Reporter indicates possible entry into stl TCA without authority/authorized.

Attributes
ACN	161780
Time
Date	199011
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : stl
State Reference	MO
Altitude	msl bound lower : 1800 msl bound upper : 1800
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : stl
Operator	other
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	government other
Function	flight crew : single pilot
Qualification	pilot : cfi pilot : atp pilot : commercial pilot : instrument
Experience	flight time last 90 days : 150 flight time total : 10000 flight time type : 100
ASRS Report	161780
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other other : unspecified cockpit
Resolutory Action	flight crew : exited penetrated airspace
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

En route from chicago to stl, contacted springfield approach for a fly-through of their arsa. Their radar disagreed with our DME by several mi with them always thinking that we were further away than we showed. Upon reaching the stl area, I briefed my partner on the DME limits of the TCA as well as what the river should look like. We negotiated the 3000' ring and the 2000' ring with no problems and the DME appeared to agree with the rings on the TCA chart. 1 min or so later I looked at the DME readout and it read 6 mi and then immediately 5 mi, which would have put us in the portion of the TCA that goes to the ground. We made an immediate turn to exit. As I looked at the ground to verify whether or not we were in the TCA, the DME readout went blank. I don't believe that we penetrated the TCA, but with no help from the DME, I can't be sure. I guess the lesson is to not relay on all toys--look outside.

Original NASA ASRS Text

Title: REPORTER INDICATES POSSIBLE ENTRY INTO STL TCA WITHOUT AUTH.

Narrative: ENRTE FROM CHICAGO TO STL, CONTACTED SPRINGFIELD APCH FOR A FLY-THROUGH OF THEIR ARSA. THEIR RADAR DISAGREED WITH OUR DME BY SEVERAL MI WITH THEM ALWAYS THINKING THAT WE WERE FURTHER AWAY THAN WE SHOWED. UPON REACHING THE STL AREA, I BRIEFED MY PARTNER ON THE DME LIMITS OF THE TCA AS WELL AS WHAT THE RIVER SHOULD LOOK LIKE. WE NEGOTIATED THE 3000' RING AND THE 2000' RING WITH NO PROBS AND THE DME APPEARED TO AGREE WITH THE RINGS ON THE TCA CHART. 1 MIN OR SO LATER I LOOKED AT THE DME READOUT AND IT READ 6 MI AND THEN IMMEDIATELY 5 MI, WHICH WOULD HAVE PUT US IN THE PORTION OF THE TCA THAT GOES TO THE GND. WE MADE AN IMMEDIATE TURN TO EXIT. AS I LOOKED AT THE GND TO VERIFY WHETHER OR NOT WE WERE IN THE TCA, THE DME READOUT WENT BLANK. I DON'T BELIEVE THAT WE PENETRATED THE TCA, BUT WITH NO HELP FROM THE DME, I CAN'T BE SURE. I GUESS THE LESSON IS TO NOT RELAY ON ALL TOYS--LOOK OUTSIDE.

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.