Hydraulic lines to slats switched during maintenance.

Attributes
ACN	321539
Time
Date	199511
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz
State Reference	US
Altitude	agl bound lower : 0 agl bound upper : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	DC-9 30
Operating Under FAR Part	Part 121
Flight Phase	ground : preflight other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	321539
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical non adherence : far other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa other other : unspecified
Resolutory Action	other
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

During maintenance on aircraft, 6 each hydraulic lines for slat operation were removed. All lines were idented so they would be returned to their respective position. After reinstallation the slats were operated using the auxiliary and alternate hydraulic pumps. The operations check was normal, and no leaks were observed. When the aircraft left the gate the flight crew reported a 'slat disagreement' light on the annunciator panel. The crew returned the aircraft to the gate. Other maintenance personnel operated the slats multiple times, thinking that there was air in the hydraulic lines, and the slats worked normally. The crew left the gate again, only to find the 'slat disagreement' light on again. After they returned to the gate the other maintenance personnel operated the slats with the engines running, where it was determined that the slats were not operating normally. 2 hydraulic lines were found to be switched in the keel area.

Original NASA ASRS Text

Title: HYD LINES TO SLATS SWITCHED DURING MAINT.

Narrative: DURING MAINT ON ACFT, 6 EACH HYD LINES FOR SLAT OP WERE REMOVED. ALL LINES WERE IDENTED SO THEY WOULD BE RETURNED TO THEIR RESPECTIVE POS. AFTER REINSTALLATION THE SLATS WERE OPERATED USING THE AUX AND ALTERNATE HYD PUMPS. THE OPS CHK WAS NORMAL, AND NO LEAKS WERE OBSERVED. WHEN THE ACFT LEFT THE GATE THE FLC RPTED A 'SLAT DISAGREEMENT' LIGHT ON THE ANNUNCIATOR PANEL. THE CREW RETURNED THE ACFT TO THE GATE. OTHER MAINT PERSONNEL OPERATED THE SLATS MULTIPLE TIMES, THINKING THAT THERE WAS AIR IN THE HYD LINES, AND THE SLATS WORKED NORMALLY. THE CREW LEFT THE GATE AGAIN, ONLY TO FIND THE 'SLAT DISAGREEMENT' LIGHT ON AGAIN. AFTER THEY RETURNED TO THE GATE THE OTHER MAINT PERSONNEL OPERATED THE SLATS WITH THE ENGS RUNNING, WHERE IT WAS DETERMINED THAT THE SLATS WERE NOT OPERATING NORMALLY. 2 HYD LINES WERE FOUND TO BE SWITCHED IN THE KEEL AREA.

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.