Pilot's Nightmare

Copyright 2004 by Paul Niquette.  All rights reserved.


 
ake-off is arguably the most dangerous maneuver.  An airplane entering into the realm of flight finds itself torn from the tranquility of the tarmac and suddenly sent galloping along the runway.  Mechanical devices inside the fuselage are getting jolted as they struggle to take up their vital flight duties.  Transient conditions prevail throughout the aircraft.  One electric motor must promptly pressurize hydraulic pipes for actuators while another torques a jack screw on its greasy shaft.  Pumps coerce oil into bearings and onto sliding surfaces.  Fuel injectors are slaking the thirsts of propulsion.  In mere seconds, engine loads have spun up and temperatures begin rising.
Indeed, combustion chambers will never be colder, lubricants more viscous, ignition systems will never be less proven, and the plane, fully loaded with fuel, will never hang heavier from its wings than at the instant those wheels first break free of the pavement.
Engine failure on take-off may well be every Pilot's Nightmare, especially when he or she has only one engine to start with.  If the symptoms are detected soon enough, of course, the take-off may be safely aborted and the plane brought to a shuddering stop before the airport boundary (see story).  Beyond that point and for the first minute after lift-off, the safety of flight is most precarious.  An engine swallowing a valve or shattering a rotor means the pilot has no choice but to proceed straight ahead no matter what obstructions are in the flight path.
There is a wry expression for the least worst outcome -- "controlled crash."  The word "controlled" assumes that during the final seconds of flight, the pilot did not wrench the plane into a panicky stall.  That would result in the worst worst outcome.
Ironically, in a multi-engine airplane, the situation can actually be worse during that crucial first minute of flight.  Asymmetrical thrust -- a good engine on one wing working against the drag of a dead engine on the opposite wing -- can flip the plane onto its back.  Twin-engine flight training is dominated by the pilot learning critical reflexes -- "step on the good engine!" (with the correct rudder-pedal) and "never to turn into a bad engine!"  The first priority after take-off is to establish "minimum controllable airspeed."  But at that speed, a crippled aircraft, flying crookedly in the sky, may not be able to maintain altitude, let alone climb.
Thus, for the aircraft with more than one power plant, a failure of one of them may result in a controlled crash at a speed typically twice that of a single-engine plane.
After that first minute of climb-out, though, the picture gets steadily brighter.  With each thousand feet in altitude above ground level, gliding distance increases by about a mile, which opens up options for emergency landing sites -- mathematically speaking, "according as the square of time aloft."  After climbing one-mile straight up, for example, the pilot has a hundred square miles to choose from and several minutes to make the choice.
 
hatever the time available for a "dead-stick landing," however, it probably won't be long enough for even the most sophisticated pilot to solve the following puzzle:

A couple of minutes after starting your take-off roll, you hear a sudden, sickening silence.  Your one and only engine has become nothing more than an ornament.  The airport from which you just departed is surrounded by buildings and houses, tall trees and utility poles.  Returning to the runway for a downwind landing is your only chance.  You start a turn to the left...

What angle of bank should you choose?
(a) 15o, (b) 30o, (c) 45o, (d) 60o, (e) 75o

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Solution





Controlled Crash: The Etymology

Once again, my good friend Richard Alexander has enriched me and now my readers with his insights...
 

The first time I used "controlled crash" to describe a plane landing was back when I was in the Navy, up on the bridge of our destroyer in planeguard station, in the South China Sea, at night, steaming into the wind at 34 knots, 1000 yards astern of a carrier. One by one, jet fighters would pass directly overhead, which lined them up for the carrier deck.

Total cloud cover had eliminated the stars and horizon for bearings. With Darken Ship conditions set, there were only a few dim shipboard navigation lights for visual reference. The stern light of the carrier in front of us was pitching and rolling through 20 feet or more, up down left right. The pilots had to synchronize their controlled crash to accommodate the complex interactions of the plane, the wind, and the deck. It was wild. Immediately when he hit the deck, each pilot would switch his engine to max power -- we'd see the tailpipe change to a fiery sunburst and hear an explosive roar -- so he could take off again if the tailhook missed all three cables.

There can be little doubt that "controlled crash" originated in the form of exquisite hyperbole, most likely to characterize carrier landings.  As appropriated here, the expression has been literally demolished.  Sorry.