DC10 flight crew experienced a pitch up at leveloff and deviated from assigned altitude.

Attributes
ACN	493784
Time
Date	200012
Day	Sat
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : gtf.vortac
State Reference	MI
Altitude	msl bound lower : 35000 msl bound upper : 35500
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zlc.artcc
Operator	common carrier : air carrier
Make Model Name	DC-10 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : enroute altitude change
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : commercial pilot : flight engineer pilot : instrument pilot : multi engine pilot : atp
Experience	flight time last 90 days : 130 flight time total : 25000 flight time type : 2000
ASRS Report	493784
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : company policies other anomaly other anomaly
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : regained aircraft control flight crew : returned to assigned altitude
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were cleared from FL330 to FL350. The altitude was set and armed by the first officer. The captain was flying the airplane. As we approached FL350 the FMA went to altitude capture and the aircraft started to level off. The autothrottles were in N1. The speed started to increase and the captain moved the vertical speed wheel. We then lost the altitude capture and I yelled 'altitude capture lost.' the captain still had his hand on the vertical speed wheel. The aircraft started a high speed buffet and the first officer pulled the autothrottle speed control to speed. The captain then took the aircraft off autoplt and the aircraft pitched up and reached FL355 before the captain started a descent. We were above FL350 for about 10 seconds.

Original NASA ASRS Text

Title: DC10 FLC EXPERIENCED A PITCH UP AT LEVELOFF AND DEVIATED FROM ASSIGNED ALT.

Narrative: WE WERE CLRED FROM FL330 TO FL350. THE ALT WAS SET AND ARMED BY THE FO. THE CAPT WAS FLYING THE AIRPLANE. AS WE APCHED FL350 THE FMA WENT TO ALT CAPTURE AND THE ACFT STARTED TO LEVEL OFF. THE AUTOTHROTTLES WERE IN N1. THE SPD STARTED TO INCREASE AND THE CAPT MOVED THE VERT SPD WHEEL. WE THEN LOST THE ALT CAPTURE AND I YELLED 'ALT CAPTURE LOST.' THE CAPT STILL HAD HIS HAND ON THE VERT SPD WHEEL. THE ACFT STARTED A HIGH SPD BUFFET AND THE FO PULLED THE AUTOTHROTTLE SPD CTL TO SPD. THE CAPT THEN TOOK THE ACFT OFF AUTOPLT AND THE ACFT PITCHED UP AND REACHED FL355 BEFORE THE CAPT STARTED A DSCNT. WE WERE ABOVE FL350 FOR ABOUT 10 SECONDS.

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.