#1 transponder momentarily failed in flight within the 30 mile veil of TCA. Used second transponder.

Attributes
ACN	122736
Time
Date	198909
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : sma
State Reference	CA
Altitude	msl bound lower : 3700 msl bound upper : 3700
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : bur
Operator	general aviation : corporate
Make Model Name	Small Transport, Low Wing, 2 Turboprop Eng
Flight Phase	climbout : intermediate altitude climbout : takeoff cruise other
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : instrument pilot : cfi
Experience	flight time last 90 days : 75 flight time total : 8000 flight time type : 400
ASRS Report	122736
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : overcame equipment problem
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

I may have violated the 30 mi perimeter around the lax-TCA. In the aircraft described above, there are 2 xponders with mode C. In departing VFR from smo, #1 transponder was selected. After given permission to contact bur approach, I called, was given a code, but they could not identify me. In troubleshooting the problem, I selected the #2 transponder, which they (bur) received immediately. The #1 transponder was and still is operating normally. I don't know why it did not function for that instance. So, I may have flown in the 30 mi perimeter around the lax TCA west/O a visible 1200 squawk and mode C operating. I never entered the TCA itself, but due to the location of smo, was within the 30 mi. Problem: at many airports you can see an operating reply light on the ground prior to takeoff as a confirmation of an operating transponder. At smo, I did not notice the light. So, it becomes possible to fly in the 30 mi perimeter west/O a transponder and mode C, and not know if until after takeoff. I don't know how the new regulation would apply to this situation.

Original NASA ASRS Text

Title: #1 TRANSPONDER MOMENTARILY FAILED IN FLT WITHIN THE 30 MILE VEIL OF TCA. USED SECOND TRANSPONDER.

Narrative: I MAY HAVE VIOLATED THE 30 MI PERIMETER AROUND THE LAX-TCA. IN THE ACFT DESCRIBED ABOVE, THERE ARE 2 XPONDERS WITH MODE C. IN DEPARTING VFR FROM SMO, #1 XPONDER WAS SELECTED. AFTER GIVEN PERMISSION TO CONTACT BUR APCH, I CALLED, WAS GIVEN A CODE, BUT THEY COULD NOT IDENT ME. IN TROUBLESHOOTING THE PROB, I SELECTED THE #2 XPONDER, WHICH THEY (BUR) RECEIVED IMMEDIATELY. THE #1 XPONDER WAS AND STILL IS OPERATING NORMALLY. I DON'T KNOW WHY IT DID NOT FUNCTION FOR THAT INSTANCE. SO, I MAY HAVE FLOWN IN THE 30 MI PERIMETER AROUND THE LAX TCA W/O A VISIBLE 1200 SQUAWK AND MODE C OPERATING. I NEVER ENTERED THE TCA ITSELF, BUT DUE TO THE LOCATION OF SMO, WAS WITHIN THE 30 MI. PROB: AT MANY ARPTS YOU CAN SEE AN OPERATING REPLY LIGHT ON THE GND PRIOR TO TKOF AS A CONFIRMATION OF AN OPERATING XPONDER. AT SMO, I DID NOT NOTICE THE LIGHT. SO, IT BECOMES POSSIBLE TO FLY IN THE 30 MI PERIMETER W/O A XPONDER AND MODE C, AND NOT KNOW IF UNTIL AFTER TKOF. I DON'T KNOW HOW THE NEW REG WOULD APPLY TO THIS SITUATION.

Data retrieved from NASA's ASRS site as of August 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.