MBB BK 117 A-3 N911BK

Summary

On 11 December 2012 at about 02:16 local time, a MBB BK 117 A-3 registered N911BK, operated by Air Methods Corporation, was involved in an accident near Compton, Illinois, United States. 3 people were on board and 3 died. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

11 December 2012 at 02:16

Classification

Accident

Location

Compton, Illinois, United States

Coordinates

41.7475, -89.0958

Aircraft

MBB BK 117 A-3

Registration

N911BK

Category

Helicopter

Engines

2

Operator

Air Methods Corporation

Operating rule

Part 135: Air Taxi & Commuter

Phase of flight

Not recorded

Route

Rockford → Mendota

Aircraft damage

Substantial

Weather

VMC

Light

Night/Dark

NTSB number

CEN13FA096

3 people died.

The inadvertent encounter with inclement weather, including snow, freezing rain, and reduced visibility conditions,  which led to the pilot’s spatial disorientation and loss of aircraft control.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The medical transport helicopter was on a night flight conducted under visual flight rules (VFR) to pick up a patient for transport. The pilot had computer-based weather information available, but it is unknown what information he reviewed before deciding to accept the flight. Weather observation stations along the route of flight were reporting VFR conditions around the time that the pilot accepted the flight. About 17 minutes into the flight, the pilot reported to the receiving hospital's communications center that he was aborting the mission due to encountering inclement weather and was returning to base. Flight track data indicated that the helicopter initiated a right turn at this time, away from a nearby lighted windmill farm toward an area with sparse ground lighting . The flight track then showed a slight descent before the end of the data. The last recorded position was about 0.75 miles east-southeast of the main wreckage site. The helicopter impacted an agricultural field in an inverted, nose-low attitude. Examination of the wreckage revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. Weather data and reports from first responders indicated that the flight likely encountered areas of snow, freezing drizzle, and supercooled liquid water. The lack of ground lighting combined with the precipitation encountered likely reduced the visibility and outside visual references available to the pilot resulting in spatial disorientation and subsequent loss of control.

Quoted verbatim from the NTSB record.