BART: MAY - JUNE - 2020

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70 - BART: MAY - JUNE - 2020 CATASTROPHE The plane, operating as US Airways Express, crashed during takeoff. A ir Midwest Flight 5481 was a regularly scheduled passenger flight from Charlotte Douglas Intl. Airport (KCLT) to Greenville- Spartanburg International Airport (KGSP). On January 9th, 2003, it was a normal morning flight for the crew, which consisted of 25-year-old Captain Katie Leslie and 27-year-old First Officer Jonathan Gibbs. The Beechcraft 1900D was handed over to them by the preceding crew with the remarks that “everything was nor- mal” and “it was a good flying air- plane”. Prior to the flight, the crew had completed the load sheet and had accepted a “heavy” bag to be loaded in the aft cargo compartment as one of the passengers was a 12 years old child instead of an adult. The pre- flight controls check showed no abnormalities. At 08:46 local time, the tower controller cleared Flight 5481 for take-off. The captain was pilot fly- ing on that sector and ordered take- off power to be set. Ten seconds after rotation and after the landing gear had been retracted, the aircraft started to pitch-up through 20° nose-up. The unexpected nose up behavior of the aircraft sur- prised the captain. She experienced difficulties controlling pitch attitude and told the first officer to help her. Even together, the pilots could not push the aircraft’s nose down. Ten seconds later, the aircraft stalled with a pitch attitude of 54°, banked to the left and entered a steep dive. The crew desperately tried to recover from the upset situation and fought against the uncontrollability of the aircraft and for their lives for another fifteen seconds before the air- craft crashed into a maintenance hangar on the airfield. All passengers and crew perished. The aircraft was destroyed by impact forces and the post-crash fire. Disturbing Investigation Results The National Transportation Safety Board (NTSB) investigated the fatal accident, and found two major short- comings that led to the disaster. The first problem was related to maintenance issues. Two nights before the accident, the aircraft had undergone maintenance work at a repair facility in Huntington, West Virginia, which had included adjust- ments of the cables for elevator con- trol. The mechanic who did the rig- ging had never worked on the Beechcraft 1900D before. He had incorrectly set the turnbuckles con- trolling the tension of the cables in a way that allowed only 7° pitch down instead of the correct 14°. As a result, elevator downward travel was limited, and thus was the pilot’s possibility for nose-down commands. The work had been part of the mechanic’s training, and no post adjustment check was conducted after the completion of the work. The airplane finally left the maintenance hangar with the elevator not being fully operational. The NTSB noted that the Federal Aviation Administration (FAA) had been aware of serious deficiencies in training procedures at the repair facil- ity but had done nothing about it. The second problem was related to the company’s mass and balance pro- gram. Air Midwest used standard pas- senger weights instead of actual weights to determine the take-off mass and the center of gravity (CG) for each flight. The “Aircraft Weight and Balance Control” guidance AC 120-27C issued by the FAA and in force at the time of the accident sug- gested to use 180 lbs for an adult pas- senger in the spring and summer and 185 lbs in the fall and winter, both weights including 20 lbs for carry-on baggage. The Air Midwest weight and balance program, w hich was approved by the FAA, used 170 lbs DON’T ASSUME ‘APPROVED’ NECESSARILY MEANS SAFE SAFETY SENSE The Air Midwest accident in 2003 shows that while weight guidelines are important, they are not hard and fast rules. Michael R. Grüninger and Capt. Andreas Grauer report BART: MAY - JUNE - 2020 - 71 for spring and summer and 175 lbs for fall and winter. During the investigation, the NTSB found out that the actual average pas- senger weight on the accident flight was more than 20 lbs higher than the standard weights considered by the accident flight weight and balance cal- culation. Furthermore, a survey con- ducted by the NTSB among 22 opera- tors showed that the average passen- ger weight for the observed flights was 196 lbs and average weight of the carry-on baggage was 16 lbs. Thus, Flight 5481 was in fact 580 lbs too heavy, and its center of gravity was 5% aft of the allowable limit. Based on the too low standard weights, the pilots felt confident that the aircraft’s weight was well below the maximum allowable take-off weight and the center of gravity with- in limitations. The combined effect of reduced pitch down elevator control and excessive take-off mass and center of gravity position left the flight crew no chance. With the retraction of the landing gear the center of gravity moved backwards and further out of the approved envelope causing the airplane to pitch-up abruptly. As the investigation report states, at the time of the accident, the elevator did not allow any further nose-down com- mand. The airplane was out of con- trol. Recovery was impossible. Approved Procedures and Data In the aftermath of the accident, both the aviation industry and the FAA reacted. The problems related to the maintenance training and supervi- sion that had contributed to the acci- dent have been discussed extensively and measures have been taken by the FAA and the involved companies to prevent similar cases from happening again. The same applies for the stan- dard weights used for M&B calcula- tions and the instructions for crews and operations personnel for prepar- ing load sheets. An aspect that has received less attention is the psychological effect of authority approvals on airline person- nel, both managerial and non-man- agerial. Standard weights are subject to approval by the authorities. Thus, such data is often not questioned any- more by responsible managers and