Date: 202102
Local time of day: 0601-1200
Location: PCT.TRACON, VA
Flight conditions: IMC
Weather elements / visibility: Icing
Light: Daylight
Aircraft: EMB ERJ 145 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class D PTC
ATC / advisory: TRACON PTC
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown; Time Pressure
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Detector: Automation Aircraft Terrain Warning; Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action
Contributing factors: ATC Equipment / Nav Facility / Buildings
Primary problem: ATC Equipment / Nav Facility / Buildings

Narrative: While on approach into CHO we were being vectored by Potomac Approach on frequency 126.4. We were on a right downwind being vectored for the ILS Runway 03. It was IMC conditions with light to moderate rime ice accumulating on the aircraft. At 3;000 ft. MSL we were given a right turn; a base turn; toward the final for Runway 03. We were just outside; south of the fix WULDU. I noticed were getting close to the localizer course for the final approach; and Potomac had not issued a turn for us to intercept the approach. I prompted Potomac approach and tried to establish communication. There was no answer on 126.4. I prompted again; and still there was no answer from Potomac. At this time we crossed over the localizer course without a turn to intercept given from Potomac. I had guard (121.5) already tuned in on comm 2. I heard Potomac approach trying to hail us on 121.5 on guard and advised us to switch to frequency 132.85. I switched to 132.85 and they gave us an immediate turn to the right to reestablish us on the localizer course. The coverage on 126.4 for the area was lost and I confirmed that with Potomac that we were trying to contact them. Apparently a Learjet overheard us trying to transmit on 126.4 and relayed it to Potomac. Once we re-established communication; Potomac gave us that right turn to intercept but it was 'too late'; The aircraft GPWS detected terrain and gave us a 'Terrain; Terrain' 'PULL UP' audio warning. I directed the First Officer to Climb the aircraft and disregard the instruction from Potomac Approach. We climbed up to 3;500 ft. MSL and got the aircraft clear of the terrain. I advise Potomac what had happened and that we were unable to intercept the approach from the vector that they gave us. Potomac than gave us more vectors to get re-established on the approach. From there we landed with no further issues. I conversed with Potomac about the drop in radio coverage on frequency 126.4. They agreed and confirmed that they could not hear us and we could not hear them on 126.4.[Problem was identified by] flight crew scan. No communication from ATC have prompting them several times. Having Guard (121.5) on comm 2 and have our audio on to re-establish communication. Being aware of the terrain in the area and seeing the aircraft GPS position on The Jepp charts. [Cause was] loss of two-way communication on 126.4 between our aircraft and Potomac approach lead us to not receiving an instruction to intercept the localizer course. Without that instruction we continued on our heading and had to re-establish communication via guard and switch to a different frequency that has radio coverage in the area. All of this lead to vectors in an area with terrain and caused us to be in a position where the aircraft GPWS was activated. [We] contacted ATC. Followed the aircraft GWPS system and climbed to avoid terrain. Advised ATC that we were responding to a GWPS annunciation. [Suggest] better radio coverage equipment is needed for the area around CHO. Suggest the importance of ALWAYS monitoring 121.5 on Comm 2 for flight crews.




Synopsis: EMB-145LR Captain reported communications loss ATC resulted in a GPWS warning requiring evasive action.