While climbing to avoid another aircraft and incurring an near midair collision the pilot of a C340 ...

Narrative:

After departing on a direct route to my destination the tower advised me that traffic; a seneca; was at 10 o'clock and two miles; frequency change approved. I acknowledged with 'copy.' I found the traffic visually and cross referenced with onboard tis and adsb traffic that the traffic was heading same direction as me; appeared to be level and slower. I continued to climb in the same direction. The traffic then turned 90 degrees right and was now; according to my tis on a collision course with me. I was unable to turn left to pass behind the traffic due to proximity and I chose not to descend due to terrain; so I maintained visual contact with the traffic and continued to climb more aggressively to avoid. I also turned slightly right to avoid the aircraft. I maintained visual contact until I was past the traffic; but I had climbed to 2;800 ft to avoid them; and 100 ft into the floor of the ont class C airspace. After passing the traffic I realized the altitude and immediately corrected to 2;500 ft and opened up VFR flight following with socal for the remainder of the flight. My onboard tis and adsb traffic were helpful tools in helping me 'see and avoid' the traffic by aiding me to determine a flight path that would avoid them. In hind sight; it would have been extremely helpful for cno tower to suggest a socal frequency for further VFR traffic information since we were outside of their airspace and operating in close proximity.

Original NASA ASRS Text

Title: While climbing to avoid another aircraft and incurring an NMAC the pilot of a C340 inadvertently entered the ONT Class C under which he had been flying. After clear of the traffic he descended and proceeded to destination.

Narrative: After departing on a direct route to my destination the Tower advised me that traffic; a Seneca; was at 10 o'clock and two miles; frequency change approved. I acknowledged with 'copy.' I found the traffic visually and cross referenced with onboard TIS and ADSB traffic that the traffic was heading same direction as me; appeared to be level and slower. I continued to climb in the same direction. The traffic then turned 90 degrees right and was now; according to my TIS on a collision course with me. I was unable to turn left to pass behind the traffic due to proximity and I chose not to descend due to terrain; so I maintained visual contact with the traffic and continued to climb more aggressively to avoid. I also turned slightly right to avoid the aircraft. I maintained visual contact until I was past the traffic; but I had climbed to 2;800 FT to avoid them; and 100 FT into the floor of the ONT Class C airspace. After passing the traffic I realized the altitude and immediately corrected to 2;500 FT and opened up VFR flight following with SOCAL for the remainder of the flight. My onboard TIS and ADSB traffic were helpful tools in helping me 'see and avoid' the traffic by aiding me to determine a flight path that would avoid them. In hind sight; it would have been extremely helpful for CNO Tower to suggest a SOCAL frequency for further VFR traffic information since we were outside of their airspace and operating in close proximity.

Data retrieved from NASA's ASRS site 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	1198737
Time
Date	201408
Local Time Of Day	1201-1800
Place
Locale Reference	ONT.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Cessna 340/340A
Operating Under FAR Part	Part 91
Flight Phase	Climb
Route In Use	Direct
Flight Plan	None
Aircraft 2
Make Model Name	PA-34-200 Seneca I
Operating Under FAR Part	Part 91
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Commercial Flight Crew Multiengine Flight Crew Instrument Flight Crew Flight Instructor
Experience	Flight Crew Last 90 Days 15 Flight Crew Total 2000 Flight Crew Type 600
Events
Anomaly	Airspace Violation All Types Conflict NMAC
Miss Distance	Horizontal 200 Vertical 100

While climbing to avoid another aircraft and incurring an near midair collision the pilot of a C340 inadvertently entered the ont class C under which he had been flying. After clear of the traffic he descended and proceeded to destination.