Short Bros SD3 60 SHERPA incident near Missoula, Montana, October 13, 2016
On October 13, 2016 at about 10:45 pm local time, a 1994 Short Bros SD3 60 SHERPA, registered N148Z, suffered minor damage in an incident during approach near Missoula, Montana (Missoula Intl airport). It was a ferry flight under public-use (government) rules. No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The failure of the nose landing gear down-lock piston to engage due to paint accumulation, which resulted in a nose landing gear collapse during landing. Also causal was the failure of the facility that performed the painting to comply with manufacturer guidance regarding painting of the airplane.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 13, 2016 · about 10:45 pm local time
- Place
- Missoula, Montana · Missoula Intl · map
- Type
- Incident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Short Bros SD3 60 SHERPA SHERPA VAR, built 1994 · all SD3 60 SHERPAs on the register
- Registration
- N148Z · registry record · serial SH3428
- Damage
- Minor damage
- Flight
- Ferry flight · public-use (government) rules
The NTSB's narrative final · quoted from the NTSB record
The airline transport pilots reported that, during a ferry flight of an airplane that had just had been repainted, while on approach at its destination, the nose gear extended but failed to lock and subsequently collapsed on landing. Postaccident examination of the nose gear confirmed the nose gear's failure to lock, which led to its collapse. Observation of the nose gear down-lock actuator piston revealed that it had been painted, which prevented the piston from engaging and locking the nose gear during extension. Before the flight, maintenance personnel and the flight crew did not observe that the nose gear down-lock actuator piston area was painted. The airplane manufacturer issued a Service Information Letter (SIL) in 2007, that described a similar incident where the nose gear failed to lock in the down position on the first flight after an airplane had been repainted. The subsequent investigation revealed paint spray on the exposed piston of the nose landing gear down-lock actuator. The SIL stated "ensure that all masking material has been removed from the exposed piston after cleaning/painting, and that the piston is free from any paint or cleaning materials." Additionally, the landing gear emergency accumulator was observed during the preflight checks to be below the specified pressure. The accumulator was serviced to an adequate pressure prior to takeoff. Subsequently, the pressure bled down during the incident flight, and when the emergency landing gear extension was used by the flight crew, the accumulator did not have adequate pressure. According to the airplane manufacturer, the emergency landing gear extension is reliant on the main system pressure being depleted so that the emergency pressure can change a control valve position. Since the airplane's main hydraulic system was operative during the flight, the inability to use the landing gear emergency extension system, because of the lack of adequate pressure, would have been inconsequential, since the main system pressure was not depleted.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Aircraft maintenance event during prior to flight
- Aircraft inspection event during prior to flight
- Sys/Comp malf/fail (non-power) during approach defining event
- Landing gear collapse during landing (landing roll)
The NTSB's findings
- cause Aircraft › Aircraft systems › Landing gear system › Gear extension and retract sys › Damaged/degraded
- cause Aircraft › Aircraft systems › Landing gear system › Nose/tail gear strut/axle › Incorrect service/maintenance
- cause Aircraft › Aircraft systems › Landing gear system › Nose/tail gear strut/axle › Inadequate inspection
- cause Organizational issues › Support/oversight/monitoring › Oversight › Oversight of maintenance › Maintenance provider
- cause Personnel issues › Task performance › Maintenance › Scheduled/routine maintenance › Maintenance personnel
- cause Personnel issues › Action/decision › Action › Incorrect action performance › Maintenance personnel
- cause Personnel issues › Task performance › Use of equip/info › Use of available resources › Maintenance personnel
Pilot
- Certificate: airline transport pilot, flight instructor
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: helicopter; instructor: instrument airplane; instructor: instrument helicopter; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 8,715 hours in all; 148 in this make and model; 82 in the last 90 days; 12 in the last 30 days; 7,755 as pilot in command; 4,610 on instruments
- Last flight review: March 6, 2015
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: left
- Injury: no injuries
Co-pilot
- Certificate: airline transport pilot, flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 6,424 hours in all; 210 in this make and model; 90 in the last 90 days; 8 in the last 30 days; 4,921 as pilot in command; 455 on instruments
- Last flight review: March 2, 2016
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 5,203.6 hours
- Last inspection: condition inspection, June 24, 2016
- Landing gear: fixed
- Engine 1: Pratt & Whitney PT6A-65R (turboprop); 23,623 hours total
- Engine 2: Pratt & Whitney PT6A-65R (turboprop); 20,256 hours total
The flight
- Departed from: IGM Kingman AZ at 7:53 pm
- Destination: MSO Missoula MT
- Flight plan: VFR
- Runway 29, 9,501 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 360° at 6 knots
- Visibility: 10 statute miles
- Sky: overcast at 7,000 ft
- Temperature: 46°F (8°C), dew point 34°F (1°C)
- Altimeter: 29.79 inHg
- Observation at 10:53 pm from MSO
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 2 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
5 documents, released by the NTSB on July 5, 2018. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Record of Email | PDF, 2 pages | View Download |
| 3 | Service Information Letter | PDF, 2 pages | View Download |
| 4 | Maintenance Manual Excerpts | PDF, 3 pages | View Download |
| 5 | Incident Pictures | PDF, 1 page | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.