A pilot reports that at certain approach angles and distances the runway and taxiway signs appear to...

Attributes
ACN	331233
Time
Date	199603
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : dca
State Reference	DC
Altitude	msl bound lower : 500 msl bound upper : 1000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : dca
Operator	common carrier : air carrier
Make Model Name	B727-200
Operating Under FAR Part	Part 121
Flight Phase	descent : approach landing other
Route In Use	approach : visual
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : atp pilot : commercial
Experience	flight time last 90 days : 350 flight time total : 6900 flight time type : 2100
ASRS Report	331233
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Airport
Air Traffic Incident	other
Situations
Airport	other physical facility

Narrative:

This report is to be a 'heads up' on a potentially dangerous situation. Although runway 36 at dca has no VASI the runway and taxiway markings on the left side approach end of runway 36 could easily be mistaken for a VASI. On the left side of runway 36's approach end of the runway there is a taxiway sign (yellow) indicating, I believe, taxiway J. Approximately 1000 ft further down on the left side is a (red) runway sign indicating runway 15. When on final these appear to be a VASI system and will always indicate red over white, should they be mistaken as such. To illustrate this point, I mentioned that we were slightly high on the ILS glide path, but appeared to be right on with regards to the VASI. For a moment the 2 other crewmembers agreed. It wasn't until I mentioned that there was no VASI that they realized it. I am sure they would have caught that fact had I given them time. Callback conversation with reporter revealed the following information: the reporter was flying a B727-200 into dca when he first noticed the apparent VASI. He rechked his approach data and noted that there was no VASI shown on runway 36, however, at certain approach angles and distances the taxiway and runway signs would appear to create a VASI-type display. Reference to the GS would show that actually following this VASI would put the aircraft below the actual GS.

Original NASA ASRS Text

Title: A PLT RPTS THAT AT CERTAIN APCH ANGLES AND DISTANCES THE RWY AND TXWY SIGNS APPEAR TO CREATE THE ILLUSION THAT THERE IS A VASI ON RWY 36 AT DCA. THERE IS NO VASI ON THIS RWY.

Narrative: THIS RPT IS TO BE A 'HEADS UP' ON A POTENTIALLY DANGEROUS SIT. ALTHOUGH RWY 36 AT DCA HAS NO VASI THE RWY AND TXWY MARKINGS ON THE L SIDE APCH END OF RWY 36 COULD EASILY BE MISTAKEN FOR A VASI. ON THE L SIDE OF RWY 36'S APCH END OF THE RWY THERE IS A TXWY SIGN (YELLOW) INDICATING, I BELIEVE, TXWY J. APPROX 1000 FT FURTHER DOWN ON THE L SIDE IS A (RED) RWY SIGN INDICATING RWY 15. WHEN ON FINAL THESE APPEAR TO BE A VASI SYS AND WILL ALWAYS INDICATE RED OVER WHITE, SHOULD THEY BE MISTAKEN AS SUCH. TO ILLUSTRATE THIS POINT, I MENTIONED THAT WE WERE SLIGHTLY HIGH ON THE ILS GLIDE PATH, BUT APPEARED TO BE RIGHT ON WITH REGARDS TO THE VASI. FOR A MOMENT THE 2 OTHER CREWMEMBERS AGREED. IT WASN'T UNTIL I MENTIONED THAT THERE WAS NO VASI THAT THEY REALIZED IT. I AM SURE THEY WOULD HAVE CAUGHT THAT FACT HAD I GIVEN THEM TIME. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR WAS FLYING A B727-200 INTO DCA WHEN HE FIRST NOTICED THE APPARENT VASI. HE RECHKED HIS APCH DATA AND NOTED THAT THERE WAS NO VASI SHOWN ON RWY 36, HOWEVER, AT CERTAIN APCH ANGLES AND DISTANCES THE TXWY AND RWY SIGNS WOULD APPEAR TO CREATE A VASI-TYPE DISPLAY. REF TO THE GS WOULD SHOW THAT ACTUALLY FOLLOWING THIS VASI WOULD PUT THE ACFT BELOW THE ACTUAL GS.

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.

A pilot reports that at certain approach angles and distances the runway and taxiway signs appear to create the illusion that there is a VASI on runway 36 at dca. There is no VASI on this runway.