Page 28 - Volume 18 Number 8

26 • TWIN & TURBINE AUGUST 2014From The Flight Deck by Kevin R. Dingmanone engine, no power on the other with the rudder pedal shoved to the floor, rolling inverted after allowing airspeed to go below Vmc. Dealing with an engine failure in a twin is not to be taken lightly, especially during takeoff. It has killed many pilots that were likely just as good a pilot as you and me. The joke about twins, with the second engine being only for taking us to the scene of the crash, is often no joke. Making the decision to abort a takeoff is no joke either.Reasons to StopUp to a predetermined speed early in the takeoff, we are trained to watch for any and all reasons to stop, not for reasons to go. In the Mad Dog, we use 80 kts as that predetermined speed. A typical list of reasons to stop before 80 kts would be: fires (engines or cabin/cockpit/ cargo), engine failures, compressor stalls, controllability issues like runaway trim, rudder hard-over, flap asymmetries and deployed thrust reversers, slow acceleration, windshear, tire failures and unusual noises or vibrations – in other words, just about anything. Once we are faster than our predetermined airspeed, but still below decision speed (V1), we are watching for only the very serious reasons to stop. They’re the big ones from above: fires, failures, stalls, controllability and windshear. Once we reach V1, we are taking the vehicle into the air no matter what, lest we attempt an abort above V1 and exit the end of the runway at an energetic, and likely deadly, velocity.As abort decisions go, while frustrating, this one was easy. Had this been LaGuardia, Burbank or Midway, the decision would have been to continue. Today, we were on a dry 13,400-foot runway, in day VMC, and we weren’t very heavy. I wasn’t concerned that the decision was wrong or that a bad result was forthcoming— and it’s not that I couldn’t deal with it in flight. I’veIwas trying to analyze, rationalize and explain away the offending engine parameter as being “close-enough” so that we could keep going. Keep going, the way I have for the last eight or ten thousand takeoffs, comparing left to right and assessing limitations. Why won’t it just quit, give me a fire light, an overtemp, or at least something out of limits?I know this airplane better than I’ve known any machine in my life; better than the back of my hand. I know what close-enough is. Maybe this is close-enough... nope, this is not close-enough; it’s getting worse, further away from close-enough. It’s acting too “different” from the previous ten-thousand times. The right engine N1 was decreasing and the EGT was rising. In three seconds it will be too late to stop. In another eight, it will quit, I know it will.Reject! Throttles idle and max brakes. Verify spoilers deployed and throw out the buckets—my FO tells tower we’re aborting as we’re pushed slightly forward into our shoulder harnesses. The instant I made the decision I was mad. Not at myself for making the wrong decision. Ironically, I was mad at the engine for not failing.Three SecondsIt always amazes me – the time compression effect. I’ve had a handful of intense events and it happens every time. Everything you’ve read so far transpired in the span of three seconds as we accelerated from 110 kts to 120 kts, 25 kts below V1. Seven seconds later, we were below 50 kts and had more than one third of the runway remaining. Total elapsed time from brake release to taxi speed: about1forty seconds. Perceived time: about five minutes. I moved my hand from the yoke to the tiller and steered onto the high-speed taxiway at 20 kts, made a PA to the folks and, after assessing our condition, headed for a gate.Black and white is easy; gray is much more difficult. A fire, engine failure or flight control problem is easy; they’re on a list of obvious reasons to stop. A sickly engine that is dying a slow death as you approach V1 means you have to use judgment and decide – is safer to fly, or stop? You’re the one that must decide, sometimes in a hurry. The decision is made using whatever knowledge, training, current conditions and experience you can muster in the three seconds you have left.Sheer TerrorAccording to aviation folklore, the pilot of an early-model bizjet once described flying the new jet as minutes of sheer terror, followed by hours of boredom, followed by minutes of sheer terror. One of the most critical phases of flight, regardless of the number and type of motors installed, is the takeoff. We’re heavier than when we land, the gear is down and some flaps and slats may be out as well. In the time between brake release and V2, the airplane is slow but we must think fast. If something goes wrong, life can get interesting, and short; especially if you are caught by surprise, without a plan. Hence, we need to make the correct decision, to fly or to abort.We read about single-engine pilots trying to return to the takeoff runway after an engine failure and the resultant stall-spin. And we hear of prop twins with full power onBefore V