entering the runway?

Thank you.

Position lights should only be used for night operations. They have no effect during daytime and during poor visibility. Put them on at night and turn them off during the day. Simple!

That's not standard practice in my company and certainly not in most other companies judging from a quick glance around the apron today.

Our company SOP is for position lights to be on all the time electical power is available to power them.

Anti-collision (reds) on just before pushback and off after engines are shut down on stand.

Strobes (whites) on as the aircraft enters any active runway and off as it exits an active runway.

MBX,

That is exactly what I have been seeing as well.
The Nav lights kind of say, "This machine is alive"

Nav light switch is never turned off on our aircraft. As soon as electrical power is applied to aircraft, whether internally or externally, the nav lights are on. Beacons go on with the first engine spooling over and strobes go on entering the runway for departure, off exiting the runway after landing. This is pretty much SOP amongst most operators on this side of the pond.

I think the UK military also have nav lites on at all times as SOP - extra collision avoidance?

Lol, I think Flying Fiona was thinking about the procedures in light aircraft:O

Have a look around chaps during the day. Now tell me what you see first. The nav lights or the Aircraft???

Many Airlines around the world don't use Nav lights for day light ops. Whats the point?

Now check the ANO and see when Nav lights should be used. I cant find anything about them being used during the day.

I tell you what, lets put are lights on every time we drive are cars!

If its SOP use them. But if it isn't DON'T.

For our operation -

Nav lights ON when it's dark. OK, if you leave them on all day, there's no problem other than shortening the bulb life.

Beacons ON just prior to engine start, and OFF after spool-down. This is advertising to the world that an engine or moving aircraft danger exists. Beacon is also ON during tow to indicate aircraft movement.

Strobes ON when entering the runway, OFF immediately upon exit (This includes any time that I'm crossing a runway). This is advertising to the world that 'I have the runway'. If, on approach, I see an aircraft at the holding point with strobe lights ON, I have only one reaction - Go Around!

Perhaps a little naively, I thought that this was universal.

Regards,

Old Smokey

Well, I was just really pointing out what happens in practice rather than what the ANO or other legislation requires. In 'our' airline we have the position lights on all the time.

And if I understand correctly, the logo and wing lights are also off when at the gate or taxiing to avoid excessive bright lighting which may blind/distract other pilots and are on (optionally I think) when entering the runway.

Is this correct?

John

Again it tends to depend on a particular company's SOPs. Our SOP is that the nose wheel light goes on for taxy on departure. Then wing landing lights on when cleared for take off. All landing lights are turned off passing 10000'/FL100 in the climb. Passing 10000'/FL100 in the descent the wing lights go on and the nose light goes on when cleared to land. Wing lights then turned off leaving the runway and nose light off when no longer required, usually turning onto stand. The logo light just tends to get turned on when it gets dark...

Also as you suggest it's pilot's discretion to turn lights off when they become a nuisance to other pilots, e.g. at the holding point with the nose light on.

Fiona, one might see the aircraft before seeing the nav lights but amongst the din of an apron one mightn't know that the aircraft has an APU running, or could be getting close to starting.

In previous lives, as others have attested above, NAV lights are on when the PU is to be started or ruinning. Let's others know that the ship is powered, and could start without too much notice.

Re driving with lights on. I average about 30,000km/year. Much of it country, highway driving with lights on day and night. An oncoming vehicle with lights on is much easier to identify than one without, and, in 20 years of drving thus, I wouldn't have replaced more than half a dozen headlights/globes.

System layout also mandates which lights are on & when. The NAV (Position) lights are normally on the Service Bus & on at all times there is power available to the aircraft. You don't notice them indaylight owing to the relatively low intensity.

Most authorities require the Flight Data Recorder to be on prior to engine start. To the best of my knowledge, all Boeings and most Bombardier aircraft do this by slaving the FDR ON to both of the Strobe lights and adding Beacon Lights ON (Red Strobes) as part of the pre-start checklist. The brighter, white, Strobes (normally refered to as Anti-Collision lights in most AFMs) are only switched on after takeoff clearance is given (as above).

BTW if you follow common military practice & switch off all strobes prior to shut down, you'll probably get a "No Fault Found" maintenance hit on a commercial jet as the FDR won't be communicating with the FDAU (or DCU on the CRJs & 604s) and the Maintenance Diagnostic Computer will log it.

FF
"I tell you what, lets put are lights on every time we drive are cars!"


What a good idea! I guess that is why in this country all cars manufactured, starting with model year 1990, have been required to have daytime running lights come on automatically.

:ok:

It was my understanding that the red anticols are turned on as soon as the aircraft's hydraulics are powered... at least this was my experience during my maintenance work (767s, MD11s) where it would be done inside the hangar to warn the personnel working there to keep clear of the landing gear, flaps and other bits that have the potential to mangle people simply by pulling a lever on the flightdeck.

So am I correct in assuming during normal operations it's done only when the first engine starts spooling up during or after pushback (the hyd demand pumps already powered)?

Sort of correct - Red anti-collision on before engine start or before moving on the pan (pushback, towing).

It stays on after shutdown until engines have run down below a specified min N1 (usually about 4-5%). The ground crew then know it is safe to approach the aircraft.

In our SOPs the first officer's before start overhead panel scan goes like this:

Pressurise hydraulics - fuel pumps on - packs off - anti-collision (red) lights on.

So obviously the hydraulics pressurise a split-second before the lights go on in our case - but all of this certainly happens before the push back is started or an engine turned.

Go around Old Smokey..?
 

I have often been given an "After the landing XX line up and wait behind" clearance at busy airports, mostly during tight take-off/landing sequencing. This will trigger the line-up checklist and item 3 is "Anti coll - white". I have therefore been at the hold with white flashing and no-one's gone around on me yet. Is it only a matter of time?

read FAA AC 120-74a a snippet posted below
8. USE OF EXTERIOR AIRCRAFT LIGHTS TO MAKE AIRCRAFT MORE CONSPICUOUS. a. General. (1) Exterior aircraft lights may be used to make an aircraft operating on the airport surface more conspicuous. Pilots may use various combinations of exterior lights to convey their location and intent to other pilots, air traffic control, and ground personnel. Certain exterior lights may also be used in various combinations to signal whether the aircraft is on a taxiway or on a runway, in position on the runway but holding for takeoff clearance, crossing an active runway, or moving down the runway for takeoff. (2) Because adherence to the guidelines in this AC are voluntary and aircraft equipment varies, flightcrews are cautioned not to rely solely on the status of an aircraft’s lights to determine the intentions of the flightcrew of the other aircraft. Additionally, flightcrews must remember to comply with operating limitations on the aircraft’s lighting systems. b. Exterior Lights. To the extent possible and consistent with aircraft equipage, operating limitations, and flightcrew procedures, pilots should illuminate exterior lights as follows: (1) Engines Running. Turn on the rotating beacon whenever an engine is running. (2) Taxiing. Prior to commencing taxi, turn on navigation, position, anti-collision, and logo lights, if available. To signal intent to other pilots, consider turning on the taxi light when the aircraft is moving or intending to move on the ground, and turning it off when stopped, yielding, or as a consideration to other pilots or ground personnel. Strobe lights should not be illuminated during taxi if they will adversely affect the vision of other pilots or ground personnel. (3) Crossing a Runway. All exterior lights should be illuminated when crossing a runway. CAUTION: Flightcrews should consider any adverse effects to safety that illuminating the forward facing lights will have on the vision of other pilots or ground personnel during runway crossings. (4) Entering the departure runway for takeoff or “position and hold.” When entering a runway either for takeoff, or when taxiing into “position and hold,” flightcrews should make their aircraft more conspicuous to aircraft on final behind them and to ATC by turning on lights (except for landing lights) that highlight the aircraft’s silhouette. Strobe lights should not be illuminated if they will adversely affect the vision of other pilots.
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9/26/03 AC 120-74A
(5) Takeoff. Turn on landing lights when takeoff clearance is received, or when commencing takeoff roll at an airport without an operating control tower. NOTE: The SOP of turning on landing lights when takeoff clearance is received is a signal to other pilots, ATC, and ground personnel that the aircraft is moving down the runway for takeoff.