Date: 201406
Local time of day: 1801-2400
Location: ZNY.ARTCC, NY
Aircraft: Large Transport
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class A ZNY
ATC / advisory: Center ZNY
Second aircraft: Medium Transport; Low Wing; 2 Turbojet Eng
Reporter organization: Government
Reporter function: Enroute; Instructor
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Communication Breakdown; Confusion; Distraction; Training / Qualification
Second reporter function: Enroute; Trainee
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Provided Assistance
Contributing factors: Aircraft; Procedure; Weather
Primary problem: Aircraft

Narrative: Training in progress. Trainee is a new radar trainee with 14 hours at his first sector. Hand off Controller on duty; about to commence a relief briefing. Aircraft X was on a vector to establish a climb to FL320 and at 250 KIAS assigned. Aircraft Y was in level flight at FL240 westbound on J230 east of COPES intersection. Aircraft X was given normal speed and resumed direct MXE to return to course; then switched to next frequency. Relief briefing commenced. Hand off and relieving Controller were discussing heavy J75 restriction which was lightly confusing (other departure fixes were closed due weather and most southbound traffic was being routed J75; placing them over COPES.) Training Controller had interjected a comment about it; and noticed Aircraft X had flattened his climb to gain forward speed. Trainee turned Aircraft Y left heading 240 to avoid; which the pilot did in a timely fashion (there was 10 miles at this point) and called receiving sector 09 to expedite Aircraft X for 500 feet; but the convergence was too steep to maintain 5.0 and 1;000 feet with 100% certainty. There may have been a loss.Greater vigilance by all parties during briefing.


Second narrative: I have approximately 14 hours of training on my first radar sector. I was training at R55. Aircraft X was on a vector west of course and was given a climb from 17;000 FT to FL280 and direct COPES intersection to resume navigation southwest bound on J75. Aircraft X was also assigned a slower than normal speed at one point so his climb rate was excellent. The problem began when Aircraft X was given normal speed which negatively affected the aircraft's rate of climb. Aircraft Y was on J230 level at FL240. The two aircraft were on courses that intersected at COPES. Aircraft X was given a frequency change to sector 09 before the conflict had been resolved and the unsafe situation continued. Upon realizing Aircraft X's climb rate was not sufficient to 'top' Aircraft Y; Aircraft Y was turned left to a 240 heading in an attempt to correct the situation. Also; I called sector 09 to ask the controller to expedite the climb of Aircraft X. This mistake is a direct result of my inexperience. I feel that the unsafe situation could have been avoided with a greater personal understanding of how a changing an aircraft's speed effect's its climb rate.


Synopsis: ZNY Controllers report of a loss of separation between two aircraft due to one aircraft slowing its speed to increase the climb rate.