B737 flight test crew had the aircraft pitch up when checking elevator power off reversion.

Attributes
ACN	468135
Time
Date	200003
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zny.artcc
State Reference	NY
Altitude	msl bound lower : 23000 msl bound upper : 23400
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zny.artcc
Operator	common carrier : air carrier
Make Model Name	B737-800
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 60 flight time total : 11000 flight time type : 5000
ASRS Report	468135
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : critical altitude deviation : excursion from assigned altitude maintenance problem : improper maintenance non adherence : clearance non adherence : company policies non adherence : far non adherence : published procedure other anomaly other anomaly other
Independent Detector	aircraft equipment : altitude alert other flight crewa other flight crewb
Resolutory Action	flight crew : regained aircraft control flight crew : returned to assigned altitude none taken : insufficient time
Consequence	other other
Factors
Maintenance	contributing factor : work cards contributing factor : schedule pressure contributing factor : tooling performance deficiency : inspection performance deficiency : installation performance deficiency : non compliance with legal requirements performance deficiency : testing
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance Company
Primary Problem	Company
Air Traffic Incident	Pilot Deviation

Narrative:

During a maintenance test hop we were doing a manual reversion at FL230. When hydraulics were turned off, the aircraft pitched up very abruptly and severely. In an attempt to control the aircraft with stabilizer and stabilizer trim we climbed about 400 ft before we could return the hydraulic system to normal power. Callback conversation with reporter revealed the following information: the reporter indicated that maintenance had replaced an elevator control tab. The job card requires the tab push rod be rigged with a special rigging tool that is specific to aircraft model. Air carrier station maintenance was unable to find the correct tool so the maintenance personnel 'just guessed at it.' air carrier flight test has rewritten the test procedure to require block altitude for testing, and require the maximum speed be approached in increments.

Original NASA ASRS Text

Title: B737 FLT TEST CREW HAD THE ACFT PITCH UP WHEN CHKING ELEVATOR PWR OFF REVERSION.

Narrative: DURING A MAINT TEST HOP WE WERE DOING A MANUAL REVERSION AT FL230. WHEN HYDS WERE TURNED OFF, THE ACFT PITCHED UP VERY ABRUPTLY AND SEVERELY. IN AN ATTEMPT TO CTL THE ACFT WITH STABILIZER AND STABILIZER TRIM WE CLBED ABOUT 400 FT BEFORE WE COULD RETURN THE HYD SYS TO NORMAL PWR. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR INDICATED THAT MAINT HAD REPLACED AN ELEVATOR CTL TAB. THE JOB CARD REQUIRES THE TAB PUSH ROD BE RIGGED WITH A SPECIAL RIGGING TOOL THAT IS SPECIFIC TO ACFT MODEL. ACR STATION MAINT WAS UNABLE TO FIND THE CORRECT TOOL SO THE MAINT PERSONNEL 'JUST GUESSED AT IT.' ACR FLT TEST HAS REWRITTEN THE TEST PROC TO REQUIRE BLOCK ALT FOR TESTING, AND REQUIRE THE MAX SPD BE APCHED IN INCREMENTS.

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.