# NTSB ATL94LA149: Miller, John Skybolt, N919JM, Muscle Shoals, AL, July 28, 1994 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 28, 1994, 09:17 local (14:17 UTC) - Place: Muscle Shoals, AL - Location: 34.7453° N, 87.6102° W: Placed by OpenAirDocs at NORTHWEST ALABAMA RGNL (MSL), within about a mile (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=34.7453&lon=-87.6102&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report March 13, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 3426 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL94LA149 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/3426/pdf - Page: https://openairdocs.org/ntsb/ATL94LA149 ## Probable cause The fatigue failure of the main landing gear strut that resulted in a loss of control. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Gear collapsed, landing - roll - landing gear,main gear strut - fractured (cause) - landing gear,main gear strut - fatigue (contributing factor) - Loss of control - on ground/water, landing - roll - On ground/water encounter with terrain/water, landing - roll ## Analysis THE PILOT STATED THAT AFTER TOUCHDOWN ON THE RUNWAY, THE AIRCRAFT VEERED OFF THE RUNWAY TO THE LEFT. EXAMINATION OF THE LEFT MAIN LANDING GEAR REVEALED THAT THE GEAR STRUT WAS FRACTURED, AND THE LEFT LANDING GEAR HAD COLLAPSED. FURTHER EXAMINATION OF THE FRACTURE SURFACE REVEALED A RADIAL AREA ABOUT 3/8 TO 1/2 INCH IN SIZE, THAT WAS QUITE DIFFERENT FROM THE HOMOGENOUS, FINE, GRAY GRANULAR APPEARANCE OF THE REMAINDER OF THE FRACTURE. THE OUTER 1/32 INCH OF THE DIFFERENT APPEARING AREA WAS DISCOLORED BLACK, WHICH REVEALED THE PRESENCE OF A PREVIOUSLY UNDETECTED FRACTURE. ## Factual narrative On July 28, 1994 at 0917 central daylight time, a Miller Skybolt, N919JM was substantially damaged following a loss of control during landing at Muscle Shoals, Alabama. The commercial pilot was not injured in the accident. The aircraft was operated by the pilot, under the provisions of 14 CFR Part 91. Visual meteorological conditions existed at the time, and no flight plan had been filed for the personal flight. The flight departed Mobile, Alabama at 0730, and was enroute to Oshkosh, Wisconsin. The pilot stated that left main landing gear strut failed during landing, and he lost control of the aircraft. The aircraft ground looped causing substantial damage to the left wing and left wing strut. Examination of the left main landing gear revealed that the left landing gear strut had fractured, and the left gear had collapsed. The pilot reported that the fracture surface was visually examined in bright sunlight. He noted a "...change in [the] crystal structure of the steel: a 3/8 to 1/2 inch radial area with a larger nodular appearance with respect to the homogenous fine gray granular appearance of the rest of the surface. The outher 1/32 inch of the different area was quite black. We, therefore, surmised the presence of a previously unknown radial crack in the member, perhaps a manufacturing defect, present all along." ## Aircraft - Registration: [N919JM](https://openairdocs.org/aircraft/N919JM), registered now, S/N 001 (OpenAirDocs) - Reported make and model: MILLER, JOHN SKYBOLT - Registry model: [Miller John N SKYBOLT-180](https://openairdocs.org/model/miller-john-n-skybolt-180) (registry code 05655CN) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 001 - Airframe hours: 138 - Engines: LYCOMING O-360-A1D 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Miller, John N. - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, December 31, 1993, 17 hours before - Departed: MOB, MOBILE, AL - Destination: OSH, OSKOSH, WI - Flight plan: VFR - Airport: MSL, Muscle Shoals, runway 29, 6,700 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; private; airplane ratings: single-engine land, single-engine sea; medical: class 3, valid medical--w/ waivers/lim; seat: rear; flight hours: 605 total, 138 in this make and model, 452 as pilot in command, 12 in the last 90 days, 6 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 7 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 61 °F - Altimeter: 29.00 inHg - Observed at: MSL ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19940728045979A](https://openairdocs.org/incident/19940728045979A), Jul 28, 1994: Amtrsn SKYBOLT, Muscle Shoals, AL, Substantial damage. Left main gear collapsed on landing. Found failed gear strut due to fatigue cracking. From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.