Montana rail officials plan to complete an investigation within two weeks into the cause of a train derailment on 3 July that resulted in the loss of six nearly complete 737 fuselages.

The investigation report could be released by the end of August, says a Montana Rail Link spokeswoman.

The incident raised concerns about Boeing's transportation system for the 737 supply chain amidst a period of sharply rising production rates.

The production system relies upon a roughly 1,560nm (2,890km) rail journey for the assembled fuselages, which move between Spirit AeroSystems factory in Wichita, Kansas, and Boeing's final assembly line in Renton, Washington. Two completed 737s roll out of the Renton factory roughly every working day – or 42 per month.

A tornado in 2011 once caused a train carrying assembled 737 fuselages to overturn, but without sustaining major damage.

In the 3 July incident, three of the 737 fuselages plunged down the embankment into the Clark Fork River.

Boeing assessed the damage to the aircraft parts for several weeks, but finally determined that all six 737 fuselages aboard the train must be scrapped.

"Boeing has determined that no parts from the damaged fuselages will be put into the production system," the company says in a statement. "We're working together with Spirit on a plan to deliver airplanes this year to all impacted customers."

Source: FlightGlobal.com