A qc inspector reports that a cabin pressure controller was changed on a dehavilland dhc-100 due to ...

Attributes
ACN	803646
Time
Date	200809
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Dash 8-100
Operating Under FAR Part	Part 121
Person 1
Affiliation	company : air carrier
Function	maintenance : inspector
Qualification	technician : airframe technician : powerplant
Experience	maintenance lead technician : 1 maintenance technician : 23
ASRS Report	803646
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper maintenance non adherence : published procedure
Independent Detector	other other : 1
Resolutory Action	other
Consequence	other
Factors
Maintenance	contributing factor : briefing contributing factor : work cards performance deficiency : inspection performance deficiency : training performance deficiency : testing performance deficiency : scheduled maintenance performance deficiency : non compliance with legal requirements
Supplementary
Problem Areas	Maintenance Human Performance Aircraft
Primary Problem	Maintenance Human Performance

Narrative:

During routine overnight maintenance; the cabin pressure controller would pop the circuit breaker when switched to automatic. Original write-up was not marked as an rii (inspection required) item due to the component named. Avionics department discovered that pressurization computer was faulty component. I did not realize that this unit required a pitot static leak check; which is an rii item. This computer controls cabin pressurization. The aircraft work package was audited but the write-up form was not changed. Aircraft was then released. The avionics lead on shift was granted a temporary rii due to having witnessed the procedure. Leak checks were within parameters. Callback conversation with reporter revealed the following information: reporter stated the cabin pressure controller on the dhc-100 is also the computer for this system. The lack of communication between the avionics group and the quality control inspectors; including the wording used on their maintenance write-up form for the pressure controller; contributed to inspection not accomplishing the required pitot/static leak check rii inspection.

Original NASA ASRS Text

Title: A QC INSPECTOR REPORTS THAT A CABIN PRESSURE CONTROLLER WAS CHANGED ON A DEHAVILLAND DHC-100 DUE TO POPPING THE CIRCUIT BREAKER WHEN PLACED IN THE 'AUTO' MODE; BUT DID NOT REALIZE THAT AN RII WAS REQUIRED.

Narrative: DURING ROUTINE OVERNIGHT MAINT; THE CABIN PRESSURE CONTROLLER WOULD POP THE CIRCUIT BREAKER WHEN SWITCHED TO AUTO. ORIGINAL WRITE-UP WAS NOT MARKED AS AN RII (INSPECTION REQUIRED) ITEM DUE TO THE COMPONENT NAMED. AVIONICS DEPT DISCOVERED THAT PRESSURIZATION COMPUTER WAS FAULTY COMPONENT. I DID NOT REALIZE THAT THIS UNIT REQUIRED A PITOT STATIC LEAK CHK; WHICH IS AN RII ITEM. THIS COMPUTER CTLS CABIN PRESSURIZATION. THE ACFT WORK PACKAGE WAS AUDITED BUT THE WRITE-UP FORM WAS NOT CHANGED. ACFT WAS THEN RELEASED. THE AVIONICS LEAD ON SHIFT WAS GRANTED A TEMPORARY RII DUE TO HAVING WITNESSED THE PROC. LEAK CHKS WERE WITHIN PARAMETERS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED THE CABIN PRESSURE CONTROLLER ON THE DHC-100 IS ALSO THE COMPUTER FOR THIS SYSTEM. THE LACK OF COMMUNICATION BETWEEN THE AVIONICS GROUP AND THE QUALITY CONTROL INSPECTORS; INCLUDING THE WORDING USED ON THEIR MAINT WRITE-UP FORM FOR THE PRESSURE CONTROLLER; CONTRIBUTED TO INSPECTION NOT ACCOMPLISHING THE REQUIRED PITOT/STATIC LEAK CHECK RII INSPECTION.

Data retrieved from NASA's ASRS site as of May 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 qc inspector reports that a cabin pressure controller was changed on a dehavilland dhc-100 due to popping the circuit breaker when placed in the 'automatic' mode; but did not realize that an rii was required.