Date: 201605
Local time of day: 1801-2400
Location: ZLA.ARTCC, CA
Flight conditions: VMC
Light: Daylight
Aircraft: Large Transport; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise; Climb
Airspace: Class A ZLA
ATC / advisory: Center ZLA
Second aircraft: Light Transport; Low Wing; 2 Turbojet Eng
Reporter organization: Government
Reporter function: Enroute
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Communication Breakdown; Situational Awareness
Second reporter function: Captain; Pilot Flying
Anomaly: Conflict Airborne Conflict; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance
Detector: Automation Aircraft RA; Person Flight Crew; Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Took Evasive Action
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: An Air Taxi checked in north bound climbing to FL230 out of approximately FL180. I climbed the aircraft to FL270 and received the read-back. I stopped them at FL270 because there was traffic west bound at FL280. When the Air Taxi was approaching BLH; I called traffic to both Air Carrier and the Air Taxi; clearly stating that the Air Taxi could expect higher when clear of that traffic. From watching the Falcon I saw that the Air Taxi climbed from FL265 to FL275 busting their assigned altitude. At the same time; another aircraft was checking in on the far left side of my radar scope; so I did not notice the altitude violation. The Air Taxi climbed to FL279 and asked for higher. I then again recalled the traffic and during the transmission I realized that the Air Taxi was now at FL279 and not their assigned FL270. I quickly keyed up again and climbed the Air Taxi to their requested final altitude of FL370 with an expeditious rate. Then I descended the Air Carrier to FL260 to regain separation and assigned an expeditious rate. At this point the aircraft were about 8 miles apart; but converging. During this time the Air Taxi began to descend because I am guessing at some point they realized their mistake. It probably happened sooner; but there is a delay in the radar data; so I was working with old information. Very shortly the Air Carrier stated they were in an RA climb. I then told the Air Taxi to immediately turn 30 degrees to the left. I clearly lost my 5 mile/1000 ft separation requirement and at this point I was just trying to keep the aircraft safe and prevent a collision. From the information I gathered from the Falcon; at the closest point the aircraft were about a mile and 100ft apart. I did not give the Air Taxi the brasher because I was quite shaken at this point; but the next controller did. If the Air Taxi would have just followed instructions to begin with; none of this would have happened.


Second narrative: Level at FL280; ATC advised us that we had traffic; an Air Taxi at 10 o'clock and that he was restricted below us to FL270. I heard the Controller advise an Air Taxi that he had traffic at 1 o'clock; an Air Carrier at FL280; and to expect higher when clear. Shortly afterward I heard the Air Taxi request a higher altitude. The Controller responded with 'I see you blew your altitude; climb and maintain FL370'. The controller then cleared the Air Taxi to 'expedite to FL370'. We then received a clearance to descend to FL260 and to 'expedite all the way down'. I selected FL260 in the altitude window and selected Level Change to ensure an idle descent. I also noted traffic low to my left on the TCAS that was less than 1;000 feet below us and climbing in very close proximity to us. I asked my First Officer (FO) to confirm our descent clearance with ATC and received a TCAS TA almost immediately followed by a 'CLIMB CLIMB CLIMB' RA. I immediately disconnected the autopilot and auto throttles and complied with the TCAS cues; and my FO advised ATC we were complying with a TCAS RA and climbing. The controller then issued an immediate 30 degree left turn to the Air Taxi. By now it was pretty hard to not see the Air Taxi streaking across our wind screen climbing like a homesick angel. TCAS finally declared 'Clear of Conflict'; received clearance to maintain FL280 and proceeded without further incident.I believe that in this case the TCAS placed us in closer proximity to the Air Taxi. Once we had visual contact with the traffic it was obvious that we weren't even close to out-climbing it; and even though we were following a TCAS climb directive; the other aircraft out-climbing us is what cleared the conflict.


Synopsis: ZLA Controller and two flight crews describe a serious airborne conflict which developed after an air taxi inexplicably climbed from their assigned FL270 into an air carrier at FL280. The aircraft at their closest were 100 feet vertically and about 1 mile horizontally.