H.I.S.L.s

[2896]

Why is one not allowed to use the H.I.S.L.s on the white setting at night? After all at night one wants to be seen and I would have thought the white setting is brighter compared to the red setting?

Yours confused 2896

[Aynayda Pizaqvick]

They are too bright. At their intensity they would wreck your night vision.

[Colonal Mustard]

You get an annoying flash every few seconds from road signs on the ground, extremely off putting when anything with a hint of reflective strip returns the flash that your A/C puts out.

[Tractor_Driver]

Not allowed?

I must be missing something.

Where is it written that it is "not allowed"?

Certainly they should not be used in circumstances where they could cause problems, like on the ground, close to other aircraft or in cloud or falling snow but If I am in clear air, mine will be on.

TD

[zorab64]

We regularly find ourselves close to a major airport and/or the flight path of incoming passenger jets - in order to assist ATC clearance to operate there, it's in our interest to make ourselves more conspicuous, especially against ground lighting where a helicopter at 1000-1500' will be camouflaged quite effetively from an inbound jet anywhere above our level.

As soon as I hear ATC inform an inbound of our presence, I'll light up everything (depending on weather conditions) to ease his workload and our mutual safety. HISLs are only an extension of an anti-collision light - the clue lies in the name!

[A.Agincourt]

HISL far more effective and unlikely to be mistaken for anything else when viewed at the same or higher level.

[Spacer]

White strobes are also unworkable when used with other a/c with NVGs (and sometimes can even back down your own goggles)

[Brilliant Stuff]

I agree making a helicopter conspicuous against the backdrop of a town and the like can be quite tricky. Therefore everything on with common sense is a good policy IMHO.

[2896]

Well Thank you chaps.

TD now that you mention it the fog in my brain is lifting. Cheers.

As for the traffic signs reflecting my flashing that does not bother me really.

As for the NVGs now that could be a problem if we were blessed with them sadly though we are not then again we operate in well lit areas.

[ShyTorque]

Not forgetting that when switchable HISLS are operated on the white setting on a helicopter, in UK the red anti-collision light must also remain switched on.

Edit:
Having just gone through my latest downloaded copy of CAP393 with a fine toothed comb, it appears that a helicopter may now also use a white anti-collision light; my original copy differentiated between aeroplanes (could be red or white) and helicopters (must be red). The newer copy now simply refers to "flying machines" with no separate reference to helicopters, so I presume the rule no longer applies.

[MightyGem]

Where is it written that it is "not allowed"?

Hmmm...I thought it was in the ANO, but I can't find it. We've had this question on OPC tests, and the answer was that helicopters can show a white HISL anti coll by day, but it must be red at night.

[2896]

Shytorque, please accept my eternal gratitude for going to the extra trouble of downloading CAP 393 and reading it in order to show me (us) what it really says.

[ShyTorque]

You're very welcome; I could think of nothing better to do at midnight, after a couple of dandelion and burdocks

[zorab64]

ST & MG - couldn't find the day/night ref either but, as our HISL is either a white flash OR red one, if I want to be sure someone will see us (& avoid collision) I don't really give a fig whether it's day or night, allowed or not.
I'll also put the strobe lights on if it merits it - they're white too - the only red light showing will be the port nav light!.