A B737 flight crew did not disconnect the autoplt on the lda runway 18 approach to dca.

Attributes
ACN	443640
Time
Date	199907
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : dca.airport
State Reference	DC
Altitude	msl single value : 1100
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : dca.tracon
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	ils other localizer other
Flight Phase	descent : approach
Route In Use	approach other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : multi engine pilot : commercial pilot : atp pilot : instrument
Experience	flight time total : 8000
ASRS Report	443640
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : commercial pilot : instrument pilot : multi engine
Experience	flight time total : 5000
ASRS Report	443641
Events
Anomaly	non adherence : clearance
Independent Detector	other flight crewa other flight crewb
Resolutory Action	none taken : detected after the fact
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On rosslyn lda 18 to dca, unable to disconnect autoplt at 3.5 NM, 1100 ft MDA fix causing aircraft to get closer than normal to bldgs on north shore of river. Recommend disconnecting autoplt earlier. Callback conversation with reporter revealed the following information: the reporter corrected the acn 443640 narrative. The autoplt disconnected in a normal manner. During the approach the runway 18 localizer is flown to the 3.5 DME fix, after which the aircraft must be flown over the river. At the 3.5 mi fix the pilot left the autoplt in the localizer track mode while trying to turn the aircraft with the heading selector. It took a few moments to realize the autoplt was still engaged in the localizer track mode which carried the aircraft past the turn point described on the approach.

Original NASA ASRS Text

Title: A B737 FLC DID NOT DISCONNECT THE AUTOPLT ON THE LDA RWY 18 APCH TO DCA.

Narrative: ON ROSSLYN LDA 18 TO DCA, UNABLE TO DISCONNECT AUTOPLT AT 3.5 NM, 1100 FT MDA FIX CAUSING ACFT TO GET CLOSER THAN NORMAL TO BLDGS ON N SHORE OF RIVER. RECOMMEND DISCONNECTING AUTOPLT EARLIER. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR CORRECTED THE ACN 443640 NARRATIVE. THE AUTOPLT DISCONNECTED IN A NORMAL MANNER. DURING THE APCH THE RWY 18 LOC IS FLOWN TO THE 3.5 DME FIX, AFTER WHICH THE ACFT MUST BE FLOWN OVER THE RIVER. AT THE 3.5 MI FIX THE PLT LEFT THE AUTOPLT IN THE LOC TRACK MODE WHILE TRYING TO TURN THE ACFT WITH THE HDG SELECTOR. IT TOOK A FEW MOMENTS TO REALIZE THE AUTOPLT WAS STILL ENGAGED IN THE LOC TRACK MODE WHICH CARRIED THE ACFT PAST THE TURN POINT DESCRIBED ON THE APCH.

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.