University of Kansas MERIDIAN UNREG

Summary

On 19 December 2011 at about 03:17 local time, a University of Kansas MERIDIAN registered UNREG, operated by University of Kansas, was involved in an accident near McMurdo, Antarctica. The number of people on board was not recorded. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

19 December 2011 at 03:17

Classification

Accident

Location

McMurdo, Antarctica

Nearest airport

Pegasus McMurdo, Antarctica (NZPG)

Coordinates

-77.0000, 166.0000

Aircraft

University of Kansas MERIDIAN

Registration

UNREG

Category

Airplane

Engines

1

Operator

University of Kansas

Operating rule

Non-U.S., Non-Commercial

Purpose of flight

Flight Test

Phase of flight

Not recorded

Route

McMurdo → McMurdo

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

DCA12CA023

Injuries not recorded.

an aerodynamic stall induced by an inadvertent autopilot Home command. The Home command was entered following a loss of the direct radio link due to improperly set failsafe settings, and an unintentional latching of Home mode from an earlier functionality test.

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

Read the full NTSB narrative

On December 20, 2011, at 1517 local time (0317, December 19, Coordinated Universal Time (UTC)), an experimental Meridian unmanned aerial system (UAS), built, owned, and operated by the University of Kansas under a National Science Foundation grant, crashed on final approach to the Pegasus Ice Runway at McMurdo Station, Antarctica. The aircraft was substantially damaged, and there were no injuries or ground damage. The aircraft was returning from a flight test in which the airplane was controlled via an over-the-horizon satellite (Iridium) control link. Approximately 60 seconds prior to the accident, the pilot took over direct control of the aircraft via 72MHz radio control (similar to a model airplane). On final approach, as the aircraft was commanded low power and nose down pitch, the aircraft lost the 72MHz link, and as programmed the flight control system switched to an autopilot Manual (Assisted) mode. The Manual (Assisted) mode commanded the aircraft to predefined “failsafe” settings of 100 knots airspeed and neutral controls, resulting in about 27 degrees of nose up pitch change. After about one second, the control mode was changed from the failsafe setting to the Home mode, which was inadvertently left latched due to a functionality test earlier in the flight. The Home mode commanded the airplane to climb toward the home waypoint, which was over the runway, and enter an orbit. The airplane was well below the home altitude and at low airspeeds for approach. The command resulted in a power-on stall and steep nose down descent. Radio control link was re-established but too late to recover from the stall. The airplane impacted the ice runway and was substantially damaged.

Quoted verbatim from the NTSB record.