Loral GZ-22 N4A

Summary

On 28 October 1999 at about 22:41 local time, a Loral GZ-22 registered N4A was involved in an accident near Mogadore, Ohio, United States. 2 people were on board and one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

28 October 1999 at 22:41

Classification

Accident

Location

Mogadore, Ohio, United States

Nearest airport

Wingfoot Lake Balloonport (4OH6)

Coordinates

41.0498, -81.4001

Aircraft

Loral GZ-22

Registration

N4A

Category

Blimp

Engines

2

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Other Work Use

Phase of flight

Not recorded

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

IAD00LA002

1 person had minor injuries.

The failure of the flight control system manufacturer to meet design (hardness) specifications that resulted in stripped splines.

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

Read the full NTSB narrative

The pilot of the fly-by-wire airship flew several traffic patterns and approaches from both the pilot and co-pilot stations. After he departed the traffic pattern and leveled the airship, it entered an uncommanded, descending left-hand turn. The control panel displayed no indication of a malfunction, and emergency and troubleshooting procedures failed to regain control of the airship. The airship landed in trees, and both the pilot and the technician on board escaped injury. Metallurgical examination of the actuators that convert electrical signals to mechanical flight control inputs revealed that the splined shafts on the output side of the starboard actuator were almost completely stripped, and provided no flight control input. The gear teeth of the splined shafts on the output side of the port actuator were worn to 25 percent of their original thickness, and did not provide full flight control input. Hardness testing revealed the output shafts of both the port and starboard actuators did not meet the manufacturer's specified hardness requirement. The manager of the airship fleet said the one-of-a-kind airship would not be rebuilt.

Quoted verbatim from the NTSB record.