Piper PA31 accident near Fairbanks, Alaska, January 12, 2020
On January 12, 2020 at about 9:23 pm local time, a 1982 Piper PA31, registered N4112K, was substantially damaged in an accident during approach near Fairbanks, Alaska (Fairbanks Intl airport). It was flown under charter and air-taxi rules (Part 135). No one was hurt; 9 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The improper installation of a hydraulic line at the right main landing gear (MLG) unlock actuator, which resulted in a total loss of system hydraulic pressure and failure of the landing gear to extend. Contributing to the accident was the failure of the right MLG shuttle valve due to corrosion, which prevented the right MLG from extending during the emergency blowdown activation.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- January 12, 2020 · about 9:23 pm local time
- Place
- Fairbanks, Alaska · Fairbanks Intl · map
- Type
- Accident
- Injuries
- No one was hurt; 9 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA31 350, built 1982 · all PA31s on the register
- Registration
- N4112K · registry record · serial 31-8353006
- Damage
- Substantial damage
- Flight
- Flight · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
The pilot was approaching the destination airport for landing when the landing gear did not extend. The pilot utilized the manual pump system, the emergency pneumatic blowdown system, and conducted maneuvers at altitude to extend and lock the gear down; the nose and left main landing gear (MLG) extended and locked, but the right MLG did not. The pilot subsequently landed with the right MLG retracted, and the right wing impacted the runway during the landing roll, resulting in substantial damage. An examination of the hydraulic system revealed no fluid in the hydraulic reservoir and a leak at the right MLG unlock actuator due to a loose fitting that exhibited stripped threads at the connection. The right MLG hydraulic shuttle valve was stuck and unable to move. After disassembly, water and corrosion was evident inside the cylinder. The hydraulic lines were all replaced during a phase inspection about one week before the accident. It is likely that the hydraulic line fitting to the right MLG unlock actuator was insufficiently tightened or was cross-threaded during installation, which resulted in wear of the threads after numerous landings. The subsequent loss of system pressure prevented the landing gear from extending normally and with the hand pump. How water intruded into the shuttle valve could not be determined, but the resulting corrosion likely prevented the valve from moving during the emergency blowdown system activation, which prevented pneumatic pressure from activating the right MLG actuator. The condition was not evident until the emergency system was utilized.
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
- Landing gear not configured during landing (landing roll)
- Abnormal runway contact during landing (landing roll)
- Sys/Comp malf/fail (non-power) during approach defining event
The NTSB's findings
- Aircraft › Fluids/misc hardware › Fluids › Hydraulic fluid › Fluid level
- Aircraft › Aircraft systems › Landing gear system › Gear extension and retract sys › Incorrect service/maintenance
Pilot
- Certificate: airline transport pilot, commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 25,055 hours in all; 19,025 in this make and model; 89 in the last 90 days; 21 in the last 30 days; 24,055 as pilot in command
- Last flight review: October 29, 2019
- Medical certificate: Class 1 (with waivers/limitations)
- Seat: left
- Injury: no injuries
Passenger
- Seat: unk
- Injury: no injuries
Passenger
- Seat: unk
- Injury: no injuries
Passenger
- Seat: none
- Injury: no injuries
Passenger
- Seat: unk
- Injury: no injuries
Passenger
- Seat: unk
- Injury: no injuries
Passenger
- Seat: unk
- Injury: no injuries
Passenger
- Seat: unk
- Injury: no injuries
The aircraft
- Airframe total time: 33,715.6 hours
- Last inspection: approved inspection programme, January 7, 2020
- Maximum gross weight: 7,368 lb
- Seats: 10
- Landing gear: retractable
- Engine 1: Lycoming TIO-540-J2B (piston); 3,012 hours total
- Engine 2: Lycoming LTIO-540-J2B (piston); 7,306 hours total
- Operator: Hageland Aviation Services
The flight
- Departed from: FAI Fairbanks AK
- Destination: GAL Galena AK
- Runway 02L, 11,800 ft by 150 ft
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: a few clouds at 8,000 ft
- Temperature: -29°F (-34°C), dew point -38°F (-39°C)
- Altimeter: 30.15 inHg
- Observation at 8:53 pm from PAFA
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| LapC | 1 | |||
| Passengers | 7 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
7 documents, released by the NTSB on November 12, 2021. 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, 11 pages | View Download |
| 2 | Pilot Statement | PDF, 2 pages | View Download |
| 3 | FAA Examination Memo | PDF, 2 pages | View Download |
| 4 | Recovery Mechanics Statements | PDF, 2 pages | View Download |
| 5 | Maintenance Record | PDF, 5 pages | View Download |
| 6 | Landing Gear System Schematic | PDF, 2 pages | View Download |
| 7 | Photographs | PDF, 5 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Other NTSB records under N4112K the same tail number, which may have belonged to a different aircraft at the time
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.