A B737-300 captain reports screws missing from left underwing aileron hinge point. Screws replaced.

Attributes
ACN	641359
Time
Date	200412
Day	Sun
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	ground : preflight ground : parked
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	641359
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper documentation maintenance problem : improper maintenance non adherence : far non adherence : published procedure
Independent Detector	other flight crewa other flight crewb
Resolutory Action	none taken : detected after the fact
Consequence	other other
Factors
Maintenance	performance deficiency : inspection performance deficiency : installation performance deficiency : non compliance with legal requirements performance deficiency : scheduled maintenance
Supplementary
Problem Areas	Maintenance Human Performance
Primary Problem	Maintenance Human Performance

Narrative:

During walkaround preflight at gate at ZZZ, first officer found 8 screws missing from left underwing aileron hinge point, of said aileron. Since this is a flight control issue, concern is raised on how those 8 screws had come out. Maintenance was notified at ZZZ, screws were replaced, ailerons were checked for free movement, and new mrd was issued and flight continued with minimal delay.

Original NASA ASRS Text

Title: A B737-300 CAPT RPTS SCREWS MISSING FROM L UNDERWING AILERON HINGE POINT. SCREWS REPLACED.

Narrative: DURING WALKAROUND PREFLT AT GATE AT ZZZ, FO FOUND 8 SCREWS MISSING FROM L UNDERWING AILERON HINGE POINT, OF SAID AILERON. SINCE THIS IS A FLT CTL ISSUE, CONCERN IS RAISED ON HOW THOSE 8 SCREWS HAD COME OUT. MAINT WAS NOTIFIED AT ZZZ, SCREWS WERE REPLACED, AILERONS WERE CHKED FOR FREE MOVEMENT, AND NEW MRD WAS ISSUED AND FLT CONTINUED WITH MINIMAL DELAY.

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.