Situation: erroneous exit of TCA while executing lda/DME runway 30L approach at stl.

Attributes
ACN	172539
Time
Date	199103
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : stl
State Reference	MO
Environment
Flight Conditions	IMC
Aircraft 1
Controlling Facilities	tracon : stl
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
ASRS Report	172539
Person 2
Affiliation	government : faa
Function	oversight : supervisor
Qualification	controller : radar
Events
Anomaly	other anomaly other
Independent Detector	other controllera
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Navigational Facility
Air Traffic Incident	other

Narrative:

The lda/DME approach to runway 30L at stl does not keep aircraft in the TCA and does not protect for other (low altitude) airspace. I was working final monitor position on 3/X/91. I was responsible for the lda/DME 30L approach. We run this approach during marginal VFR WX to keep from reducing arrival capacity. Being a non-precision approach, there are crossing restrictions during certain stages of the approach. The crossing restrictions do not keep aircraft in the TCA and violate low altitude airspace. On this date and every time this approach is used in low ceilings, the aircraft hurry down to the next altitude. During this session I observed at least 12 aircraft violate both the low sector and descend below the TCA. Callback conversation with reporter revealed the following: reporter stated the problem was brought to FAA facility management supervisor's attention and approach fixes have been added to keep aircraft from exiting the TCA while executing a lda/DME runway 30L approach.

Original NASA ASRS Text

Title: SITUATION: ERRONEOUS EXIT OF TCA WHILE EXECUTING LDA/DME RWY 30L APCH AT STL.

Narrative: THE LDA/DME APCH TO RWY 30L AT STL DOES NOT KEEP ACFT IN THE TCA AND DOES NOT PROTECT FOR OTHER (LOW ALT) AIRSPACE. I WAS WORKING FINAL MONITOR POS ON 3/X/91. I WAS RESPONSIBLE FOR THE LDA/DME 30L APCH. WE RUN THIS APCH DURING MARGINAL VFR WX TO KEEP FROM REDUCING ARR CAPACITY. BEING A NON-PRECISION APCH, THERE ARE XING RESTRICTIONS DURING CERTAIN STAGES OF THE APCH. THE XING RESTRICTIONS DO NOT KEEP ACFT IN THE TCA AND VIOLATE LOW ALT AIRSPACE. ON THIS DATE AND EVERY TIME THIS APCH IS USED IN LOW CEILINGS, THE ACFT HURRY DOWN TO THE NEXT ALT. DURING THIS SESSION I OBSERVED AT LEAST 12 ACFT VIOLATE BOTH THE LOW SECTOR AND DSND BELOW THE TCA. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR STATED THE PROB WAS BROUGHT TO FAA FAC MGMNT SUPVR'S ATTN AND APCH FIXES HAVE BEEN ADDED TO KEEP ACFT FROM EXITING THE TCA WHILE EXECUTING A LDA/DME RWY 30L 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.