A B757-200 on leveloff at FL360 heard loud bang under captain's seat. Diverted. Maintenance found la...

Attributes
ACN	657098
Time
Date	200505
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 36000
Environment
Flight Conditions	VMC
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 120 flight time total : 15000 flight time type : 5500
ASRS Report	657098
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa other flight crewb
Resolutory Action	other
Consequence	other other other
Supplementary
Problem Areas	Environmental Factor Flight Crew Human Performance Aircraft
Primary Problem	Aircraft

Narrative:

While performing the control check on taxi out; I heard a slight noise as the controls were pushed to the forward stop. The control check was repeated several times while observing normal indications on the lower EICAS. We performed a maintenance check on the aft panel noting no discrepancies. Checked hydraulic quantities normal. Takeoff and climb out normal. Shortly after leveling at FL360 a loud bang was heard under the captain's seat. Flight controls operated normally. Clearance to return to ZZZ was requested. No emergency declared. Flight attendants were briefed that the flight would be on the ground I chicago in 30 mins and the approach and landing would be normal. No cabin preparation. The approach and landing were normal. Maintenance found a large spring broken loose in the forward east&east compartment. Callback conversation with reporter revealed the following information: the airplane operated normally and no flight control changes were noted. On the ground maintenance recovered a broken spring from the forward east&east compartment and reporter believes it came from the elevator feel system. No emergency was declared.

Original NASA ASRS Text

Title: A B757-200 ON LEVELOFF AT FL360 HEARD LOUD BANG UNDER CAPT'S SEAT. DIVERTED. MAINT FOUND LARGE SPRING BROKEN IN FORWARD E&E COMPARTMENT.

Narrative: WHILE PERFORMING THE CTL CHK ON TAXI OUT; I HEARD A SLIGHT NOISE AS THE CTLS WERE PUSHED TO THE FORWARD STOP. THE CTL CHK WAS REPEATED SEVERAL TIMES WHILE OBSERVING NORMAL INDICATIONS ON THE LOWER EICAS. WE PERFORMED A MAINT CHK ON THE AFT PANEL NOTING NO DISCREPANCIES. CHKED HYD QUANTITIES NORMAL. TKOF AND CLBOUT NORMAL. SHORTLY AFTER LEVELING AT FL360 A LOUD BANG WAS HEARD UNDER THE CAPT'S SEAT. FLT CTLS OPERATED NORMALLY. CLRNC TO RETURN TO ZZZ WAS REQUESTED. NO EMER DECLARED. FLT ATTENDANTS WERE BRIEFED THAT THE FLT WOULD BE ON THE GND I CHICAGO IN 30 MINS AND THE APCH AND LNDG WOULD BE NORMAL. NO CABIN PREPARATION. THE APCH AND LNDG WERE NORMAL. MAINT FOUND A LARGE SPRING BROKEN LOOSE IN THE FORWARD E&E COMPARTMENT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE AIRPLANE OPERATED NORMALLY AND NO FLT CTL CHANGES WERE NOTED. ON THE GND MAINT RECOVERED A BROKEN SPRING FROM THE FORWARD E&E COMPARTMENT AND RPTR BELIEVES IT CAME FROM THE ELEVATOR FEEL SYS. NO EMER WAS DECLARED.

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.

A B757-200 on leveloff at FL360 heard loud bang under captain's seat. Diverted. Maintenance found large spring broken in forward east&east compartment.