Small aircraft unable to transmit squawks emergency code instead of radio failure.

Attributes
ACN	287373
Time
Date	199411
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mso
State Reference	MT
Altitude	msl bound lower : 4200 msl bound upper : 4200
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Controlling Facilities	tower : mso
Operator	other
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	descent : approach other other
Flight Plan	None
Person 1
Affiliation	government other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : cfi
Experience	flight time last 90 days : 150 flight time total : 1980 flight time type : 450
ASRS Report	287373
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
Events
Anomaly	aircraft equipment problem : less severe non adherence : far other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

As I approached msd class D airspace, I listened to ATIS, then attempted to contact tower. I received no answer. I repeated several times, circling to remain outside of class D. I tried adjusting radios, rechked all connections, tried a hand held microphone, checked radio panel switch settings, and still received no answer to my xmissions. I was expected to land at mso to pick up a passenger, so decided to use my transponder to notify tower of radio failure, and wait for a light signal to land. I knew which runway was in use and had other traffic in sight. There was no danger of collision at any time. Unfortunately, my memory convinced me that radio failure code was 7700 instead of 7600, and I was so sure that I didn't check my checklist to verify. I heard tower trying to contact me, and blinked my navigation lights as requested by tower. I was cleared to land and given a green light (later found out tower did not see my light response, so didn't know I could receive). I was at first surprised to see crash/rescue vehicles coming to meet me on the taxiway, then realized I was squawking emergency. Red face. I called tower on phone to apologize, and gave pilot information to crash/fire personnel. I will not again forget radio failure squawk code.

Original NASA ASRS Text

Title: SMA UNABLE TO XMIT SQUAWKS EMER CODE INSTEAD OF RADIO FAILURE.

Narrative: AS I APCHED MSD CLASS D AIRSPACE, I LISTENED TO ATIS, THEN ATTEMPTED TO CONTACT TWR. I RECEIVED NO ANSWER. I REPEATED SEVERAL TIMES, CIRCLING TO REMAIN OUTSIDE OF CLASS D. I TRIED ADJUSTING RADIOS, RECHKED ALL CONNECTIONS, TRIED A HAND HELD MIKE, CHKED RADIO PANEL SWITCH SETTINGS, AND STILL RECEIVED NO ANSWER TO MY XMISSIONS. I WAS EXPECTED TO LAND AT MSO TO PICK UP A PAX, SO DECIDED TO USE MY XPONDER TO NOTIFY TWR OF RADIO FAILURE, AND WAIT FOR A LIGHT SIGNAL TO LAND. I KNEW WHICH RWY WAS IN USE AND HAD OTHER TFC IN SIGHT. THERE WAS NO DANGER OF COLLISION AT ANY TIME. UNFORTUNATELY, MY MEMORY CONVINCED ME THAT RADIO FAILURE CODE WAS 7700 INSTEAD OF 7600, AND I WAS SO SURE THAT I DIDN'T CHK MY CHKLIST TO VERIFY. I HEARD TWR TRYING TO CONTACT ME, AND BLINKED MY NAV LIGHTS AS REQUESTED BY TWR. I WAS CLRED TO LAND AND GIVEN A GREEN LIGHT (LATER FOUND OUT TWR DID NOT SEE MY LIGHT RESPONSE, SO DIDN'T KNOW I COULD RECEIVE). I WAS AT FIRST SURPRISED TO SEE CRASH/RESCUE VEHICLES COMING TO MEET ME ON THE TXWY, THEN REALIZED I WAS SQUAWKING EMER. RED FACE. I CALLED TWR ON PHONE TO APOLOGIZE, AND GAVE PLT INFO TO CRASH/FIRE PERSONNEL. I WILL NOT AGAIN FORGET RADIO FAILURE SQUAWK CODE.

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.