PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 12; Flight Crew Total 285; Flight Crew Type 285
Communication Breakdown
ATC Issue All Types; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors
Given clearance to descend and maintain what we understood as 3000. We read back 3000 and were not corrected. Upon descent through 3600 ATC advised us that we had descended below their assigned altitude of 5000. At the time of the correction; we climbed to 4000 and continued the approach.
PA28 pilot reports being cleared to descend to 3000 feet by PDX Approach (P80) and reading it back without correction. Passing 3600 feet ATC advised that the clearance was to 5000 feet and to climb back to 4000 feet.