- Date
- February 3, 1993, 13:27 local (18:27 UTC)
- Place
- Marietta, GA
- Injuries
- 7 fatal
- Damage
- Destroyed
- Phase of flight
- Other
- Aircraft
- N130XLockheed L382E-44K-20
- Weather
- Visual (VMC) · Day
- Status
- Completed · report March 18, 1994
- Report
- Approved by Office Director
- FAA report
- 19930203001389A
- Case key
- 8743
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
Disengagement of the rudder fly-by-wire flight control system resulting in a total loss of rudder control capability while conducting ground minimum control speed tests. The disengagement was a result of the inadequate design of the rudder's integrated actuator package by its manufacturer; the operator's insufficient system safety review failed to consider the consequences of the inadequate design to all operating regimes. A factor which contributed to the accident was the flight crew's lack of engineering flight test training.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
The acft was designed & used as the company's engineering test bed. An evaluation of the fly-by-wire rudder actuator & ground minimum control speed (vmcg) was being conducted. During the final hi-speed ground test run, the acft abruptly veered left & became airborne. It entered a left turn, climbed to about 250 ft, departed controlled flt & impacted the grnd. Investigation revealed a design feature in the rudder actuator that removes hyd pressure within the actuator if the rudder position commanded by the pilot exceeded the actual rudder actuator position for a specified time, and the rudder aerodynamically trails. The actuator previously disengaged in flt. The company did not conduct a system safety review of the rudder bypass feature & its consequences to all flt regimes, nor of the vmcg test. The flt test plan specified that engine power be retarded if the rudder became ineffective. Neither plt had received training as an experimental test plt. The company allowed experimental flt tests at a confined, metropolitan arpt.
Aircraft
- Registration
- N130X
- Reported as
- Lockheed L382E-44K-20 (L382E-44K-)
- Category
- Airplane
- Serial number
- 4412
- Airframe hours
- 6,708
- Engine
- Allison 501-M71K, 5,250 horsepower, turbo prop
- Damage
- Destroyed
- Fire
- On-Ground
- Flight
- Part 91
- Operator
- Lockheed Aero. Systems Co.
- Registered owner
- Lockheed Aero. Systems Co.
- Airworthiness certificate
- Special, Experimental (Special)
- Last inspection
- Continuous airworthiness · March 5, 1991 · 29 hours before
- Departed
- MGE
- Destination
- MGE
- Flight plan
- Company VFR
- Airport
- MGE · Dobbins Afb, runway 11, 10,000 × 300 ft, concrete
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 42
- Certificates
- Airline transport, Flight instructor, Flight engineer
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 1, Valid Medical--no waivers/lim.
- Seat
- Left
- Toxicology
- Performed
- Flight hours
- 7,658 total · 1,260 in this make and model · 5,276 as pilot in command · 74 in the last 90 days · 16 in the last 30 days
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 130° at 3 knots
- Visibility
- 7 statute miles
- Lowest ceiling
- None
- Temperature
- 50 °F, dew point 10 °F
- Altimeter
- 30.00 inHg
- Observed at
- MGE, 1 nm away
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.