No fatalities

27 Feb 2009: BELL 407 — Dallas Police Department — Lancaster, TX

Lancaster, TX, United States

On 27 Feb 2009, a BELL 407 operated by Dallas Police Department was involved in an aviation accident near Lancaster, TX. No fatalities were reported. Investigators recorded the probable cause as: The failure of the pilot to maintain adequate main rotor rpm and the failure of the CFI to provide appropriate instruction during the maneuver. This summary draws on records from NTSB; 12 related events involving the same aircraft type or operator are linked below.

SourcesNTSBPrimary reportUpdated 1778583330Data APIEditorial standards

During forced landing practice, a helicopter's main rotor rpm decayed, causing the front of the skids to drop and blades to strike the tail boom auxiliary fins, resulting in blade damage.

Incident Overview

A commercial pilot, under the instruction of a certified flight instructor (CFI), was practicing a forced landing maneuver. After the maneuver was initiated, the CFI observed that the helicopter was not descending quickly enough and therefore limited the amount of collective the commercial pilot could apply. As the helicopter slowed, the main rotor revolutions per minute (rpm) decreased.

Landing Sequence

The rear of the skids made contact with the runway first. Following this touchdown, the main rotor rpm continued to decay. Subsequently, the front of the skids dropped approximately eight to ten inches onto the runway surface. During this landing, two main rotor blades struck both auxiliary fins located on the tail boom.

Damage Assessment

Examination of the main rotor blades that were damaged revealed substantial delamination and inner core damage on both blades. No other damage or injuries were reported in the source.

Operational Context

The flight was a training exercise with a CFI providing instruction. The forced landing practice was conducted on a runway, but no other details about the location, date, or aircraft registration were provided in the source.

Contributing factors

Prop/rotor parameters — Not attained/maintainedInstructor/check pilotPilot