APOPKA, Fla. -

A search is under way for a Central Florida pilot after he threatened to crash the aircraft into his ex-girlfriend's home, according to investigators.

The Federal Aviation Administration identified the pilot as 63-year-old Michael Sills, of Winter Garden. Sills' girlfriend reported to authorities that her ex-boyfriend was suicidal due to their relationship break-up. She told authorities she received text messages from him on Tuesday saying, "In plane." "Calling police is to late."

Investigators found Sills' car at the Orlando Apopka Airport on Tuesday, but his plane remains missing.  Investigators said blood was found inside Sills' car and the vehicle's exhaust system appeared to be rigged for a suicide attempt.

Sills, according to investigators, threatened to crash his Piper aircraft into his girlfriend's house on Azalea Way, or another building. 

[PICS: Search continues]

The plane has a range of about 500 miles. Metro PCS tracked Sills' phone ping to the Zellwood area of Orange County.

The FAA said it has not ruled out the possibility that the plane crashed in an unknown location. No reports of a small plane crashing have been reported to the FAA as of Friday afternoon.

Neighbors tell Local 6 Sills' threats have them feeling nervous.

"This morning was the first I heard he threatened to crash the plane into the house. scary thought especially because they haven't found that plane yet it's a little worrisome," said neighbor Michael Karns, who said Sills was pleasant with him. "He pretty much every time he came out we would stop and have a few words."

Watch Local 6 News for more on this story.