Narrative:

In cruise flight at 10;500 ft at about 240 kts GS; contacted center to request flight following and was given a squawk. Within 5 minutes was told leaving sector and to squawk VFR; and try to contact [the next controlling agency] if desired. About 1 minute later while looking up the frequency for next possible controller; I looked up and was shocked to see a regional airliner crossing immediately overhead; passing from west to east. I had not changed altitude; speed or heading.I've never passed that close to another aircraft without being in formation with them. I can't imagine the controller was unaware of how close we passed; and I feel certain the airliner must have had TCAS activated by the encounter. The encounter really shook me for several minutes; which later turned to anger; as I never would have expected to be that close to another aircraft; especially a passenger aircraft if either of us were in contact with ATC. Perhaps the airliner had received an advisory and had me in sight; but I doubt it as [my aircraft] is camouflaged and very difficult to see in flight.I plan to call ATC to ask about the incident; and hope I will learn that the situation was in fact under control. Regardless; I feel strongly that I should have been advised before being dismissed from the freq.; if just out of courtesy.

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Original NASA ASRS Text

Title: The pilot of a vintage military aircraft reported that while in cruise an airliner crossed overhead without warning.

Narrative: In cruise flight at 10;500 ft at about 240 kts GS; contacted Center to request flight following and was given a squawk. Within 5 minutes was told leaving sector and to squawk VFR; and try to contact [the next controlling agency] if desired. About 1 minute later while looking up the frequency for next possible controller; I looked up and was shocked to see a regional airliner crossing immediately overhead; passing from west to east. I had not changed altitude; speed or heading.I've never passed that close to another aircraft without being in formation with them. I can't imagine the controller was unaware of how close we passed; and I feel certain the airliner must have had TCAS activated by the encounter. The encounter really shook me for several minutes; which later turned to anger; as I never would have expected to be that close to another aircraft; especially a passenger aircraft if either of us were in contact with ATC. Perhaps the airliner had received an advisory and had me in sight; but I doubt it as [my aircraft] is camouflaged and very difficult to see in flight.I plan to call ATC to ask about the incident; and hope I will learn that the situation was in fact under control. Regardless; I feel strongly that I should have been advised before being dismissed from the freq.; if just out of courtesy.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.