COOKSON, Oklahoma - The National Transportation Safety Board has released its first report on a plane crash that seriously injured two men earlier this month.

The single-engine Ercoupe 415-C built in 1946 crashed at about 10:50 a.m. on April 12, 2014 after taking off from Tenkiller Airport in Cookson, Oklahoma.

The Oklahoma Highway Patrol identified the two men on board as John McCreary, 75 and Albert Demarco, Jr., 85, both of Ozark, Arkansas.

The NTSB says the plane was owned by Demarco but it was being flown by McCreary when it crashed.

According to the NTSB's preliminary report on the crash, witnesses reported the plane had engine trouble on its first takeoff attempt but was able to land on the runway. The witnesses say the plane then taxied back to the departure end of the runway and took off again.

The witness told the NTSB the plane climbed to about a 100 feet then the wings moved back and forth, the airplane then pitched up then descended into trees.

The men were brought to a Tulsa hospital where their conditions had improved in the days after the crash.

The next report issued by the NTSB on the incident will be the factual report, followed by its probable cause report. It usually takes the NTSB at least several months to finish an investigation on a particular crash.