Near midair collision in the traffic pattern.

Attributes
ACN	549017
Time
Date	200205
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : bet.airport
State Reference	AK
Altitude	agl bound lower : 1500 agl bound upper : 1700
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : bet.tower tower : myf.tower
Operator	common carrier : air carrier
Make Model Name	Beech 1900
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	approach : traffic pattern
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tower : bet.tower
Operator	common carrier : air carrier
Make Model Name	Twin Otter DHC-6
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	approach : traffic pattern
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 5000 flight time type : 1100
ASRS Report	549017
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	airspace violation : entry conflict : nmac non adherence : published procedure non adherence : far
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	other
Miss Distance	horizontal : 300 vertical : 150
Supplementary
Problem Areas	Flight Crew Human Performance Company ATC Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Our aircraft on IFR flight plan was cleared for a visual approach, and then cleared to land. Monitoring of bethel tower, only 2 cessnas were on frequency -- one was landing on runway 29, the other calling approximately 10 mi out to enter zone. We were beginning descent from 2000 ft MSL in traffic pattern. Through approximately 1500-1700 ft AGL on right base turning final, we had a TCASII TA. We looked around but couldn't see any other aircraft. Then a company Y twin otter that had not previously called tower, called on CTAF to say they would do a 360 degree turn at present position on a 2 mi final. We didn't see the twin otter until he was wing-high beginning the turn. Since we were cleared to land, we had the right-of-way. Once on the ground, we reported the near midair collision to our company. Other bethel-based pilots have reported numerous conflicts with company Y twin otters in the area due to company Y reluctance to use proper radio techniques.

Original NASA ASRS Text

Title: NMAC IN THE TFC PATTERN.

Narrative: OUR ACFT ON IFR FLT PLAN WAS CLRED FOR A VISUAL APCH, AND THEN CLRED TO LAND. MONITORING OF BETHEL TWR, ONLY 2 CESSNAS WERE ON FREQ -- ONE WAS LNDG ON RWY 29, THE OTHER CALLING APPROX 10 MI OUT TO ENTER ZONE. WE WERE BEGINNING DSCNT FROM 2000 FT MSL IN TFC PATTERN. THROUGH APPROX 1500-1700 FT AGL ON R BASE TURNING FINAL, WE HAD A TCASII TA. WE LOOKED AROUND BUT COULDN'T SEE ANY OTHER ACFT. THEN A COMPANY Y TWIN OTTER THAT HAD NOT PREVIOUSLY CALLED TWR, CALLED ON CTAF TO SAY THEY WOULD DO A 360 DEG TURN AT PRESENT POS ON A 2 MI FINAL. WE DIDN'T SEE THE TWIN OTTER UNTIL HE WAS WING-HIGH BEGINNING THE TURN. SINCE WE WERE CLRED TO LAND, WE HAD THE RIGHT-OF-WAY. ONCE ON THE GND, WE RPTED THE NMAC TO OUR COMPANY. OTHER BETHEL-BASED PLTS HAVE RPTED NUMEROUS CONFLICTS WITH COMPANY Y TWIN OTTERS IN THE AREA DUE TO COMPANY Y RELUCTANCE TO USE PROPER RADIO TECHNIQUES.

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.