Page 34 - Mar17ABS

From the Flight Deck
by Kevin R. Dingman
32 • TWIN & TURBINE
March 2017
Unintended Consequences
Aviate, navigate, communicate
It was late at night; it had been a long day and you’re tired. Since the airplane was ready and the wind on the ramp was gusting to more than 30 kts., you did an “abbreviated” walkaround. Anyway, the flight will take less than an hour and the weather is supposed to be decent. The departure was
snowy, windy and bumpy. So bumpy in fact, that it kicked off the autopilot in the climb. When you broke out on top just a minute into the departure to the sight of the moon and stars, not to mention that the ride smoothed out rather nicely, it was proof that you had made the right decision to leave tonight. You scooch in your seat, exhale a breath and admire the moonlit clouds. This is why you fly. Tower sends you to departure control.
Climbing through 2,500 feet and headed to the northwest, departure gives you a right turn to north and a climb to 17,000. The autopilot is still off so you look out the window and start a turn and the climb. Just 100 below, the cloud deck is visible as it moves by at 200 kts, slowly dropping away. The appearance of ice that accumulated during the climb is a surprise. Surface temperature was 33 degrees F. The math was easy: the freezing level was at 1,000 AGL. Curious though, the moon makes the wing look shiny, like it’s still wet. You double-check anti-ice systems and turn to your passengers: How’s the temperature? Everybody warming up? Sorry about the bumps. It should be smooth the rest of the way, you tell them. They all nod in acknowledgement as they, too, admire the view of the moonlit cloud layer. A shudder surprises you because it’s been smooth since exiting the clouds. No traffic, but it felt like wake turbulence. As you turn back to the front, the autopilot should have rolled out of the turn just about now. Then you remember that it’s off.
Say Altitude
Why is the bank angle 45 degrees? It should be about 30 degrees. You push the yolk to the left. The ride feels like we’re on a dirt road with tightly spaced waves of hard packed dirt, “chatter bumps.” Like the ridges on a paved highway that announce an approaching toll booth. Why is the airplane vibrating like this? It must have something to do with the ice. You roll to the left more and pull back.
Faintly, you smell an electric train. You know that smell: ionized ozone. Electricity. Probably your imagination. The vibration gets worse; it’s more like a shudder now. Scanning the motors you see the right engine is winding down. Time slows down. You instinctively push the rudder and look out the window. The inboard half of the wing isn’t as shiny as the outboard half. It looks like there was clear ice on the wing itself. Back on the ramp you thought it was wet. Some of the ice on the wing must have broken loose. The beautiful cloud deck that had fallen away is approaching; it’s just below you again. The yolk is almost fully to the left as you return your view to the engine gauges. Maybe the ice did something to the motor, maybe to the wing too. Two seconds later you re-enter the clouds. The moonlight is gone and it gets dark. Back on the instruments. This bank angle can’t be right. How can it be 60 degrees? That must be the electrical smell: the horizon display. Where’s the standby?
A calm voice in your headset says your call sign and asks you to say altitude. You push the left rudder and pull back. The airplane is shaking as the bank increases