What Can Be Done to Make Your Aircraft More Visible?

The Pulselite® system provides an answer

Airlines that have outfitted the Pulselite system to their fleet have experienced a 20% to 30% reduction or more to their bird strike problem; that equates a minimum of $250 million dollars saved worldwide annually.

  • Pulselite Commercial Application


    The greatest benefit of the Pulselite system is found on commercial aircraft. In the air everyday, in all weather and conditions visibility is key to safety. Airlines that pulse their lights exhibit a lower occurrence of near miss events.

  • Pulselite Increases Lamp Life

    Increase lamp-life up to 5 times

    The Pulselite allows the filament and bulb to run at a lower temperature. The bulb retains full rated candle power; less heat, less stress, more visibility. It's a win-win situation. If you're turning on your landing lights for visibility, you might as well get the best visual benefit and save on bulb replacements and maintenance.

  • Bird Strike Attack

    Reduce the Likelihood of Bird Strikes

    Is there a means by which birds might better discern aircraft position and speed, so as to reduce collisions? We know that vision is a primary and highly developed sensory pathway in birds. Recent work has shown that light can be an effective tool as a repellent and, potentially, as an alert, especially when bird strikes cost the international airline industry over $1.28 billion annually.

Pulselite® Improves Recognition

  • FAA Aircraft Mounted Light Evaluation

    February 2004 “...The Pulselites offered increased conspicuity estimated to be 1/2 to 3/4 mile over an aircraft holding in position with the landing lights on steady. Once observed, the motion of the reflected Pulselite off of the runway surface in front of the holding aircraft was pronounced”

    National Highway Traffic Safety Administration

    Development and testing of techniques for increasing the conspicuity of motorcycles and motorcycle drivers (October 1979)

    by P. L. Olson, R. Halstead-Nussloch, M. Sivak

  • Sunstate/Qantaslink Trial Finding

    78% of Air Traffic Controllers agreed that the Pulselite® enhanced aircraft visibility.

    Control Tower Comments

    Rockhampton Tower "Aircraft are easier to see."

    Hamilton Tower “Definitely easier to see particularly in hazy conditions.”

    Cairns Tower “Definitely easier to see from the Tower.”

    Mackay Tower “We have found the aircraft a little easier to see at longer distances. RT chatter also supports this.”

  • Department of Transportation

    Alerting Lights on Locomotives - In a similar transportation analogy, the DOT required Railway Locomotives to be outfitted with pulsing ditch lights (like aircraft recognition lights) in 1995. The resulting documented improvements in railway grade crossing accidents has been outstanding.

    • CalTrain – Accident reduction 76.4%
    • Conrail – Accident reduction 74.3%
    • Norfolk Southern – Accident reduction 54.6%

    Improved Conspicuity of Aircraft

    Approximately 74% of the airline’s pilots who responded to the pilot survey believe that the Pulselite® system enhances their aircraft’s visibility.

Prepared for Sunstate Airlines/QantasLink by Peter Reardon Enterprises Pty Limited

The Hazard: Bird Strikes to Civil Aircraft

Bird Hazards to Aircraft

  • Departure VS. Arrival

    • Approach:

      7.9 Nautical Miles

    • Departure:

      1.5 Nautical Miles

    Approaching planes spend the most time in bird zones (Below 3000 ft.)

    Most bird strikes happen outside the range of airport countermeasures.

  • Wildlife Strikes

    • Takeoff Run

      9,931 Bird strikes

    • Climb

      9,000 Bird strikes

    • Descent

      1,816 Bird strikes

    • Approach

      18,883 Bird strikes

    • Landing Roll

      8,532 Bird strikes

    The largest number of strikes occur in the approach phase of flight.

    Wildlife strikes to civil aircraft in the United States 1990-2005

  • Flying in the Bird Zone

    • 500 ft.

      28,806 Bird Strikes 1,023 (3.6%) causing substantial damage

    • 3,500 ft.

      7,469 Bird Strikes 445 (6%) causing substantial damage

    • 3,500+ ft.

      2,686 Bird Strikes 85 (3.2%) causing substantial damage

    Only 5% of reported strikes with civil aircraft causing substantial damage above 3,500 ft. AGL. Dolbeer's Rule: Above 500 ft. AGL, bird strikes decline by 32% every 1000 ft.

    Cleary, E.C., R.A. Dolbeer, and S.E. Wright, 2003. Wildlife strikes to civil aircraft in the United States, 1990-2002.

Bird Strikes to Civil Aircraft - Night VS. Day

Wildlife strikes to civil aircraft in the United States, 1990-2002

The Research: US Department of Agriculture

Float Plane Pilots Notice Dramatic Decrease in Bird Strikes

In the early 1990’s float plane operators in the Pacific Northwest, British Columbia and Alaska began reporting that along with the improved recognition and increased lamp life, bird strikes were dramatically reduced by pulsing their landing and taxi lights.

Armed with this important information, Precise Flight approached the USDA to initiate avian testing with pulsing lights.

Aircraft Mounted Light Experimental Technique

Biologists at the National Wildlife Research Center Sandusky, OH, field station have developed an experimental procedure to test the use of aircraft-mounted light as a potential technique to reduce bird strikes.

Test groups of birds were exposed to the approach of a vehicle fitted with 2 aircraft landing lights spaced at 12 feet apart on top of the vehicle. The vehicle was driven at a consistent speed of 75miles/hour toward a flight cage immediately next to the road. Flock responses behaviors of brown-headed cowbirds, Canada geese, European starlings, herring gulls, and mourning doves were recorded by a video camera and then quantified.

Birds were exposed to various, no lights, pulsing lights, and steady lights. The biologists were able to show that birds exhibit earlier and more cohesive avoidance reactions to approaching vehicles in response to light and other external stimuli.

Responses to the vehicle differed markedly among species. Further, because of the effects of varying ambient light conditions on bird response to the approaching vehicle, the biologists suspect that contrast to background lighting is likely important to increasing avian awareness of approaching aircraft. The results indicate that bird strikes may be reduced in the future by enhancing the visibility of aircraft. Additional research has been planned involving varying pulse frequencies and specific light wavelengths.

The studies found that 91 to 99 percent of birds “exhibited alert behavior” when exposed to incandescent pulsing lights.

The tests also showed that the pulsing lights were most effective in low-light conditions, such as cloudy days, nighttime, dusk and dawn.

The Solution: Precise Flight Pulselite®

Sunstate/Qantaslink Pulselite® Trials 2002-2003

The use of the Pulselites® on the DHC8-300 fleet indicates that activation of pulsing lights in accordance with company standard operating procedures resulted in a reduction of wildlife strikes by approximately 50%.

The fleet was averaging approximately 3.65 strikes/aircraft/year prior to the evaluation and approximately 1.83 strikes/aircraft/year with Pulselites®. The results were so impressive the airline purchased the Pulselite® system for the entire DHC-8 fleet. (Prepared for Sunstate Airlines/QantasLink by Peter Reardon Enterprises Pty Limited)

Qantas 737 Pulselite® Trials 2005-2007

  • Qantas Success Stories

    • 5 B737-400 aircraft
    • 5 B737-800 aircraft

    An averaged B737 bird strike reduction rate between approximately -10% and -35% with a pulsed or modulated light system operational has the ongoing potential to save a 100 aircraft Airlines approximately $2.5 to $8.9 million per year respectively. (Pulselite® system B737 Operational Evaluation by Qantas Airlines)

    Their Business Case was based on the early results and funded the purchase for the remainder of the B737 fleets BEFORE the evaluation period was completed (confident and satisfied with the product and wildlife reduction rates).

  • B737-800 Group Results

    Achieved a 66% (day and night) bird strike reduction rate per 1,000 departures, compared to a non-Pulselite® equipped B737-800 group.

    Daylight only bird strike reduction rate was 49%.

  • B737-400 Group Results

    Achieved a 54% (day and night) bird strike reduction rate per 1,000 departures, compared to a non-Pulselite® equipped B737-400 group.

    Daylight only bird strike reduction rate was 30%.

Alaska Airlines and Horizon Air 2008-2010

Alaska Air Group is committed to the Pulselite system to decrease the incidence of bird strikes and to increase air-to-air conspicuity for other aircraft and ATC.

Alaska Airlines

Alaska commenced a fleet-wide fitment of Pulselite on their Boeing 737 series aircraft in 2010. The system was endorsed by their safety, maintenance & engineering groups, and the senior pilot corps. The cost analysis they performed exceeded their internal criteria warranting fleet-wide implementation. With a business case based on known operating/damage costs and a conservative 25 - 30% bird strike reduction proved by Qantas, Horizon, and USDA research, they successfully demonstrated to management the justification (a less than a 2 year ROI) for installing the system.

Horizon Air

Horizon initiated a fleet-wide fitment program on their Bombardier Q400 aircraft in 2008.

Pulselite® Increases Lamp Life

Pulsing the lights extend lamp life by a minimum of 300%.

Smooth transitions between ‘dim’ and ‘bright’ mode reduces operation temperature of lamp filaments and eliminates constant electrical jolts and spikes of ‘on-off’ circuitry.

Incandescent lights are like car engines “For car engines the engine wear is maximum at initial turn on, and wear increases if we run the engine at maximum performance. Your car engine will last longer if you run it at a normal cruise speed. Similarly, an incandescent filament has its highest potential for damage when the light is turned on from cold and is run at maximum filament temperature. Pulsing the light allows the filament to run at approximately 70% of normal filament output and only allows the filament to cool to a 15% output state before rising again. Reduced average voltage on the lamp is key to long lamp life just as reduced speeds on your car are key to it’s longevity.” -Scott Philiben, Aircraft Modification Engineer

Sunstate/Qantaslink Trial Findings

The average lamp life for the Pulselite equipped aircraft was approximately 1860 hours compared to approximately 630 hours for the non-Pulselite aircraft, i.e. the Pulselite system extended the lamp life by a factor of three (3).

Applying trend analysis to the factual data collected indicates that the Pulselite equipped DHC8-300 fleet may experience extended lamp life in the range of approximately 800 hours to 3,000 hours, or more while the non-Pulselite fleet may expect to continue an average of approximately 600 hours for their lamp life. (Prepared for Sunstate Airlines/QantasLink by Peter Reardon Enterprises Pty Limited)