Narrative:

Departing from runway 24 at teb we were given the teb 5 departure. We departed teb as published in the SID when I went to initiate a climb to 2000 ft after reaching 4.5 DME that new york approach controller asked us if we had stopped at 1500 ft. We replied to new york that we did stop at 1500 ft until 4.5 DME. No more was said until we were handed off to the next controller. We checked in with the next controller and asked if there was an issue with our altitude readout. The controller responded that he had no altitude readout on us at all. We switched to the #2 transponder and had our altitude checked again and the controller confirmed he had a positive altitude readout. We informed the controller that we had been questioned earlier in the flight and that we would have it looked it. We switched back to the #1 transponder again later in the flight and it was fine. The corrective actions were to confirm the altitude readout with the controller and to switch to the second transponder after believing that our #1 transponder was producing an intermittent altitude readout. The teb 5 departure is not a complex departure; however; it does require the crew to be vigilant in ensuring that it is flown precisely due to the complex and high density nature of the airspace around it. It only takes one slight distraction in the cockpit to have an error.

Related reports:

Google
 

Original NASA ASRS Text

Title: AN HS125 800 FLT CREW DEPARTING TEB ON THE TEB 5 DEP WAS QUESTIONED BY ATC REGARDING THEIR ALT BECAUSE XPONDER #1 ALT ENCODING WAS INOP.

Narrative: DEPARTING FROM RWY 24 AT TEB WE WERE GIVEN THE TEB 5 DEP. WE DEPARTED TEB AS PUBLISHED IN THE SID WHEN I WENT TO INITIATE A CLB TO 2000 FT AFTER REACHING 4.5 DME THAT NEW YORK APCH CTLR ASKED US IF WE HAD STOPPED AT 1500 FT. WE REPLIED TO NEW YORK THAT WE DID STOP AT 1500 FT UNTIL 4.5 DME. NO MORE WAS SAID UNTIL WE WERE HANDED OFF TO THE NEXT CTLR. WE CHKED IN WITH THE NEXT CTLR AND ASKED IF THERE WAS AN ISSUE WITH OUR ALT READOUT. THE CTLR RESPONDED THAT HE HAD NO ALT READOUT ON US AT ALL. WE SWITCHED TO THE #2 XPONDER AND HAD OUR ALT CHKED AGAIN AND THE CTLR CONFIRMED HE HAD A POSITIVE ALT READOUT. WE INFORMED THE CTLR THAT WE HAD BEEN QUESTIONED EARLIER IN THE FLT AND THAT WE WOULD HAVE IT LOOKED IT. WE SWITCHED BACK TO THE #1 XPONDER AGAIN LATER IN THE FLT AND IT WAS FINE. THE CORRECTIVE ACTIONS WERE TO CONFIRM THE ALT READOUT WITH THE CTLR AND TO SWITCH TO THE SECOND XPONDER AFTER BELIEVING THAT OUR #1 XPONDER WAS PRODUCING AN INTERMITTENT ALT READOUT. THE TEB 5 DEP IS NOT A COMPLEX DEP; HOWEVER; IT DOES REQUIRE THE CREW TO BE VIGILANT IN ENSURING THAT IT IS FLOWN PRECISELY DUE TO THE COMPLEX AND HIGH DENSITY NATURE OF THE AIRSPACE AROUND IT. IT ONLY TAKES ONE SLIGHT DISTR IN THE COCKPIT TO HAVE AN ERROR.

Data retrieved from NASA's ASRS site as of January 2009 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.