Date: 201603
Local time of day: 1801-2400
Location: ZDV.ARTCC, CO
Aircraft: Embraer Phenom 300
Operator: Corporate
Operating under: Part 91
Flight plan: IFR
Mission: Passenger
Flight phase: Climb; Initial Climb
Airspace: Class A ZDV
ATC / advisory: Center ZDV
Second aircraft: B737 Undifferentiated or Other Model
Reporter organization: Government
Reporter function: Enroute
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Situational Awareness
Second reporter function: Enroute
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
Result: Air Traffic Control Separated Traffic; Air Traffic Control Issued New Clearance
Contributing factors: Human Factors; Airspace Structure; Procedure
Primary problem: Procedure

Narrative: I was conducting On the Job Training (OJT) instruction on the radar associate position at the time. Sector initiated a handoff on Aircraft X; departing and climbing to 26;000 feet to the northeast. The radar controller acknowledged Aircraft X and climbed the aircraft to 27;000 feet; then shortly after issued a climb to 33;000 feet. During this time; the adjacent sector had started a handoff on Aircraft Y; departing westbound. The data block on aircraft x showed temporary 26;000 feet. Once the radar controller decided these two aircraft were in potential conflict; he advised Aircraft X that he 'needed them through 27;000 feet in 30 seconds.' during this entire scenario; not once did the adjacent sector call us regarding either of the two aircraft. Aircraft X indicated 26;800 feet when the radar controller asked the aircraft to 'say altitude leaving.' Aircraft X responded '27;200 feet' just as separation appeared to have been lost.Unfortunately; this is a common occurrence when working this sector. The adjacent sector has a habit of climbing two aircraft to 26;000 feet and handing them off to this sector with no positive separation ensured. Many times they take it a step further and actually switch both aircraft to our frequency. I assume they are expecting that most 'ski country' departures are high enough performing to 'get above' the departure.This is not an uncommon scenario. I have personally tried to address this by bringing it to my front line manager's attention when it happens. This has been the subject of 'crew breakouts' more than once. I have not noticed a decrease in the frequency of this behavior. It is always a challenge to work with the adjacent sector when any kind of significant volume or complexity exists. It is very common to receive aircraft on headings and assigned speeds with nothing being coordinated. Perhaps it has to do with the fact that this sector deals with low volume and low complexity for much of the year. Then during ski season; they are behind the curve.


Second narrative: I was working the radar position while training was in progress on the Radar Assist position. We were working a busy session with many departures as well as overflights. It is common to have many aircraft on headings and to use altitude leaving due to many head on climbing and descending situations. This was no exception. In the middle of this I was handed Aircraft X departing climbing to 26;000 feet. I climbed Aircraft X to 27;000 feet due to overflight traffic and moved on to do other tasks.I was alerted to the situation when Conflict Alert went off and I saw the alert flashing on my scope. I saw Aircraft X out of 26;100 feet climbing slowly with Aircraft Y head on level at 26;000 feet. The aircraft were about 1 minute apart from losing separation. I told Aircraft X to be at 27;000 feet in 30 seconds and climbed Aircraft X to 31;000 feet to ensure a fast rate of climb. When the aircraft were 5 miles apart I observed Aircraft X at 26;800 feet and Aircraft Y at 26;000 feet. I attempted to get a report from Aircraft X but by the time they reported out of 27;200 feet the targets had just lost separation. I believe the final result was 4.5 miles and 800 feet. It was too close to call while on position but the sector team decided to turn it in any way since it was a very close and very dangerous situation. Going back and looking at the radar replay; the other sector did not use altitude leaving rules so we had no form of positive separation. Aircraft Y appeared to have been cleared to 26;000 feet while Aircraft X was still at 25;800 feet.This is a recurring issue with that Sector controllers. Little or no separation is used with aircraft departing these airports in conflict. It is common to have two aircraft head on climbing to the same altitude. This isn't always an issue but we don't consistently get timely communication with the aircraft to solve conflicts. I wasn't even aware that there was a head on situation until after conflict alert went off. That is never a situation that one controller should put another one into. There was absolutely no reason for this situation to have happened aside from missing traffic.This makes me believe that the complexity is too great for that airspace and for an area that doesn't consistently see busy traffic. I don't know if this is a training issue or if this is simply a matter of that Area only having a few weeks of intense traffic but aircraft in the ski country area are constantly being handled in an inefficient; if not dangerous manner. Aircraft are constantly in conflict but appropriate steps are not always taken to insure positive separation. It is also important to note that their sector was combined with another sector during this time. Their sector had a Radar Controller side; Radar Assist Controller; and Tracker Controller but nobody was aware of this event beyond our sector control team.I'm not sure if new procedures for these airports need to be implemented or additional training be required for controllers using approved positive separation like altitude leaving. This is a recurring issue that has caused a great deal issues for all parties involved but nothing has been done to fix it in an effective way. It has improved over the years but additional steps need to be taken to insure a safe environment for the flying public in this area.


Synopsis: ZDV ARTCC Sector controllers were handed off two aircraft on converging routes at the same altitude. The reporters state this is a common occurrence of aircraft received from a particular sector.