DA42 Twin Star
Flight Crew Instrument; Flight Crew Flight Instructor; Flight Crew Commercial; Flight Crew Multiengine
Flight Crew Last 90 Days 9; Flight Crew Total 575; Flight Crew Type 20
Workload; Training / Qualification; Troubleshooting
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR
Aircraft Equipment Problem Dissipated; Flight Crew Overcame Equipment Problem; General Maintenance Action
Procedure; Human Factors; Aircraft
Prior to flight; I queried my flight school about the status of the aircraft following an ECU (engine control unit) B failure on the left engine I had experienced during a previous flight. They had a flight instructor meet with me before the flight and he described an operating procedure that they allegedly received from the aircraft manufacturer. This procedure included avoiding touch-and-go landings and keeping the engines below 1200 rpm on the ground. As I had not planned for any touch-and-go landings; I was not worried about adhering to that requirement. However; I found it difficult to adhere to the advice I received about keeping the engines below 1200 rpm while on the ground. The airplane itself idles at 900 rpm and that gives me very little throttle to work with in order to get the airplane to move. However; I was able to successfully taxi the airplane out of its home airport at ZZZ while adhering to this requirement. The flight to ZZZ1 went smoothly and I encountered no problems. However; I found it necessary to bring the airplane above 1200 RPM to taxi to the runway while attempting to leave ZZZ1. Due in part to the relatively high density altitude of 7000 feet combined with the upsloping taxiway out of ZZZ1; I had to bring the engines up to approximately 1700 RPM to taxi to the runway. I ran the before takeoff checklist before takeoff; which included an ECU health test on both engines. The aircraft indicated no problems with ECU health prior to takeoff.With an aircraft inbound with intentions to land in the opposite direction from the runway I intended to use for takeoff; I began my takeoff roll after coordinating with the incoming aircraft via CTAF. At approximately 60 knots and 1/2 way down the runway; I noticed a dual ECU failure on the right engine. I elected to continue the takeoff since the ability to stop in the remaining distance was questionable; and the severe dropoff at the end of the runway increased the hazard to me should I be unable to stop. The engine was still producing power; but I noted it was maxed at 80% load on the right engine and the prop was overspeeding at approximately 2200 RPM. I climbed to approximately 1000 feet AGL before beginning my troubleshoot procedure. I reduced power to approximately 65% load to prevent the overspeeding of the propeller and pulled out the Dual ECU Failure emergency checklist. I climbed to an altitude that would ensure safe single-engine diversion to ZZZ2 airport and followed the procedure; which called for reducing the power to zero on the problematic engine and bringing it back up to full power. Upon following this procedure; both of the ECU Failure warnings on the right engine disappeared and I monitored the engine instruments to verify proper operation. The problem seemingly cleared itself and I proceeded with my flight to the aircraft's home base in ZZZ. I encountered no more issues for the rest of the flight.At aircraft check-in; I wrote up the aircraft with an abbreviated description of my incident and left my phone number with the flight school in case they had any questions for me regarding my incident. I checked on the progress of the aircraft's maintenance about a week later and discovered that no one had translated my writeup of the aircraft to the electronic squawk list visible online. I asked what was being done to fix the problem and my flight school told me they could not replicate the problem and considered the aircraft safe. I became agitated and declared that I believe that by not putting my write-up in the squawk list and continuing to rent the airplane to potentially unsuspecting pilots that they are in effect renting an unsafe airplane. In what I feel is an act of retaliation for my challenge to their concern for safe operation of their aircraft; the flight school then pulled my qualifications on the airplane and refused to rent it to me (and only me; as far as I am aware) until I had completed another checkout with one of their instructors. As of date the aircraft is still being rented; and no mention of my incident has been written down and made available for other pilots.I feel that by renting an aircraft with the requirement to operate the aircraft in a manner inconsistent with the approved flight manual that they are subjecting their renters to unnecessary and avoidable risk. I do not feel as though company in ZZZ has the same concern for safety that I do and I have ceased my business there. I only worry that another pilot may encounter the same problem that I had with a different outcome.
DA42 pilot reported a dual ECU failure in flight after a single reported ACU failure on the right engine on a previous flight.