Large transport on visual approach descends well below proper altitude on base leg.

Attributes
ACN	169584
Time
Date	199101
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : mem
State Reference	TN
Altitude	agl bound lower : 400 agl bound upper : 2000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : mem tower : mem tracon : slc
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent : approach descent other
Route In Use	approach : visual
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 80 flight time total : 4500 flight time type : 75
ASRS Report	169584
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	other anomaly other other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	flight crew : became reoriented flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

The aircraft was vectored on a left downwind for runway 36R. The aircraft was descending from 6000' MSL to assigned altitude of 2000' MSL at point a. At point B approach control asks if we have the airport and another aircraft on final approach for same runway. The captain reports both the airport and the other aircraft in sight. Approach control clears us for the visibility approach to runway 36R. The first officer (PF) sees the other aircraft pass off the left wing tip. At point C approach asks if we are starting base. First officer starts base and continues descent and approach control passed the flight over to the tower. First officer is following a G/south indication for vertical planning to the runway. At point D captain calls going through 500' AGL. First officer stops descent at approximately 400' AGL, then G/south indication goes off full scale to indicate aircraft is too low. At point east first officer turns to intercept final, then shortly after real G/south is captured. Aircraft is landed on runway 36R.

Original NASA ASRS Text

Title: LGT ON VISUAL APCH DESCENDS WELL BELOW PROPER ALT ON BASE LEG.

Narrative: THE ACFT WAS VECTORED ON A L DOWNWIND FOR RWY 36R. THE ACFT WAS DSNDING FROM 6000' MSL TO ASSIGNED ALT OF 2000' MSL AT POINT A. AT POINT B APCH CTL ASKS IF WE HAVE THE ARPT AND ANOTHER ACFT ON FINAL APCH FOR SAME RWY. THE CAPT RPTS BOTH THE ARPT AND THE OTHER ACFT IN SIGHT. APCH CTL CLRS US FOR THE VIS APCH TO RWY 36R. THE F/O (PF) SEES THE OTHER ACFT PASS OFF THE L WING TIP. AT POINT C APCH ASKS IF WE ARE STARTING BASE. F/O STARTS BASE AND CONTINUES DSNT AND APCH CTL PASSED THE FLT OVER TO THE TWR. F/O IS FOLLOWING A G/S INDICATION FOR VERT PLANNING TO THE RWY. AT POINT D CAPT CALLS GOING THROUGH 500' AGL. F/O STOPS DSNT AT APPROX 400' AGL, THEN G/S INDICATION GOES OFF FULL SCALE TO INDICATE ACFT IS TOO LOW. AT POINT E F/O TURNS TO INTERCEPT FINAL, THEN SHORTLY AFTER REAL G/S IS CAPTURED. ACFT IS LANDED ON RWY 36R.

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.