A corporate aircraft departed sun and during climb through 7;500 ft took evasive action to a TCAS TA...

Narrative:

We departed sun IFR in VMC; cleared to initially climb and maintain 11;000 ft. Radar service was not available. We were still in contact with sun tower. There was no reported traffic. Climbing through approximately 6;000 ft MSL we observed a TCAS target at 12 o'clock; less than 5 miles; 2;100 ft above us. We were unable to establish visual contact and; when queried; sun tower advised no reported traffic and no radio contact. As we continued our climb; our horizontal and vertical separation decreased and at about 600 ft vertical separation we realized we were nearly directly beneath the target. I stopped the climb at about 7;800 ft and then descended to 7;500 ft (MSL) and advised sun tower of our deviation. Note: our TCAS is not equipped to give RA; only TA. TCAS showed the target slightly to our left; so I started a gentle right turn and was able to establish visual on the other aircraft; very close and above us to the left in what appeared to be straight and level; unconcerned flight parallel to our own flight path. It was a large twin engine aircraft. Advising sun tower of our intentions; we continued to diverge to the right at 7;500 ft maintaining visual separation both with the traffic and terrain until we had sufficient clearance to resume our climb and original heading/route. The other aircraft gave no indication of having ever seen us and took no evasive action as long as we had it in sight.causes of problem: 1) mix of IFR and non-participating VFR traffic in non-radar environment. 2) lack of vigilance and traffic/airspace awareness on part of the other aircraft. 3) poor upper forward and vertical cockpit visibility in our aircraft.corrective suggestions: 1) pilots should monitor and participate on local airport traffic frequencies for positions and activities of other aircraft; even when it is not required to be in contact with the ATC facility in use; i.e. Overflights of class D; in this case. 2) pilots should avoid or at least exercise extreme vigilance when in known departure/arrival areas; i.e. Class C/D/east transition areas; etc. 3) pilots should utilize radar services whenever available. 4) when radar service is unavailable; pilots should exercise extreme vigilance. 5) if TCAS is available; monitor frequently for targets that may are not yet a threat but may become so. We were aware of our traffic well before it became a threat; thanks to TCAS. 6) believe your TCAS; but do not neglect visual scan; especially in VMC. 7) when responding to a TA; it is best to do so in a vertical plane just as you would for a RA; that is; climb; level or descend; not turn. That was my reaction due to my airline training and part 121 experience. 8) be prepared to deviate from your clearance if necessary; but remember to inform ATC. 9) encourage aircraft manufacturers to improve flight deck visibility; especially forward and upward. Those who have flown an aircraft with skylight windows will understand what I mean.

Original NASA ASRS Text

Title: A Corporate aircraft departed SUN and during climb through 7;500 FT took evasive action to a TCAS TA with a large aircraft whose crew was apparently not on any ATC frequency.

Narrative: We departed SUN IFR in VMC; cleared to initially climb and maintain 11;000 FT. Radar service was not available. We were still in contact with SUN Tower. There was no reported traffic. Climbing through approximately 6;000 FT MSL we observed a TCAS target at 12 o'clock; less than 5 miles; 2;100 FT above us. We were unable to establish visual contact and; when queried; SUN Tower advised no reported traffic and no radio contact. As we continued our climb; our horizontal and vertical separation decreased and at about 600 FT vertical separation we realized we were nearly directly beneath the target. I stopped the climb at about 7;800 FT and then descended to 7;500 FT (MSL) and advised SUN Tower of our deviation. Note: our TCAS is not equipped to give RA; only TA. TCAS showed the target slightly to our left; so I started a gentle right turn and was able to establish visual on the other aircraft; very close and above us to the left in what appeared to be straight and level; unconcerned flight parallel to our own flight path. It was a large twin engine aircraft. Advising SUN Tower of our intentions; we continued to diverge to the right at 7;500 FT maintaining visual separation both with the traffic and terrain until we had sufficient clearance to resume our climb and original heading/route. The other aircraft gave no indication of having ever seen us and took no evasive action as long as we had it in sight.Causes of problem: 1) Mix of IFR and non-participating VFR traffic in non-radar environment. 2) Lack of vigilance and traffic/airspace awareness on part of the other aircraft. 3) Poor upper forward and vertical cockpit visibility in our aircraft.Corrective suggestions: 1) Pilots should monitor and participate on local airport traffic frequencies for positions and activities of other aircraft; even when it is not required to be in contact with the ATC facility in use; i.e. overflights of Class D; in this case. 2) Pilots should avoid or at least exercise extreme vigilance when in known departure/arrival areas; i.e. Class C/D/E transition areas; etc. 3) Pilots should utilize radar services whenever available. 4) When radar service is unavailable; pilots should exercise extreme vigilance. 5) If TCAS is available; monitor frequently for targets that may are not yet a threat but may become so. We were aware of our traffic well before it became a threat; thanks to TCAS. 6) Believe your TCAS; but do not neglect visual scan; especially in VMC. 7) When responding to a TA; it is best to do so in a vertical plane just as you would for a RA; that is; climb; level or descend; not turn. That was my reaction due to my airline training and Part 121 experience. 8) Be prepared to deviate from your clearance if necessary; but remember to inform ATC. 9) Encourage aircraft manufacturers to improve flight deck visibility; especially forward and upward. Those who have flown an aircraft with skylight windows will understand what I mean.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1106348
Time
Date	201308
Local Time Of Day	0601-1200
Place
Locale Reference	SUN.Tower
State Reference	ID
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft Low Wing 1 Eng Retractable Gear
Operating Under FAR Part	Part 91
Flight Phase	Climb
Route In Use	Direct
Flight Plan	IFR
Aircraft 2
Make Model Name	Medium Large Transport
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Flight Plan	None
Person 1
Function	Pilot Flying First Officer
Qualification	Flight Crew Flight Engineer Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 21875 Flight Crew Type 80
Person 2
Function	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 15700 Flight Crew Type 5700
Events
Anomaly	Conflict Airborne Conflict Deviation - Procedural Published Material / Policy
Miss Distance	Horizontal 200 Vertical 600

A corporate aircraft departed sun and during climb through 7;500 ft took evasive action to a TCAS TA with a large aircraft whose crew was apparently not on any ATC frequency.