What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
N199Y was VFR at 16,500 ft. southwest bound, about 15 miles north of westminister VORTAC, N4 was southeast bound, level at FL180 with a pilot's discr etionary descent clearance to 12,000 ft. when N4 was passing two miles behind N199Y on divergent courses, N4 began to decent, ntap data showed the aircraft reached 17,600 ft. for one swweep of the radar display and then climbed back up to FL180. Given that seperation was ensured and that the targets would not merge, no traffic advisory was required as per FAA order 7110.65L. The atc's involved were working 13 other aircraft at the time of the maneuver. The pilot of N4 called this facility to advise us of the maneuver he executed. The pilot said he received a traffice advisory from his TCAS and clumbed back up to FL180.
As the FAA filed it
N199Y WAS VFR AT 16,500 FT. SOUTHWEST BOUND, ABOUT 15 MILES NORTH OF WESTMINISTER VORTAC, N4 WAS SOUTHEAST BOUND, LEVEL AT FL180 WITH A PILOT'S DISCR ETIONARY DESCENT CLEARANCE TO 12,000 FT. WHEN N4 WAS PASSING TWO MILES BEHIND N199Y ON DIVERGENT COURSES, N4 BEGAN TO DECENT, NTAP DATA SHOWED THE AIRCRAFT REACHED 17,600 FT. FOR ONE SWWEEP OF THE RADAR DISPLAY AND THEN CLIMBED BACK UP TO FL180. GIVEN THAT SEPERATION WAS ENSURED AND THAT THE TARGETS WOULD NOT MERGE, NO TRAFFIC ADVISORY WAS REQUIRED AS PER FAA ORDER 7110.65L. THE ATC'S INVOLVED WERE WORKING 13 OTHER AIRCRAFT AT THE TIME OF THE MANEUVER. THE PILOT OF N4 CALLED THIS FACILITY TO ADVISE US OF THE MANEUVER HE EXECUTED. THE PILOT SAID HE RECEIVED A TRAFFICE ADVISORY FROM HIS TCAS AND CLUMBED BACK UP TO FL180.