Date: 201702
Local time of day: 1801-2400
Location: ELP.Airport, TX
Flight conditions: VMC
Light: Night
Aircraft: Large Transport; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class C ELP
ATC / advisory: TRACON ELP
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: First Officer; Pilot Flying
Anomaly: Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Detector: Automation Aircraft Other Automation; Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: I was pilot-monitoring and we were approaching 40 miles from the El Paso VOR with the airport in sight on a clear windy night. We were descending on the SAMMR3 and still talking to ABQ. ABQ Center's transmission quality had deteriorated and I contacted ABQ to make sure we hadn't missed the hand off to ELP Approach. I held the VHF Radio Comm Test button for squelch control and ABQ answered and handed us off to ELP Approach. I told Approach we were descending on the SAMMR3 and had the current ATIS and requested 26L. I recall he cleared us direct to BUSEY which was on the GPS RNAV approach. We were unable to fly the GPS approach; I asked for a fix on the 26L VOR approach and Approach cleared us direct FEMOL. I entered the fix then selected Direct to FEMOL. After we checked and executed direct to FEMOL.As I was configuring the aircraft; I looked up to see our altitude decreasing below 7;000 feet and I became confused as to our assigned altitude. I asked my flying partner why we were descending to 6000 feet since I had just read the FEMOL crossing altitude of 6900 feet. At the same time we got a transmission from Approach telling us to climb to 8000 feet. I told my flying partner to climb immediately to 8000 feet and we completed the rest of the approach and landing without incident. I recall our lowest altitude was around 6400 feet; I didn't see the radar altimeter tape ever move off its peg; but I did hear the EGPWS annunciate 'obstacle...obstacle' at the same time we got the 'climb to 8000' instruction from Approach.One reason was the workload that had us descending head's down on the arrival. It was a VFR night and we were anticipating a visual approach. My flying partner had a plan to configure the aircraft early to control our speed on the approach. ELP was reporting high winds and I thought that was a prudent choice. We got direct FEMOL from ATC and that was the last transmission we heard until we were told to climb to 8000 feet. Perhaps our workload caused us to hyper-focus and cause BOTH of us to not hear the radio transmissions? Could holding down the squelch button have caused our loss of communications? I looked for additional information in our manuals and found no reference to the test button except as a squelch control. Bottom line: we lost situational awareness in a mountainous area.Charted FMS visual approaches with DME crossing altitudes to 26L would help pilots maintain situational awareness when making visual approaches at night in mountainous terrain. It would also be helpful to add GPS position updating to our INS FMS aircraft. But then we would be able to fly GPS RNAV approaches. I got engrossed in cleaning up the FMS display when I should have been monitoring my flying partner and our altitude more closely. I spent years flying aircraft in and out of mountain airports in the Pacific Northwest. I know firsthand how dangerous an altitude mistake can be. I am very disappointed that we allowed this to happen and I will much more aware in the future.


Second narrative: [Report narrative contained no additional information.]


Synopsis: Air carrier flight crew reported they received an EGPWS obstacle warning during a night VOR Runway 26L approach to ELP.