Near midair collision between an IFR PA28 and a descending, turning IFR twin 15 mi southwest of bos,...

Attributes
ACN	559493
Time
Date	200209
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : bos.airport
State Reference	MA
Altitude	msl single value : 4000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : k90.tracon
Operator	general aviation : personal
Make Model Name	PA-28 Cherokee/Archer II/Dakota/Pillan/Warrior
Operating Under FAR Part	Part 91
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : k90.tracon
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	descent : approach
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument
Experience	flight time last 90 days : 57 flight time total : 205 flight time type : 125
ASRS Report	559493
Person 2
Function	observation : passenger
Events
Anomaly	conflict : nmac non adherence : published procedure non adherence : required legal separation other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance controller : issued alert flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew other
Miss Distance	horizontal : 0 vertical : 100
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance Airspace Structure
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error Intra Facility Coordination Failure

Narrative:

On IFR flight plan bed-mvy. Was climbing to 5000 ft. Cape approach instructed me to stop climb and descend to 4000 ft due to descending faster traffic on my right. Traffic came in sight with me about 4000 ft, which I was told to descend to at about the same time. The other plane, a twin engine propeller, was descending and making a left turn towards us. ATC directed me to 'descend immediately.' when I saw the other plane headed at us, I dove approximately 1000-2000 FPM and made steep left turn. The other plane crossed overhead. My wife in the right front seat could see the pilot's faces. It appeared that no instructions to stop the descent or turn were given to the other aircraft, who may have been preparing to land at bos. The vector given to me for a revised heading seemed to take me closer to the path of the faster descending aircraft. ATC could have had the other plane turn to pass behind us, to level off above us and have us descend earlier than we were instructed. Had the faster plane stopped its descent (until past us) there would have been no conflict.

Original NASA ASRS Text

Title: NMAC BTWN AN IFR PA28 AND A DSNDING, TURNING IFR TWIN 15 MI SW OF BOS, MA.

Narrative: ON IFR FLT PLAN BED-MVY. WAS CLBING TO 5000 FT. CAPE APCH INSTRUCTED ME TO STOP CLB AND DSND TO 4000 FT DUE TO DSNDING FASTER TFC ON MY R. TFC CAME IN SIGHT WITH ME ABOUT 4000 FT, WHICH I WAS TOLD TO DSND TO AT ABOUT THE SAME TIME. THE OTHER PLANE, A TWIN ENG PROP, WAS DSNDING AND MAKING A L TURN TOWARDS US. ATC DIRECTED ME TO 'DSND IMMEDIATELY.' WHEN I SAW THE OTHER PLANE HEADED AT US, I DOVE APPROX 1000-2000 FPM AND MADE STEEP L TURN. THE OTHER PLANE CROSSED OVERHEAD. MY WIFE IN THE R FRONT SEAT COULD SEE THE PLT'S FACES. IT APPEARED THAT NO INSTRUCTIONS TO STOP THE DSCNT OR TURN WERE GIVEN TO THE OTHER ACFT, WHO MAY HAVE BEEN PREPARING TO LAND AT BOS. THE VECTOR GIVEN TO ME FOR A REVISED HDG SEEMED TO TAKE ME CLOSER TO THE PATH OF THE FASTER DSNDING ACFT. ATC COULD HAVE HAD THE OTHER PLANE TURN TO PASS BEHIND US, TO LEVEL OFF ABOVE US AND HAVE US DSND EARLIER THAN WE WERE INSTRUCTED. HAD THE FASTER PLANE STOPPED ITS DSCNT (UNTIL PAST US) THERE WOULD HAVE BEEN NO CONFLICT.

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.

Near midair collision between an IFR PA28 and a descending, turning IFR twin 15 mi southwest of bos, ma.