During approach an iai westwind 1124 operating under far part 91 descended 1;000 ft below assigned a...

Attributes
ACN	1083078
Time
Date	201301
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Make Model Name	IAI1124/1124A Westwind
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Flight Plan	IFR
Person 1
Function	Pilot Not Flying First Officer
Experience	Flight Crew Last 90 Days 75 Flight Crew Total 3000 Flight Crew Type 300
Person 2
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 42 Flight Crew Total 15000 Flight Crew Type 3000
Events
Anomaly	Deviation - Altitude Overshoot Deviation - Procedural Clearance Inflight Event / Encounter CFTT / CFIT
Miss Distance	Vertical 1000

Narrative:

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.

Original NASA ASRS Text

Title: 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.

Narrative: 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.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

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.