Light Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 300; Flight Crew Total 14000; Flight Crew Type 5000
Communication Breakdown; Confusion; Distraction; Workload
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Flight Crew Took Evasive Action; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors; Weather
While being vectored to the ILS 16 at HPN; I miss heard a vector heading of 270 and descended to 2;000. I read back 170 and a descent to 2;000. While turning the aircraft in moderate turbulence to 170 and descending; I flew into a downdraft and the rate of descent increased and the aircraft showed a low altitude alarm even though I was able to stop the aircraft at 1;900 and climb back to 2;000. The Controller questioned if we were having a problem and asked why we were not on a heading 270. We turned back and a new vector to the ILS 16 we were given with no further comments.
An Air Taxi Captain at 2;000 FT on approach to HPN misunderstood N90 vectors and turned to 170 vs 270 and then; in turbulence; descended below 2;000 FT causing a low altitude alarm.