HS 125 Series
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Situational Awareness; Workload; Distraction
Deviation / Discrepancy - Procedural Landing Without Clearance; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter CFTT / CFIT
Flight Crew Became Reoriented
Human Factors; Weather
Approaching SDL we descended through a cloud layer with moderate turbulence and icing; breaking into the clear at 8000' MSL. We were trying to descend and slow for traffic taking the runway. We were approaching runway 21 from the northeast when we broke out and reported runway in sight and we could see the high rocky terrain on the approach end of 21; all the while still in moderate turbulence. We were cleared for the visual to 21 and handed to Tower on 119.9. About that time we mistakenly selected 119.0 and got a terrain warning; then seconds later we got wind shear with + or - 15 to 20 knots. The winds on landing were 27017G26. With all that was going on we never contacted Tower until we got on the ground. We were never behind or unsafe but with several abnormal issues going on we neglected to do the normal function of communicating. I believe this could have been avoided with a more detailed briefing that follows the steps from approach to landing.
On approach into SDL runway 21; we were descending from altitude in and out of the clouds with icing conditions. During the descent we broke out of the clouds and the visibility was 10 miles or greater. We were in moderate to severe turbulence with high terrain in the vicinity of the airport at which point we were cleared for the visual 21. During the gear down check list; I was given a frequency for Tower. At that time I input the frequency into the number two com. At the same time we hit severe turbulence and also got a terrain warning. As we corrected the warning and continued the approach I pressed the wrong button on the radio and never switched to Tower; and mistakenly used the cleared for the visual as cleared to land. During the turbulence I was having a difficult time in programming the FMS as well as the radio. The visibility was unrestricted below 7000' and there were no other aircraft in or on the runway at the time of approach and landing. On the approach it was a very high work load maintaining the aircraft's stability and configuration for airspeed and descent rate for a safe landing.
H25B flight crew reported landing without clearance because of a high workload; including a GPWS terrain warning and severe turbulence.