A PA28 CFI and student reported an near midair collision with a baron at bed, ma.

Attributes
ACN	597173
Time
Date	200310
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : bed.airport
State Reference	MA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : bed.tower
Operator	general aviation : instructional
Make Model Name	PA-28 Cherokee Arrow IV
Operating Under FAR Part	Part 91
Navigation In Use	ils localizer & glide slope : 29
Flight Phase	descent : approach
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tower : bed.tower
Operator	general aviation : personal
Make Model Name	Baron 58/58TC
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Route In Use	approach : traffic pattern
Flight Plan	None
Person 1
Affiliation	other
Function	instruction : instructor
Qualification	pilot : cfi
ASRS Report	597173
Person 2
Affiliation	other
Function	instruction : trainee
Events
Anomaly	conflict : nmac non adherence : required legal separation
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Miss Distance	horizontal : 0 vertical : 300
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Ambiguous

Narrative:

We (student and instructor) were shooting a practice instrument approach (ILS runway 29) at hanscom field. We were communicating with tower who was sequencing us in with other landing traffic. Tower was also talking to another plane (baron) and told that plane they would follow us. Tower gave that plane at least 3 calls to clarify our position so they could sequence in behind us. As we were descending through 700 ft on the ILS, I noticed the plane off our left approaching us. He was base and started turning final. I took the controls from my student who was under the hood, and the plane passed 300 ft below us. The baron then reported having spotted us right above him.

Original NASA ASRS Text

Title: A PA28 CFI AND STUDENT RPTED AN NMAC WITH A BARON AT BED, MA.

Narrative: WE (STUDENT AND INSTRUCTOR) WERE SHOOTING A PRACTICE INST APCH (ILS RWY 29) AT HANSCOM FIELD. WE WERE COMMUNICATING WITH TWR WHO WAS SEQUENCING US IN WITH OTHER LNDG TFC. TWR WAS ALSO TALKING TO ANOTHER PLANE (BARON) AND TOLD THAT PLANE THEY WOULD FOLLOW US. TWR GAVE THAT PLANE AT LEAST 3 CALLS TO CLARIFY OUR POS SO THEY COULD SEQUENCE IN BEHIND US. AS WE WERE DSNDING THROUGH 700 FT ON THE ILS, I NOTICED THE PLANE OFF OUR L APCHING US. HE WAS BASE AND STARTED TURNING FINAL. I TOOK THE CTLS FROM MY STUDENT WHO WAS UNDER THE HOOD, AND THE PLANE PASSED 300 FT BELOW US. THE BARON THEN RPTED HAVING SPOTTED US RIGHT ABOVE HIM.

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.