A passenger reported an near midair collision to the crew.

Attributes
ACN	252689
Time
Date	199309
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : gwo
State Reference	MS
Altitude	msl bound lower : 35000 msl bound upper : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zme
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Flight Plan	IFR
Aircraft 2
Operator	other
Make Model Name	Military Transport
Navigation In Use	Other Other
Flight Phase	cruise other
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : cfi pilot : atp
Experience	flight time last 90 days : 150 flight time total : 7000 flight time type : 4000
ASRS Report	252689
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : nmac other anomaly other
Independent Detector	other other : unspecified
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

During cruise at FL350, the #1 flight attendant informed us we should report the near miss that just occurred. None of the 3 pilots in the cockpit had seen any traffic. We had no traffic on our active TCASII display. We told ATC about his comment and they showed no traffic anywhere near us. He asked the previous controller and he also showed only us anywhere near our vicinity. The captain went back to talk to this passenger. He described in detail it was a bmb who lit up his after burner after passing directly under us. I don't know what to add!

Original NASA ASRS Text

Title: A PAX RPTED AN NMAC TO THE CREW.

Narrative: DURING CRUISE AT FL350, THE #1 FLT ATTENDANT INFORMED US WE SHOULD RPT THE NEAR MISS THAT JUST OCCURRED. NONE OF THE 3 PLTS IN THE COCKPIT HAD SEEN ANY TFC. WE HAD NO TFC ON OUR ACTIVE TCASII DISPLAY. WE TOLD ATC ABOUT HIS COMMENT AND THEY SHOWED NO TFC ANYWHERE NEAR US. HE ASKED THE PREVIOUS CTLR AND HE ALSO SHOWED ONLY US ANYWHERE NEAR OUR VICINITY. THE CAPT WENT BACK TO TALK TO THIS PAX. HE DESCRIBED IN DETAIL IT WAS A BMB WHO LIT UP HIS AFTER BURNER AFTER PASSING DIRECTLY UNDER US. I DON'T KNOW WHAT TO ADD!

Data retrieved from NASA's ASRS site as of July 2007 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.