C340 pilot advises that strobe lights on power line towers on the approach path to the ast ILS runwa...

Attributes
ACN	685038
Time
Date	200601
Place
Locale Reference	airport : ast.airport
State Reference	OR
Altitude	msl bound lower : 300 msl bound upper : 400
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zse.artcc
Operator	general aviation : personal
Make Model Name	Cessna 340/340A
Operating Under FAR Part	Part 91
Navigation In Use	ils localizer & glide slope : 26
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : multi engine pilot : private
Experience	flight time last 90 days : 20 flight time total : 700 flight time type : 100
ASRS Report	685038
Person 2
Affiliation	government : faa
Function	controller : radar
Events
Anomaly	inflight encounter other
Independent Detector	other flight crewa
Supplementary
Problem Areas	FAA Airport ATC Facility
Primary Problem	FAA

Narrative:

Approximately 1.5 miles from the approach end of runway 26 at ast; there are two power line towers. They each have white strobe lights on the top. While on the ILS recently; as I descended on the glideslope I could start to see breaks in the overcast and the ground below. However; I still had no forward visibility. As I passed over the towers; I saw one of the strobe lights. I realized that because of the position of the tower to the approach end of the runway; the white strobe could be mistaken for part of the sequenced approach light system by a pilot unfamiliar with the area. I believe that this is a serious safety issue because in times of poor visibility; a pilot who mistakes the strobe on the tower for the approach light system might become disoriented. I suggest that the strobes be changed to red instead of white. This could be accomplished at minimum expense; and clearly differentiate the tower strobes from the approach light system directly ahead on the approach. A disoriented; unfamiliar; or inexperienced pilot may begin to descend from the glideslope thinking the approach lights were in sight with disastrous results.callback conversation with reporter revealed the following information: reporter feels that the presence of these towers should be shown in some clear fashion on the IAP aeronautical chart. He suggests a note such as; 'caution; flashing obstacle strobe lights on the arrival path at X.X NM may be mistaken for approach lights.'

Original NASA ASRS Text

Title: C340 PLT ADVISES THAT STROBE LIGHTS ON POWER LINE TWRS ON THE APCH PATH TO THE AST ILS RWY 26 CAN BE MISTAKEN FOR APCH LIGHTS. NOT ALL OBSTACLE STROBE LIGHTS ARE DEPICTED ON THE COMMERCIAL APCH PLATE.

Narrative: APPROX 1.5 MILES FROM THE APCH END OF RWY 26 AT AST; THERE ARE TWO POWER LINE TWRS. THEY EACH HAVE WHITE STROBE LIGHTS ON THE TOP. WHILE ON THE ILS RECENTLY; AS I DSNDED ON THE GLIDESLOPE I COULD START TO SEE BREAKS IN THE OVERCAST AND THE GND BELOW. HOWEVER; I STILL HAD NO FORWARD VISIBILITY. AS I PASSED OVER THE TWRS; I SAW ONE OF THE STROBE LIGHTS. I REALIZED THAT BECAUSE OF THE POSITION OF THE TWR TO THE APCH END OF THE RWY; THE WHITE STROBE COULD BE MISTAKEN FOR PART OF THE SEQUENCED APCH LIGHT SYSTEM BY A PLT UNFAMILIAR WITH THE AREA. I BELIEVE THAT THIS IS A SERIOUS SAFETY ISSUE BECAUSE IN TIMES OF POOR VISIBILITY; A PLT WHO MISTAKES THE STROBE ON THE TWR FOR THE APCH LIGHT SYSTEM MIGHT BECOME DISORIENTED. I SUGGEST THAT THE STROBES BE CHANGED TO RED INSTEAD OF WHITE. THIS COULD BE ACCOMPLISHED AT MINIMUM EXPENSE; AND CLEARLY DIFFERENTIATE THE TWR STROBES FROM THE APCH LIGHT SYSTEM DIRECTLY AHEAD ON THE APCH. A DISORIENTED; UNFAMILIAR; OR INEXPERIENCED PLT MAY BEGIN TO DSND FROM THE GLIDESLOPE THINKING THE APCH LIGHTS WERE IN SIGHT WITH DISASTROUS RESULTS.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR FEELS THAT THE PRESENCE OF THESE TWRS SHOULD BE SHOWN IN SOME CLEAR FASHION ON THE IAP AERO CHART. HE SUGGESTS A NOTE SUCH AS; 'CAUTION; FLASHING OBSTACLE STROBE LIGHTS ON THE ARR PATH AT X.X NM MAY BE MISTAKEN FOR APCH LIGHTS.'

Data retrieved from NASA's ASRS site as of January 2009 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.

C340 pilot advises that strobe lights on power line towers on the approach path to the ast ILS runway 26 can be mistaken for approach lights. Not all obstacle strobe lights are depicted on the commercial approach plate.