At 5:23 in the afternoon on June 29, 1953, a DC-3A
aircraft N15569, was cleared to takeoff from Runway 25R at the Los
Angeles
International Airport in southern California. The aircraft
belonged
to Western Air Lines and had just completed a major overhaul at the
company
maintenance facility located on the field. The total time of the
airframe on the day of the accident was 30,793 hours. This was to
be the first test flight after the overhaul was completed and
signed
off by the Company Chief Maintenance Inspector, Mr. Joseph Stromisky.
Pilot, Captain Robert V. Johnson, age 31, and Copilot William E. Williams, age 27, completed their pre-flight inspection on the company ramp and then boarded the DC-3A and prepared for takeoff. Mr. Stromisky was also onboard and riding in the jump seat at the rear of the cockpit, check list in hand, preparing for an uneventful check flight.
The engine start was normal and all instruments were in the green. Satisfied that all systems were operating normally, Williams called Ground Control and requested taxi clearance to the active runway. Western Air 569 was cleared to the Runway 25R engine run-up area.. Captain Johnson released the brakes and advanced the power just enough to get the DC-3A moving. In the run-up area, he and William would again check the engines and all other systems before taking the active runway for departure.
At 5:25 Johnson taxied the DC-3A onto the runway, lined up with the center line, and advanced the throttles to begin the takeoff roll. With the Tower Operators looking on, the lightly loaded aircraft moved quickly down the runway and lifted into the air.
However, soon after becoming airborne the Tower Operator observed the right wing dip down and scrape the runway surface. Fearing that the pilots had lost control of the DC-3A, the Tower Operator pushed the alarm button to notify the crash and fire crews.
In the cockpit, Captain Johnson was totally confused by the reaction of the aircraft. He was trying desperately to get the right wing back into the air, but everything he did only made matters worse. The aircraft continued down the runway with only fifteen feet of altitude and the right wing still scraping on the concrete. Soon the DC-3A started to veer off the runway to the right. Captain Johnson still did not understand what was wrong with his aircraft, but wisely elected to abort the takeoff. While struggling to keep the DC-3A going straight down the runway, Johnson began to pull the throttles back from the full power position. The aircraft immediately fell to the runway and collapsed the right landing gear. In an instant, the right engine broke off the wing, followed shortly by the entire right wing itself. The aircraft then slammed the nose section into the runway and began to cartwheel over on its nose. Soon the tail section was pointing straight up in the air as the aircraft continued to slide for a short distance. Then, with a great crash, the aircraft fell over on its back and came to rest upside down. It was only 2,830 feet from the point where it began its takeoff roll.
Within seconds a fire erupted in the stub of the what was once the right wing section. In the mangled cockpit section, Captain Johnson, and copilots Williams were both hurt, but alive. However, the Company Inspector was not as lucky. He was killed either by the crash, or the ensuing fire. The fire and rescue crews, having been alerted by the tower operator of an aircraft out of control, arrived on the scene within a few minutes and extinguished the flames. The airport was appropriately shut down until it could be determined if the situation would be a danger to other aircraft.
The wreckage of the DC-3A had not yet cooled before the investigation had began to determine what went wrong with the takeoff. At first it was thought that a gust of wind from the ten m.p.h. left crosswind had upset the aircraft as it moved down the runway. The thought was that the pilot simple did not correct for the crosswind. That idea was soon eliminated after a short interview with the pilots. They stated that the control wheel was held in the full left wing down position during the crash sequence, but they were still not successful in leveling the wings..
Damage to the aircraft was extensive. The right wing, with its aileron and flap attached, lay on the ground in an upright position, torn from the fuselage. The entire fuselage, with its undamaged left wing and aileron attached, lay inverted. The nose section of the fuselage from the wing leading edge forward, was completely severed by the impact and fire, and the cockpit area was demolished. Only the aircraft and engine control cables and some electric wiring extending from the cockpit rearward into the center section were still attached and unbroken. The empennage was intact except for the tips of the right stabilizer and elevator, which were found to be bent and torn. The right engine and right landing gear had been torn free, but the left engine and landing gear remained attached to the structure.
Inspection of the control pedestal revealed the throttles to be in approximately the cruise position, carburetor mixture controls were set for takeoff and climb, propeller controls were in the full low pitch position, and all flight control trim tabs were in the neutral positions.
During the brief interview with the still recovering pilot, he (Captain Johnson) felt that something was wrong with the aileron control, because he felt that he should have been able to level the wings with the amount of left control input he was using. So the investigation began by a thorough examination of the flight controls, with specific attention being paid to the aileron control system.
An immediate inspection was made of all flight control cables. All cable attachments to the aircraft control surfaces were found attached and safety wired. The was no evidence that normal movement of the controls had been impaired prior to impact. The aileron trim tab control drum of the right wing was found with its cable attached to the center of the drum and with four loops of cable on both sides of the center, corresponding with the control trim tab being in the neutral position. Similarly, the rudder and elevator control trim tabs were observed to be in neutral position. This corresponded with their indicated positions on the cockpit control pedestal.
However, after a complete disassembly and study of the flight control system, it was determined that the aileron control cable within the pilot's control column had been reversed. This explained why the pilot was not able, despite full left control input, to raise the right wing.
Specifically, the replacement pulleys, one aluminum and one micarta, located at the elbows of both control columns is, aluminum pulley aft, and micarta pulley forward. Over each of these pulleys passes a control cable. The ends of these cables attach to the end of a bicycle chain that runs over the sprocket attached to the shaft of the control wheel.
With the above mentioned pulleys being transposed, the assembly mechanic, from then on correctly following a diagram in the DC-3A Overhaul Manual, fastened the cable passing over the micarta pulley to the upper end of the bicycle chain and the one passing over the aluminum pulley to the lower end of the chain. The above mentioned error resulted from the mechanic assuming that the diagram was of the Captain's left side looking forward. Although this diagram was ambiguous in that it did not illustrate graphically which wheel was depicted, nor the direction from which it was viewed,. Instructions applicable to the diagram indicated that it referred to the copilot's wheel looking aft. The result was a reverse motion of the ailerons. The assembly mechanic was not aware that he had made a mistake.
Both control columns were then installed in the aircraft a few days later. Mr. Stromisky, the Chief Inspector, had signed off on the Plane Overhaul Record indicating that he was satisfied with the work.
The next step in the overhaul procedure was the rigging, or connecting and adjusting, of the entire control system. This was done and likewise signed off by another mechanic, a rigger, on the Plane Overhaul Record as having been completed satisfactorily. In addition the same Mr. Stromisky signed off the Plane Overhaul Record, again indicating that he was satisfied the work had been done properly.
Next it was time to check the full travel of the controls against the full travel of the control surfaces. A mechanic in the cockpit moved the controls while the travel of the control surfaces was observed by another mechanic and the Chief Inspector Mr. Stromisky.
All controls and control surfaces moved freely and with full travel. Actually the normal aileron control, or pilot control wheel rotation, was reversed in relation to aileron motion, but this went unnoticed. This phase of the work was also signed off by Mr. Stromisky.
During the pre flight inspection of the aircraft by Captain Johnson the improperly rigged ailerons were not noticed. In the cockpit, just before takeoff, Captain Johnson had checked for full and free travel of all control surfaces as required by Western Air Lines company policy. However, the policy did not require a check to be made of the proper direction of control surface travel in relation to the control wheel movement. This check was not then required of flight crews.
On July 3, 1953 four days after this accident Western Air Lines, in revision No. 132 of their DC-3A Overhaul Manual, specified that checks be made by maintenance, inspection, and flight crews of not only free and full travel of controls, but direction of the control surfaces travel in relation to movement of the cockpit controls. This simple check is now taught to the basic student pilot on his very first ride in the airplane.
It is ironic that Mr. Stromisky, the Chief Maintenance Inspector and man who signed off on all the work performed during the overhaul, was onboard that day, and was the only man killed.
Note: All of the information contained in this story
came
from the official Civil Aeronautics Board Accident Investigation
Report,
file No. 1-0039 and dated February 8, 1954.
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