B757 FLC HAS TROUBLE DISTINGUISHING VASI PAPI LIGHT COLORS AT LGA.

Narrative

THIS NASA ASRS RPT CONCERNS THE COLORATION OF THE VASI'S AND PAPI'S ON LGA RWY 4 AND RWY 31. THE CONCERN IS OF THE 'WASHED OUT' COLOR OF THE RED PORTION (LOW) AND THE 'YELLOWISH' TINT OF THE WHITE (HIGH) PORTION. I AM BASED IN NEW YORK AND HAVE FREQUENTLY FLOWN IN AND OUT OF LGA AS A COPLT OVER THE LAST 3 YRS. THE VASI'S ON RWY 31 AND ESPECIALLY THE PAPI'S ON RWY 4 APPEAR TO HAVE MARGINAL RED (LOW) COLORATIONS. THIS CONDITION IS EXACERBATED DURING DRIZZLE/RAIN ON INST-TO-VISUAL TRANSITIONS. AS PIC AND SIC; THE TRANSITION FROM IFR TO VFR ON AN ILS RWY 4 APCH WITH LOW CEILINGS APPEARS TO BE THE MOST PRONOUNCED PROB. DURING THESE CONDITIONS; THE TENDENCY HAS BEEN TO TRANSITION TO VFR SOMEWHERE BTWN 500-800 FT AGL AND PERCEIVE THE PAPI'S TO SHOW ALL 'HIGHS.' WHEN UPON CLOSER SCRUTINY; THEY ACTUALLY MATCH THE ILS GS DEPICTION IN THE COCKPIT (2 REDS; 2 WHITES). I THINK THE ILS RWY 4 PAPI AND RWY 31 VASI ARE INADEQUATE. THEY ARE CERTAINLY WELL BELOW AVERAGE COMPARED TO ANY DOMESTIC ARPT I HAVE EVER FLOWN INTO. IN ADVERSE WX CONDITIONS; THEY APPEAR MONO- CHROMATIC AND THE COMMON PERCEPTION IS 'HIGH.' LGA TWR/FAA OFFICIALS CORDIALLY LISTENED TO MY CONCERN; BUT SAID THEY HAD NOT RECEIVED OTHER COMPLAINTS. THIS DOES NOT SURPRISE ME. NO INCIDENTS HAVE OCCURRED. MOST CREWS ARE HAPPY TO BE DONE FOR THE DAY OR IMMEDIATELY FLY OUT AGAIN; AND MOST PROBABLY DO NOT LIVE HERE. I WAS A LNDG SIGNAL OFFICER IN THE MIL FOR SEVERAL YRS EMPLOYING THE FRESNEL LENS AND OTHER OPTICAL LNDG SYS; SO I FEEL A STRONG SENSE OF RESPONSIBILITY TO VOICE THIS CONCERN. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATES THAT ON ONE PARTICULAR APCH IN IMC CONDITIONS; THE CAPT WAS ON THE GS. WHEN THEY BROKE OUT AT 600-900 FT; THE CAPT TRANSITIONED TO VISUAL CUES; AND ALMOST IMMEDIATELY WENT LOW ON THE GS. THE RPTR CALLED OUT THE DEV; AND WHEN THE CAPT WENT BACK ON INSTS; HE CORRECTED TO THE GS. DURING THE DEV; THE CAPT SAW THE 'ON GS' INDICATION ON THE VASI. THE RPTR ALSO STATED THAT THE VASI LIGHTS AT LGA WERE LESS DISTINGUISHABLE BTWN RED AND WHITE THAN HE HAD OBSERVED AT OTHER ARPTS.