E10 Controller described a TCAS RA event apparently resulting from failed intra/inter facility coordination and incomplete strip markings.
Synopsis
E10 Controller described a TCAS RA event apparently resulting from failed intra/inter facility coordination and incomplete strip markings.
Narrative
I was working FD/CD. NID called for P2 clearance for fighter jet X; fighter jet Y; [and] fighter jet Z. I cleared all 3; P2. I then realized what I did because the over flight was at or above FL310 doesn't have to miss Panamint; and [also] at or above FL240 over Isabella. I told the RADAR position I messed up with the P2 clearance and I left it up to him to tell NID Tower what he wanted since the over flights were Owen; Saline; [and] Panamint at or above FL370 and Isabella at or above FL240. He called NID Tower back and gave the aircraft P2 with Isabella at or below FL230. I thought I heard P2 at or below FL230 so I wrote that on the strip. The RADAR Controller briefs the next Controller and told him the P2 was at or below FL230 on the strip. The RADAR Controller lowered the over flight to [the] north to at or above FL240. After another relief; Air Carrier XA was [at] about NID 045/040 at FL260 and reported a TCAS/RA climb. Air Carrier XA climbed to FL266. Fighter jet X climbed to FL260 with fighter jet Y at FL240 below fighter jet X. Air Carrier XA had the fighter jet flight in sight. The RADAR Controller did not issue traffic because he was talking to other aircraft in the area. I should have told NID Tower myself that the fighter jets were cleared P2 at or below FL230. I left it to the Controller to decide what to give to the Tower. I should have left the strip alone and let the RADAR Controller write what he told the Tower.
Second reporter narrative
I was working all the facility RADARs combined and had been on position for a short time. The previous Controller told me fighter jet X; 2/F18s; were cleared FL230 and below. The flight strips for the F18s showed they'd been cleared FL230 and below. The status information board showed we were running over flights at and above FL240. Air Carrier XA was in level flight at FL260. At the time of the incident; most of my traffic was in the Antelope section of the facility. The two F18s were the only players in the restricted airspace. They called to confirm a restriction in the Isabella work area. I told them they were cleared FL230 and below. I don't remember if I said at the time if they were cleared 'Isabella at and below FL230' or 'Poncho 2 at and below FL230' (the Poncho 2 would have included all 4 work areas); but either way I was under the impression they weren't issued an altitude above FL230. The fighter jet flight stayed below FL230 the entire time they were working over R2524 and told me they were moving to Panamint work area. While they were in the area; Air Carrier XA reported a TCAS alert and said they were climbing 500 FT and had traffic in sight. This is when I noticed the fighter jets were above FL260 and I told them their clearance was only FL230 and below. They said they were only restricted [in] Isabella below FL230. I re-cleared the flight [for] Pancho 2 below FL230. It seems the problem started two controllers before I took the sector. Flight Data issued a standard Poncho 2 to the fighter jet flight and the Controller at the time called NID Tower to restrict the flight in the Isabella work area at and below FL230. Over flights for the complex were FL370 at the time. He neglected to mark the flight strip properly and it showed a clearance for a Poncho 2 all work areas at and below FL230. When he was relieved he told the relieving Controller the fighter jet flight was cleared FL230 and below. Once all other flights had left the airspace the relieving Controller lowered the complex over flights to FL240 thinking the fighter jets were only cleared FL230 and below. When I accepted the position from this Controller; he told me the flight was cleared FL230 and below and everything seemed standard for that hour of the evening. There were no indications of a problem. I don't know how quickly the F18s climbed above FL230 to FL260; as the first indication I had of a problem was the TCAS call from Air Carrier XA. The error could have been avoided if the first Controller had marked his flight strips properly or told the Controller relieving him of the amended clearance issued to the fighter jets. I would recommend a heightened awareness of the importance of strip marking and relief briefings.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.