Southern Airways Flight 242

Southern Airways Flight 242 was the flight of a DC -9- 31 of the U.S. airline Southern Airways, which had to make an emergency landing during a thunderstorm on a highway in Georgia on April 4, 1977 due to failure of all engines. During the emergency landing 63 people died on board the aircraft and nine people at a gas station that was hit by debris of the aircraft.

Course

On April 4, 1977 launched Flight 242, a DC -9, the Southern Airways from Huntsville (Alabama ) to Atlanta (Georgia ). The weather information, which referred Southern Airways from an external source, were already out of date at this time: For example, although warnings were known because of a tornado, but the weather conditions were underestimated. Captain Bill McKenzie and his co-pilot Lyman Keele could see a bad weather front a few minutes after takeoff on their weather radar. But they underestimated this also due to a measurement error of the device and its bad monochrome screen. A warning of the airport that tornadoes now raging nearby, the crew reached too late. The aircraft flew at an altitude of about 4200-5200 meters. Shortly after the radio message, the engines began to stutter while the aircraft flew directly into a hail storm. The hailstones the size of a baseball damaged the cockpit windows. Having only turned out the left engine and then the power, the situation came to a head. The energy problems were initially solved and even the engine to be started again, but the engines still stuttered. Shortly thereafter, the pilots were instructed to rise and gave thrust, but forgetting about the stuttering of the engines. Seconds later, it came with two engines to a flameout. Attempts to restart the engines were unsuccessful. Without the engines of the power went out in the machine.

The two pilots started the auxiliary power unit (APU ), but lost in the two minutes in which they were without power, more in height. After the power was restored by APU and thus the instruments and radio work again, report the pilots emergency and asked for the nearest airport. Flight control led to the machine according to Dobbins. Had flight control no knowledge of an airport, on which the machine was located at the time of the Polk Country or Cornelius Moore Airport. Flight 242 initiated a turn and was able to escape the storm. When the captain noticed that they came too close to the ground, he decided, despite a necessary trajectory change, to solicit an even closer airport. Finally, he was assigned Cartersville. By turning maneuver the machine continued to lose height.

When the pilot realized that they could not reach the airport in Cartersville, they decided to land on a highway. When putting, which was perceived by survivors as a very gentle, the aircraft jumped a few seconds after contact with the ground suddenly again something in the air. On the second touchdown the landing gear failed and the aircraft landed hard on the street. The DC-9 broke it into several large and some small parts. Aircraft debris destroyed while a near gas station, which nine people died on the ground. 63 Of the 85 people on board were killed, including the two pilots. Overall, there were 72 fatalities. The 22 surviving passengers were mostly severely injured, one person suffered only minor injuries.

Accident factors

The following factors and errors almost all participants contributed to the accident at:

Weather

Neither Southern Airways nor the departure airport had proper weather reports, the weather radar on board could not fully recognize and represent the tornado and its foothills.

Pilot error

The two pilots were exposed to a high workload and high levels of stress. Your heaviest pilot error was the inappropriate use of the stuttering engines, one of the most important principles in aviation. Also they changed one too many times the price because they hoped their chance to reach an airport to improve. Through this last turn of Doubbins by Cornelius Moore, they lost more and more quickly in height, as if they had lost in driving the original target.

Air traffic control

The air traffic control had no weather data available for the pilots was not informed all available at the touch of airports and the pilots could not in crisis situation the best possible advice.

Technology

Since, according to the NTSB report, the maintenance records did not show any errors or discrepancies, was a blockage by ice and hail, which blocked major pressure equalization valves, accepted as the reason. Since ice and hail melted after the crash, only the damage patterns and the recordings of the two flight recorders could substantiate this claim.

On- board systems

The on-board weather radar Bendix Corporation had only a monochrome screen that no thermal image display ( color display required) permitted and also very inaccurate captured the clouds and thus showed gaps where there were none. Today's models provide temperature differences is through appropriate colors and allow the pilot to estimate the likely weather conditions. Today's systems acquire larger areas and their exact position on the plane, what the errors in the detection compensates completely, because by enlargement / reduction of the detection radius these gaps are shown wirlichkeitsgetreu.

Consequences for civil aviation

The airports are better connected and all have their own weather radar systems. The weather radar on airplanes has been greatly improved, including color display for showing the heat distribution of air that gives the pilot information about what may await him in a storm cloud. The training in dealing with engine failures in difficult situations and the basic rules in the training have been improved. Many airlines that wanted to increase security, then and to this day onboard technician or a third pilot, even on short or even all flights or on machines for which it is not necessary to have a sat.