A G5 flight crew overshoots their assigned altitude on leveloff when the flight guidance computer fails to automatic capture the altitude west of teb, nj.

Home

Browse by month

Random

Latest

About

Contact

Attributes
ACN	536758
Time
Date	200202
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : teb.airport
State Reference	NJ
Altitude	msl bound lower : 10000 msl bound upper : 10500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : n90.tracon
Operator	general aviation : corporate
Make Model Name	Gulfstream V
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	climbout : intermediate altitude
Route In Use	departure : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 50 flight time total : 11000 flight time type : 200
ASRS Report	536758
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : critical altitude deviation : overshoot non adherence : clearance other anomaly
Independent Detector	aircraft equipment other aircraft equipment : mistrim light other controllera other flight crewa other flight crewb
Resolutory Action	controller : issued advisory flight crew : returned to assigned altitude flight crew : regained aircraft control flight crew : overcame equipment problem
Consequence	faa : reviewed incident with flight crew other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

After departing teb, ATC cleared us to 10000 ft on an assigned heading. Autoplt and autothrottles were engaged, vertical speed of 2000 FPM was commanded. I noticed that the aircraft was not following the speed command, we were approximately 230 KTS rather than 250 KTS as programmed. I disengaged the autoplt and flew the command bars to establish to normal profile. When the parameters were met, autoplt was re-engaged and seemed to perform normally. Approaching 10000 ft the aircraft started to pitch up, trim ran toward full nose up and the 'elevator mistrim nose up' EICAS message appeared. I pushed tcs to override the autoplt but we passed 10000 ft. At that point the power increased to full climb power as the programmed autospd increased to 300 KTS from 250 KTS. This increased the pitch up moment. Autothrottles and autoplt were both disengaged, but there was an altitude excursion of 500 ft before I was able to return to 10000 ft. ATC noticed the altitude and had us confirm we were cleared to 10000 ft. It would have required a violent negative 'G' force to have stopped the climb at 10000 ft. We were in VMC conditions and had no TCASII traffic near our altitude. FGC (flight guidance computer) #2 was selected and no further problems were encountered. On the previous flight of this aircraft, the crew had squawked the FGC #1. Maintenance wrote off the squawk as 'could not duplicate #1 iac (integrated avionics control) operations checks good.' after this flight the #1 iac was replaced.

Original NASA ASRS Text

Title: A G5 FLC OVERSHOOTS THEIR ASSIGNED ALT ON LEVELOFF WHEN THE FLT GUIDANCE COMPUTER FAILS TO AUTO CAPTURE THE ALT W OF TEB, NJ.

Narrative: AFTER DEPARTING TEB, ATC CLRED US TO 10000 FT ON AN ASSIGNED HEADING. AUTOPLT AND AUTOTHROTTLES WERE ENGAGED, VERT SPD OF 2000 FPM WAS COMMANDED. I NOTICED THAT THE ACFT WAS NOT FOLLOWING THE SPD COMMAND, WE WERE APPROX 230 KTS RATHER THAN 250 KTS AS PROGRAMMED. I DISENGAGED THE AUTOPLT AND FLEW THE COMMAND BARS TO ESTABLISH TO NORMAL PROFILE. WHEN THE PARAMETERS WERE MET, AUTOPLT WAS RE-ENGAGED AND SEEMED TO PERFORM NORMALLY. APCHING 10000 FT THE ACFT STARTED TO PITCH UP, TRIM RAN TOWARD FULL NOSE UP AND THE 'ELEVATOR MISTRIM NOSE UP' EICAS MESSAGE APPEARED. I PUSHED TCS TO OVERRIDE THE AUTOPLT BUT WE PASSED 10000 FT. AT THAT POINT THE PWR INCREASED TO FULL CLB PWR AS THE PROGRAMMED AUTOSPD INCREASED TO 300 KTS FROM 250 KTS. THIS INCREASED THE PITCH UP MOMENT. AUTOTHROTTLES AND AUTOPLT WERE BOTH DISENGAGED, BUT THERE WAS AN ALT EXCURSION OF 500 FT BEFORE I WAS ABLE TO RETURN TO 10000 FT. ATC NOTICED THE ALT AND HAD US CONFIRM WE WERE CLRED TO 10000 FT. IT WOULD HAVE REQUIRED A VIOLENT NEGATIVE 'G' FORCE TO HAVE STOPPED THE CLB AT 10000 FT. WE WERE IN VMC CONDITIONS AND HAD NO TCASII TFC NEAR OUR ALT. FGC (FLT GUIDANCE COMPUTER) #2 WAS SELECTED AND NO FURTHER PROBS WERE ENCOUNTERED. ON THE PREVIOUS FLT OF THIS ACFT, THE CREW HAD SQUAWKED THE FGC #1. MAINT WROTE OFF THE SQUAWK AS 'COULD NOT DUPLICATE #1 IAC (INTEGRATED AVIONICS CTL) OPS CHKS GOOD.' AFTER THIS FLT THE #1 IAC WAS REPLACED.

Data retrieved from NASA's ASRS site as of July 2007 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.