IAI1124/1124A Westwind
Flight Crew Last 90 Days 75; Flight Crew Total 3000; Flight Crew Type 300
Physiological - Other; Distraction
Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Flight Crew Took Evasive Action; Flight Crew Became Reoriented; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Returned To Clearance
1) How the problem arose - under extreme turbulence we were cleared to initial approach altitude of 3;000 FT. The altitude was inadvertently set to 2;000 FT.(2) Contributing factors - extreme turbulence and hard to see the panel.(3) How it was discovered - Tower told us Approach reported a low altitude alert was given on our aircraft.(4) Corrective action - saw altitude was inadvertently set then reset to correct altitude and climbed immediately back to 3;000 FT for the initial approach altitude; then continued approach to landing.(5) Summary - due to a diversion because of weather and fuel situation after holding for approximately 30 minutes; the decision was made to divert. Turbulence was extreme on approach and the altitude was misentered for initial approach altitude; but was corrected when Tower advised us of low altitude alert.
[This report contains no additional information.]
During approach an IAI Westwind 1124 operating under FAR Part 91 descended 1;000 FT below assigned altitude; generating a Low Altitude Alert from the Tower.