Small transport has near midair collision with light transport on descent into bos.

Attributes
ACN	265220
Time
Date	199403
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : bos
State Reference	MA
Altitude	msl bound lower : 5000 msl bound upper : 5000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : bos tower : cps
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 135
Flight Phase	cruise other descent other
Route In Use	enroute : on vectors
Flight Plan	VFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Saab-Scania Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : commercial pilot : cfi pilot : atp
Experience	flight time last 90 days : 170 flight time total : 8000 flight time type : 5000
ASRS Report	265220
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	conflict : nmac
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action none taken : insufficient time other
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 500 vertical : 400
Supplementary
Primary Problem	ATC Human Performance

Narrative:

En route to bos on a VFR flight plan at 5500 ft. Flight X a do-228 entered mht airspace and asked for radar advisories. Mht ATC was working a saab 340 flight Y IFR en route to bos (do-228 was about 3-5 mi ahead of the saab). Mht ATC advised the saab crew that they had do-228 traffic at 12 O'clock, 5 mi. Saab crew acknowledged that they were looking. Mht ATC asked flight X what the heading was to bos, I stated it was 190 degrees. Mht ATC advised the saab crew of my heading. I am not sure what their response was to ATC. Mht ATC then handed us over to ZBW (about 24 DME from bos). Bos ATC cleared flight X into the class B airspace. Descend and maintain 4500 ft. Turn right to a heading of 240 degrees, vectors to final. Moments later at 5000 ft on the 240 degree heading my first officer looked out the right window and saw a saab 340 pass just under neath us in a nose-down attitude. The saab crew checked in the ZBW and stated that they just had to make an emergency maneuver to avoid hitting a dornier. ZBW response was roger! The saab crew then asked bos what happened back there? Was the do- 228 roaming around out there and whose airspace was he in? ZBW said that he wasn't sure whose airspace (bos or mht) the do-228 was in (it was around the 20 DME). The saab crew then stated that it was close. To make a simple story, we crossed each other's path at the same altitude. This could have been avoided in a couple of ways: mht ATC knew he had 2 aircraft on the same heading landing at the same airport. When he handed the do-228 off to ZBW, he should have notified him (bos) about the saab which is behind the do-228 that is on the same heading and is much faster. How about a heading change or a speed reduction for the saab? The sabb crew either never saw us or failed to maintain visual contact with us (do-228). This happened in a transition period (handoff). I feel that the saab crew was unprofessional over the radio. He made it sound like the do-228 was roaming around out there lost, where in fact I had a clearance to operate in the bos class B airspace with instruction from ATC.

Original NASA ASRS Text

Title: SMT HAS NMAC WITH LTT ON DSCNT INTO BOS.

Narrative: ENRTE TO BOS ON A VFR FLT PLAN AT 5500 FT. FLT X A DO-228 ENTERED MHT AIRSPACE AND ASKED FOR RADAR ADVISORIES. MHT ATC WAS WORKING A SAAB 340 FLT Y IFR ENRTE TO BOS (DO-228 WAS ABOUT 3-5 MI AHEAD OF THE SAAB). MHT ATC ADVISED THE SAAB CREW THAT THEY HAD DO-228 TFC AT 12 O'CLOCK, 5 MI. SAAB CREW ACKNOWLEDGED THAT THEY WERE LOOKING. MHT ATC ASKED FLT X WHAT THE HDG WAS TO BOS, I STATED IT WAS 190 DEGS. MHT ATC ADVISED THE SAAB CREW OF MY HDG. I AM NOT SURE WHAT THEIR RESPONSE WAS TO ATC. MHT ATC THEN HANDED US OVER TO ZBW (ABOUT 24 DME FROM BOS). BOS ATC CLRED FLT X INTO THE CLASS B AIRSPACE. DSND AND MAINTAIN 4500 FT. TURN R TO A HDG OF 240 DEGS, VECTORS TO FINAL. MOMENTS LATER AT 5000 FT ON THE 240 DEG HDG MY FO LOOKED OUT THE R WINDOW AND SAW A SAAB 340 PASS JUST UNDER NEATH US IN A NOSE-DOWN ATTITUDE. THE SAAB CREW CHKED IN THE ZBW AND STATED THAT THEY JUST HAD TO MAKE AN EMER MANEUVER TO AVOID HITTING A DORNIER. ZBW RESPONSE WAS ROGER! THE SAAB CREW THEN ASKED BOS WHAT HAPPENED BACK THERE? WAS THE DO- 228 ROAMING AROUND OUT THERE AND WHOSE AIRSPACE WAS HE IN? ZBW SAID THAT HE WASN'T SURE WHOSE AIRSPACE (BOS OR MHT) THE DO-228 WAS IN (IT WAS AROUND THE 20 DME). THE SAAB CREW THEN STATED THAT IT WAS CLOSE. TO MAKE A SIMPLE STORY, WE CROSSED EACH OTHER'S PATH AT THE SAME ALT. THIS COULD HAVE BEEN AVOIDED IN A COUPLE OF WAYS: MHT ATC KNEW HE HAD 2 ACFT ON THE SAME HDG LNDG AT THE SAME ARPT. WHEN HE HANDED THE DO-228 OFF TO ZBW, HE SHOULD HAVE NOTIFIED HIM (BOS) ABOUT THE SAAB WHICH IS BEHIND THE DO-228 THAT IS ON THE SAME HDG AND IS MUCH FASTER. HOW ABOUT A HDG CHANGE OR A SPD REDUCTION FOR THE SAAB? THE SABB CREW EITHER NEVER SAW US OR FAILED TO MAINTAIN VISUAL CONTACT WITH US (DO-228). THIS HAPPENED IN A TRANSITION PERIOD (HDOF). I FEEL THAT THE SAAB CREW WAS UNPROFESSIONAL OVER THE RADIO. HE MADE IT SOUND LIKE THE DO-228 WAS ROAMING AROUND OUT THERE LOST, WHERE IN FACT I HAD A CLRNC TO OPERATE IN THE BOS CLASS B AIRSPACE WITH INSTRUCTION FROM ATC.

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.