ELBA, N.Y. — The investigation continues into the deadly Mercy Flight helicopter crash in the Genesee County town of Elba on Tuesday.

A medical helicopter pilot and flight instructor were killed after a helicopter went down during a training flight around 1 p.m.

Investigators from the National Transportation Safety Board, the Federal Aviation Administration and helicopter manufacturer Bell will be on the scene for the next three-to-five days collecting data, NTSB Air Safety Investigator Aaron McCarter announced Wednesday.

McCarter said at some point during the flight, the tail rudder separated from the helicopter. That helps keep the nose pointed in the right direction.

Investigators believe they will be able to download from data units intact to help analyze what happened.

The wreckage is spread over about 2,000 feet.

McCarter says it is not known which of the two pilots were in control at the time it crashed, but investigators will be looking at the pilots experience with this type of helicopter, along with any technical and mechanical issues and the weather to try to figure out what happened.

"That wreckage is going to be transported back to this facility down in Delaware, where we will do, basically, a two-dimensional assembly of it on a hangar floor,” McCarter said. “We will be doing a thorough engine check. We're going to be checking the rotor blades. We're going to be checking the tail rotor, downloading the data, sending it off. That should help determine, or at least lead us in the right direction of what happened."

Buffalo-based Mercy Flight identified the pilot as James Sauer, 60, of Churchville, a retired New York State Police pilot. The Rochester Police Department says Sauer worked as an RPD officer from 1993 to 2001.

The flight instructor, who worked for the helicopter manufacturer, was identified by state police as Stewart Dietrick, 60, of Prosper, Texas.

McCarter says a preliminary report will take 10 days, while it will be about a year for the factual report and determination of the cause of the crash.