Tall buldings and red lights

[Fuji Abound]

Driving through France at night got me thinking.

There are lots of red lights (?!). Of course they are on "tall" builidngs - although I cant remember the height for a building to be defined "tall".

.. .. .. but why do we go to the cost of putting th lights there and running them all of which must be considerable.

Ah, I hear you argue to stop us flying into them.

.. .. .. but these lights are on every tall building not just those near airports where you could reasonable expect aircraft to be low and possibly of course. Cross country who else might be low?
Well I suppose in England it is poosible us GA types flying IFR off airways to find ourselves close to such tall buildings if we allow our altitude keeping to "drift". However in France night IFR cross country is only permitted in airways. I suppose an aircraft might lose power, and end up making an approach for a forced landing and these red lights might then prevent a collision with a tall building BUT the risk cost relationship seems doubtful.

So do the red lights go back to the early days of avaition or do we just remain very cautious giving the pilot should he find himself that close to the ground at night every opportunity of avoiding high objects or is it to cater for low level heli traffic or military aircraft which presuambly even in France are authorised to fly low level at night.

[FlyingForFun]

No idea what the history of the red lights is. But I'm a bit confused about why you're talking about IFR flights. An IFR flight must be 1000' above the nearest obstacles within 5nm. If you are legally flying IFR, whether on airways or not, you'd have to "drift" a bl00dy long way before tall buildings become a problem. And that's assuming you can actually see the lights on the buildings, of course, which you won't be able to if you're in IMC!

The lights, I would have thought, are far more important to VFR aircraft. Minimum height rules allow for far less lateral distance from the tall buildings, as well as less vertical clearance from them in many cases. If the building is away from built up areas and over 500' high, you can legally be below the top of the building, 500' to its side. (This doesn't apply in the UK, of course, because VFR flight at night is not legal in the UK.) I'm not suggesting for one moment that this is safe or sensible, but if you were to decide that this is what you are (quite legally) going to do, it would be very useful to be able to see the building in question! There are less extreme examples, of course, which are more likely to actually happen than this, but this gives you the idea!

FFF
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[2Donkeys]

Tall buildings provide superb navigational aids, particularly in the relatively recent times when a PPL/Night rating didn't necessarily come with a course of radionavigation, and GPS didn't exist.

If you turn the lights out, it makes spotting them much harder. I'm not suggesting that all those lights are specifically for inept PPLs without GPSes, but it can only help.

[tyro]

Speaking as an " inept PPL without GPS" I'd like to see all my favourite landmarks lit as navigational aids. First on my list for installation a big strobe would be the Kingsclere mast near Newbury. This stands out for miles around on clear days, but is always the first feature to disappear in haze.

[TC_LTN]

First on my list for installation a big strobe would be the Kingsclere mast near Newbury. This stands out for miles around on clear days, but is always the first feature to disappear in haze.

Kingsclere is lit (according to the AIP). I assume we are talking about the radio mast located at 511828N 0011443W which should be lit with a single light. At 496m AGL, details of any unserviceability and return to service of the light on the obstacle should be promulgated by NOTAM. If you suspect the light is permanently u/s, I suggest you contact;

Directorate of Airspace Policy,
ORA, K6,
CAA House,
45-59 Kingsway,
London WC2B 6TE.
Telephone: [phone].

[tyro]

TC_LTN

I don't doubt such a big structure is lit to the limited extent required by law for close-up collision avoidance. What I'm thinking of is something eye-catching at a distance such as, for example, the strobe on Canary Wharf.

[Kolibear]

I'm very pleased to see this thread as it reminded me that, like F_A, I was driving through northern France, admiring the wind farms and wondering 'How are they illuminated'?

If there is a red light on the top of the mast, then thats not the highest part of the structurew when the blade comes up to the 12 o'clock position? So is there a light in the tip of each blade?

Any ideas please?

[vintage ATCO]

I think you mean 496ft there, TC_LTN

CAP168 says where physically practicable high intensity flashing white obstacle lights should be used to indicate the presence of an obstacle if its height is 150m (yes, metres) or more, or a tower supporting overhead wires, cables, etc, at any height where an aeronautical study indicates such lights to be essential for recognition of the presence of the obstruction.

Tyro why don't you ask the question of DAP?

As for windfarms, Kolibear, obstacles have to be lit at the highest practicable point. Presumably it is considered not practical on one of the vanes!

[TC_LTN]

I think you mean 496ft there, TC_LTN

Err, yes

496 meters would certainly warrent a strobe or two, IWHT

[Fly Stimulator]

Kolibear,

I was driving through northern France, admiring the wind farms and wondering 'How are they illuminated'?

I flew past a wind farm just south of Perpignan last week and noticed that they had a series of strobes which gave the impression of a light running to-and-fro along the line of towers. The apparent movement was quite an effective way of making the lights noticeable.

The lights were of course on the towers not the blades. If you were close enough for that to make a difference you would probably have a range of other things to worry about too!

[FWA NATCA]

The mistake that you guys are making is that you are thinking fixed wing aircraft only. One must not forget about the always present low flying helicopters that roam throughout the country side flying IFR (I fly roads).

Mike
NATCA FWA

[Tinstaafl]

We had a problem at our base about inadequately lit wind turbines. Fortunately more lights were added when more turbines were installed. Pity the new turbines are only 500m offset from final on a ridge... That puts the top of the turbines above final. At least there are lights at the base of the turbine masts, which makes a difference

Don't know who designed the light installation on the generator housing. The twit designed it so that the light is lower than the front of the (backwards sloping) generator housing. End result is that the light is occluded if you're on the blade side at or below the axle.


I can't see why it would be difficult to have a light on each blade tip. Surely an inductance loop at the blade root + 2 wires to a light at the tip. Have the inductance arranged so that a current is generated as the blade passes over the top. The effect would be a blinking light in sync withs each blade as it goes past the coil.

[Floppy Link]

The French military fast jets do a fair bit of wazzing about low level at night, or at least they used to. Maybe the lights are for them?
Great sight and sound to see a Mirage on afterburner pass overhead quite low. Almost spilt the wine though...