Thursday, September 18, 2008

Update on the Air Tahoma Convair 580 crash in Ohio

Air TahomaThe U.S. National Transportation Safety Board (NTSB) has released its preliminary report on the September 1, 2008 crash of a Convair 580 freighter owned and operated by Air Tahoma, Inc. The aircraft was completely destroyed when it impacted terrain as it was attempting to return to the Rickenbacker International Airport (LCK), Columbus, Ohio shortly after departing LCK for Mansfield Lahm Regional Airport (MFD), Mansfield, Ohio. All three crew members on board -- the captain, first officer, and a company pilot sitting in the observer seat -- were killed in the accident.

According to the NTSB's preliminary report, the aircraft (registration number N587X) was operating under 14 CFR Part 91 rules (non-revenue) at the time of the accident. An instrument flight rules (IFR) flight plan had been filed. According to the NTSB, visual meteorological conditions prevailed at the time of the accident.

Here is how the NTSB report describes the initial findings regarding the Air Tahoma Convair accident (re-pragraphed for easier reading):
The accident flight was the first flight following a maintenance "C" check, which included flight control cable rigging as part of the check. The flight was also intended to be a training flight for the first officer and the company pilot seated in the observer seat.

The flight contacted the LCK air traffic control (ATC) at 1139 for its IFR clearance. At 1147, the flight was cleared to taxi. At 1200, the flight received its takeoff clearance, and the airplane started its takeoff roll about 1203. About one minute later, at 1204, the flight contacted ATC and stated that it needed to return to LCK, and it was cleared to land on runway 5L. ATC asked the flight if it needed equipment and the flight responded, "Negative." About 1206, the airplane impacted a cornfield about one mile southwest of the approach end of runway 5L.

The inspection of the wreckage revealed that the airplane had impacted the terrain on a southerly heading. The cut through the high corn that was produced by the airplane's landing gear, fuselage, and wings indicated that it was in a slight right wing down attitude on a glide path of about 10 degrees at impact. The initial contact with the corn revealed three parallel cuts through the corn that were consistent with the landing gear being in the down position.

Both left and right propeller gearboxes separated from the engines and were found near the initial impact point. All four blades from both propeller hubs were separated from the hubs and were found throughout the wreckage path. Both propeller hubs were located about 1,250 feet from the initial impact point, the furthest wreckage found in the debris field.

The debris field stretched from about 665 feet from the initial point of impact to an abandoned set of railroad tracks within a tree line. The main wreckage was found about 160 feet south of the railroad tracks, or about 825 feet from the initial impact point.

Approximately 10 feet of the forward portion of the airplane, which included the cockpit, separated from the fuselage at impact. The portion was lying on its right side (as viewed looking forward) and was consumed by fire.

The fuselage was partially consumed by fire just forward of the vertical stabilizer between about Fuselage Station (FS) 623.00 and FS 798.

The left wing had separated from the fuselage and was about 50 feet from the fuselage. It was partially consumed by fire and pieces of the wing were found in the debris field.

The right wing had separated from the fuselage, and a part of the wing was consumed by fire lying under the cockpit section next to the fuselage. Sections of the lower right wing were found in the debris field.

Both engines had separated from the wings and were found in the main wreckage. A ground fire had consumed a swath of corn along the debris field. [NTSB ID: CHI08MA270]
The NTSB reports that both Cockpit Voice Recorder (CVR) and Flight Data Recorder (FDR) were retrieved from the tail section of the wreckage and were sent to the National Transportation Safety Board's Vehicle Recorder Division for inspection. The investigation is ongoing.