Helicopter pilot transposes and uses wrong transponder code.

Attributes
ACN	348150
Time
Date	199609
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : lla
State Reference	LA
Altitude	msl bound lower : 500 msl bound upper : 500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zhu
Operator	general aviation : corporate
Make Model Name	Helicopter
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : instrument
Experience	flight time last 90 days : 120 flight time total : 6800 flight time type : 2100
ASRS Report	348150
Person 2
Affiliation	government : faa
Function	controller : non radar
Qualification	controller : non radar
Events
Anomaly	non adherence : clearance
Independent Detector	other other : unspecified
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On sat at XA20 hours, I returned from a DVFR flight south of the 28TH parallel. I was in the process of changing my transponder code back to my discrete code (abbc) for flight plan waiver operations north of the 28TH. At this time I experienced radio problems with my local field and irregular radio xmissions from my flight following as well. I was loading and unloading passenger while still running. I made a transposition error and placed acbb in the transponder. On sun at approximately XB20 hours, my company flight following asked me to check my transponder code. I actually looked at the code twice before I realized my transposition error. I immediately changed to the correct code and notified my superior. Confusion during a critical cockpit task contributed to placing the wrong code in the transponder. Attention to detail is the only defense against this error.

Original NASA ASRS Text

Title: HELI PLT TRANSPOSES AND USES WRONG XPONDER CODE.

Narrative: ON SAT AT XA20 HRS, I RETURNED FROM A DVFR FLT S OF THE 28TH PARALLEL. I WAS IN THE PROCESS OF CHANGING MY XPONDER CODE BACK TO MY DISCRETE CODE (ABBC) FOR FLT PLAN WAIVER OPS N OF THE 28TH. AT THIS TIME I EXPERIENCED RADIO PROBS WITH MY LCL FIELD AND IRREGULAR RADIO XMISSIONS FROM MY FLT FOLLOWING AS WELL. I WAS LOADING AND UNLOADING PAX WHILE STILL RUNNING. I MADE A TRANSPOSITION ERROR AND PLACED ACBB IN THE XPONDER. ON SUN AT APPROX XB20 HRS, MY COMPANY FLT FOLLOWING ASKED ME TO CHK MY XPONDER CODE. I ACTUALLY LOOKED AT THE CODE TWICE BEFORE I REALIZED MY TRANSPOSITION ERROR. I IMMEDIATELY CHANGED TO THE CORRECT CODE AND NOTIFIED MY SUPERIOR. CONFUSION DURING A CRITICAL COCKPIT TASK CONTRIBUTED TO PLACING THE WRONG CODE IN THE XPONDER. ATTN TO DETAIL IS THE ONLY DEFENSE AGAINST THIS ERROR.

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.