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buzzc152
30th Jun 2015, 14:39
Anyone know what dictates whether runway centerline lights are put to the left or right of the centerline marking ?

Bergerie1
30th Jun 2015, 15:30
Depends on which direction you are landing!

coldair
30th Jun 2015, 15:49
Excellent answer, Bergerie1 :)




coldair

Dream Land
30th Jun 2015, 16:11
Did someone really ask that? :ugh:

GlobalNav
30th Jun 2015, 16:23
That's OK. It's early.

Always wondered why some nails have the head on the wrong end.
My dad said they were for the other side of the house.

buzzc152
30th Jun 2015, 19:03
Come on, you know what I mean. It's a genuine question. Regardless of which way you're looking at them, is there a reason for them to go on one side or the other ? I seem to remember that they have to be within .8m of the centreline but which side ?

Bergerie1
30th Jun 2015, 19:06
buzz
I say again, it depends on which way you are landing (or taking-off). Since most runways are used in both directions, I am sure you can see the issue.

Cows getting bigger
30th Jun 2015, 19:46
I don't know about lateral displacement but I do know that they shouldn't protrude more than 16mm from the surface. :ok:

In homage to Paul Daniels, "Not a lot of people know that"

buzzc152
30th Jun 2015, 19:48
Ok, let me start again Bergerie. I'm well aware that the lights will APPEAR to the left or right from the perspective of someone standing at one end or the other. That's pretty obvious and quite clearly not what Im getting at.
Let me ask it in a different way. Let's take a runway, 27/09. On this runway the lights are on the south side of the centerline, and will always be on the south side whichever way you approach it. My question is ; is there a reason to put the lights on the south side rather than the north or is it random ?
Not sure how else I can ask the same question.....

RAT 5
30th Jun 2015, 20:04
Always wondered why some nails have the head on the wrong end.
My dad said they were for the other side of the house.

The ones with the heads on the top are for the floor; the ones with the heads on the bottom are for the ceiling. Everybody knows that.

Nobody has mentioned Corollas yet; nor north/south hemisphere. Could it be the left/right political bent of the airport manager.
I always remember one pain in the ar&e captain who demanded I keep it on the centreline for takeoff. I did so and we went 'dunk, bunk, thump, dunk, down the runway. I shifted it a foot off the noise and was berated. After takeoff I called, "95". He was confused and I said, "the number of centreline lights we just flattened." Perhaps I should have used the white paint, not the lights.

Bergerie1
30th Jun 2015, 20:19
buzz,
Now that is an interesting question! I have never noticed whether they are on the south or the north side. Can anyone enlighten us?

Goldenrivett
30th Jun 2015, 20:38
Hi buzzc152,
is there a reason to put the lights on the south side rather than the north or is it random ?
If you have parallel runways, then you put the lights towards the "inside" of the centreline so the power cables are shorter.

See LHR27L.png (http://www.blackholes.org.uk/PP/LHR%2027L.png)
& LHR27R.png (http://www.blackholes.org.uk/PP/LHR%2027R.png)

thanks to Google Earth.

vapilot2004
30th Jun 2015, 21:07
Within 2 feet of the centerline is the rule in the states. I am unaware of an FAA or ICAO standard about which side, however I have been told the Australians prefer the left side of center on the most frequently used landing direction - obviously in locations with a prevailing wind.

In Scotland the rule is nearest to the power source - to save on wire. :}

ad-astra
30th Jun 2015, 23:29
Seem to remember a similar thread a long time ago and one poster suggested the lighting was located on the side closest/furthest away from where the (original) Control Tower was located. Australian instance.
Fact, fiction, urban myth. I don't think the issue was resolved then either.
All I know is that some FO's have an uncanny ability to hit every one on a takeoff roll. I could not do it if I tried!

misd-agin
1st Jul 2015, 00:19
Heard for years that, in general, it's on the side away from the tower.

Something to look for.

misd-agin
1st Jul 2015, 00:24
Hitting them on takeoff roll - years ago, on a Dash 7, the Captain would line up with the nose wheels straddling the lights. PNF would estimate how many were hit on the takeoff roll and a $0.10 contribution per light went into the beer fund for that night.

chevvron
1st Jul 2015, 01:17
They're not offset but always on the centreline.
The Trident airliner was designed for use in Cat 3 conditions and it was so accurate that they designed the nosewheel offset so that it didn't hit the centreline lights when carrying out an autoland.

FLCH
1st Jul 2015, 01:49
They're not offset but always on the centreline.
The Trident airliner was designed for use in Cat 3 conditions and it was so accurate that they designed the nosewheel offset so that it didn't hit the centreline lights when carrying out an autoland.

I was under the impression that the avionics at the time took up so much space the nosewheel had to be moved off to the side to fit it all in.

My bad if I'm wrong.

chevvron
1st Jul 2015, 05:24
I did add a smiley; don't know if I'm right or you are but that's the story I was told!

ACMS
1st Jul 2015, 10:28
Boy some here have a lot of excess brain capacity...........:sad:

Worry about important stuff.....:ok:

dixi188
1st Jul 2015, 13:15
Maybe the lights are on the centre line and it's the white line that is off centre.
Always thought the raised lights were for blind pilots so they use them like Braille.;);)

lurkio
1st Jul 2015, 13:53
I thought they were there to see if my haemorrhoid ointment was working.

Anybody know what height taxiway lights must be because in Belfast they have some absolutely enormous teeth loosening buggas.

Musket90
1st Jul 2015, 18:47
I think Goldenrivett's reasoning is the best.

If power supply is closer from one side of the runway then it means less cabling so less cost !

Colours389
2nd Jul 2015, 23:23
I have for more years than I care to remember avidly browsed this forum and found it an excellent place to get a more in-depth understanding of aviation. This thread however is the first article that has ever made me laugh out loud. The quick-witted and wonderfully sharp sense of humour has been a pleasure to read. RAT 5, Bergerie1 et al please continue, your comments are appreciated. As an aside, I well remember being in the jump seat of a B757 (prior to 9/11) and hearing the thump, thump, thump as we accelerated down the runway.

ZeBedie
2nd Jul 2015, 23:43
What I don't get is why the lights aren't on the painted centreline - why should there be separated? Back in the day, they weren't separated, were they?

Only possible reason - easier to paint the lines if you don't have to worry about the lights.

Cows getting bigger
3rd Jul 2015, 07:53
Lurkio - 25mm but then you knew that? :O

stilton
3rd Jul 2015, 09:27
Some runways have them recessed.


Why can this not be the standard, then there's no issue ? :ugh:

Bergerie1
3rd Jul 2015, 09:53
ZeBedie,
Another good question. Why, indeed, are the lights not aligned with the painted markings?

Jwscud
3rd Jul 2015, 10:41
If you can align the aircraft by the inch on landing you're a better man than me!

what next
3rd Jul 2015, 11:38
Why, indeed, are the lights not aligned with the painted markings?

Maybe so that they don't have to cover all the lights when repainting the centreline every now and then? That's how a lazy person like myself would do that at home :)

Capt Claret
3rd Jul 2015, 12:48
Why, indeed, are the lights not aligned with the painted markings?


It couldn't possibly be to assist avoiding the ker-thunk, ker-thunk on the take off run or landing roll. Could it? :\

Bergerie1
3rd Jul 2015, 12:56
Capt C, I was never clever enough!!

mnttech
3rd Jul 2015, 13:44
FAA AC 150/5340-30H
Runway centerline lighting.
(1) Location. The runway centerline lights are located along the runway centerline at 50 ft. (15m) equally spaced longitudinal intervals. The longitudinal tolerance for runway centerline lights is 2 ft. (0.6 meter). See Figure 33 for a graphic of the runway centerline lighting layout. The line of runway centerline lights may be uniformly offset laterally to the same side of the physical runway centerline a maximum of 2.5 ft. (0.8 m) (tolerance 1 inch (25.4 mm) measured from the physical runway centerline to the fixture centerline. For any new runway, the light base installation must be no closer than 2 ft. (0.6 m) (measured to the edge of the fixture base) to any pavement joints. Runway extensions of existing runways must use
the convention already established for that runway. See paragraph 4.3 and Figure 45 for additional information about the taxiway centerline lighting location requirements related to runway centerline lights for major taxiway turnoffs. See AC 150/5340-1 for additional information about runway centerline marking widths and location.

EEngr
3rd Jul 2015, 15:42
easier to paint the lines if you don't have to worry about the lights.What, me worry?

http://www.improbable.com/wp-content/uploads/2013/02/images-3-250x187.jpeg

RAT 5
3rd Jul 2015, 16:29
I've noticed over the many years of observation that many F/O's land right of centreline. I asked many, why? The best answer I had was "I didn't want to break the lights, and I'm saving the white paint so it lasts longer." Can't argue with that.

It's a bit like the Air UK F27 crew who landed wheels up: why? "Our pay rise was denied due to increased costs so I was trying to save tyre wear."

Musket90
3rd Jul 2015, 20:16
Might be better to have the centreline lights on the actual centreline and have the paint markings offset as it's easier to see in daylight where the runway edges are.

captjns
3rd Jul 2015, 23:54
Anyone know what dictates whether runway centerline lights are put to the left or right of the centerline marking ? Is the airport North or South of the Equator?:} Anyway, real pilots don't need center line lighting.:ok:

Microburst2002
4th Jul 2015, 07:33
I have had several questions moved to the Question forum, and I don't understand why this one remains in this.

capster
6th Jul 2015, 07:37
Why are cats eyes used to mark the centreline of roads?

Because if they used cats arses they would have to kill twice as many cats.

aerobat77
6th Jul 2015, 08:03
Now that is an interesting question! I have never noticed whether they are on the south or the north side. Can anyone enlighten us?

for runway 18/36 this question becomes really interesting .

amazing thread :ok:

Chiller
7th Jul 2015, 05:48
I think you'll find, that in the USA, in most cases (not all), the painted center line is on the side of the main terminal complex.