What aircraft was involved and where did it happen?

The accident on 2005-12-23 involved a Beech 36, registration N5942S, operated by Edwin Mack, at Livermore, CA.

What was the probable cause of the accident?

The pilot's failure to maintain the appropriate glidepath alignment during an instrument landing system approach, resulting in collision with terrain. A contributing factor to the accident was the failure of the air traffic controllers to issue a minimum safe altitude warning (MSAW) alert.

Terrain Collision During Instrument Approach (N5942S)

On December 23, 2005, a Beech 36 (registration N5942S) operated by Edwin Mack was involved in an aviation accident near Livermore, CA. Investigators recorded the probable cause as: The pilot's failure to maintain the appropriate glidepath alignment during an instrument landing system approach, resulting in collision with terrain. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 8 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data API Editorial standards

An airplane collided with terrain nine miles from its destination airport during an ILS approach. The altimeter was found with a loose 10,000-foot pointer.

Introduction

An airplane collided with terrain approximately 9 miles from its destination airport. The pilot had been cleared for the instrument landing system (ILS) approach into the airport.

Flight Path

During the descent, the airplane was below the glideslope but tracking the localizer. The pilot contacted the air traffic control tower controller and was cleared to land. The last recorded radar target for the airplane was at 1,600 feet mean sea level (msl), and the initial impact occurred at 1,400 feet msl. Radar data indicated that the target maintained a descent rate of about 1,100 feet per minute during the last minute of flight and was flying at a radar-derived ground speed of approximately 112 knots.

Air Traffic Control

The en route controller received a minimum safe altitude alert (MSAW), but he had transferred control of the airplane 1 minute prior to the receipt of the initial MSAW alert. The airplane crossed a named intersection at 3,300 feet msl after it was cleared to cross the intersection at 4,000 feet msl while under the en route controller's control. The en route controller did not advise the pilot of the altitude deviation. The air traffic control tower controller did not issue an MSAW to the pilot, even though the equipment was configured to receive MSAW alerts. The tower controller said that he did not recall receiving the alerts, and no recording was available to indicate whether or not an aural MSAW alert was received. An evaluation of the operation of the MSAW alerting system following the accident showed that it was functional.

Aircraft Examination

Examination of the airframe and engine did not reveal any mechanical anomalies to preclude normal operation. Metallurgical examination of the altimeter showed that the 10,000-foot pointer was not at its correct position at the time of impact and, at an undetermined time prior to the accident, moved aft on its shaft and became loose. The effect of the 10,000-foot pointer on the pilot's flight performance could not be ascertained with the available evidence.

Controlled flight into terrain

2005-12-23: Beech 36 (N5942S) — Edwin Mack — Livermore, CA

Introduction

Flight Path

Air Traffic Control

Aircraft Examination

More accident analyses

Introduction

Flight Path

Air Traffic Control

Aircraft Examination

Related events

Same aircraft family

More accident analyses