light spacings

[captain coldfront]

Can anyone tell me the standard spacings for centreline and edge lights please? Or suggest a reference.

[FlightDetent]

15/60m usual CAT II runways,
30/60m

FD. (un-real)

[dv8]

From our company's B4

'The spacing of TDZ lights is always 30m There is no standard for Centreline and edge lighting If spacing is not known ask ATC'

[OverRun]

Edge lighting
The longitudinal spacing of runway edge lights must be uniform and be:
(a) for an instrument runway, 60 m +0 / -5 m;
(b) for a non-instrument runway, 90 m ± 10 m, or 60 m +0 / -5 m if there is an intention to upgrade the runway to an instrument runway at some time in the future.
(c) for non-precision instrument runways intended to be used in visibility conditions of 1.5 km or greater, where existing edge lights are spaced at 90 m ±10 m, it is acceptable to retain this spacing until the next replacement or improvement of the edge lighting system. (This situation typically arises from an existing non-instrument runway being upgraded to a non-precision instrument runway, but without re-installing the runway edge lights to the 60 m +0 / -5 m standard.)

Centreline lights
Runway centreline lights must be located from the threshold to the end at longitudinal spacing of approximately:
(a) 15 m on a runway intended for use in runway visual range conditions less than a value of 300 m; and
(b) 30 m on a runway intended for use in runway visual range conditions of 300 m or greater.


Source: Australian Manual of Standards Part 139 - Aerodromes Chapter 9: Visual Aids Provided by Aerodrome Lighting. These [new] OZ rules are aligned closely to ICAO.

But let me pull out ICAO Annex 14, vol.1, section 5:
Edge: not more than 60m for instrument runways, and not more than 100m for non-instrument runways.
Centre 7.5m or 15m on cat III runways. 7.5m, 15m, or 30m on Cat II or other runways.

There, that should throw some light on the subject (groan).

[captain coldfront]

Thanks for the info guys.

Now I'm no longer in the dark !

[Sir George Cayley]

For completeness you may want to consult the UK CAA CAP168 document. In it you'll see that the UK posts a difference to ICAO Annex 14 wrt 7.5m spacing on strait sections of lights on TWYs

Sir George Cayley

[compressor stall]

Just hijacking this thread for ozmates.

How do you know exactly what the edge spacing is as a pilot? In what manual are they printed? How do you know as the mist is thickening if they plan to upgrade the runway out in the boonies that you are landing at (your rule B)?

(The idea being trying to count lights to calculate RVR for takeoff in cr@p).

[OverRun]

compressor stall

I’ve been trying to think of a good answer, and I can’t.

I don’t think the light spacing is printed in any manual – certainly not ERSA. There is some medium term move to standardise the [drafting] drawings of an airport which will (may) show the light spacing, but that is of no use to you in the cockpit.

The light spacing could change on you, and the only slight hint might be a temporary NOTAM about runway works that certainly wouldn’t mention the light spacing changes. The only mitigator I can think of is that (a) I wouldn’t think the rule B is a common occurrence – not many runways get upgraded to an instrument runway very often. And (b) the runway lights last a long time and get replaced sort of once in 20 years.

But it is quite possible for a light spacing change to ‘slip between the cracks’, and I can’t think of a reliable and practical way of preventing it.

[DFC]

Light spacing is published in the AIP entry for the appropriate aerodrome.

For aerodromes with human observer RVR, the whole system is calibrated on a regular basis and only observations made from the "calibrated" observation point are allowed.

If there are no RVR reports available and you are making an assessment from the cockpit then a call to ATC will give you the spacing at any aerodrome - even if they have to ring the aerodrome manager for the info!.

Regards,

DFC

[OverRun]

DFC, I'm not sure that the light spacing is still published in the AIP entry for the appropriate aerodrome, and would appreciate a pointer to it.

What I found is that the general AIP (June 2005) says (wrt to edge lighting) much the same as I quoted above:

4.4 Runway Edge Lighting
4.4.1 Runway edge lighting has longitudinal spacing of 60M for instrument runways but may be up to 90M for non-instrument runways and for non-precision approach runways at country aerodromes.


Then I trawled through the AIP online, and the aerodrome charts in the DAPs and they don't show it (links below for non-Oz PPRUNERs)
http://www.airservices.gov.au/publications/pending/dap/BRMAD01-103.pdf
http://www.airservices.gov.au/publications/pending/dap/BUDAD01-101.PDF

So a mate checked his Jepps, and the light spacings have been removed from those except "where not standard."

Here-in lies the rub - since it is standard according to the MOS Part 139 to have 60m OR 90m spacing on the same class of runway, a change from one to the other shouldn't trigger a "non-standard" action. So there is no reason for the plates to show anything to reflect the change.

Turning to a practical example, Broome 10/28 is a non-precision approach runway with a DME/NDB and a GPS approach.
(using my simple-man's rule of thumb: instrument runway = ILS; non-precision approach runway = GPS/DME/VOR/NDB; non-instrument runway = nothing)

At present its lights are at 90m spacing. If they get replaced (because the earth leakage has got too high because the cables are old and rotten or the ants have eaten too much insulation and it is cheaper to replace than repair), then they'll have to get replaced to the 60m spacing.

I still can't see where any pilot will get told about that. There is no tower, so you'd call Brisbane (4000 kms away). And come night-time, the airport manager is tucked up in bed or down the footy club. I can't see a reliable and practical answer. Can anyone else?

[OzExpat]

You've come up with a damned good question there Stallie. And, like everyone else so far, I just wish that I could come up with a damned good answer! :uhoh: I have an idea that the light spacings in PNG are standardised on 60 metres, but I won't be able to check on that until next week.

Meantime, I'll keep watching this thread to see if anyone else can come up with a "damned good answer"! :D

[Bill Smith]

You have come up with a beauty CS ! I was sure that it used to be published in AIP/Jepp info but can't find it anywhere.
If you are lucky enough to work with a company that supplies you with a RTOW book, it is in the port information. Well it is in ours anyway.
As suggested earlier looks like a call to the Aerodrome Manager. What a pain in the arse.
Would be so easy to have the info on the 10-9 page.

I imagine that it is recognised, it is 60 Mtrs for instrument runways and UP TO 90M for non instrument runways.

When in doubt in the Boonies get some one to run down the strip in the car and measure it :-)
Plan "B" stay in bed until the weather gets better

[411A]

UL153:
Good morning tower, UL153, ready for departure.

Tower:
Ah....good morning AirLanka, we have a slight problem, the RVR has just gone Tango Uniform.

UL153:
We can see three edge lights on each side of the runway (confirmed at 60m spacing...ICAO standard).

Tower:
Well then, if you have the required visibility, cleared for takeoff.

Nice folks in DXB.

[compressor stall]

I did ask the question on here about 18 months ago after taking off in light misty fog in predawn gloom in my previous job - got me thinking of a way to calculate it. Needless to say, no answers then either!

Not too much call for lights in the current job; surface and horizon definition however..... :E

[DFC]

OverRun,

Then I trawled through the AIP online, and the aerodrome charts in the DAPs and they don't show it (links below for non-Oz PPRUNERs)

The AIP does indeed show the light spacing.

The Entry for Broom YBRM clearly states that the light spacing on Runway 10/28 is 90m.

You can see it for yourself at

http://www.airservices.gov.au/publications/current/ersa/FAC_YBRM_17-Mar-2005.pdf

Which is the appropriate part of the AIP for that kind of information.

When making an assessment of visibility for take-off, if one assumes that the light spacing is 60m then one will never be taking off with less than the required Visibility/RVR.

However, one must remember that an important part of the pilot assessment is that a suitable number of lights are visibile to enable the flight path orientation to be maintained. In that respect the spacing is meaningless. Thus any cockpit assessment must be based on having a suitable number of lights visible regardless of the spacing.

When departing from an aerodrome with no ATC, and no operations staff in poor visibility, how can one ensure in light winds and fog that a) There are no obstructions on the runway or b) some other pilot isn't counting the runway lights at the same time on the other end!

Where I spend most of my time, low visibility operations require safeguarding.

Regards,

DFC

[OverRun]

Thanks for that DFC.

I now see that the latest online ERSA has got BME with a 90m light spacing. That puts me to shame, because I had picked up my [older] paper ERSA and it wasn’t there for the aerodromes I checked. Guess that’ll teach me about not using the latest . . .

Look, on this light spacing thing, I’m not trying to enter into a pissing contest with you about which document does what. The fact is I’m still not sure where the light spacing can be found for certain.

The latest Broome ERSA shows it (and I am told that the airport manager doesn’t spend his evenings at the footy club). But now when I used the online ERSA and checked the latest (June) Bundaberg (because that airport was mentioned earlier) it doesn't show it, nor do some of the other WA RPT airports show light spacing such as Kalgoorlie (apart from the short 18/36 runway) http://www.airservices.gov.au/publications/pending/ersa/FAC_YPKG_9-June-2005.pdf), nor does Newman (http://www.airservices.gov.au/publications/pending/ersa/FAC_YNWN_9-June-2005.pdf), nor does Port Hedland (http://www.airservices.gov.au/publications/pending/ersa/FAC_YPPD_9-June-2005.pdf) The March ERSA’s don’t show it either, such as http://www.airservices.gov.au/publications/current/ersa/FAC_YPPD_17-Mar-2005.pdf).

It’s nice to have the time now to chase the references and debate what shows what, or doesn’t. But we’re on post number 16 now and 13 days since the question was first raised, and there is still uncertainty about where light spacing can be found for certain. Bit tough if someone needs this information in a hurry.

[DFC]

Look at it simply.

Check with the Authorities but I would expect that when the light spacing is 60m it is not mentioned because that is the standard spacing. It is only mentioned when the spacing is more than 60m.

If one assumes that in the absence of information in the AIP that the light spacing is 60m then one will always be safe because should the actual spacing be 90m you will be underestimating the RVR i.e. the RVR will be greather than you think it is because the lights are more than 60m appart.

eg you can see 10 lights - you assume spacing is 60m and think the RVR is 600m. If the actual spacing is 90m then the true RVR is 900m.

What does your operations manual say about the pilot assessment of visibility at these airports?

Seems to me that you are trying LVPs at uncontrolled airfields which is never a good idea!

Regards,

DFC

[OverRun]

DFC,

You’re right - when the light spacing is 60m it is not mentioned in the (latest) ERSA because that is the standard spacing. It is only mentioned when the spacing is more than 60m.

I checked with Kalgoorlie Airport (60m on main, 90m on cross runway - both are non-precision instrument runways, and the latest ERSA has only the 90m spacing on the cross runway mentioned). Kununurra said they have 90m spacing and I see this is mentioned in the latest ERSA. Karratha said 60m spacing and I see this is not mentioned in the latest ERSA. But **** airport (name omitted) "don't know the spacing? 90m I think. I'd have to go and pace it out". Their light spacing is not mentioned in the latest ERSA.

One airport made the comment that the latest aerodrome audit by CASA required non-standard spacings of 90m on non-precision instrument runways to be noted in ERSA. I guess this is a 2005 innovation and is a rolling change and they haven't got to **** airport yet, but within a short space of time the spacing of lights at non-precision instrument runways in Australia should be 60m unless otherwise noted in ERSA.

I wonder how many pilots have wrongly (unsafely) calculated RVR based on light spacings? I'll leave it to one of them to comment. Your thought of assuming 60m in the absence of other information makes sense.