Narrative:

Phx was on west flow with a high arrival rate. A large storm from the southeast was rolling in with a dust storm north of it heading towards iwa. I had two IFR inbounds that iwa tower approved to land opposite direction because the dust storm was now on a 7 mile final. My next two IFR inbounds did not want to attempt the active runway so iwa changed runways. I was making point outs to the finals sectors to go further north than usual because of the dust storm.at the time I got a handoff aircraft X was issued a 170 heading and 10000 feet. Aircraft X was on vectors in a box holding pattern waiting for pilot to say intentions. Iwa now had 1/2 mile visibility. Aircraft X didn't respond to the initial heading and altitude I issued as I moved on to another clearance for a different airplane. Aircraft X came back and asked for a southbound heading for weather. I reissued 170 heading and 10000 feet. I heard the read back and moved on. A few minutes later I realized he was at 8200 feet in the 9800 foot minimum vectoring altitude. I asked aircraft X for their current altitude and to say assigned altitude and to stop his descent. He responded with 7000 feet as his assigned altitude. After listening to the replay; the pilot was issued 10000 feet and read back 7000 feet. I then climbed him back to 10000 feet and continued holding for a few more minutes until he diverted. The low altitude alert never went off.

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Original NASA ASRS Text

Title: P50 Controller vectoring an aircraft in a holding pattern reported an aircraft assigned 10;000 feet read back 7;000 feet and descended to 8;200 feet which was below the Minimum Vectoring Altitude.

Narrative: PHX was on west flow with a high arrival rate. A large storm from the southeast was rolling in with a dust storm north of it heading towards IWA. I had two IFR inbounds that IWA Tower approved to land opposite direction because the dust storm was now on a 7 mile final. My next two IFR inbounds did not want to attempt the active runway so IWA changed runways. I was making point outs to the finals sectors to go further north than usual because of the dust storm.At the time I got a handoff Aircraft X was issued a 170 heading and 10000 feet. Aircraft X was on vectors in a box holding pattern waiting for pilot to say intentions. IWA now had 1/2 mile visibility. Aircraft X didn't respond to the initial heading and altitude I issued as I moved on to another clearance for a different airplane. Aircraft X came back and asked for a southbound heading for weather. I reissued 170 heading and 10000 feet. I heard the read back and moved on. A few minutes later I realized he was at 8200 feet in the 9800 foot Minimum Vectoring Altitude. I asked Aircraft X for their current altitude and to say assigned altitude and to stop his descent. He responded with 7000 feet as his assigned altitude. After listening to the replay; the pilot was issued 10000 feet and read back 7000 feet. I then climbed him back to 10000 feet and continued holding for a few more minutes until he diverted. The Low Altitude Alert never went off.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.