An hs-125 departing teb deviated from the charted course when the FMS dumped the departure procedure...

Attributes
ACN	791578
Time
Date	200806
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : teb.airport
State Reference	NJ
Altitude	msl single value : 3000
Environment
Flight Conditions	VMC
Weather Elements	Thunderstorm
Light	Dusk
Aircraft 1
Controlling Facilities	tracon : n90.tracon
Operator	general aviation : corporate
Make Model Name	HS 125 Series
Operating Under FAR Part	Part 91
Navigation In Use	other other ndb
Flight Phase	climbout : initial
Route In Use	departure sid : teb
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : multi engine pilot : atp pilot : commercial
Experience	flight time last 90 days : 36 flight time total : 8500 flight time type : 150
ASRS Report	791578
Person 2
Affiliation	company : corporate
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 250 flight time total : 15000 flight time type : 50
ASRS Report	791576
Events
Anomaly	aircraft equipment problem : less severe non adherence : published procedure non adherence : clearance other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended or assigned course
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

After waiting over five hours to depart teb due to thunderstorms we were cleared via the teb 5 departure off runway 1. We loaded the FMS; we departed runway 1. Soon after departure the FMS dropped the departure; we had the raw data tuned as a back-up. This is a very complex departure with 3 altitude changes and numerous heading changes within the first mins after liftoff. By the time we switched to the raw data we were past the pnj NDB. Altitude was maintained and there was no conflict with other aircraft.supplemental information from acn 791576: FMS dropped waypoints had raw data tuned to pnj NDB but you have 2 turns and 3 altitudes in a matter of 1 to 2 mins after departure. Altitude was maintained but pnj was missed due to close proximity of the airport and of course the question what happened to the waypoints and by then you have missed pnj.

Original NASA ASRS Text

Title: AN HS-125 DEPARTING TEB DEVIATED FROM THE CHARTED COURSE WHEN THE FMS DUMPED THE DEP PROC.

Narrative: AFTER WAITING OVER FIVE HRS TO DEPART TEB DUE TO THUNDERSTORMS WE WERE CLEARED VIA THE TEB 5 DEP OFF RWY 1. WE LOADED THE FMS; WE DEPARTED RWY 1. SOON AFTER DEP THE FMS DROPPED THE DEP; WE HAD THE RAW DATA TUNED AS A BACK-UP. THIS IS A VERY COMPLEX DEP WITH 3 ALT CHANGES AND NUMEROUS HEADING CHANGES WITHIN THE FIRST MINS AFTER LIFTOFF. BY THE TIME WE SWITCHED TO THE RAW DATA WE WERE PAST THE PNJ NDB. ALTITUDE WAS MAINTAINED AND THERE WAS NO CONFLICT WITH OTHER ACFT.SUPPLEMENTAL INFO FROM ACN 791576: FMS DROPPED WAYPOINTS HAD RAW DATA TUNED TO PNJ NDB BUT YOU HAVE 2 TURNS AND 3 ALTS IN A MATTER OF 1 TO 2 MINS AFTER DEP. ALT WAS MAINTAINED BUT PNJ WAS MISSED DUE TO CLOSE PROXIMITY OF THE ARPT AND OF COURSE THE QUESTION WHAT HAPPENED TO THE WAYPOINTS AND BY THEN YOU HAVE MISSED PNJ.

Data retrieved from NASA's ASRS site as of May 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.