Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 41
Communication Breakdown; Situational Awareness
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Flight Crew Took Evasive Action
Human Factors; Procedure
On arrival to OKC 17L; cleared the 'visual approach outside of GOLFS waypoint on the ILS; Captain choose your go direct to HANGS'. We were offset to the east approximately 7 NM. Outside of GOLFS; altitude is 4;000 ft; inside to HANGS is 3;000 ft; so Captain dialed in 3;000 ft as we were inside of GOLFS; but we were still offset of the final course. We got an Obstacle Alert at approximately 3;300 ft; approximately 1-2 NM northeast of a tower group depicted on the approach plate. Approach Control called out the towers as the Captain initiated a climb of a couple hundred feet to increase the tower crossing clearance altitude. We could have coordinated and reviewed the approach plate and plan better prior to executing the cutoff of course to final. The towers in question were the highest obstacles on the approach. Additionally; the towers were very difficult to see at night because the lights blended into the city surrounding lights and at times appeared to be straight; lighted roads. A little better briefing and review would have prevented the alert. Aircraft systems worked flawlessly however; as well as ATC involvement helped to gain altitude to increase the altitude crossing safety margin. Fly the instrument approach plate as depicted to avoid any threats is a good idea.
Air carrier flight crew received Obstacle Alert for towers during approach and climbed to avoid them.