Date: 201407
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Light: Dusk
Aircraft: MD-83
Operator: Air Carrier
Operating under: Part 121
Flight phase: Parked
Aircraft component: Engine Air Anti-Ice
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Technician
Reporter qualification: Maintenance Airframe; Maintenance Powerplant
Human factors: Communication Breakdown
Second reporter function: Technician
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Maintenance
When detected: Aircraft In Service At Gate
Result: General Maintenance Action
Contributing factors: Human Factors; MEL; Aircraft
Primary problem: Human Factors

Narrative: MD-83 aircraft inbound with a discrepancy that the anti-ice light came on for the right engine. On inspection found the right engine; right anti-ice valve would not electrically move to the 'open' position. Placarded the right engine; right anti-ice valve in 'open' position as instructed in MEL. I don't know. There was no discrepancy written in logbook after I placed the MEL. Once again I was in compliance with the MEL. I was in compliance with everything with this MEL. It flew six legs after I placarded the valve with no discrepancy before it landed in ZZZ and stayed 2.7 days. Evening shift. Gate location.


Second narrative: MD-83 Aircraft had an inbound pirep; right engine anti-ice valve light on. Performed troubleshooting; found right outboard anti-ice valve inoperative. Placarded valve per MEL. Accomplished Minimum Performance Downgrade. Four other Maintenance personnel were involved. On the Line during Day shift late morning. After the Aircraft flew for six days with no faults; Maintenance Control attempted to clear the MEL to find it was out of compliance. Between those six days; someone performed undocumented maintenance on the aircraft. The [electrical] jumper that is suppose to be in the special items book is missing and needs to be replaced for future MELs. Ramp location.

Second callback: Reporter stated the aircraft had been acquired during a merger. Whenever one of the PW JT-8D engine anti-ice valve's failed to operate; an avionics 3-pin electrical plug (jumper) would be connected to the signal side of the disconnected cannon plug to prevent the cockpit light from coming 'On'. The connector would be taped; then bagged to protect from water or fluid and the valve safety wired to the 'Open' position. He signed-off for the Aircraft Performance Downgrade while another Technician signed for the jumper installation. Reporter stated when Maintenance Control tried to clear the MEL six days later while the aircraft was at their Air Carrier's Base Station; Maintenance found the right engine; right Anti-Ice Valve in the normal 'Closed' position and the Cannon plug reconnected to the valve. Since he and another Technician were the last ones to sign-off work accomplished; he was being accused of not performing the MEL procedures required for dispatch. He does not know if a new valve was installed; but they now know that work on that engine had been performed at his Maintenance station a few days after he had MEL'd the anti-ice valve. No paperwork has been found documenting the rework accomplished. He suspects someone had failed to sign-off for correcting the problem. No flight write-ups had occurred since the initial valve light discrepancy deferral.

Synopsis: Two Aircraft Maintenance Technicians (AMTs) report about an MEL disconnect procedure they had performed on the right engine; right outboard anti-ice valve on an MD-83 aircraft. The valve was later found to be connected and not in compliance with the MEL dispatch requirements they had signed for. Technician notes that undocumented maintenance had occurred.