Robinson R44 N440SH

Summary

On 30 September 2018 at about 21:35 local time, a Robinson R44 registered N440SH, operated by Charm City Helicopters, was involved in an accident near Westminster, Maryland, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

30 September 2018 at 21:35

Classification

Accident

Location

Westminster, Maryland, United States

Nearest airport

Parking Garage (NONE)

Coordinates

39.5714, -76.9897

Aircraft

Robinson R44

Registration

N440SH

Category

Helicopter

Year built

2005

Engines

1

Operator

Charm City Helicopters

Operating rule

Part 91: General Aviation

Purpose of flight

Positioning

Phase of flight

Not recorded

Route

Westminster → Westminster

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA18LA269

Nobody was injured.

The pilot's attempt to move the helicopter from a sloped surface after an overspeed event, which resulted in a loss of helicopter control and impact with a car. The overspeed event resulted from misrouted and damaged wiring in the magneto, which subsequently resulted in errant and random signals to the governor.

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

Read the full NTSB narrative

The commercial pilot stated that, during takeoff, the helicopter experienced an engine and main-rotor overspeed and that he then conducted a precautionary landing on a down-sloping portion of a parking deck. Skid marks indicate that only the toes and tails of the landing gear's skids contacted the deck upon landing rather than the full length of each skid tube. The pilot disembarked the passengers and then "attempted to reposition the helicopter to its original spot." He "increased the throttle to return to normal engine rpm," but the helicopter "started spinning uncontrollably." As the helicopter rotated around its mast, the owner/operator, who was standing beside the helicopter, ducked to avoid the tailboom before it struck a parked car. The pilot said that he stopped the engine and the helicopter's rotation by pulling the mixture control. The tail rotor blades and vertical stabilizer sustained substantial damage.   During a test run of the helicopter, when the engine was operating in the governed range, an engine overspeed occurred, similar to that described by the pilot. When the engine was operating with the governor in the "off" position, the engine rpm was controllable with no anomalies noted. Disassembly of the magneto that sent the signal to the governor controller module revealed that the wiring was misrouted and damaged, which resulted in errant, random signals to the governor and the subsequent loss of helicopter control.

Quoted verbatim from the NTSB record.