American Blimp A-60+ N614LG

Summary

On 26 September 2006 at about 16:15 local time, a American Blimp A-60+ registered N614LG was involved in an incident near Manchester, Massachusetts, United States. One person was on board and nobody was injured. The aircraft was slightly damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

26 September 2006 at 16:15

Classification

Incident

Location

Manchester, Massachusetts, United States

Nearest airport

Beverly Municipal Airport (BVY)

Coordinates

42.5603, -70.9106

Aircraft

American Blimp A-60+

Registration

N614LG

Category

Blimp

Engines

2

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Other Work Use

Phase of flight

Not recorded

Route

Beverly → Unknown

Aircraft damage

Minor

Weather

VMC

Light

Day

NTSB number

NYC06IA229

Nobody was injured.

A malfunction of the rudder control system, and the pilot's inadequate preflight inspection. Contributing to the incident was the inadequate design of the chain keeper guards.

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

Read the full NTSB narrative

Prior to departure, the operator's maintenance personnel performed engine starts, runups, and pressure checks. While a mechanic was performing the engine runups, a gust of wind kited the blimp and then forced it down, fully collapsing the wheel strut which was mounted to a truss assembly in the bottom of the control car in close proximity to the rudder control system's idler shaft assembly drive sprockets. The pilot of the blimp who witnessed the incident, discussed the incident with a mechanic, then entered the control car and moved the rudder pedals and control wheel each way to insure that there were no flight control restrictions; however, prior to departure, the pilot did not perform a pre-unmasting flight control check with the aid of the crew chief, which was required by the aircraft flight manual. After applying power and lifting off, the nose of the blimp began to move left. The pilot could not arrest the turn with the application of right rudder. There was no response or feedback from the rudder and the blimp began to drift to the east. The pilot tried to steer using differential power but, when he added power on either engine, it only increased the rate of turn to the left. As the blimp continued to drift eastward while simultaneously turning left, the blimp approached a metropolitan area and the Atlantic Ocean. The pilot then descended so that if the blimp drifted towards an "open" area, a rapid descent could be initiated to the ground. The descent was then continued by venting helium from the blimp's envelope. As the blimp continued to descend the pilot realized that there were no open areas in which to land, and as the blimp was headed into the wind, he brought both engines to idle and held both helium valves full open until the blimp settled into trees. Post incident examination of the blimps rudder control system revealed that the pedal cable/chain assembly had slipped off of the idler shaft assembly outboard drive sprocket. Further examination revealed that the sprocket was partially surrounded by two metallic tabs, one located above the sprocket, and one located below the sprocket, which acted as a chain keeper guard; however, the front and left side of the sprocket was unguarded.

Quoted verbatim from the NTSB record.