Following Senator McCaskill’s property taxes and airplane debacle, it becomes evident that several planes in St. Louis County are unaccounted for.

Eugene Leung is the Director of Revenue for St. Louis County. He says there are 11 hangar operators in the county, all of which receive annual notices — this year’s went out on Jan. 3. However, of those 11, he says only five have responded. Nearly a thousand planes are reportedly kept in the county, all of which are subject to property taxes.

Leung admits it’s a less-than-perfect system, and although the hangar owners are required by law to account for the planes on their property, owners of the planes are required to self-report them as well. In McCaskill’s case, neither happened.

Leung says there are hangars at the Spirit of St. Louis airport in Chesterfield as well as at the Creve Couer airport — the Creve Couer airport has not responded to his office’s request for a list of planes there. And, he says, there could be other hangars in the county he doesn’t know about.

AUDIO: Jessica Machetta reports 1 min

He admits his staff is small and it’s tough to track planes down: if they’re parked in a hangar and the doors are closed, assessor staff members are not allowed to enter private property. Also, of course, he adds many times the planes are en route to other places and in the air.

If one plane accounts for nearly $300,000 in property taxes and there could be dozens — even hundreds more — unaccounted for, that could mean a huge revenue loss for the county. Leung says he realizes that and if anyone has any ideas on how to more efficiently track and tax them, he’d be happy to listen.

Leung did not know which hangar owner / operator was responsible for passing on notices to McCaskill or her staff over the past four years. McCaskill’s office says Midwest Aviation Center (MWAC) is the FBO — Fixed Base Operator — where her plane has been parked.

McCaskill’s staff says after Politico reported that one trip she took might have erroneously been billed to taxpayers, she ordered a full review of the financial records surrounding the plane. That’s when she discovered property taxes had not been paid. She has remitted the full amount of back taxes plus penalties to the county.