No missing parts or tampering found on Obama plane

WASHINGTON -- An initial examination of the plane that had maintenance problems while carrying Democratic presidential candidate Barack Obama found no evidence of missing parts or tampering, federal investigators said Thursday.

The Midwest Airlines MD-81 made a precautionary landing in St. Louis on Monday after leaving Chicago for Charlotte, N.C.

The National Transportation Safety Board released some preliminary findings from the on-scene investigation Thursday.

The pilots of the Midwest Airlines MD-81 felt it took more than the usual amount of force to manipulate the aircraft controls, NTSB spokeswoman Bridget Serchak said.

The federal agency stated that an emergency evacuation slide located in the tail cone of the plane partially inflated and that an inflation bottle, typically containing a mix of nitrogen and carbon dioxide, was empty.

It is not clear exactly why or when that happened, Serchak said. Flight crew statements indicate the crew did not hear the slide deploy in flight, according to the NTSB.

An examination of the hardware associated with the slide did not reveal any evidence of missing components or tampering, the agency said.

Investigators also reported that there did not to appear to be any punctures in the slide. There were marks on it, though, that were consistent with rubbing of cables, according to the agency. Also, a railing of the catwalk, used to walk from the back of the plane into the tail, was broken. The broken railing may have affected elevator control cables, investigators said.

The slide and hardware are being sent to the manufacturer for a detailed look under the supervision of the NTSB. The flight recorders have been removed and will be examined by federal investigators in Washington. Authorities are also researching the certification of the slide and its service history.

A preliminary report is expected to be released this month. The full investigation could take a year or longer.