Small aircraft had near midair collision with cessna in traffic pattern class D airspace. Evasive ac...

Attributes
ACN	310087
Time
Date	199507
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : bed
State Reference	MA
Altitude	agl bound lower : 500 agl bound upper : 500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : bed
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	descent : approach other
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	Cessna Aircraft Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 80 flight time total : 1200 flight time type : 550
ASRS Report	310087
Person 2
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Events
Anomaly	conflict : nmac non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	Other
Miss Distance	horizontal : 0 vertical : 100
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

At the end of an IFR flight, after declaring runway in sight, I switched from boston approach ATC to bedford tower, 4 mi out. I next reported mid-field right downwind and was told that I was '#3 following the cessna on right base.' a baron was approaching but not over the runway threshold. Immediately after I was given my sequence, the baron requested confirmation of clearance to land. I, therefore, counted this baron as #1 in the sequence and started looking for the cessna on right base. As I got another 1.5 mi downwind, I saw a cessna on long final and assumed that this was the #2 plane that I was following and informed tower 'cessna in sight.' as I got close to landing, suddenly another cessna appeared below me and I went around. I informed the tower of this and complained that they had misled me on my sequence being #3. They informed me that they don't count airplanes (ie, the baron) on short approach (and, in this case, not yet over the runway). I believe that most pilots assume that any plane not actually on the runway is counted in the sequence. Controllers seem to think they have some discretion on their part as to what to count. Obviously, ambiguity, as to which aircraft are counted and which are not, can be fatal.

Original NASA ASRS Text

Title: SMA HAD NMAC WITH CESSNA IN TFC PATTERN CLASS D AIRSPACE. EVASIVE ACTION TAKEN ACFT GAR. SEE AND AVOID CONCEPT.

Narrative: AT THE END OF AN IFR FLT, AFTER DECLARING RWY IN SIGHT, I SWITCHED FROM BOSTON APCH ATC TO BEDFORD TWR, 4 MI OUT. I NEXT RPTED MID-FIELD R DOWNWIND AND WAS TOLD THAT I WAS '#3 FOLLOWING THE CESSNA ON R BASE.' A BARON WAS APCHING BUT NOT OVER THE RWY THRESHOLD. IMMEDIATELY AFTER I WAS GIVEN MY SEQUENCE, THE BARON REQUESTED CONFIRMATION OF CLRNC TO LAND. I, THEREFORE, COUNTED THIS BARON AS #1 IN THE SEQUENCE AND STARTED LOOKING FOR THE CESSNA ON R BASE. AS I GOT ANOTHER 1.5 MI DOWNWIND, I SAW A CESSNA ON LONG FINAL AND ASSUMED THAT THIS WAS THE #2 PLANE THAT I WAS FOLLOWING AND INFORMED TWR 'CESSNA IN SIGHT.' AS I GOT CLOSE TO LNDG, SUDDENLY ANOTHER CESSNA APPEARED BELOW ME AND I WENT AROUND. I INFORMED THE TWR OF THIS AND COMPLAINED THAT THEY HAD MISLED ME ON MY SEQUENCE BEING #3. THEY INFORMED ME THAT THEY DON'T COUNT AIRPLANES (IE, THE BARON) ON SHORT APCH (AND, IN THIS CASE, NOT YET OVER THE RWY). I BELIEVE THAT MOST PLTS ASSUME THAT ANY PLANE NOT ACTUALLY ON THE RWY IS COUNTED IN THE SEQUENCE. CTLRS SEEM TO THINK THEY HAVE SOME DISCRETION ON THEIR PART AS TO WHAT TO COUNT. OBVIOUSLY, AMBIGUITY, AS TO WHICH ACFT ARE COUNTED AND WHICH ARE NOT, CAN BE FATAL.

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.

Small aircraft had near midair collision with cessna in traffic pattern class D airspace. Evasive action taken aircraft go around. See and avoid concept.