Near midair collision between small aircraft X and small transport Y. See and avoid concept.

Attributes
ACN	272709
Time
Date	199405
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ign
State Reference	NY
Altitude	msl bound lower : 7000 msl bound upper : 7000
Environment
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	descent other
Route In Use	enroute airway : zbw
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument
Experience	flight time last 90 days : 25 flight time total : 5100 flight time type : 2900
ASRS Report	272709
Person 2
Affiliation	Other
Function	observation : passenger
Qualification	pilot : private
Events
Anomaly	conflict : nmac non adherence : far other anomaly other
Independent Detector	other flight crewa other other : unspecified cockpit
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	vertical : 200
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

ZBW, left 9000 ft for 7000 ft. 1 traffic callout observed, a propeller twin descending from para-drop. He was safely below us. Perhaps 10 mins, or less, later my tcad, ryan, told us a 'no altitude.' target very close. My wife, right seat, spotted another propeller. Twin, white, just below our right side traveling right to left under us. It must have been squawking 1200 because tcad 'saw' it. I pulled up and turned right clearly saw twin below us. It soon turned to its left and was out of my sight. Called boston. Controller said he had no target near us! Yet that plane was squawking 1200 with altitude. Off or my tcad would not have reported him. Is center radar blind to a 1200 code? I don't expect any 'fix,' but thought you should know of each near-miss.

Original NASA ASRS Text

Title: NMAC BTWN SMA X AND SMT Y. SEE AND AVOID CONCEPT.

Narrative: ZBW, LEFT 9000 FT FOR 7000 FT. 1 TFC CALLOUT OBSERVED, A PROP TWIN DSNDING FROM PARA-DROP. HE WAS SAFELY BELOW US. PERHAPS 10 MINS, OR LESS, LATER MY TCAD, RYAN, TOLD US A 'NO ALT.' TARGET VERY CLOSE. MY WIFE, R SEAT, SPOTTED ANOTHER PROP. TWIN, WHITE, JUST BELOW OUR R SIDE TRAVELING R TO L UNDER US. IT MUST HAVE BEEN SQUAWKING 1200 BECAUSE TCAD 'SAW' IT. I PULLED UP AND TURNED R CLRLY SAW TWIN BELOW US. IT SOON TURNED TO ITS L AND WAS OUT OF MY SIGHT. CALLED BOSTON. CTLR SAID HE HAD NO TARGET NEAR US! YET THAT PLANE WAS SQUAWKING 1200 WITH ALT. OFF OR MY TCAD WOULD NOT HAVE RPTED HIM. IS CTR RADAR BLIND TO A 1200 CODE? I DON'T EXPECT ANY 'FIX,' BUT THOUGHT YOU SHOULD KNOW OF EACH NEAR-MISS.

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.