Second Officer’s Log:
Winter 1976, B727, YWG Departure Gate
Arctic air gripped the prairies as Winnipeg’s overnight temperature plummeted to -40°. A frigid wind sucked heat from everything it touched, including our Boeing 727. I peered at it through my reflection in the boarding lounge window. The plane sat frozen in pools of feeble yellow light that seeped from terminal building fixtures into the morning darkness. Snow swirls drifted and snaked across the frozen concrete, depositing hard mounds of snow around the aircraft’s tires. The aerodynamic curves of our plane looked more like an ice-sculpture than a flying machine. But a flying machine it was and this morning it was scheduled for an urgent mission: to “rescue” our crew and a load of hopeful passengers from the depths of a Winnipeg winter and deliver us to the gentler climes of San Francisco.
As I made my way down the bridge, hunching my shoulders against the bone-chilling cold, I was puzzled. Why was the plane still dead, dark and frozen this close to departure time? I had expected the ramp crews to have the lights on and the heat turned up full-blast. Suddenly, at the far end of the walkway, the ramp door swung open and a burst of snow swooshed in with a wintery blast, propelling a parka-clad agent. He spotted me, waved a greeting and headed towards me. He was holding the bare heel of his other hand against his frozen cheek.
“The ramp equipment wouldn’t start. None of it. Not the GPU [Ground Power Unit], not the heater, and so far, not even the push-back tractor.”
“Maybe the APU [auxiliary power unit] will start,” I said, doubtfully. The B727 auxiliary power unit was infamously unreliable at starting in cold weather. I thought of the cozy bed I’d left at home and wondered if I’d be seeing the warm waves of the Pacific Ocean today after all.
I led the way into the dim flight deck where I fumbled for a flashlight. Starting an airliner is a cascading process. Everything depends on one little battery that cranks the APU turbine. Once this starts, the APU electrical generator brings to life all the lights, controls and switches. The APU compressor supplies “bleed air” to heat the cabin and more importantly, to spin our main engines at startup time.
However, before starting the APU there is a critical test required. The integrity of the fire protection system must be verified. This test is required because no one likes carrying flammable liquids on board an aircraft, but it has been determined—and often confirmed by inattentive pilots—that engines won’t run without a steady supply of highly-flammable jet fuel. Designers mitigate this risk by installing automatic detection systems that watch for uncontained fires and put them out. As it happens, starting turbines in extremely cold weather is known for increasing the chances of starting just such fires. So, I dutifully pressed the test-switch.
Nothing. I held the test-switch longer. Still nothing. The icy-cold sensors, driven by a half-hearted, totally frozen APU battery, could not generate enough heat to trigger the test. I thought about starting the APU anyway. But as a new second officer, with a brand-new mortgage on a modest house in the suburbs, I reckoned that burning an aircraft to the ground was a “bad thing” and should be avoided. Employers are fussy about stuff like that. Paying back the cost of a torched plane from my paltry new pilot paychecks would take a long time—a very long time.
Instead, we called for the mechanic. Within minutes a burly, bundled-up form tromped into the flight deck, pulling off ice-encrusted leather mitts and his breath-frosted snorkel-hood. “I just got the push-back tractor going. Now, what did you guys break?” He looked irked, anticipating yet another cold-related problem about to be dropped in his lap. I explained. He reached over and hit the APU start button, ignoring the fire-protection test. He apparently had no mortgage to pay nor job security issues—and little fear of fire. But the frozen battery could barely crank the turbine. It would not spin fast enough to properly initiate the start sequence.
We were stumped and stuck in Winnipeg.
— to be continued —
— From “Uplift – A Pilot’s Journey.”