A bell 430 captain reported an near midair collision with a T6 at gon, a contract tower.

Attributes
ACN	594812
Time
Date	200309
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : gon.airport
Altitude	msl single value : 1200
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : gon.tower
Operator	general aviation : corporate
Make Model Name	Bell Helicopter Textron Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	descent : intermediate altitude
Route In Use	approach : visual arrival : vfr
Flight Plan	None
Aircraft 2
Operator	other
Make Model Name	Texan T6 Harvard
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude
Person 1
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : commercial pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 60 flight time total : 9600 flight time type : 700
ASRS Report	594812
Person 2
Affiliation	company : corporate
Function	flight crew : first officer
Events
Anomaly	conflict : nmac non adherence : required legal separation
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	other
Miss Distance	horizontal : 100
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	ATC Human Performance

Narrative:

As we were descending for visual approach into gon under tower control from 1300 ft cruise altitude, I noticed a wwii-era T-6 texan advanced trainer, approximately 500 ft below and in front, beginning a right climbing turn in my direction. After pointing it out to my first officer, I also noted that the T-6 was not changing in aspect towards my aircraft. Feeling a collision was imminent as the aircraft continued to climb nose-on, I lowered collective (bell 430 helicopter -- 7 passenger, 2 pilots) and initiated a left descending turn. I estimate our aircraft passed within 100 ft, and as the texan turned left I added collective in a right climbing turn to keep the aircraft in sight -- slightly exceeding mast torque normal limitations as a result (no damage or maintenance action required). I reported the incident to gon tower and bridgeport, ct, FSS.

Original NASA ASRS Text

Title: A BELL 430 CAPT RPTED AN NMAC WITH A T6 AT GON, A CONTRACT TWR.

Narrative: AS WE WERE DSNDING FOR VISUAL APCH INTO GON UNDER TWR CTL FROM 1300 FT CRUISE ALT, I NOTICED A WWII-ERA T-6 TEXAN ADVANCED TRAINER, APPROX 500 FT BELOW AND IN FRONT, BEGINNING A R CLBING TURN IN MY DIRECTION. AFTER POINTING IT OUT TO MY FO, I ALSO NOTED THAT THE T-6 WAS NOT CHANGING IN ASPECT TOWARDS MY ACFT. FEELING A COLLISION WAS IMMINENT AS THE ACFT CONTINUED TO CLB NOSE-ON, I LOWERED COLLECTIVE (BELL 430 HELI -- 7 PAX, 2 PLTS) AND INITIATED A L DSNDING TURN. I ESTIMATE OUR ACFT PASSED WITHIN 100 FT, AND AS THE TEXAN TURNED L I ADDED COLLECTIVE IN A R CLBING TURN TO KEEP THE ACFT IN SIGHT -- SLIGHTLY EXCEEDING MAST TORQUE NORMAL LIMITATIONS AS A RESULT (NO DAMAGE OR MAINT ACTION REQUIRED). I RPTED THE INCIDENT TO GON TWR AND BRIDGEPORT, CT, FSS.

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.