Dash 8-300
Maintenance Airframe; Maintenance Powerplant
Time Pressure; Situational Awareness; Distraction; Communication Breakdown; Workload
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Aircraft; Staffing; Procedure; Human Factors
I was the Inspector on shift and myself and two other mechanics where finishing up the rigging and final checks after a scheduled engine change (one mechanic working on the replaced engine; the other doing rig checks and replacing the ibv servo screen on the other). I was busy going from one engine; where one mechanic was working; to the other to inspect the rig; servo valve change on the opposite engine and back to the final checks before run-up on the replaced engine. On top of this we had a spare in work; which suddenly had to go out. The Lead [Mechanic] was busy with other duties on the plane with the engine change; so I was also working on closing out the [Work] package and making sure all the paperwork was correct on the spare. When it came time to close the cowlings; I helped lift the lower cowl while the mechanics secured it and hooked up the connector; hose; and jumpers. We ops checked the deice light and bypass door function. I inspected the lower cowling deck and internal area of the intake for for FOD and cleanliness; and we closed the cowling. Myself and two other mechanics secured the cowlings; but I do not remember who hooked up the deice hose for the cowling. We found out the next day that the deice supply hose was connected to the oil cooler drain valve; which can be done since they are adjacent to each other and look similar. The intake deice boot and one boot on the wing were found to be inoperative on the first flight of the day. These two boots inflate together.The event occurred plain and simply because we were in a hurry to get the engine change done and the aircraft ready for a early afternoon evaluation flight for another maintenance issue. While also trying to get the spare [aircraft] which had just arrived an hour or so earlier; finished up to go out. The item was corrected by Line maintenance.[Recommend] several things will help. Slowing down and taking the time to review what you have just done even when you are rushed by time constraints; lack of manpower and a heavy workload. Revising the engine installation work card to include installing the lower cowling; and the connections required; and operational checks for the ice light; bypass door; and deice system. As it stands now the engine removal card has a step that says 'remove cowlings'. The installation card just says 'install access panels'. And on the list of required operational checks there is nothing to check the airframe deice system; which if there was we would have discovered the problem. Installing a lower cowling is not an Required Inspection Item (RII) item; but I feel it should be made an inspection item on the engine installation card since an engine replacement is a large and complex task. Distractions/interruptions. Deicing capabilities to left nacelle intake boot affected.Flight delay. Staff [shortage]. Rotating shifts.
An Aircraft Inspector describes how conditions in their workplace involving time constraints; lack of manpower; heavy workload; lack of RII Inspection requirements and lack of an Operational Check of the Engine and Airframe Deice System contributed to a deice supply hose being connected to the oil cooler drain valve on a DHC-8-300 aircraft during an engine change.