ATC equipment problem navigation ILS.

Attributes
ACN	326963
Time
Date	199601
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : geg
State Reference	WA
Altitude	agl bound lower : 400 agl bound upper : 400
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : bwi
Operator	common carrier : air taxi
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 135
Navigation In Use	ils localizer & glide slope : iolj
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	observation : company check pilot
Qualification	pilot : atp
Experience	flight time last 90 days : 20 flight time total : 13000 flight time type : 500
ASRS Report	326963
Person 2
Affiliation	company : air taxi
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	other anomaly other other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	faa : investigated
Supplementary
Primary Problem	Navigational Facility
Air Traffic Incident	other
Situations
Navigational Aid	Unspecified

Narrative:

Aircraft was at 400 ft AGL on the runway 03 ILS approach. The autoplt was coupled. The aircraft suddenly went into a left bank as it tried to stay on the localizer. The localizer indication showed full left deflection at this time. The GS indication was centered. This deflection caused the aircraft to enter a descending left turn. The autoplt was disconnected and a go around was made. 2 weeks prior to this approach a cessna 401 crashed with 3 fatals while shooting the same approach. That aircraft also made an abrupt left turn off the localizer prior to crashing. ILS runway 03 at geg should be flight checked again. Callback conversation with reporter revealed the following information: reporter stated he was giving a part 135 pilot a 6 month check ride when the incident occurred. He reported the incident to FAA navaids in the regional office. They flight checked the ILS system with the same aircraft flying 6 approachs and could not recreate the problem. Reporter stated there were no aircraft in the ILS critical area when the approach was made. FAA and NTSB are continuing to investigate.

Original NASA ASRS Text

Title: ATC EQUIP PROB NAV ILS.

Narrative: ACFT WAS AT 400 FT AGL ON THE RWY 03 ILS APCH. THE AUTOPLT WAS COUPLED. THE ACFT SUDDENLY WENT INTO A L BANK AS IT TRIED TO STAY ON THE LOC. THE LOC INDICATION SHOWED FULL L DEFLECTION AT THIS TIME. THE GS INDICATION WAS CTRED. THIS DEFLECTION CAUSED THE ACFT TO ENTER A DSNDING L TURN. THE AUTOPLT WAS DISCONNECTED AND A GAR WAS MADE. 2 WKS PRIOR TO THIS APCH A CESSNA 401 CRASHED WITH 3 FATALS WHILE SHOOTING THE SAME APCH. THAT ACFT ALSO MADE AN ABRUPT L TURN OFF THE LOC PRIOR TO CRASHING. ILS RWY 03 AT GEG SHOULD BE FLT CHKED AGAIN. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED HE WAS GIVING A PART 135 PLT A 6 MONTH CHK RIDE WHEN THE INCIDENT OCCURRED. HE RPTED THE INCIDENT TO FAA NAVAIDS IN THE REGIONAL OFFICE. THEY FLT CHKED THE ILS SYS WITH THE SAME ACFT FLYING 6 APCHS AND COULD NOT RECREATE THE PROB. RPTR STATED THERE WERE NO ACFT IN THE ILS CRITICAL AREA WHEN THE APCH WAS MADE. FAA AND NTSB ARE CONTINUING TO INVESTIGATE.

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.