"Omni 441 Experimental Heavy" callsign
 

Last weekend I was doing airwork south of KRIC and heard "Omni 441 Experimental Heavy" talking to Potomac Apprch doing some approaches, and then doing 2 Right and 2 Left 360 turns at 5000 feet, then they told Apprch they're headed back to Dulles.

I've been told that OAI (Omni Air International) uses the callsign "Omni Air" so this might not be OAI.

If it had been "Omni 441 Heavy" I would have not given them much thought - just a charter airline out there maybe doing checkrides... but having "Experimental" thrown into the callsign really made me wonder what it was.

Anyone have any knowledge about this callsign and why they're operating in Experimental category?

-FP

Interesting

I could only find this

A 767-300

Maybe test flight(s) after maintenance/modifications which may have significantly changed the performance characteristics of the aircraft, i.e., beyond the parameters of its original type certificate.

The aircraft must be flown to show compliance with FARs and an experimental certificate can be obtained for this purpose.