Two mechanics report a 7th stage intermediate pressure (ip) check valve had not been installed on a ...

Attributes
ACN	884390
Time
Date	201004
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Night
Aircraft 1
Make Model Name	MD-90 Series (DC-9-90) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Parked
Component
Aircraft Component	Pneumatic Valve/Bleed Valve
Person 1
Function	Technician
Qualification	Maintenance Airframe Maintenance Powerplant
Experience	Maintenance Technician 32
Person 2
Function	Technician
Qualification	Maintenance Powerplant Maintenance Airframe
Experience	Maintenance Technician 30
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Procedural Published Material / Policy Deviation - Procedural FAR

Narrative:

The quick engine change (qec) fittings were being installed on an engine in the engine shop april 2010. The environmental control system (ecs) bleed air ducts were partially installed by mechanic 'X' and the intermediate pressure stage (ip) 7th stage check valve was not installed in the duct prior to the duct being installed. The qec was incomplete and it was decided that the remaining ducts would be robbed off the removed engine in ZZZ once the [replacement] engine arrived. The qec installation paperwork was signed off as 'transferred to aircraft non-routine #xx'.I was assigned to go to ZZZ with mechanic 'X' to finish the qec installation. We completed the installation of the remaining ducts and I signed off the non-routine [write-up] as completed. The engine was installed on the aircraft and flew three days later. Upon return to work [at my base]; it was determined it was a possibility that the ip check valve may not have been installed. We contacted maintenance control and ZZZ was advised to check on the installation of the check valve; (the aircraft overnights in ZZZ). The check valve was not installed and ZZZ later installed the check valve without incident.

Original NASA ASRS Text

Title: Two Mechanics report a 7th stage intermediate pressure (IP) check valve had not been installed on a V2500 engine in the engine shop prior to installation on an MD-90 aircraft. The check valve was later installed at a downline station.

Narrative: The quick engine change (QEC) fittings were being installed on an engine in the engine shop April 2010. The environmental control system (ECS) bleed air ducts were partially installed by Mechanic 'X' and the intermediate pressure stage (IP) 7th stage check valve was not installed in the duct prior to the duct being installed. The QEC was incomplete and it was decided that the remaining ducts would be robbed off the removed engine in ZZZ once the [replacement] engine arrived. The QEC installation paperwork was signed off as 'transferred to aircraft non-routine #XX'.I was assigned to go to ZZZ with Mechanic 'X' to finish the QEC installation. We completed the installation of the remaining ducts and I signed off the non-routine [write-up] as completed. The engine was installed on the aircraft and flew three days later. Upon return to work [at my base]; it was determined it was a possibility that the IP check valve may not have been installed. We contacted Maintenance Control and ZZZ was advised to check on the installation of the check valve; (the aircraft overnights in ZZZ). The check valve was not installed and ZZZ later installed the check valve without incident.

Data retrieved from NASA's ASRS site as of April 2012 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.

Two mechanics report a 7th stage intermediate pressure (ip) check valve had not been installed on a V2500 engine in the engine shop prior to installation on an md-90 aircraft. The check valve was later installed at a downline station.