Narrative:

I was a passenger in seat 3A, a window seat on the left side, in the first class cabin, of air carrier X into west palm beach. We had just flown a right downwind and base leg to runway 27R, and were settled on final, about 3 mi east of the airport, approaching the coastline. I was following the approach with interest (I'm a low time VFR private pilot), and suddenly I saw small transport Y pass directly across our path, from right to left, and no more than 300-400' below us. He was white with blue trim. As soon as he passed underneath of us he made a very steeply banked right turn (the kind of which stall/spin accidents are easily made) and finally stabilized onto his final approach to runway 27L. He landed safely, as did we. Our flight crew had to apply very hard braking, because they had to arrest our descent to avoid him on final, making our approach a bit high and fast. I talked with the flight crew briefly as I exited the plane, and they were talking about how close it had been. They did say that ATC and they knew the twin was there,and that ATC had sent him across us. It seems to me that if that's true the flight crew of either of the planes would be much less at fault than the ATC controllers were. You be the judge. My judgement is that it was way below legal minimum sep rules, and would legitimately be judged a near midair.

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Original NASA ASRS Text

Title: NMAC BETWEEN LGT-ACR AND GA-TWIN.

Narrative: I WAS A PAX IN SEAT 3A, A WINDOW SEAT ON THE LEFT SIDE, IN THE FIRST CLASS CABIN, OF ACR X INTO WEST PALM BEACH. WE HAD JUST FLOWN A RIGHT DOWNWIND AND BASE LEG TO RWY 27R, AND WERE SETTLED ON FINAL, ABOUT 3 MI E OF THE ARPT, APCHING THE COASTLINE. I WAS FOLLOWING THE APCH WITH INTEREST (I'M A LOW TIME VFR PVT PLT), AND SUDDENLY I SAW SMT Y PASS DIRECTLY ACROSS OUR PATH, FROM RIGHT TO LEFT, AND NO MORE THAN 300-400' BELOW US. HE WAS WHITE WITH BLUE TRIM. AS SOON AS HE PASSED UNDERNEATH OF US HE MADE A VERY STEEPLY BANKED RIGHT TURN (THE KIND OF WHICH STALL/SPIN ACCIDENTS ARE EASILY MADE) AND FINALLY STABILIZED ONTO HIS FINAL APCH TO RWY 27L. HE LANDED SAFELY, AS DID WE. OUR FLT CREW HAD TO APPLY VERY HARD BRAKING, BECAUSE THEY HAD TO ARREST OUR DSCNT TO AVOID HIM ON FINAL, MAKING OUR APCH A BIT HIGH AND FAST. I TALKED WITH THE FLT CREW BRIEFLY AS I EXITED THE PLANE, AND THEY WERE TALKING ABOUT HOW CLOSE IT HAD BEEN. THEY DID SAY THAT ATC AND THEY KNEW THE TWIN WAS THERE,AND THAT ATC HAD SENT HIM ACROSS US. IT SEEMS TO ME THAT IF THAT'S TRUE THE FLT CREW OF EITHER OF THE PLANES WOULD BE MUCH LESS AT FAULT THAN THE ATC CTLRS WERE. YOU BE THE JUDGE. MY JUDGEMENT IS THAT IT WAS WAY BELOW LEGAL MINIMUM SEP RULES, AND WOULD LEGITIMATELY BE JUDGED A NEAR MIDAIR.

Data retrieved from NASA's ASRS site as of August 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.