Controllers reported having marginal communication with an aircraft that had entered extreme icing conditions resulting in descent below the MVA and return to departure airport.
Synopsis
Controllers reported having marginal communication with an aircraft that had entered extreme icing conditions resulting in descent below the MVA and return to departure airport.
Narrative
The side took the hand-off on Aircraft X about 2 min west of ZZZZZ intersection. The aircraft checked on & the side issued the altimeter. Just east of ZZZZZ Aircraft X told us they wanted to return to ZZZ; because of icing; and that they wanted to stay at 080. We told them to stand by to coordinate with ZZZ Departure. ZZZ Departure told us to give them a left turn direct @ 080. The side issued that; and the aircraft began descending. I keyed up & issued a low alt alert to let them know the MIA was 080. They kept descending; and didn't acknowledge it. So; I issued the low alt again. They still didn't acknowledge it. So; I asked if they heard the low alt alert; because radio coverage could be spotty there at times. They did; and we shipped them to ZZZ Departure. Departure ended up calling back about 20 min later to tell us that they got into severe icing; and that they [requested priority handling] for them because they ended up descending below there MVAs in their airspace. At the time of the event there was no precipitation painted on the scope; and we had no PIREPs yet.
Second reporter narrative
I took the hand-off on Aircraft X about 2 min west of ZZZZZ intersection. The aircraft checked on; the altimeter was issued. Just east of ZZZZZ Aircraft X told us they wanted to return to ZZZ; because of icing but never stated intensity and that they wanted to stay at 080. We told them to stand by to coordinate with ZZZ Departure. ZZZ Departure told us to give them a left turn direct @ 080. The clearance was issued and the aircraft began descending. My trainer keyed up & issued a low alt alert to let them know the MIA was 080. They kept descending; and didn't acknowledge it. So; my trainer reissued the low alt again. They still didn't acknowledge it. So; my trainer asked if they heard the low alt alert; because radio coverage could be spotty there at times. They did; and we shipped them to ZZZ Departure. Departure ended up calling back about 20 min later to tell us that they got into severe icing; and that they [requested priority handling] for them because they ended up descending below there MVAs in their airspace. At the time of the event there was no precipitation painted on the scope; and we had no PIREPs yet.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.