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View Full Version : Strobe lights………….do you think they are essential?


Ultra long hauler
22nd Jul 2011, 16:58
Hi,

while I am kitting my LSA out, I recently decided to install strobes (LED, together with positioning lights) on the wings plus an additional strobe at the rear.

Why?

1) I find aircraft with strobes turned on much easier to spot, air to air.
2) It looks nice! (cool, if you like).

Other people say it´s a waste of money / weight……….but I think the anti collision argument is valid.

I don´t know about the legislation where you fly, but given the choice--> would you install them?

###Ultra Long Hauler###

RTN11
22nd Jul 2011, 17:10
I don't think they add a lot to daytime anti collision, to be honest landing lights stand out a lot better, and are usually the first to burn out.

Even with wing tip strobes, traffic info passed by ATC can be very difficult to spot. I think the colour of the aircraft and bright landing lights are probably more significant.

Daysleeper
22nd Jul 2011, 17:10
depends.... are you going to be flying in low light (dusk/night/dawn) or over dark backgrounds or high dark terrain?

If not then fairly useless for collision avoidance.

A good explination can be found half way down...

this canadian air force website (http://www.airforce.forces.gc.ca/dfs-dsv/pub/nr-sp/index-eng.asp?id=10461)

but to quote it a bit....
In theory, to be visible at three nautical miles on a very dark day, a strobe light must have an effective intensity of around 5000 candelas (see figure 15). In full daylight, the strobe must have an effective intensity greater than 100,000 candelas (Harris 1987).Most existing aircraft strobes have effective intensities of between 100 and 400 candelas.

Field trials have generally confirmed the ineffectiveness of strobes in daylight.

The following US military trials are outlined in a US Air Force report (Schmidlapp 1977):

In 1958 the USAF Air Training Command conducted flight tests to compare strobe anticollision lights with rotating beacons. It was concluded that in daylight conditions, no lighting system could be expected to prevent collisions.
Further tests in 1958 at the USAF Wright-Patterson Base again found that strobe lights were ineffective in daylight.
A major US Army study was conducted in 1970 in which observers on a hilltop were required to sight approaching helicopters equipped either with strobes of 1800, 2300 or 3300 effective candela or a standard red rotating beacon. It was found that none of the lights were effective against a background of daytime sky, however strobes were helpful when the aircraft was viewed against the ground.
USAF tests in 1976 found extremely poor performance of strobe lights on aircraft. In all cases, the aircraft was sighted before the strobe. In addition, it was found that after two years service on aircraft, strobe lights were about half as intense as expected.
Extensive trials in 1977 by the US Air Force Aeronautical Systems Division used strobes fitted on a tower and observers at various distances and viewing angles. The results indicated that in daylight, even a strobe of 36000 candelas was not particularly conspicuous. However, strobes were more visible when the background illumination was less than 30 candelas per square metre, equivalent to a very dark day.
FAA studies have also concluded that there is no support for the use of strobes in daylight. A 1989 FAA study of the effectiveness of see-and-avoid concluded that aircraft colours or lights played no significant role in first directing a pilot’s attention to the other aircraft during daytime (Graham 1989).
An earlier FAA study considered that there was ‘little hope that lights can be made bright enough to be of any practical value in daylight’ (Rowland and Silver 1972). A major FAA review of the aircraft exterior lighting literature concluded that during daytime, the brightest practical light is less conspicuous than the aircraft, unless there is low luminescence of background. (Burnstein and Fisher 1977).

In conclusion, while strobes are not likely to be helpful against bright sky backgrounds, they may make aircraft more visible against terrain or in conditions of low light.

gasax
22nd Jul 2011, 18:28
Plain strobes are ok - the single flash ones. However my firned fitted the multiple flash versions - 4 flashes and then a pause. In lower light conditions they were very effective in catching your attention.

Obviously in bright sunlight strobes are of no particular use - but when the light levels go down - pretty good.

Rod1
22nd Jul 2011, 18:29
Lots of studies say strobes are no help in well lit conditions. I fitted one on the back of my MCR but probably would not bother again.

Rod1

Jan Olieslagers
22nd Jul 2011, 18:40
My vast experience of close on 200 hours was mostly gathered without any, so it is obvious they are not essential. I am here and alive and shouting my usual nonsense, who could want strobes anyway?

Fokkerwokker
22nd Jul 2011, 19:33
Strobes are good for a gloomy day but the real attention-getters are the 'wig wag' function for landing lights, where they can flash on/off.

There is a significant difference to an aircraft's conspicuity if they are heading towards you with those flashing away. I see it a lot in Alaska and it really does make a difference.

Lookout is a very poorly practiced discipline these days and anything to alert an aviator of a 'head to head' has just got to be a bonus.

patowalker
22nd Jul 2011, 21:02
I don´t know about the legislation where you fly, but given the choice--> would you install them?

Negative. Had them on previous homebuilt, but saved time, money and weight by omitting them on present homebuilt.

Shoestring Flyer
23rd Jul 2011, 08:11
I take the view that anything that just might help someone see me has got to be a good thing.
It doesn't matter if they can't be seen on some days....they just might help someone see you on that one day when otherwise they might not have.
Your choice of course but they only have to save your skin once in a lifetime of differing light conditions and they then obviously become worth it!

The Heff
23rd Jul 2011, 13:56
I think that strobe lights should be recommended but not essential. They're useful on the ground, because if you see a stationary aircraft with strobes on then you are aware that the aircraft is either starting-up or shutting down, and when it starts up you can expect the aircraft to move.

However, strobe lighting doesn't really improve safety on the ground because common sense would advise aircrew and groundcrew airside to stay away from propellers as a general rule, and the responsibility is with the pilot to ensure all persons are a safe distance from the propeller before starting anyway. Anticipation just increases awareness, not necessarily safety.

The only time I've ever noticed strobe lights in the air is when flying at night; but as the OP's LSA won't be cleared for night-flying this is really a poor argument for strobes in this case. More importantly, I'll address the OP's second point:

It looks nice! (cool, if you like).

Aeroplanes are cool, full stop. Flashy bling to jazz the airframe up are not required, the aircraft will look just as cool without them. :8

foxmoth
23rd Jul 2011, 14:49
Strobe lights………….do you think they are essential?

The only things that are ESSENTIAL are:- wings (can be fixed or rotary) and a set of controls, anything else - engine/instruments etc are just nice to have!:E

strobe lighting doesn't really improve safety on the ground Well, as they should not be on until just before to, and off after landing that should be a given:rolleyes:

Ultra long hauler
24th Jul 2011, 17:20
are you going to be flying in low light (dusk/night/dawn) or over dark backgrounds or high dark terrain?



Obviously in bright sunlight strobes are of no particular use - but when the light levels go down - pretty good.

Actually, I do fly in low light situations quite a bit……but that´s due to the local weather and my preference for late afternoon flying.

Strobes are good for a gloomy day but the real attention-getters are the 'wig wag' function for landing lights, where they can flash on/off.

There is a significant difference to an aircraft's conspicuity if they are heading towards you with those flashing away. I see it a lot in Alaska and it really does make a difference.

Lookout is a very poorly practiced discipline these days and anything to alert an aviator of a 'head to head' has just got to be a bonus.
Thank you……..an encouraging bit of experience from you.
I have spotted planes quicker air to air because of the strobes.

I take the view that anything that just might help someone see me has got to be a good thing.
It doesn't matter if they can't be seen on some days....they just might help someone see you on that one day when otherwise they might not have.
Your choice of course but they only have to save your skin once in a lifetime of differing light conditions and they then obviously become worth it!
My thoughts exactly!!!
I looked for other club aircraft air to air, I KNEW they were close……….and yet I had trouble spotting them. Happens to be fact that I spotted the ones with strobes just a touch earlier than the ones without.
Those couple of seconds may prove to be vital one day………..



The only time I've ever noticed strobe lights in the air is when flying at night; but as the OP's LSA won't be cleared for night-flying this is really a poor argument for strobes in this case.

As was mentioned above, it doesn´t have to be night to have lower light situations…………so I don´t think my argument was that poor to be honest with you.

The only things that are ESSENTIAL are:- wings (can be fixed or rotary) and a set of controls, anything else - engine/instruments etc are just nice to have!
Yes yes, maybe "essential" was a poor choice of words.
However, I´d like to include some kind of propulsion to get up there, a landing gear (depending on what type of aircraft) and perhaps a sitting (or standing) arrangement to your list!!!

who could want strobes anyway?
Uuuhhm, me?????????

###Ultra Long Hauler###

Jumbo Driver
24th Jul 2011, 18:59
No, IMHO strobe lights are NOT essential.

I think strobes may sometimes improve visibility in the air for light aircraft. However the down side is the extra weight and expense involved, which some may think are worth it and some (like me) don't.

Either way, they should NEVER be used on the ground unless and until you are either on the active runway, just about to enter it or just vacating it.


JD
:)

Pitts2112
24th Jul 2011, 23:38
I would say they aren't essential but, if having them will give you peace of mind, then maybe the added complexity, weight, and maintenance will be worthwhile.

If you're going to install strobes, look seriously into the multiple-flash ones, the ones that flash 3 or 4 times. I don't know the proper name for them. I came upon an aircraft in the air that had those and they made a marked impression on me in terms of how good they were at attracting attention. And they did save time in the actual spotting in low light.

I think the logic is like this - the first flash gets your attention. The continued flashing sequence is then long enough for you to turn your eye and make visual contact. With standard strobes, the first flash catches your attention, but by the time you've moved your eye, the flash sequence has stopped, so you have to wait another second or whatever for the sequence to start again to see it and then make definite contact.

I don't think the difference would be life-savings critical, but I remember being impressed with the system the first time and I encountered it in flight. If you're going to put something in, you might as well put those in as anything else.

aviate1138
25th Jul 2011, 05:48
Get LED lights fitted. Some really bright ones available now and they use considerably less power and have MTBF times of 100,000 hrs or similar.

Some info here…..

Strobe Lights, Strobe & Navigation, Red Beacon, Landing & Taxi, Aeroled, Whelen, Airplanes - EAI (http://www.experimentalaircraft.info/articles/aircraft-lights.php)

foxmoth
25th Jul 2011, 11:40
However, I´d like to include some kind of propulsion to get up there, a landing gear (depending on what type of aircraft) and perhaps a sitting (or standing) arrangement to your list!!!

not my IDEAL method of getting airborne, but:-
Hang Gliding - An Introduction | Airways Airsports (http://www.airways-airsports.com/hanggliding)

:ok:

BackPacker
25th Jul 2011, 12:40
However the down side is the extra weight and expense involved, which some may think are worth it and some (like me) don't.

Just wondering. If you're doing a homebuild and fit two of those three-in-one wingtip mounted units (nav, tail and strobe), plus associated wiring, switches and such, how much weight is really involved?

FleetFlyer
26th Jul 2011, 08:35
My two cents on this subject is that they are worth having but not essential. Subjectively, I find it much easier to pick up other aicraft with strobes and would be very happy if the white aeroplane I fly was equipped with strobes. In ten years of flying I have had three close calls, at least one of which would have been much less likely had I a strobe equipped aeroplane.

As other posters have said; They only need to save your life once to be worth having.

Ultra long hauler
26th Jul 2011, 17:13
Just wondering. If you're doing a homebuild and fit two of those three-in-one wingtip mounted units (nav, tail and strobe), plus associated wiring, switches and such, how much weight is really involved?
3 kg, if that! Probably less!
I hand carried my 3 lights from the states, and including the cables and everything it can´t be very heavy, really!

In ten years of flying I have had three close calls, at least one of which would have been much less likely had I a strobe equipped aeroplane.

Why thank you!
My point of view exactly………..though, I am 9.5 years behind you.

###Ultra Long Hauler###

Hen Ddraig
27th Jul 2011, 10:14
Strobes, about as much use as a high viz jacket. But a lot more expensive.


Time to spare, go by air.

Hen ddraig