PA28 pilot reported an icing encounter that necessitated a deviation from an assigned altitude.

Attributes
ACN	1746169
Time
Date	202006
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Tower
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	PA-28R Cherokee Arrow All Series
Operating Under FAR Part	Part 91
Flight Phase	Descent
Route In Use	Direct
Flight Plan	IFR
Person 1
Function	Single Pilot
Qualification	Flight Crew Instrument
Experience	Flight Crew Last 90 Days 19 Flight Crew Total 484 Flight Crew Type 479
Events
Anomaly	ATC Issue All Types Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Inflight Event / Encounter Loss Of Aircraft Control Inflight Event / Encounter Weather / Turbulence

Narrative:

ATC requested that I descend from 8;000 ft. I entered the clouds and picked up ice very quickly. Pitot iced over and lost altitude & vsi (vertical speed indicator) gauges. I began trouble-shooting; immediately turned on pitot heat. Immediately turned on defroster for windscreen de-icing (very busy in a bumpy situation) and most important to keep cool and wings level. Lost altitude and was reminded by ATC (air traffic control) not to deviate from assigned altitude. I informed ATC that I was rapidly picking up ice and was busy resolving. I was aviating and navigating; but possibly not communicating as clearly I could have. I was busy being safe... Losing my altimeter was not helpful at that time. ATC requested that I call them after landing at ZZZ airport. Proceeded to perform the RNAV 1 (area navigation) and called ATC on the ground. It was summer and I was not expecting ice to build up so fast.

Original NASA ASRS Text

Title: PA28 pilot reported an icing encounter that necessitated a deviation from an assigned altitude.

Narrative: ATC requested that I descend from 8;000 ft. I entered the clouds and picked up ice very quickly. Pitot iced over and lost altitude & VSI (Vertical Speed Indicator) gauges. I began trouble-shooting; immediately turned on pitot heat. Immediately turned on defroster for windscreen de-icing (very busy in a bumpy situation) and most important to keep cool and wings level. Lost altitude and was reminded by ATC (Air Traffic Control) not to deviate from assigned altitude. I informed ATC that I was rapidly picking up ice and was busy resolving. I was aviating and navigating; but possibly not communicating as clearly I could have. I was busy being safe... Losing my altimeter was not helpful at that time. ATC requested that I call them after landing at ZZZ airport. Proceeded to perform the RNAV 1 (Area Navigation) and called ATC on the ground. It was summer and I was not expecting ice to build up so fast.

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.