Date: 201705
Local time of day: 1801-2400
Location: ZKC.ARTCC, KS
Aircraft: Cessna Twin Piston Undifferentiated or Other Model
Flight plan: IFR
Flight phase: Cruise
Airspace: Class A ZKC
ATC / advisory: Center ZKC
Second aircraft: Cessna Citation Undifferentiated or Other Model
Reporter organization: Government
Reporter function: Enroute
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Distraction; Communication Breakdown; Situational Awareness; Workload
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Detector: Person Air Traffic Control
When detected: In-flight
Contributing factors: Human Factors; Procedure; Staffing; Weather
Primary problem: Weather

Narrative: I was working [the] sector alone with weather impacting nearly the entire sector. There was extreme weather on both sides of the sector and multiple aircraft were deviating through. Aircraft X checked on at FL250 requesting lower; that wasn't my airspace so I called sector 27 and got control. I descended him to FL230 per request and he read it back. All aircraft were deviating both east and west as they worked their way around the weather. I had several aircraft on frequency all deviating and all climbing and descending through each other. Aircraft Y came to me from approach and I tried to stop Aircraft Z below the jet. I was going to jump the jet above but was unable to get a response in time from Aircraft Z. I went to Plan B and used vectors and 160/170. At that same time [a flight of four military aircraft] requested immediate descent due to possible icing. Their first request was stepped on; I was able to get them to 190B200 because Aircraft Z was level at 170 and we had low altimeters. I attempted to climb Aircraft Z but noticed that the trailing aircraft of [the flight of four] were very far behind the lead; so I let him know that he could have higher shortly. While my focus was on these three aircraft I noticed that Aircraft X was not at his assigned altitude of FL230. I asked his altitude several times and he finally got back to me and said he was correcting. He was right on the edge of the most severe weather that I had in my sector and I was worried he was unable to control his aircraft. After I got a hold of him he said he noticed what he did and said he was correcting. I still was showing him at 217 and he reported level at 220. At that time [the flight of four] also reported level at 200 as they were around the weather. I wasn't sure if the pilot got disoriented or lost control for a little bit and my initial concern his ability to fly the plane straight and level. I issued several traffic alerts to the [the flight of four] and Aircraft X. I'm not sure if separation was lost because they both reported level; but my main concern was the safety of the two flights involved; and their ability to continue to fly through the weather. The weather was called for both Aircraft Z and I know Aircraft X did not have any radar on board. I think the pilot of Aircraft X got disoriented and scared and what happened was a result of that.There were a couple point outs that I had someone give to 27 verbally because I was too busy and eventually was able to point them out.




Synopsis: Kansas City Center Controller reported a possible loss of separation due to an aircraft descending through an assigned altitude and deviating for weather.