Date: 201405
Local time of day: 1201-1800
Location: ZSU.ARTCC, PR
Aircraft: Widebody; Low Wing; 4 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZSU
ATC / advisory: Center ZSU
Second aircraft: Large Transport
Reporter organization: Government
Reporter function: Enroute
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Distraction; Training / Qualification; Communication Breakdown
Second reporter function: Enroute; Trainee
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: Taxi
Result: Air Traffic Control Separated Traffic
Contributing factors: Human Factors; Equipment / Tooling; ATC Equipment / Nav Facility / Buildings
Primary problem: ATC Equipment / Nav Facility / Buildings

Narrative: Aircraft Y was southbound on L462 at flight level 370. After the aircraft progressed [to] DAWIN the pilot requested to climb to FL390.  I verified with the D-side who was training at the time if Aircraft Y was good for climb to FL390 and waited for him to coordinate the revised altitude with TTPP.  He said yes and I ask again if there was anyone behind him to confirm.  He said no; and then I issued the climb clearance.  At some point while this was happening Aircraft X was trying to call but the transmissions were breaking up due to a frequency blind spot in the area and I was distracted with switching transmitters and receivers to establish communications with Aircraft X.  To make matters worse our long range radar is out of service for maintenance so coverage is limited in that specific area.  That is why I ask for the Developmental to double check if Aircraft Y was good for climb. When Aircraft Y was climbing out of FL385; Aircraft X appeared on radar about 7 miles behind and to the west of Aircraft Y westbound.  I advised Aircraft Y about the unidentified traffic and ask if he had to respond to an RA.  The reply from Aircraft Y was negative.I could have made eye contact with the trainer to ensure that Aircraft Y was good for climb.  The frequency blind spots really need to be fixed and Management needs to be more proactive about collecting data for resolution.  The workforce has developed a workaround mentality and will not report it.  If I was not distracted with establishing comms; I would have reached to mark the strip of Aircraft X and seen the traffic.


Second narrative: The sectors were combined at the time that training commenced; the sector started to become very saturated and the traffic level was rapidly rising.  My trainer and I decided to notify the Supervisor that it would be best to de-combine the sectors soon.  The sectors were de-combined shortly thereafter.  This sector is primarily responsible for non-radar separation and helping set-up the Radar controller with adequate separation leading up to radar-identification.  ZNY Controller called to coordinate Aircraft X at a boundary time (which was about equidistant between two actual boundary fix points (DAWIN & OBIKE)).  I scanned for traffic and approved the Aircraft X at FL380; boundary time and Mach number; as there was only one other aircraft at FL380 with adequate lateral separation and the aircraft was vertically separated from all other traffic in the non-radar bay.  ZNY later called to coordinate the Aircraft Y at DAWIN flying southeast bound at FL370.  The proper traffic search was applied and I approved the Aircraft Y at FL370 and subsequent DAWIN time; as there was more than enough crossing times and in-trail times for the two other aircraft at FL370; otherwise the aircraft was vertically separated from all other aircraft in the non-radar bays. I was monitoring the R-side and overheard the Aircraft Y check-in on the frequency requesting for FL390.  I jumped on the landlines to call Piarco ACC; to coordinate the level revision; as I had already previously coordinated the Aircraft Y at FL370.  Piarco ACC approved the revised level of FL390.  An experienced D-side would be expected to implement the correct strip-markings (to show the re-coordination) and begin another thorough traffic search of the bay (as the aircraft is now requesting a new FL-assignment).  However; with my limited knowledge and experience; I did not perform an adequate traffic search and I told the R-side that FL390 is good with Piarco ACC; however; I now realize that this dialog could be easily misconstrued as if I am acknowledging that the aircraft is clean to climb from FL370 thru FL390.  The R-side then asked me if the Aircraft Y was clear of any other aircraft in trail at the time.  I replied affirmative; as there was proper 'in-trail' spacing between the aircraft in front of Aircraft Y at FL370.  The R-side climbed the Aircraft Y to FL390; almost immediately thereafter Aircraft X checked on frequency a few minutes late and was not tagged up or radar-identified yet.  The R-side immediately realized the situation and asked the aircrafts if they had responded to a TCAS or RA alert (which they replied negative).It is also definitely worth mentioning that the PICO (one of the three primary radar sensors that our radar scopes utilize at ZSU) was out of service (OTS); therefore; the radar coverage of the scopes have many blind spots around the northern parts of the sector and aircraft do not tag-up properly until 20-25 miles into our airspace.  The radio frequencies also have dead spots out in the same area.  My trainer also didn't realize that I had not notified the R-side about the possible crossing situation; and that I should have notified the R-side to wait until he sees Aircraft X on radar and passes before climbing the Aircraft Y through his flight level. There were many contributing factors that led up to the development of this imminent situation.I would recommend that the radar sensors be re-assessed; as it seems that some of the surrounding foreign ATC facilities have better radar coverage than our facility.  Also; the frequency dead spots also need to be re-assessed.Otherwise; there were many contributing factors that went wrong; and slowly built up to a more imminent situation.


Synopsis: Three controllers report of separation loss due to equipment issues related to frequency blind spots and long range radar being released to maintenance.