Lear 45 crew climbs early on the teb 5 due to confusion over the 4.5 fix displayed in the FMC.

Attributes
ACN	738895
Time
Date	200705
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : teb.airport
State Reference	NJ
Altitude	msl bound lower : 1500 msl bound upper : 1750
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : n90.tracon
Operator	general aviation : personal
Make Model Name	Learjet 45
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	climbout : initial
Route In Use	departure sid : teb
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 25 flight time total : 8000 flight time type : 20
ASRS Report	738895
Person 2
Affiliation	other
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : instrument pilot : commercial pilot : cfi
Experience	flight time last 90 days : 75 flight time total : 676 flight time type : 281
ASRS Report	739070
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : published procedure
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued alert flight crew : returned to assigned altitude
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

PF was using the FMS to identify the 4.5 teb DME fix on the teb 5 SID. The FMS identifies this fix as 4.5. It does not display distances from teb. PF confused this FMS fix 4.5 as distance from teb; and initiated climb from 1500 to 2000 ft. At 1750 ft departure identified diversion and corrected. Nowhere does this FMS show distance from teb. It would be best if the SID and the FMS identified this point with a 5 letter identifier; as opposed to 4.5. Another improvement would be to have the FMS display distance from the DME selected and tuned while in the FMS mode.callback conversation with reporter revealed the following information: the aircraft was a lear 45 and the FMS was a universal 1D which is different from the other FMC's in the fleet. The primary problem was inexperience with this FMC and not realizing that the teb VOR needed to be manually tuned and displayed on the PNF side to identify the 4.5 DME.supplemental information from acn 739070: after departing runway 24 at teb; we expedited the teb 5 SID. I maintained 1500 ft MSL until I read 4.5 DME on the pfd; unfortunately that 4.5 DME was the distance to the next fix (unnamed due to being my 4.5 DME from teb VOR). I saw the 4.5 DME being displayed and began a climb to 2000 ft MSL before actually reaching 4.5 DME from teb VOR.

Original NASA ASRS Text

Title: LEAR 45 CREW CLBS EARLY ON THE TEB 5 DUE TO CONFUSION OVER THE 4.5 FIX DISPLAYED IN THE FMC.

Narrative: PF WAS USING THE FMS TO IDENTIFY THE 4.5 TEB DME FIX ON THE TEB 5 SID. THE FMS IDENTIFIES THIS FIX AS 4.5. IT DOES NOT DISPLAY DISTANCES FROM TEB. PF CONFUSED THIS FMS FIX 4.5 AS DISTANCE FROM TEB; AND INITIATED CLB FROM 1500 TO 2000 FT. AT 1750 FT DEP IDENTIFIED DIVERSION AND CORRECTED. NOWHERE DOES THIS FMS SHOW DISTANCE FROM TEB. IT WOULD BE BEST IF THE SID AND THE FMS IDENTIFIED THIS POINT WITH A 5 LETTER IDENTIFIER; AS OPPOSED TO 4.5. ANOTHER IMPROVEMENT WOULD BE TO HAVE THE FMS DISPLAY DISTANCE FROM THE DME SELECTED AND TUNED WHILE IN THE FMS MODE.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE ACFT WAS A LEAR 45 AND THE FMS WAS A UNIVERSAL 1D WHICH IS DIFFERENT FROM THE OTHER FMC'S IN THE FLEET. THE PRIMARY PROB WAS INEXPERIENCE WITH THIS FMC AND NOT REALIZING THAT THE TEB VOR NEEDED TO BE MANUALLY TUNED AND DISPLAYED ON THE PNF SIDE TO IDENTIFY THE 4.5 DME.SUPPLEMENTAL INFO FROM ACN 739070: AFTER DEPARTING RWY 24 AT TEB; WE EXPEDITED THE TEB 5 SID. I MAINTAINED 1500 FT MSL UNTIL I READ 4.5 DME ON THE PFD; UNFORTUNATELY THAT 4.5 DME WAS THE DISTANCE TO THE NEXT FIX (UNNAMED DUE TO BEING MY 4.5 DME FROM TEB VOR). I SAW THE 4.5 DME BEING DISPLAYED AND BEGAN A CLB TO 2000 FT MSL BEFORE ACTUALLY REACHING 4.5 DME FROM TEB VOR.

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.