Mechanics use an unauthorized method to service aircraft landing gear shock struts.

Attributes
ACN	235237
Time
Date	199303
Day	Wed
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : den
State Reference	CO
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport
Flight Phase	other
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	235237
Person 2
Affiliation	company : air carrier
Function	other personnel other oversight : supervisor
Qualification	other other : other
Events
Anomaly	aircraft equipment problem : critical non adherence : published procedure non adherence other
Independent Detector	other other : unspecified
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Airport
Air Traffic Incident	other

Narrative:

A work-card for servicing the medium large transport of an medium large transport called for jacking the plane, bleeding the air out of the struts followed by compressing the struts with a bottle jack until hydraulic fluid emerged from a bleed port on each of the struts. Fluid was then to be renewed by pumping until it once more emerged from the bleed port as a clean solid stream. Nitrogen was to be renewed (after removing the bottle jack) and finally, the plane would be lowered back to the ground. Actual procedure was as follows: the plane was never jacked. Nitrogen was bled from the struts -- fluid exiting the bleed ports as the struts were compressed by the weight of the plane. Fluid was renewed until clean fluid poured from the bleed ports in a clean, solid stream. Nitrogen was renewed until the struts were at the improper ht. All these procedures were performed on the ground. 2 mechanics did this on the go-ahead of the assistant supervisor and supervisor of their work crew. Of the 4 men involved, the one with the least understanding and experience signed off the strut servicing job.

Original NASA ASRS Text

Title: MECHS USE AN UNAUTH METHOD TO SVC ACFT LNDG GEAR SHOCK STRUTS.

Narrative: A WORK-CARD FOR SVCING THE MLG OF AN MLG CALLED FOR JACKING THE PLANE, BLEEDING THE AIR OUT OF THE STRUTS FOLLOWED BY COMPRESSING THE STRUTS WITH A BOTTLE JACK UNTIL HYD FLUID EMERGED FROM A BLEED PORT ON EACH OF THE STRUTS. FLUID WAS THEN TO BE RENEWED BY PUMPING UNTIL IT ONCE MORE EMERGED FROM THE BLEED PORT AS A CLEAN SOLID STREAM. NITROGEN WAS TO BE RENEWED (AFTER REMOVING THE BOTTLE JACK) AND FINALLY, THE PLANE WOULD BE LOWERED BACK TO THE GND. ACTUAL PROC WAS AS FOLLOWS: THE PLANE WAS NEVER JACKED. NITROGEN WAS BLED FROM THE STRUTS -- FLUID EXITING THE BLEED PORTS AS THE STRUTS WERE COMPRESSED BY THE WT OF THE PLANE. FLUID WAS RENEWED UNTIL CLEAN FLUID POURED FROM THE BLEED PORTS IN A CLEAN, SOLID STREAM. NITROGEN WAS RENEWED UNTIL THE STRUTS WERE AT THE IMPROPER HT. ALL THESE PROCS WERE PERFORMED ON THE GND. 2 MECHS DID THIS ON THE GO-AHEAD OF THE ASSISTANT SUPVR AND SUPVR OF THEIR WORK CREW. OF THE 4 MEN INVOLVED, THE ONE WITH THE LEAST UNDERSTANDING AND EXPERIENCE SIGNED OFF THE STRUT SVCING JOB.

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.