Date: 201606
Local time of day: 1201-1800
Location: PRC.Tower, AZ
Weather elements / visibility: Windshear; Rain
Light: Daylight
Aircraft: Medium Transport; Low Wing; 2 Turboprop Eng
Operator: Government
Operating under: Part 91
Mission: Training
Flight phase: Final Approach
Airspace: Class D PRC
ATC / advisory: Tower PRC
Second aircraft: Small Aircraft; High Wing; 1 Eng; Fixed Gear
Reporter organization: Government
Reporter function: Local; Supervisor / CIC
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Distraction; Workload; Human-Machine Interface
Anomaly: ATC Issue All Types; Deviation - Track / Heading All Types; Inflight Event / Encounter Weather / Turbulence
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Air Traffic Control Provided Assistance; Flight Crew Executed Go Around / Missed Approach
Contributing factors: ATC Equipment / Nav Facility / Buildings; Human Factors; Procedure; Weather
Primary problem: Weather

Narrative: We started to get convective activity northeast of the airport and we observed blowing dust and virga. An aircraft was making an approach to Runway 21L and reported going around due to a windshear alert. After going around the aircraft made right traffic and came back around to successfully land. I then had an aircraft making a practice approach straight in for Runway 21L. The wind started to get very erratic and strong at the airport and I suggested to the aircraft to discontinue the approach and in discussion it was decided the aircraft would hold VFR east of the airport until the cell passed to the west. I then had a [corporate jet] straight in and another air taxi coming in from the west. I told all of the aircraft about the erratic winds and they wanted to come in to make approaches. Our primary wind instruments; the SAWS (Stand Alone Weather Sensors); has been out for a couple of weeks and gave wind checks when I could because and I had to keep going to the back of the room to view the wind from the ASOS. The ASOS was not reliable either as it showed missing off and on throughout the incident. The [corporate jet] went around and I maneuvered him northeast to re-sequence him onto the flow. I was not getting any wind readouts from my ASOS and told the [air taxi] who was next that the wind sock near the approach end was indicating that winds were out of the east and the sock was straight out. The [air taxi] went around and departed east to hold and talk to his company. The [small high wing aircraft] was next to the runway and I suggested Runway 03R since the wind socks were indicating winds out of the east/northeast. The [high wing] concurred and was told to enter the right downwind for Runway 03R. I told the [corporate jet]; who was 5 miles east of the airport; to enter right downwind Runway 03R. None of my wind indicators were working at the time. There appeared to be another wind shift and the wind socks were indicating winds out of the Southwest. I told all of the aircraft and the [corporate jet] was in a position to make straight in Runway 21l so I made him #1 and cleared him to land; again without winds from my instruments. The [high wing] was instructed to enter a left downwind for Runway 21L and #2 to follow the [corporate jet]. The [corporate jet] landed without incident; followed by the [high wing]; and then the [air taxi] was instructed to intercept final for Runway 21L and landed safely. Our SAWS has been out for a couple of weeks and while it is usually a nuisance to have to go back to the ASOS to read off the winds; this was a situation where the absence of ASOS winds prevented me from not only advising the aircraft of accurate wind reports but also allowing me to better plan for landing runways. The CIC position was combined at my position; Local 1; because of minimal staffing on the evening shift. I should have called up the other CIC qualified controller that was on lunch but I was concentrating so hard on the task at hand that I did not think about it until after the fact. I also had to enter a couple of pilot reports during this time period which added to the stress and workload. Fix the SAWS and address inadequate staffing. I plan to have management look at our operation at the time of the incident and see if I could have done anything better. I plan to write up a lessons learned to share with the facility. Having operational personnel enter Pilot Reports is a bad idea as it places an additional burden during times when the operation should be the absolute priority.




Synopsis: PRC Tower Controller reported of constant wind changes and trying to get all aircraft to land safely. Towers SAWS (Stand Alone Weather Sensors) was out of service and the Controller had to cross the room to read the ASOS (Automated Surface Observation System).