Safety in numbers

With the drag of a windmilling propeller, the airspeed slowed from 150 knots to below 120 before the mnemonic “Pitch, Power, Clean, Identify, Verify, Feather” could be completed. With Feather, the propeller shuddered to a stop and the little twin seemed relieved. The right engine hummed as airspeed inched back to 125. The airplane seemed quieter, almost peaceful. Airwork followed: some 15-degree-bank turns, a left and right one-eighty showing off the twin’s maneuverability. At a density altitude of almost 7,000 feet, a slight climb was still possible. After an air start, some simulated engine-out landings followed back at the airport. The exercise was both training and confirmation.

 

Bought 33 years ago for my family’s recurring trips to the Bahamas, the little twin proved, once again, that pilot and airplane could sustain an engine failure and convey its passengers to a safe landing. In a normal year, this exercise would suffice, but a tragic accident demanded something more.

On November 19, 2022, a couple died in a Twin Comanche on a day-visual approach into Winston-Salem, North Carolina, a week prior to our planned Thanksgiving visit to the same city where our daughter’s family lives. Although a final determination has not been made, preliminary evidence collected by the NTSB suggests an engine failure and loss of control—in twin-speak, a VMC rollover. As local radio and TV blared the news, our daughter phoned distressed by a tragedy that hit too close to home. She, her husband, and two daughters are not just a regular destination for our flights, but regular passengers as well. The accident couple’s circumstances seemed to mirror our own. The retirement-age couple was making one of many regular trips to visit their son and grandchildren. The pilot was also an experienced long-time Twin Comanche owner.

Reading accident reports invites a rationalization. We want to exclude ourselves from the same fate—to declare ourselves safe. But we can also use an accident to ask: “What can I improve?” The Winston-Salem accident drove me to reassess my own role in becoming a safe multiengine pilot.

‘Songbird’ and the pig

The starting point is the question: Why fly a multiengine aircraft? For my generation of would-be pilots, Sky King and Penny’s Cessna 310B filled childhood dreams with the roar and flair of a hot rod of the air. Sky’s Songbird was aptly named. The twin’s vibrato turns heads on takeoff. It climbs fast, lifts more, and offers other capabilities that most singles cannot match. But that other attraction of the twin, its ability to fly on one engine, depends on a deep understanding of the twin’s alter ego: the “pig.” To honor the “pig” means having a clear understanding of what a twin can and cannot do on one engine.

When an airliner lines up for takeoff, its occupants can be assured that, should an engine fail during takeoff roll, the aircraft will either be able to stop on the remaining runway or continue the takeoff, climb out clearing all obstacles, and return for a safe landing. The reciprocating-engine-powered twin can never offer this assurance. It can offer part of this assurance under some circumstances; and absolutely none under other circumstances. The determination is entirely up to the pilot.

Scenario 1: Engine failure on takeoff, but before gear retraction

When an engine fails on takeoff, but before gear retraction, the twin (generally) will not fly. A pilot’s best options, depending on runway length, are an aborted takeoff that stops on the runway or overruns; or, if already airborne, landing back on remaining runway or landing (under control) beyond the runway. These are the same options available to the pilot of a single with an important difference. The pilot of a twin must immediately close both throttles—a decision not made in the moment, but committed to before taking the runway.

Scenario 2: Engine failure on takeoff but following gear retraction

The twin’s engine-out promise begins in this phase of flight, but this situation requires the greatest pilot understanding and mental preparation. First, because the twin (generally) cannot fly with a windmilling propeller, recognition and propeller feathering must occur without delay to continue flying. But even with the gear retracted, propeller feathered, and airspeed at VXSE the aircraft may not be capable of clearing obstacles in the departure flight path.

Scenario 3: When pigs can fly

As the light twin accelerates and gains altitude, it enters the realm of its engine-out promise, a promise that may cover a flight from climb through approach. An airspeed well above VMC and a safe maneuvering altitude allow a little more time to recognize the failure, follow procedure, and feather the propeller. Then, with one engine feathered at any density altitude below its engine-out service ceiling, the twin will fly quite nicely. Important caveat: A flight that must be conducted entirely above the engine-out service ceiling foregoes the twin’s “engine-out promise.”

Headwork

“Staying prepared for an engine failure emergency is 80 percent mental.” —Ron Zasadzinski, “Training for Engine Failure,” ABS magazine

The mental component of becoming a safe multiengine pilot can be broken down into two parts: Know before you go and Mental rehearsal. In each of the three zones of potential engine failure, it is possible for the pilot to know the engine-out options and to rehearse beforehand actions that must take place. For example, takeoff runway length, accelerate-stop distance, and combined takeoff plus landing distance determine the range of outcomes for an engine failure occurring during takeoff and prior to gear retraction. Mental rehearsal means that the pilot has mentally committed to close both throttles and mentally accepted the fore-determined outcome before taking the runway. The other two zones of engine failure offer their own “know before you go” and “mental rehearsal” dimensions.

Mental preparation improves with a predefined operational envelope. How short of a runway is acceptable? What engine-out climb rate? These and many other factors define the “safe-on-one” envelope. For the twin pilot, this is a balancing act. Tighter constraints reduce utility while looser ones can turn the twin into a single with twice the chance of engine failure.

The rare success story

Pilots have made and continue to make safe landings following an engine failure in reciprocating-engine-powered twins. Unfortunately, there is a good chance you have never heard any “success” stories. Failure gets the spotlight; success does not garner much attention.

Six success stories contributed to this article: two involving Beech Barons, three Twin Comanches, and one Cessna 421. Three engine failures occurred during initial climbout, three at a safe maneuvering altitude. Four events involved instantaneous complete engine failures—three of the oil-spewing, parts clanking kind and one because of a maintenance error, a loose fuel line. Two less-sudden failures resulted from failing magnetos and a fuel servo defect that caused an engine to cut in and out.

All six pilots credit their immediate action to feather a failing engine for their successful outcome. Four of the six pilots cited recurrent training as a contributing factor to their success. Four were known to be involved in type clubs or other model-specific forums.

On becoming a safe pilot

In many ways, becoming a safe multiengine pilot is little different than becoming a safe pilot of any type of aircraft. In a dynamic environment of uncountable variables, safety is always a process of becoming. The choice is not “safe” or “unsafe” but the ongoing action of becoming.

Chris Burns is a retired airline captain and the owner of a Piper Twin Comanche.