Narrative:

On apr/fri/04, I was the flight instructor for an instructional flight originating from gai airport. The airport is located within the washington ADIZ. I obtained a standard briefing and filed 2 ADIZ flight plans. After departing gai at approximately XA20 local, we proceeded to exit the ADIZ to the northwest. The incident occurred on the return to gai. After completing our flight maneuvers outside of the ADIZ, I contacted potomac approach requesting our discrete transponder code for our flight back to gai. The approach controller assigned a code and instructed me to report 10 mi from gai. During this time, I was providing instruction to my student on GPS navigation and landmarks. When we were about 10 mi from the airport, I reported to the approach controller and called the airport in sight. He instructed me to 'change to CTAF and remain on the squawk.' I read back his instructions and thanked him for his help. The controller said 'you're welcome.' at this point, I instructed the student to begin a descent and to maneuver for the 45 degree entry to runway 14. When we were turning downwind, I noticed that the transponder was squawking 1200. I immediately reentered our discrete transponder code. I believe that my student accidentally hit the VFR button on the transponder as we started our descent. The VFR button is above the power control. Of course, there is the possibility that I never entered the correct discrete transponder code. I feel that due to the attention I was giving my student on GPS navigation and showing the importance of smooth control input, I became too distraction. Also, the fact that the approach controller never queried me on what I was squawking led me to assume that I was squawking the correct code. The controllers should use a standard phrase to let us pilots know that they see our transponder. Potomac approach controllers use different phrases such 'proceed on course,' or 'beacon code observed.' I feel that if they have a standard phrase that is in use would allow everyone to minimize errors. I have also started to institute a more sterile cockpit environment before entering the ADIZ. I will never assume that the controller's lack of query of my transponder code means that I'm squawking the correct code. And I will monitor the transponder more closely while in the ADIZ.

Related reports:

Google
 

Original NASA ASRS Text

Title: WRONG XPONDER CODE USED DURING AN APCH TO DEST ARPT WITHIN THE DC ADIZ, 2 NM N OF GAI, MD.

Narrative: ON APR/FRI/04, I WAS THE FLT INSTRUCTOR FOR AN INSTRUCTIONAL FLT ORIGINATING FROM GAI ARPT. THE ARPT IS LOCATED WITHIN THE WASHINGTON ADIZ. I OBTAINED A STANDARD BRIEFING AND FILED 2 ADIZ FLT PLANS. AFTER DEPARTING GAI AT APPROX XA20 LCL, WE PROCEEDED TO EXIT THE ADIZ TO THE NW. THE INCIDENT OCCURRED ON THE RETURN TO GAI. AFTER COMPLETING OUR FLT MANEUVERS OUTSIDE OF THE ADIZ, I CONTACTED POTOMAC APCH REQUESTING OUR DISCRETE XPONDER CODE FOR OUR FLT BACK TO GAI. THE APCH CTLR ASSIGNED A CODE AND INSTRUCTED ME TO RPT 10 MI FROM GAI. DURING THIS TIME, I WAS PROVIDING INSTRUCTION TO MY STUDENT ON GPS NAV AND LANDMARKS. WHEN WE WERE ABOUT 10 MI FROM THE ARPT, I RPTED TO THE APCH CTLR AND CALLED THE ARPT IN SIGHT. HE INSTRUCTED ME TO 'CHANGE TO CTAF AND REMAIN ON THE SQUAWK.' I READ BACK HIS INSTRUCTIONS AND THANKED HIM FOR HIS HELP. THE CTLR SAID 'YOU'RE WELCOME.' AT THIS POINT, I INSTRUCTED THE STUDENT TO BEGIN A DSCNT AND TO MANEUVER FOR THE 45 DEG ENTRY TO RWY 14. WHEN WE WERE TURNING DOWNWIND, I NOTICED THAT THE XPONDER WAS SQUAWKING 1200. I IMMEDIATELY REENTERED OUR DISCRETE XPONDER CODE. I BELIEVE THAT MY STUDENT ACCIDENTALLY HIT THE VFR BUTTON ON THE XPONDER AS WE STARTED OUR DSCNT. THE VFR BUTTON IS ABOVE THE PWR CTL. OF COURSE, THERE IS THE POSSIBILITY THAT I NEVER ENTERED THE CORRECT DISCRETE XPONDER CODE. I FEEL THAT DUE TO THE ATTN I WAS GIVING MY STUDENT ON GPS NAV AND SHOWING THE IMPORTANCE OF SMOOTH CTL INPUT, I BECAME TOO DISTR. ALSO, THE FACT THAT THE APCH CTLR NEVER QUERIED ME ON WHAT I WAS SQUAWKING LED ME TO ASSUME THAT I WAS SQUAWKING THE CORRECT CODE. THE CTLRS SHOULD USE A STANDARD PHRASE TO LET US PLTS KNOW THAT THEY SEE OUR XPONDER. POTOMAC APCH CTLRS USE DIFFERENT PHRASES SUCH 'PROCEED ON COURSE,' OR 'BEACON CODE OBSERVED.' I FEEL THAT IF THEY HAVE A STANDARD PHRASE THAT IS IN USE WOULD ALLOW EVERYONE TO MINIMIZE ERRORS. I HAVE ALSO STARTED TO INSTITUTE A MORE STERILE COCKPIT ENVIRONMENT BEFORE ENTERING THE ADIZ. I WILL NEVER ASSUME THAT THE CTLR'S LACK OF QUERY OF MY XPONDER CODE MEANS THAT I'M SQUAWKING THE CORRECT CODE. AND I WILL MONITOR THE XPONDER MORE CLOSELY WHILE IN THE ADIZ.

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.