How to handle in-flight emergencies is something were taught before we even solo. As a rule, when the aircrafts complexity increases, so do the number of procedures we must perform in an emergency, along with their relative importance. While the increased automation of todays bizjets and Transport-category aircraft have relieved their pilots of some tasks, those of us stuck bouncing around in older, non-automated aircraft still have to learn the correct sequence of tasks as well as the various techniques for verifying what we are about to do is correct and, afterward, ensuring what we did had the desired effect. In my flying career, Ive made my share of mistakes, but none more egregious than switching off the mags to the “good” engine after my instructor simulated the others failure. Only a couple of nanoseconds elapsed before I recognized the error, but that episode has stayed with me since. Since then, Ive been fortunate to experience only one other actual in-flight emergency; it ended well, with no scratches to airplane or occupants. There have been a few close calls, however, mostly involving my own forgetfulness or ineptitude, I freely admit. In those cases, promptly applying my training and the various memory items learned, along with the airplanes checklists, quickly isolated or fixed the problem. Sometimes an unhurried precautionary landing at a suitable airport followed. Most often, a diversion was not necessary. In my experience, the first few seconds after an abnormal situation is noted are the most critical. Its during this time that the pilots impression of the abnormality are first formed. As we know from life, as well as the FAAs Law of Primacy, first impressions can have the greatest impact. When one of a twins engines fail at a critical point, we have to respond correctly the first time. Background
Before departure, the main fuel tanks were topped off to 50 gallons per side, and the auxiliary fuel tanks contained 30 gallons of fuel per side.
The flight departed the Collegedale (Tenn.) Municipal Airport (3M3) at 1318. Visual conditions prevailed and an IFR flight plan had been filed with the clearance presumably to be obtained once airborne. Observed weather in the area included light and variable winds at three knots, visibility 10 miles, few clouds at 11,000 feet, temperature 52 degrees Fahrenheit, dew point temperature 32 degrees Fahrenheit, altimeter 30.10.
According to the surviving ATP, the pilot took off from Runway 3 without performing an engine run-up. At between 200 to 300 feet on the initial climb, the right engine lost power and the airplane yawed into it. The pilot lowered the airplanes nose to gain airspeed, then pulled the right power lever rearward. But nothing else happened. The pilot did not feather the right propeller; instead, he began manipulating the boost pump switches.
At one point during the accident sequence, the ATP passenger did not think the left engine was producing full power: “One [manifold pressure gauge] needle was at zero and the other was at 25 inches. The manifold pressure should have been 39 inches of manifold pressure. I assumed the zero reading on the manifold pressure was the right engine.”
Just before the airplane hit the trees, the pilot feathered the right engine. The ATP passenger observed the right propeller going into the feather position, and the propeller came to a complete stop.
Investigation
The top and bottom spark plugs on the left engine were “worn out-severe.” No scoring or leading edge damage was present on any of the left engines propeller blades-the manufacturers teardown inspection report stated: “The left propeller was being operated under conditions of low power at impact.”
Examination of the left engine revealed the starter adapter gear teeth had failed due to overload. Its oil filter element contained ferrous material; the oil sump contained ferrous metal debris and 10 gear teeth from the starter adapter shaft, and two pieces of aluminum from the crankcase. The engines right magneto produced a bright blue spark across a seven millimeter gap through the full range of the test bench rpm on ignition tower six. No spark was observed on the remaining ignition towers.
The left fuel selector valve was in the auxiliary position. The right selector valve was in the off position. The landing gear was retracted; flaps were at least partially extended. The NTSB noted the Cessna 421 POH states, “with flaps extended 25-degrees the airplane will experience a 430 feet per minute rate of descent…with a windmilling propeller.”
Probable Cause
The NTSB determined the probable cause of this accident to include the “pilots improper identification of a partial loss of engine power on initial takeoff climb resulting in a collision with trees and the ground. A factor was…partial failure of the left engine starter adapter due to overload.”
From the record, its hard to determine which engine was the larger problem. Post-crash investigation revealed the left engine wasnt producing full power; since the right engine had already been secured-although in a leisurely fashion-the flights outcome wasnt in question.
If, in fact, the right engine lost power (the ATPs memory of which engine failed could be faulty), the pilot took his time securing it while in a situation-initial climb of a heavy piston twin-demanding a quicker response. Since the only real anomalies found with the right engine involved worn spark plugs, were left wondering if the pilot identified the wrong engine as having failed. We also can wonder why the ATP didnt step in at a critical time.
If both engines were experiencing problems, theres little the pilot could have done except close both throttles and land straight ahead. From the record, it appears the pilot identified and secured the wrong engine; sometimes, an accident raises more questions than it answers.
