The Gimli Glider Incident: Robert Pearson’s Masterful Maneuvers
On July 23, 1983, Air Canada Flight 143 faced a critical challenge when it ran out of fuel mid-flight. The incident, known as the Gimli Glider, was a testament to the skill and quick thinking of the pilots, Captain Robert Pearson and First Officer Maurice Quintal. Robert Pearson’s maneuvers, particularly the gliding approach, descent management, landing configuration, controlled landing, and the unique forward slip, were crucial in ensuring a successful emergency landing.
Emergence of the Gliding Approach
After realizing the flight was running out of fuel, Pearson converted the Boeing 767 to a glider. At this stage, the aircraft had a glide ratio of about 15:1, which meant for every 1500 feet of altitude, the plane could travel approximately 15,000 feet horizontally. Pearson focused on maintaining a controlled descent to optimize the gliding performance.
Descent Management for Land
Managing the altitude and airspeed carefully was essential. Pearson adjusted the aircraft's pitch to ensure optimal glide performance. His goal was to reach the nearest suitable landing area, which turned out to be an abandoned airstrip at Gimli, Manitoba. This area, though suitable for a glider landing, posed challenges due to its mixed terrain, including a former airstrip and a recreational vehicle park.
Landing Configuration for Precision
As the plane approached the airstrip, Pearson configured it for landing. This involved lowering the landing gear and flaps at the appropriate times to ensure a stable approach. Proper configuration helped in optimizing the landing gear for impact and ensuring the wings were in the correct position for touch down.
Controlled Approach and Landing
Pearson executed a final approach with a focus on a smooth touchdown. He aligned the aircraft with the runway and adjusted his speed to ensure a safe landing. Throughout the process, he maintained calm and composed demeanor, a key factor in achieving a successful landing.
Emergency Procedures and Forward Slip
During the landing, Pearson and Quintal had to quickly assess the runway conditions. The aircraft was higher than normal and approaching at a steeper angle due to the absence of engine power. Upon realizing the altitude problem, Pearson initiated a forward slip. This maneuver, involving rudder deflection and opposite aileron movement, forces the side of the fuselage, vertical stabilizer, and other surfaces to face the relative wind, increasing drag and thus allowing the aircraft to lose altitude without gaining speed.
A forward slip is a basic flight maneuver used by pilots of gliders and smaller aircraft. It's not a common sight with large commercial airliners, but it served Pearson well in the critical situation. Personally, I once used a Grumman AA1B—a 2-seater airplane—with flaps that did little to control landing speed. In such scenarios, a slip was often the preferred method to manage altitude effectively without altering speeds.
The forward slip is a triple role maneuver, as described earlier, which includes:
Hedging the Airspeed
By increasing drag, the aircraft can be made to descend without increasing its speed.
Hedging the Path
Using the rudder and another aileron, the path of the aircraft can be adjusted without creating a turn, which helps in maintaining a straight approach to the landing area.
Hedging the Attitude
By banking the aircraft slightly with the aileron, the aircraft's pitch attitude can be altered, similar to a light application of the elevator.
During the Gimli Glider landing, Pearson successfully used the forward slip to manage the plane's attitude and approach, ensuring it landed smoothly on the runway without any injury to the 61 passengers and crew.
Conclusion
Robert Pearson’s calm demeanor, quick thinking, and piloting skills were the backbone of the Gimli Glider incident. His ability to execute the gliding approach, descent management, landing configuration, and especially the forward slip, were instrumental in ensuring a safe landing. This incident is a remarkable example of what can be achieved through exceptional aeronautical skill and adaptability under pressure.