Moderators: richierich, ua900, PanAm_DC10, hOMSaR

 
Jacobrhassell
Topic Author
Posts: 11
Joined: Sun Aug 07, 2022 8:07 pm

Beacon Light Question

Thu Aug 18, 2022 5:47 pm

Hi,

I’ve had a question lingering in my head since I was 8 years old and saw planes at night.

Why do some planes have a blinking beacon light (<.1 sec flash) and others have a steady on and off (>.5 sec flash. For example, look at a short video of an A321 beacon: https://youtube.com/shorts/Igtk8WaCoKU?feature=share
vs
E75L beacon: https://youtube.com/shorts/1zxn5Us5DD4?feature=share

I know some people may not be able to tell, but I’d appreciate an answer.

So far I’ve seen the blinking beacon on:
- A320 and A320N family
- A350
- A330-2/300 AND -8/900
- A380
- B737 classic & NG
- B747-400 & -8
- B757
- B767
- B777-2/300
- All CRJs
- E75S

And the longer blink with:
- A220
- 737 MAX
- B777x
- B787
- E135/40/45 family
- E75L

Is it just more advanced lights? If so, why is there a need for the flash to be longer? It appears to be in the newer aircraft, and almost none of Airbus’ aircraft.

Thanks for the help,
Jake
 
atlamt
Posts: 256
Joined: Thu Sep 13, 2001 12:15 am

Re: Beacon Light Question

Thu Aug 18, 2022 5:54 pm

Led vs. strobe light. The strobes flash as the capacitors in the light discharge. Very bright but a short duration. The led's have a driver that controls the length of time the led is on. The slightly longer duration is more visible while still having the strobe effect.
 
User avatar
rjsampson
Posts: 642
Joined: Sat Jul 31, 2010 12:00 am

Re: Beacon Light Question

Thu Aug 18, 2022 8:27 pm

Jacobrhassell wrote:
Is it just more advanced lights? If so, why is there a need for the flash to be longer?
Jake


As atlamt said, the longer flash is the newer LED light, which is more advanced. There is a need for the LED flash to be longer. The older flashlamps (strobe) lights as atlamt said, discharge a large amount of energy instantaneously, creating an extremely intense burst of light. So intense, that if the amount of light emitted from the burst were continuous, it would be blinding (well, not literally), but its extremely short duration has the intended effect of high visibility.

An LED beacon by contrast doesn't operate with sudden capacitive discharge. Its brightness (which can certainly be quite high), needs more "on time" to have the achieve a similar level to that of a flashlamp.
 
Jacobrhassell
Topic Author
Posts: 11
Joined: Sun Aug 07, 2022 8:07 pm

Re: Beacon Light Question

Fri Aug 19, 2022 1:42 am

rjsampson wrote:
Jacobrhassell wrote:
Is it just more advanced lights? If so, why is there a need for the flash to be longer?
Jake


As atlamt said, the longer flash is the newer LED light, which is more advanced. There is a need for the LED flash to be longer. The older flashlamps (strobe) lights as atlamt said, discharge a large amount of energy instantaneously, creating an extremely intense burst of light. So intense, that if the amount of light emitted from the burst were continuous, it would be blinding (well, not literally), but its extremely short duration has the intended effect of high visibility.

An LED beacon by contrast doesn't operate with sudden capacitive discharge. Its brightness (which can certainly be quite high), needs more "on time" to have the achieve a similar level to that of a flashlamp.


So why does Airbus refuse to implement this advanced light? Even on the new A350 and A330-900, it’s still the “strobe” light.

Thanks for the help!
 
Jacobrhassell
Topic Author
Posts: 11
Joined: Sun Aug 07, 2022 8:07 pm

Strobe & Beacon Light Question

Fri Aug 19, 2022 2:12 am

Hello,

I’ve noticed that on some E145s, the beacon light pattern is: Bottom, Top, Strobe, Bottom, Top, Strobe. However, some others I’ve seen (Even for the SAME airline!), the lights go BOTH, Strobe, BOTH, Strobe.

Why are there 2 different patterns for the same aircraft in the same airline?
 
User avatar
Starlionblue
Posts: 21337
Joined: Fri Feb 27, 2004 9:54 pm

Re: Beacon Light Question

Fri Aug 19, 2022 3:29 am

Jacobrhassell wrote:
rjsampson wrote:
Jacobrhassell wrote:
Is it just more advanced lights? If so, why is there a need for the flash to be longer?
Jake


As atlamt said, the longer flash is the newer LED light, which is more advanced. There is a need for the LED flash to be longer. The older flashlamps (strobe) lights as atlamt said, discharge a large amount of energy instantaneously, creating an extremely intense burst of light. So intense, that if the amount of light emitted from the burst were continuous, it would be blinding (well, not literally), but its extremely short duration has the intended effect of high visibility.

An LED beacon by contrast doesn't operate with sudden capacitive discharge. Its brightness (which can certainly be quite high), needs more "on time" to have the achieve a similar level to that of a flashlamp.


So why does Airbus refuse to implement this advanced light? Even on the new A350 and A330-900, it’s still the “strobe” light.

Thanks for the help!


I don't think it is a questions of "refusing". :D

There are probably multiple reasons involving costs and tooling.
 
kabq737
Posts: 807
Joined: Wed Apr 15, 2015 3:06 am

Re: Beacon Light Question

Fri Aug 19, 2022 5:17 am

Jacobrhassell wrote:
rjsampson wrote:
Jacobrhassell wrote:
Is it just more advanced lights? If so, why is there a need for the flash to be longer?
Jake


As atlamt said, the longer flash is the newer LED light, which is more advanced. There is a need for the LED flash to be longer. The older flashlamps (strobe) lights as atlamt said, discharge a large amount of energy instantaneously, creating an extremely intense burst of light. So intense, that if the amount of light emitted from the burst were continuous, it would be blinding (well, not literally), but its extremely short duration has the intended effect of high visibility.

An LED beacon by contrast doesn't operate with sudden capacitive discharge. Its brightness (which can certainly be quite high), needs more "on time" to have the achieve a similar level to that of a flashlamp.


So why does Airbus refuse to implement this advanced light? Even on the new A350 and A330-900, it’s still the “strobe” light.

Thanks for the help!


I could be wrong but if I were to guess I bet it’s a customer option.
 
kalvado
Posts: 3832
Joined: Wed Mar 01, 2006 4:29 am

Re: Beacon Light Question

Fri Aug 19, 2022 11:24 am

Could also be a difference in led design for longer ir shorter pulse.
At the very least, from the OP list - 320 has an external all- LED retrofit option for 320ceo from Collins, including beacons.
 
User avatar
dennypayne
Posts: 442
Joined: Tue Mar 13, 2012 3:38 am

Re: Strobe & Beacon Light Question

Fri Aug 19, 2022 3:40 pm

Starlionblue wrote:
Jacobrhassell wrote:
So why does Airbus refuse to implement this advanced light? Even on the new A350 and A330-900, it’s still the “strobe” light.


I don't think it is a questions of "refusing". :D

There are probably multiple reasons involving costs and tooling.


Not to mention you can’t just decide to change a part of a certified design without at least some additional certification effort.
 
kalvado
Posts: 3832
Joined: Wed Mar 01, 2006 4:29 am

Re: Strobe & Beacon Light Question

Fri Aug 19, 2022 4:08 pm

I am not sure if Collins is the sole supplier of those lights for Airbus, but they have some interesting brochures.
At least for A350 Collins doesn't offer any strobes in their brochure:
https://www.collinsaerospace.com/-/medi ... 825e869998

A320: https://www.collinsaerospace.com/-/medi ... d885f0df56
Both LED and Xe options for CEO, LED only for sharklets.

https://www.collinsaerospace.com/-/medi ... a766246a52
A380 - LED beacon coming soon.

https://www.collinsaerospace.com/-/medi ... a21d4a2791
330/340 have only Xe option
 
IFlyVeryLittle
Posts: 323
Joined: Mon Jan 29, 2018 7:31 pm

Re: Strobe & Beacon Light Question

Fri Aug 19, 2022 6:29 pm

These were all rotating flashing lights back in the old days, right?
 
greg85
Posts: 204
Joined: Tue Jun 26, 2007 9:45 am

Re: Strobe & Beacon Light Question

Fri Aug 19, 2022 7:21 pm

 https://youtu.be/02yLHYM7Wew


Here’s how to kick it old skool.
 
User avatar
zeke
Posts: 17515
Joined: Thu Dec 14, 2006 1:42 pm

Re: Beacon Light Question

Sat Aug 20, 2022 2:09 am

Jacobrhassell wrote:

So why does Airbus refuse to implement this advanced light? Even on the new A350 and A330-900, it’s still the “strobe” light.

Thanks for the help!


A picture is worth a 1000 words, Nuff said

Image
 
User avatar
rjsampson
Posts: 642
Joined: Sat Jul 31, 2010 12:00 am

Re: Strobe & Beacon Light Question

Sat Aug 20, 2022 9:55 pm

IFlyVeryLittle wrote:
These were all rotating flashing lights back in the old days, right?


Certainly many.. but flashlamps ("strobes") go well back into the old days as well.
 
kalvado
Posts: 3832
Joined: Wed Mar 01, 2006 4:29 am

Re: Beacon Light Question

Sun Aug 21, 2022 11:16 am

zeke wrote:
Jacobrhassell wrote:

So why does Airbus refuse to implement this advanced light? Even on the new A350 and A330-900, it’s still the “strobe” light.

Thanks for the help!


A picture is worth a 1000 words, Nuff said

Image

Where are the flashing beacons in this photo?
 
shamrock137
Posts: 457
Joined: Mon Jul 25, 2005 7:10 am

Re: Beacon Light Question

Sun Aug 21, 2022 11:17 am

Jacobrhassell wrote:

So why does Airbus refuse to implement this advanced light? Even on the new A350 and A330-900, it’s still the “strobe” light.

Thanks for the help!


Airbus still uses LED's, they just choose to program theirs with a fast flash pattern. Any A320/321 with sharklets has LED wing tip strobes, same with the 350. Boeing just chooses to use a slower pulse type flash pattern.

Jacobrhassell wrote:
Hello,

I’ve noticed that on some E145s, the beacon light pattern is: Bottom, Top, Strobe, Bottom, Top, Strobe. However, some others I’ve seen (Even for the SAME airline!), the lights go BOTH, Strobe, BOTH, Strobe.

Why are there 2 different patterns for the same aircraft in the same airline?


In my experience the E145 flashes totally randomly. The lights aren't synched so when they are all switched on, they appear to flash at the same time, but slowly fall out of sync. What I've seen for the E145 at some airlines is that the beacons are being replaced by LED's as they burn out. So you will have an aircraft with the top beacon as a strobe, and the bottom beacon as LED. The CRJ series has a distinct top bottom flash for the red beacon.

Airbus has the most distinct and consistent flash pattern. The top and bottom strobe are synched, as well as the wing and tail strobes. The red beacons will flash at the same time. When the white wing and tail strobes are turned on, they will flash opposite the beacons, so you'll always see Red, White, Red, White on an Airbus. Additionally the wingtip strobes will flash twice, while the tail strobe flashes once. I'm not sure how accurate this is, but I was told its supposed to be easier to determine if an aircraft is facing towards or away from you at a greater distance then the nav lights are visible. the MD-11 had the same pattern. Exception to the rule is the A220, which was designed by Bombardier. Quirk to this aircraft is that the weight on wheels sensor changes the brightness of the red beacon. When the aircraft takes off, the beacon gets brighter.
 
User avatar
LaunchDetected
Posts: 448
Joined: Fri Jul 13, 2012 4:42 pm

Re: Strobe & Beacon Light Question

Mon Aug 22, 2022 8:27 am

kalvado wrote:
I am not sure if Collins is the sole supplier of those lights for Airbus, but they have some interesting brochures.
At least for A350 Collins doesn't offer any strobes in their brochure:
https://www.collinsaerospace.com/-/medi ... 825e869998


A350 strobe lights (and almost all the other exterior lights) are supplied by Safran.
First MSN were fitted with HID technology then LED was introduced (around MSN 300), both technologies are not interchangeable.
 
Jacobrhassell
Topic Author
Posts: 11
Joined: Sun Aug 07, 2022 8:07 pm

Re: Strobe & Beacon Light Question

Mon Aug 22, 2022 2:01 pm

Thanks for everyone’s help!
 
GalaxyFlyer
Posts: 10342
Joined: Fri Jan 01, 2016 4:44 am

Re: Strobe & Beacon Light Question

Mon Aug 22, 2022 9:44 pm

IFlyVeryLittle wrote:
These were all rotating flashing lights back in the old days, right?


The requirement for anti-collision beacons was promulgated in August, 1971. Lots of military planes didn’t get them for a few years on. The F-100 had beacons installed as they went thru depot work. If you were flying one with a beacon, the rest of formation would’ve scoff at the “fire truck”.

Yes, a variety of rotating beacons until strobes became widespread in the ‘80s. Cessnas had just a flashing light early on. The KC-135 had a huge one with various colors for signaling.
 
User avatar
KatanaDV20
Posts: 8
Joined: Sat Nov 25, 2017 10:12 pm

Re: Strobe & Beacon Light Question

Wed Aug 31, 2022 10:53 pm

I much prefer the rapid flashing strobes vs. the sleepy pulses. The double flash strobe on the Airbuses specially.

The aggressive WHAP-WHAP really gets noticed, not to mention it looks cool too! =)
 
Redbellyguppy
Posts: 273
Joined: Sat Apr 01, 2017 3:57 am

Re: Strobe & Beacon Light Question

Thu Sep 15, 2022 1:40 pm

You know who prefers the LED long flash though? Despite how cool it looks? Pilots in line for takeoff at night. They aren’t nearly as blinding as the xenon strobes.

Who is online

Users browsing this forum: kalvado, PolarRoute, teachpdx and 11 guests

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos