An air carrier B767 freighter flight crew complains that at mht there is at night an optical illusion caused by the placement of 2 large, bright red lights on the top of the localizer array. These lights are, apparently, beyond the normal red runway end lights and they appeared, to the reporter, to make the runway seem much shorter than it is actually.

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Attributes
ACN	382768
Time
Date	199710
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : mht
State Reference	NH
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : takeoff ground other : taxi landing other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 70 flight time total : 5300 flight time type : 400
ASRS Report	382768
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Airport
Air Traffic Incident	other
Situations
Airport	other physical facility

Narrative:

I am submitting this report because of what I perceive to be non standard runway lighting at mht. Runway 35 has the normal row of red lights at the end. However, slightly behind those lights are two larger and much brighter red lights. A call to the tower informed me that those lights are on the localizer array. At night those 2 bright lights appear to create an optical illusion of the runway being extremely short. Contributing to this illusion is MALSR approach lights, no centerline lights, and a slight slope to the runway. I have landed the B767 many times on 7000 ft runways, however I must confess that I found this optical illusion quite startling. Other pilots at our company in different aircraft fleets have also noted this phenomenon. It is felt that a notation should be made on the approach plates warning of this illusion and of the 2 lights that appear to be causing it. Better yet, remove those lights from the localizer array.

Original NASA ASRS Text

Title: AN ACR B767 FREIGHTER FLC COMPLAINS THAT AT MHT THERE IS AT NIGHT AN OPTICAL ILLUSION CAUSED BY THE PLACEMENT OF 2 LARGE, BRIGHT RED LIGHTS ON THE TOP OF THE LOC ARRAY. THESE LIGHTS ARE, APPARENTLY, BEYOND THE NORMAL RED RWY END LIGHTS AND THEY APPEARED, TO THE RPTR, TO MAKE THE RWY SEEM MUCH SHORTER THAN IT IS ACTUALLY.

Narrative: I AM SUBMITTING THIS RPT BECAUSE OF WHAT I PERCEIVE TO BE NON STANDARD RWY LIGHTING AT MHT. RWY 35 HAS THE NORMAL ROW OF RED LIGHTS AT THE END. HOWEVER, SLIGHTLY BEHIND THOSE LIGHTS ARE TWO LARGER AND MUCH BRIGHTER RED LIGHTS. A CALL TO THE TWR INFORMED ME THAT THOSE LIGHTS ARE ON THE LOC ARRAY. AT NIGHT THOSE 2 BRIGHT LIGHTS APPEAR TO CREATE AN OPTICAL ILLUSION OF THE RWY BEING EXTREMELY SHORT. CONTRIBUTING TO THIS ILLUSION IS MALSR APCH LIGHTS, NO CTRLINE LIGHTS, AND A SLIGHT SLOPE TO THE RWY. I HAVE LANDED THE B767 MANY TIMES ON 7000 FT RWYS, HOWEVER I MUST CONFESS THAT I FOUND THIS OPTICAL ILLUSION QUITE STARTLING. OTHER PLTS AT OUR COMPANY IN DIFFERENT ACFT FLEETS HAVE ALSO NOTED THIS PHENOMENON. IT IS FELT THAT A NOTATION SHOULD BE MADE ON THE APCH PLATES WARNING OF THIS ILLUSION AND OF THE 2 LIGHTS THAT APPEAR TO BE CAUSING IT. BETTER YET, REMOVE THOSE LIGHTS FROM THE LOC ARRAY.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.