The U.S. Coast Guard ended its search in the Gulf of Mexico for a small aircraft piloted by an LSU medical school graduate who officials believe crashed last week en route from Missouri, where he worked as a trauma surgeon, to Gonzales.

Steven Stone Schumacher, 63, was traveling alone in a Piper Aztec twin-engine plane. His family reported him missing hours after he was scheduled to arrive Wednesday night, officials said.

Crews spent roughly 21 hours searching for the plane, covering more than 62,500 square-nautical miles before calling it off Sunday, the Coast Guard said.

"After the utmost consideration and review of all factors involved in this search and rescue case, the Coast Guard has made the difficult decision to suspend its active search efforts,” said Cmdr. Drew Casey, search and rescue mission coordinator from the Eighth Coast Guard District, in a statement. “We extend our sincere condolences to the family and friends of Mr. Steven Schumacher.”

The plane's last position over the Gulf was 440 miles off Louisiana's coast, and federal air controllers weren't able to contact Schumacher. He was expected to arrive in Gonzales about 8:30 p.m. Wednesday, officials said.

The Coast Guard and Mexican Navy had been searching for the plane but found no signs of it. 

Schumacher, a trauma surgeon in Cape Girardeau, Missouri, graduated from the LSU School of Medicine. He was a resident at the New Orleans Charity Hospital's department of surgery, according to the Missouri health care system