Flight crew took off with the improper transponder code set. Upon receiving the correct code from AT...

Attributes
ACN	1307768
Time
Date	201511
Local Time Of Day	0601-1200
Place
Locale Reference	SJC.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Medium Large Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Takeoff
Route In Use	Vectors
Flight Plan	IFR
Component
Aircraft Component	Transponder
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	ATC Issue All Types Deviation - Procedural FAR Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy

Narrative:

Upon calling departure; the air traffic control notified us that we were squawking the wrong transponder code and assigned us a heading in line with the SID. He immediately reminded us of the proper code for that flight. I put the transponder in standby mode until I entered the correct code but then I failed to return it to the number two position. After flying on that heading for a few minutes I queried the controller about our next vector towards our route. He didn't remember who or where we were. I caught that the transponder was still in standby and eventually he vectored us on course. I didn't finish going through our pre departure clearance and my first officer missed my oversight. Normally I run a little top-to-bottom flow of the pre departure clearance but this time I zeroed in on the change in the route and I never got back to the rest of it. I brief four key areas of the pre departure clearance in my briefings but I don't expect the same technique from my first officers. In the future I will listen for those four items and verbally add them myself if need be. I will also stop placing the transponder in standby while changing codes.

Original NASA ASRS Text

Title: Flight crew took off with the improper transponder code set. Upon receiving the correct code from ATC; the crew left the transponder in the Standby mode while flying the ATC-assigned heading. ATC had apparently lost track of the flight until queried by the crew.

Narrative: Upon calling Departure; the Air Traffic Control notified us that we were squawking the wrong transponder code and assigned us a heading in line with the SID. He immediately reminded us of the proper code for that flight. I put the transponder in standby mode until I entered the correct code but then I failed to return it to the number two position. After flying on that heading for a few minutes I queried the controller about our next vector towards our route. He didn't remember who or where we were. I caught that the transponder was still in standby and eventually he vectored us on course. I didn't finish going through our PDC and my First Officer missed my oversight. Normally I run a little top-to-bottom flow of the PDC but this time I zeroed in on the change in the route and I never got back to the rest of it. I brief four key areas of the PDC in my briefings but I don't expect the same technique from my First Officers. In the future I will listen for those four items and verbally add them myself if need be. I will also stop placing the transponder in standby while changing codes.

Data retrieved from NASA's ASRS site 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.

Flight crew took off with the improper transponder code set. Upon receiving the correct code from ATC; the crew left the transponder in the standby mode while flying the ATC-assigned heading. ATC had apparently lost track of the flight until queried by the crew.