Narrative:

This was a passenger trip from teb with a scheduled departure time of xa:00 local. Normal preflight; start; and after starting engines checklists were completed to include a detailed departure brief by the captain. During the after starting checklist it was determined that our #1 aoa system would not test properly. After checking with our maintenance department it was determined that we could not dispatch with this aircraft. Another aircraft was brought on line and we did a quick swap of aircraft with passengers; bags; catering; and refueling. After the captain submitted his paperwork to the maintenance department on the broken aircraft he again briefed the departure and set the navaids for the departure. We taxied out and took off about xb:40. We had a teb 5 radar vectors brezy departure clearance which requires us to stay at 1500 feet until 4.5 DME from teb VOR and then climb to 2000 feet on a 280 heading. As we made our turn in the departure to a 280 degree heading I noticed that the captain was approaching 1700 feet and climbing. Having flown this departure numerous times; and without referencing the current DME distance; I told the captain that I felt we should still be holding 1500 feet. It was a clear day and I felt we had not traveled the required distance in order to climb to 2000 feet. The captain seemed a bit confused at that moment as he had noticed the DME in excess or the 4.5 NM required to climb to 2000 feet. Just after I spoke; departure control advised us that we should be at 1500 feet. Departure control made a second transmission almost immediately following the first telling us to go down to 1500 feet. We descended back down to 1500 feet and I advised ATC that we were correcting. Very shortly thereafter departure cleared us to 6000 feet and the rest of the flight proceeded normally to destination. It was at that time that I noticed that our VOR navaids were automatic tuned to 116.6. This is the DME that the captain had used to climb from 1500 to 2000 feet and neither one of us had noticed this until this moment. How the system had automatic tuned itself from the teb VOR frequency; 108.4 to 116.6 is still unknown. In hindsight I would advise that the altitude of 1500 feet be set in the altitude select window and that we confirm together that we have indeed met the requirements to climb by verifying the VOR frequency and the distance displayed by the DME.

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Original NASA ASRS Text

Title: G-IV FLT CREW EXCEEDS 1500 FT ALTITUDE RESTRICTION ON THE TEB 5 WHEN FMC AUTO TUNES A NEW VOR.

Narrative: THIS WAS A PASSENGER TRIP FROM TEB WITH A SCHEDULED DEPARTURE TIME OF XA:00 LOCAL. NORMAL PREFLIGHT; START; AND AFTER STARTING ENGINES CHECKLISTS WERE COMPLETED TO INCLUDE A DETAILED DEPARTURE BRIEF BY THE CAPTAIN. DURING THE AFTER STARTING CHECKLIST IT WAS DETERMINED THAT OUR #1 AOA SYSTEM WOULD NOT TEST PROPERLY. AFTER CHECKING WITH OUR MAINTENANCE DEPARTMENT IT WAS DETERMINED THAT WE COULD NOT DISPATCH WITH THIS AIRCRAFT. ANOTHER AIRCRAFT WAS BROUGHT ON LINE AND WE DID A QUICK SWAP OF AIRCRAFT WITH PASSENGERS; BAGS; CATERING; AND REFUELING. AFTER THE CAPTAIN SUBMITTED HIS PAPERWORK TO THE MAINTENANCE DEPARTMENT ON THE BROKEN AIRCRAFT HE AGAIN BRIEFED THE DEPARTURE AND SET THE NAVAIDS FOR THE DEPARTURE. WE TAXIED OUT AND TOOK OFF ABOUT XB:40. WE HAD A TEB 5 RADAR VECTORS BREZY DEPARTURE CLEARANCE WHICH REQUIRES US TO STAY AT 1500 FEET UNTIL 4.5 DME FROM TEB VOR AND THEN CLIMB TO 2000 FEET ON A 280 HEADING. AS WE MADE OUR TURN IN THE DEPARTURE TO A 280 DEGREE HEADING I NOTICED THAT THE CAPTAIN WAS APPROACHING 1700 FEET AND CLIMBING. HAVING FLOWN THIS DEPARTURE NUMEROUS TIMES; AND WITHOUT REFERENCING THE CURRENT DME DISTANCE; I TOLD THE CAPTAIN THAT I FELT WE SHOULD STILL BE HOLDING 1500 FEET. IT WAS A CLEAR DAY AND I FELT WE HAD NOT TRAVELED THE REQUIRED DISTANCE IN ORDER TO CLIMB TO 2000 FEET. THE CAPTAIN SEEMED A BIT CONFUSED AT THAT MOMENT AS HE HAD NOTICED THE DME IN EXCESS OR THE 4.5 NM REQUIRED TO CLIMB TO 2000 FEET. JUST AFTER I SPOKE; DEPARTURE CONTROL ADVISED US THAT WE SHOULD BE AT 1500 FEET. DEPARTURE CONTROL MADE A SECOND TRANSMISSION ALMOST IMMEDIATELY FOLLOWING THE FIRST TELLING US TO GO DOWN TO 1500 FEET. WE DESCENDED BACK DOWN TO 1500 FEET AND I ADVISED ATC THAT WE WERE CORRECTING. VERY SHORTLY THEREAFTER DEPARTURE CLEARED US TO 6000 FEET AND THE REST OF THE FLIGHT PROCEEDED NORMALLY TO DESTINATION. IT WAS AT THAT TIME THAT I NOTICED THAT OUR VOR NAVAIDS WERE AUTO TUNED TO 116.6. THIS IS THE DME THAT THE CAPTAIN HAD USED TO CLIMB FROM 1500 TO 2000 FEET AND NEITHER ONE OF US HAD NOTICED THIS UNTIL THIS MOMENT. HOW THE SYSTEM HAD AUTO TUNED ITSELF FROM THE TEB VOR FREQUENCY; 108.4 TO 116.6 IS STILL UNKNOWN. IN HINDSIGHT I WOULD ADVISE THAT THE ALTITUDE OF 1500 FEET BE SET IN THE ALTITUDE SELECT WINDOW AND THAT WE CONFIRM TOGETHER THAT WE HAVE INDEED MET THE REQUIREMENTS TO CLIMB BY VERIFYING THE VOR FREQUENCY AND THE DISTANCE DISPLAYED BY THE DME.

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.