A Captain reported he refused to fly a DHC-8-Q400 aircraft because he felt the aircraft was unsafe due to a comprised rudder control system which was being deferred using an MEL that neither applied to the problem nor was fully complied with. Captain was removed from the flight; which departed with another Captain.

Narrative

I was Pilot in Command (PIC) of an Air Carrier flight. I refused to fly the aircraft after conversing with Dispatch; Maintenance Control; the Maintenance Shift Supervisor; and the Director of Operations; who was serving as Duty Officer. I believed that the aircraft was unsafe to fly due to a compromised rudder control system which was being deferred using an MEL that neither applied to the problem nor was fully complied with.Upon acceptance Inspection of the aircraft I found a [safety] wire connecting the Captain's Rudder Pedal Adjustment handle to an open screw hole in the Pitot Static Isolation Panel. The wire was approximately six inches long. The panel was being pulled out of position by the wire's tension as the panel was only being held by one of its two attachment screws. An MEL sticker was placed near the wire. The sticker and Release indicated that the aircraft was operating under MEL 27-20-2 titled Rudder Pedal Adjustment. The original write-up stated that the rudder pedals would not stay adjusted. That is; the rudder pedals were slipping during use. On the Dash-8; rudder inputs are carried through the adjustment mechanism and the entire mechanism moves to translate the input to the rudder control actuators. Therefore; the rudder pedal adjustment levers and rudder input mechanisms cannot be compromised in any way. If they are; pressure on the rudder pedal may result in movement of adjustment lever within the adjustment mechanism and no actual movement of the rudder controls. The rudder pedal adjustment system consists of a handle attached to a flexible shaft that translates the adjustment input to a screw jack and adjustment levers that change the position of the pedals. MEL 27-20-2 allows the aircraft to operate if the rudder pedal adjustment input is inoperative. Step one of the maintenance procedure states: Turn the rudder adjustment handle; ensure the pedal adjustment shaft does not move forward or back. Meaning that if movement of the rudder adjustment handle does not result in movement of the adjustment shaft the aircraft can be deemed airworthy provided all the conditions of the MEL's maintenance procedure are met. This Air Carrier used an operative rudder [pedal] adjustment handle to prevent the pedals from sliding. This means that the aircraft was depending on a piece of [safety] wire and a partially detached panel to ensure the rudder pedals remained functional. It also meant that the mechanical defect or wear that prevented the pedals from remaining adjusted as designed was not addressed. The rudder control system was compromised. By disabling the rudder adjustment handle with wire; step one of the MEL cannot be complied with. Therefore the MEL cannot be applied. The MEL does not allow for the use of wire or the removal of screws from other components. When I informed Maintenance Control that I did not believe the aircraft was safe they offered to send a Mechanic to the airplane to adjust the pedals to fit me. I asked how they were going to do that and they said the Mechanic would rewire the handle in a position that fit me. Based upon what I saw; my knowledge of the Dash-8; and Maintenance's explanations I determined that the MEL did not apply to the problem at hand and; baring that; was not being complied with. I informed the flight's Dispatcher that I felt the aircraft was unsafe and that I was refusing to fly it. The Dispatcher transferred the call to the Dispatch Supervisor who then conferenced the Director of Operations; who was serving as Duty Officer; onto the call. I explained my concerns to the Director of Operations who asked me when the original write up took place. I informed him it was written up ten days ago. He then asked if I thought all of the Captains that had flown the plane since then were wrong to have done so. I told him it was not my place to judge them. He then hung up. The Dispatch Supervisor informed me that the flight was going to be changed to an available aircraft that was on a neighboring gate. I was then called by the Dispatch Supervisor and informed that the Director of Operations had ordered that I be removed from the flight. The crew; with a new Captain; was later returned to the aircraft I refused and the flight departed with revenue passengers on board. This safety concern was begun by this Air Carrier's improper use of an MEL and was compounded by their refusal to correct the mistake when it was brought to their attention and their decision to remove the reporting Captain from flying rather than the aircraft. The aircraft remained in service for a total of 10 days in that condition before repairs were made.