# NTSB investigations: Hydraulic power system NTSB aviation accident and incident investigations since 1962: the probable cause, findings, aircraft, crew, weather and docket of each, linked to the FAA registry and the FAA’s own reports. Page 1 of 2 · 66 cases ## Latest cases - [NTSB WPR26LA343](https://openairdocs.org/ntsb/WPR26LA343.md): Aerovodochody L-29 Delfin · Roswell, NM · Accident · No injuries · Class 4 · Limited · Final report · Sep 12, 2026 · N29AD · Substantial damage > The malfunction of a diode in the airplanes electrical system that resulted in low batter power and subsequent landing gear collapse. - [NTSB WPR24LA157](https://openairdocs.org/ntsb/WPR24LA157.md): Cessna P210 · Daggett, CA · Accident · No injuries · Class 3 · Limited · Final report · May 16, 2024 · N4769K · Substantial damage > The pilot’s failure to detect the tripped alternator circuit breaker in flight, which resulted in a drained battery that prevented the landing gear from fully extending to the down-and-locked position. Contributing to the accident was the improperly installed… - [NTSB DCA24LA095](https://openairdocs.org/ntsb/DCA24LA095.md): Boeing 737-823 · Dallas, TX · Incident · No injuries · Class 2 · Limited · Final report · Feb 11, 2024 · N991AN · Minor damage > Improper maintenance due to human error during a braking system modification diminished braking performance. Contributing to the diminished braking performance was the lack of a functional check to verify the flexible hydraulic hoses and transducer wiring… - [NTSB DCA24FA002](https://openairdocs.org/ntsb/DCA24FA002.md): Boeing 757-236 · Chattanooga, TN · Accident · No injuries · Class 2 · Field · Final report · Oct 5, 2023 · N977FD · Substantial damage > The failure of the alternate gear extension system, which prevented the landing gear from being lowered. The cause of the system failure was a broken wire, due to tensile overload, between the alternate gear extend switch and the alternate extension power… - [NTSB ERA23LA202](https://openairdocs.org/ntsb/ERA23LA202.md): Rockwell International 112 · Miami, FL · Accident · No injuries · Class 3 · Limited · Final report · Apr 18, 2023 · N12RX · Substantial damage > Failure of the right main landing gear due to inadequate hydraulic pressure as result of a torn O-ring that was installed on the hydraulic pack’s check valve during overhaul. - [NTSB WPR22LA341](https://openairdocs.org/ntsb/WPR22LA341.md): Cessna 750 · Mesa, AZ · Accident · No injuries · Class 3 · Limited · Final report · Sep 7, 2022 · N15TZ · Substantial damage > The pilot’s improper decision to depart on the accident flight with a known hydraulic leak, resulting in an in-flight hydraulic system failure, and the pilot’s attempt to land during an unstabilized approach, which resulted in a loss of control during the… - [NTSB CEN22LA378](https://openairdocs.org/ntsb/CEN22LA378.md): Cessna 210B · Clinton, AR · Accident · No injuries · Class 3 · Limited · Final report · Aug 9, 2022 · N9637X · Substantial damage > A fatigue crack in the hydraulic actuator, which resulted in the loss of hydraulic fluid and the pilot’s inability to fully extend the landing gear. - [NTSB ERA22LA148](https://openairdocs.org/ntsb/ERA22LA148.md): Cessna 525 · Middle River, MD · Accident · No injuries · Class 3 · Limited · Final report · Mar 7, 2022 · N22AU · Substantial damage > And undetermined failure of the brake system. Contributing to the accident was the failure of the pilots to locate and operate the emergency brake control, which resulted in a runway excursion and collision with terrain and an object. - [NTSB ERA22LA005](https://openairdocs.org/ntsb/ERA22LA005.md): Cessna 210 · Columbia, SC · Accident · No injuries · Class 4 · Limited · Final report · Oct 5, 2021 · N6318B · Substantial damage > A failure of the landing gear hydraulic power pack for reasons that could not be determined. - [NTSB DCA21LA229](https://openairdocs.org/ntsb/DCA21LA229.md): Boeing 767-332 · Seattle, WA · Accident · Serious injuries · Class 4 · Limited · Final report · Sep 1, 2021 · N196DN · No damage > The flightcrew’s failure to set the hydraulic panel correctly during the execution of the pushback checklist, and when the hydraulic panel setting was corrected, that resulted in the airplane coming to a sudden stop and a flight attendant receiving a serious… - [NTSB WPR21LA323](https://openairdocs.org/ntsb/WPR21LA323.md): Cessna 177RG · Albuquerque, NM · Accident · No injuries · Class 3 · Limited · Final report · Aug 15, 2021 · N8029G · Substantial damage > The failure of the nose gear hydraulic flex line, which resulted in a loss of hydraulic fluid which prevented the main landing gear from fully extending and locking into place during landing. - [NTSB CEN21LA216](https://openairdocs.org/ntsb/CEN21LA216.md): Aerospatiale AS350 B2 Ecureuil · Yukon, OK · Accident · No injuries · Class 3 · Limited · Final report · May 12, 2021 · N841BP · Destroyed > The pilot receiving instruction’s untimely and unidentified inadvertent activation of the hydraulic cut-off switch, which turned off the hydraulic system while the helicopter was at slow airspeed followed by a rapid power increase, which resulted in a loss of… - [NTSB WPR20LA288](https://openairdocs.org/ntsb/WPR20LA288.md): Cessna 210 · Chino, CA · Accident · No injuries · Class 3 · Limited · Final report · Aug 26, 2020 · N9540T · Substantial damage > The failure of the engine-driven hydraulic pump, which resulted in the main landing gear not fully extending and locking into place during landing. Contributing to the accident was the failure of the emergency gear extension system for reasons that could not… - [NTSB WPR20LA280](https://openairdocs.org/ntsb/WPR20LA280.md): Arrow-Falcon Exporters UH-1H · Coalinga, CA · Accident · 1 fatal · Class 3 · Limited · Final report · Aug 19, 2020 · N711GH · Destroyed > The pilot’s inability to maintain control of the helicopter due to a hydraulic system failure for reasons that could not be fully determined due to the thermal destruction from the postimpact fire. - [NTSB ENG20LA031](https://openairdocs.org/ntsb/ENG20LA031.md): Airbus Helicopters AS350 · Clewiston, FL · Incident · No injuries · Class 3 · Limited · Final report · May 3, 2020 · N1WT · No damage > Seizure of the hydraulic pump pulley bearing due to its improper installation by the manufacturer, leading to a failure of the hydraulic pump belt and the resultant partial loss of hydraulic assistance to the pedals. - [NTSB DCA20LA100](https://openairdocs.org/ntsb/DCA20LA100.md): Sikorsky S61 · Camp Dwyer, Afghanistan · Accident · Serious injuries · Class 3 · Limited · Final report · Apr 20, 2020 · N908CH · Substantial damage > Fatigue cracking of the auxiliary servo cylinder’s pedal damper check valve housing and its bolts, which caused the sudden and uncommanded movement of the helicopter’s left pedal and a subsequent left yaw that continued until ground impact. Contributing to… - [NTSB WPR20LA104](https://openairdocs.org/ntsb/WPR20LA104.md): Piper PA46 · San Jose, CA · Accident · No injuries · Class 3 · Limited · Final report · Feb 28, 2020 · N304LA · Substantial damage > The failure to properly service the hydraulic power pack prevented a normal landing gear extension. Contributing to the accident was the failure of the landing gear emergency release valve to function properly for reasons that could not be determined based on… - [NTSB CEN19TA333](https://openairdocs.org/ntsb/CEN19TA333.md): Lancair Lancair 320 · Bolivar, MO · Accident · No injuries · Class 3 · Final report · Sep 25, 2019 · N52WL · Substantial damage > Inadequate maintenance of the airplane, which resulted in a lack of adequate hydraulic fluid, malfunction of the landing gear extension system, and the landing gear collapse on landing. - [NTSB CEN19LA246](https://openairdocs.org/ntsb/CEN19LA246.md): Swearingen SA227 · El Paso, TX · Accident · No injuries · Class 3 · Limited · Final report · Jul 27, 2019 · N681TR · Substantial damage > Failure of the left main landing gear to fully extend due to a lack of hydraulic fluid and during emergency extension procedures, which resulted in the collapse of the landing gear during landing and the subsequent runway excursion and collision with a sign. - [NTSB CEN18LA349](https://openairdocs.org/ntsb/CEN18LA349.md): North American T-28B · Minneapolis, MN · Accident · Serious injuries · Limited investigation · Final report · Aug 23, 2018 · N215SF · Destroyed > The fire during approach for reasons that could not be determined based on the available evidence, which resulted in impact with terrain during approach for a precautionary landing. - [NTSB ANC18LA043](https://openairdocs.org/ntsb/ANC18LA043.md): Cessna 210 · Ramona, CA · Accident · No injuries · Class 3 · Limited · Final report · Jun 1, 2018 · N9410M · Substantial damage > The failure of the engine-driven hydraulic pump due to the installation of improper cap screws, which resulted in a gap in the pump housing, a subsequent hydraulic leak, and the landing gear collapsing. - [NTSB ERA18LA067](https://openairdocs.org/ntsb/ERA18LA067.md): Cessna 172RG · Martinsburg, WV · Accident · No injuries · Limited investigation · Final report · Jan 21, 2018 · N9415B · Substantial damage > A hydraulic leak in the right main landing gear actuator, which resulted in the main landing gear not extending. - [NTSB GAA17CA570](https://openairdocs.org/ntsb/GAA17CA570.md): Piper PA 31 · Saipan · Accident · No injuries · Data collection · Final report · Aug 30, 2017 · N4078J · Substantial damage > Impact with multiple birds while retracting the landing gear, which resulted in the subsequent failure of the right inboard main landing gear door actuator hose and prevented the pilot from being able to extend the landing gear. - [NTSB WPR17LA165](https://openairdocs.org/ntsb/WPR17LA165.md): Lake LA 4 · Byron, CA · Accident · No injuries · Class 3 · Limited · Final report · Jul 25, 2017 · N7628L · Substantial damage > The pilot’s failure to activate the hydraulic system during the approach, and his failure to ensure that the landing gear was down and locked before touchdown. Contributing to the accident was the pilot's decision to operate the airplane with an inoperative… - [NTSB ANC17LA014](https://openairdocs.org/ntsb/ANC17LA014.md): Piper PA 32R-300 · McGrath, AK · Accident · Serious injuries · Limited investigation · Final report · Nov 21, 2016 · N4352F · Minor damage > The failure of the nose landing gear to extend and lock due to the failure of the alternator and reduced battery power due to the cold ambient temperature, which prohibited the electrically-driven hydraulic pump from supplying adequate hydraulic pressure to… - [NTSB WPR16LA187](https://openairdocs.org/ntsb/WPR16LA187.md): Jurcan Seawind 3000 · Renton, WA · Accident · No injuries · Limited investigation · Final report · Sep 18, 2016 · N57TJ · Substantial damage > The failure of the landing gear system to either fully retract or extend due to a cracked hydraulic fitting flare, which resulted in the loss of hydraulic pressure. - [NTSB WPR16FA040](https://openairdocs.org/ntsb/WPR16FA040.md): Airbus Helicopters AS350 · Superior, AZ · Accident · 2 fatal · Field investigation · Final report · Dec 16, 2015 · N74317 · Substantial damage > The pilot's loss of helicopter control in mountainous terrain as the result of operating the helicopter outside the performance envelope of its hydraulic system and encountering the servo transparency phenomenon. Contributing to the accident was the pilot's… - [NTSB ERA15LA296](https://openairdocs.org/ntsb/ERA15LA296.md): Bell 47G 3B 1 · Camden, AL · Accident · No injuries · Limited investigation · Final report · Aug 3, 2015 · N4002G · Substantial damage > A failure of the helicopter's hydraulic flight control systems for reasons that could not be determined due to the fire damage, and the pilot's inability to turn off the hydraulic system to relieve control pressure. - [NTSB WPR15LA234](https://openairdocs.org/ntsb/WPR15LA234.md): Cessna 180J · Dixie, ID · Accident · No injuries · Limited investigation · Final report · Jul 26, 2015 · N52095 · Substantial damage > The failure of the right brake hydraulic line during taxi due to fatigue, which caused a loss of hydraulic fluid and rendered the brake inoperative. - [NTSB CEN15MA290](https://openairdocs.org/ntsb/CEN15MA290.md): Airbus Helicopters AS350B3E · Frisco, CO · Accident · 1 fatal · Class 1 · Major · Final report · Jul 3, 2015 · N390LG · Destroyed > Airbus Helicopters' dual-hydraulic AS350 B3e helicopter's (1) preflight hydraulic check, which depleted hydraulic pressure in the tail rotor hydraulic circuit, and (2) lack of salient alerting to the pilot that hydraulic pressure was not restored before… - [NTSB CEN15IA014](https://openairdocs.org/ntsb/CEN15IA014.md): Raytheon Hawker · Denver, CO · Incident · No injuries · Incident investigation · Final report · Oct 15, 2014 · N694ES · Minor damage > The failure of the main landing gear tire, which resulted in separation of the servo block and subsequent total loss of all hydraulic system pressure and prevented the landing gear from extending before landing. - [NTSB CEN14IA329](https://openairdocs.org/ntsb/CEN14IA329.md): Eurocopter AS 350 B3 · Temple, TX · Incident · No injuries · Incident investigation · Final report · Jun 26, 2014 · N808LF · Minor damage > The pilot’s failure to reposition the yaw servo hydraulic switch to the “on” position during the pretakeoff hydraulic system check, which resulted in a complete lack of hydraulic boost to the tail rotor system and increased the load required to move the… - [NTSB WPR14TA248](https://openairdocs.org/ntsb/WPR14TA248.md): Lockheed SP 2H · Fresno, CA · Accident · No injuries · Final report · Jun 16, 2014 · N4692A · Substantial damage > The collapse of the nosewheel landing gear due to the disengagement of the nosewheel landing gear pin. Contributing to the accident was the failure of the main hydraulic system due to overpressurization for reasons that could not be determined during… - [NTSB WPR14FA137](https://openairdocs.org/ntsb/WPR14FA137.md): Eurocopter AS 350 B2 · Seattle, WA · Accident · 2 fatal · Field investigation · Final report · Mar 18, 2014 · N250FB · Destroyed > The loss of helicopter control due to a loss of hydraulic boost to the tail rotor pedal controls at takeoff, followed by a loss of hydraulic boost to the main rotor controls after takeoff. The reason for the loss of hydraulic boost to the main and tail rotor… - [NTSB CEN14LA127](https://openairdocs.org/ntsb/CEN14LA127.md): Piaggio P180 - Avanti II · Springfield, IL · Accident · No injuries · Limited investigation · Final report · Jan 31, 2014 · N700FE · Substantial damage > The pilot's decision to reengage the hydraulic system following the successful extension of the landing gear using the emergency extension procedures. Contributing to the accident was the failure of the directional control valve in the gear-up position and… - [NTSB WPR14LA105](https://openairdocs.org/ntsb/WPR14LA105.md): Piper PA 23-250 · Camarillo, CA · Accident · No injuries · Limited investigation · Final report · Jan 28, 2014 · N5977Y · Substantial damage > The inadequate hydraulic pressure due to a damaged O-ring in the hydraulic powerpack, which prevented the right main landing gear (MLG) downlock from locking in the extended positon and allowed the right MLG to collapse during landing. - [NTSB WPR14LA059](https://openairdocs.org/ntsb/WPR14LA059.md): Cessna 210 · Florence, OR · Accident · No injuries · Limited investigation · Final report · Nov 29, 2013 · N6575X · Substantial damage > The failure of the hydraulic power pack, which prevented the extension of the landing gear and resulted in a partial gear-up landing. - [NTSB DCA13MA081](https://openairdocs.org/ntsb/DCA13MA081.md): Boeing 747-400 BCF · Bagram, Afghanistan · Accident · 7 fatal · Class 1 · Major · Final report · Apr 29, 2013 · N949CA · Destroyed > National Airlines' inadequate procedures for restraining special cargo loads, which resulted in the loadmaster's improper restraint of the cargo, which moved aft and damaged hydraulic systems Nos. 1 and 2 and horizontal stabilizer drive mechanism components,… - [NTSB CEN13IA059](https://openairdocs.org/ntsb/CEN13IA059.md): Fairchild SA227-AC · Minneapolis, MN · Incident · No injuries · Incident investigation · Final report · Nov 10, 2012 · N619BA · Minor damage > Loose electrical connections to the hydraulic system and anomalies in the hydraulic shuttle valve and power pack, which resulted in an uncommanded gear unlock and collapse of the left main landing gear. Contributing to the accident was the operator’s failure… - [NTSB CEN12LA420](https://openairdocs.org/ntsb/CEN12LA420.md): Cessna T210M · Colorado Springs, CO · Accident · No injuries · Limited investigation · Final report · Jul 20, 2012 · N311TM · Substantial damage > The failure of the right hydraulic main gear down-lock actuator hose in flight. - [NTSB DCA12IA096](https://openairdocs.org/ntsb/DCA12IA096.md): Airbus A320 · Las Vegas, NV · Incident · No injuries · Incident investigation · Final report · Jun 17, 2012 · N552JB · No damage > the failure of the right main landing gear door retraction flexible hydraulic line in the Green hydraulic system, which led to prolonged operation of the power transfer unit and subsequent overheating and loss of pressure in the Yellow hydraulic system,… - [NTSB ANC12LA017](https://openairdocs.org/ntsb/ANC12LA017.md): Pzl-Swidnik SW-4 · Fairbanks, AK · Accident · No injuries · Limited investigation · Final report · Jan 15, 2012 · SP-SSW · Substantial damage > A loss of control during a simulated hydraulic emergency, which resulted in an inadvertent dynamic rollover from the which the pilot could not recover. - [NTSB ERA11WA472](https://openairdocs.org/ntsb/ERA11WA472.md): Agusta AW139 · Brazil · Accident · 4 fatal · Foreign investigation · Aug 19, 2011 · PR-SEK · Substantial damage > On August 19, 2011, at 1948 coordinated universal time (16:48 local time), an Agusta, AW139, helicopter, Brazilian registration PT-SEK, impacted into the Atlantic Ocean, near an oil rig, identifier P-65, the helicopter sank in waters with a recorded floor… - [NTSB CEN11IA379](https://openairdocs.org/ntsb/CEN11IA379.md): Bombardier CL-600-2B19 · Milwaukee, WI · Incident · No injuries · Incident investigation · Final report · Jun 7, 2011 · N866AS · Minor damage > The failure of the right main landing gear (MLG) to extend normally, which resulted from the combination of a slightly worn uplock pin, the operation of the hydraulic pumps below their specified operating pressures, and contamination within the landing gear… - [NTSB CEN11FA359](https://openairdocs.org/ntsb/CEN11FA359.md): Eurocopter AS 350 B2 · Fort Worth, TX · Accident · Minor injuries · Field investigation · Final report · May 29, 2011 · N747CH · Substantial damage > The pilot’s loss of control due to his not maintaining adequate airspeed and altitude during a simulated hydraulic flight control failure. Contributing to the accident was the flight instructor’s inadequate supervision and delayed remedial response. - [NTSB WPR11GA144](https://openairdocs.org/ntsb/WPR11GA144.md): Eurocopter AS 350 B2 · Riverside, CA · Accident · Minor injuries · Final report · Feb 24, 2011 · N965SD · Substantial damage > The failure of both pilots to follow proper procedures during a simulated hydraulic emergency that resulted in a loss of helicopter control. Contributing to the accident was the flight instructor’s delayed remedial action. - [NTSB CEN11FA193](https://openairdocs.org/ntsb/CEN11FA193.md): Gulfstream Aerospace GV-SP · Appleton, WI · Accident · No injuries · Field investigation · Final report · Feb 14, 2011 · N535GA · Substantial damage > The pilot flying's (PF) decision to land on a shorter-than-recommended runway with a known left hydraulic system failure rather than go around as suggested by the pilot-not-flying, his failure to immediately apply emergency brakes following the detection of… - [NTSB ERA11FA133](https://openairdocs.org/ntsb/ERA11FA133.md): Potez-Air Fouga CM 170 Magister · Kissimmee, FL · Accident · 2 fatal · Field investigation · Final report · Feb 2, 2011 · N415FM · Substantial damage > The pilot/mechanic's improper decision to continue a tight-turning landing pattern after a loss of hydraulic pressure, and his subsequent failure to maintain adequate airspeed during that pattern, which resulted in an accelerated maneuver stall. Contributing… - [NTSB CEN10LA572](https://openairdocs.org/ntsb/CEN10LA572.md): Cessna 172RG · Tulsa, OK · Accident · Serious injuries · Limited investigation · Final report · Sep 28, 2010 · N5145U · Destroyed > A shorted terminal lug on the landing gear hydraulic pump which resulted in a cabin fire. Contributing to the accident was the lack of clear installation procedures for the hydraulic pump. - [NTSB ERA10TA501](https://openairdocs.org/ntsb/ERA10TA501.md): Eurocopter AS-350 · Covington, GA · Accident · Minor injuries · Final report · Sep 24, 2010 · N91DK · Substantial damage > The flight instructor's loss of control of the helicopter during the intentional demonstration of a low speed, hydraulics-off maneuver, that was warned against in the helicopter manufacturer's flight manual. Next page: https://openairdocs.org/ntsb-findings/010229/cases.md?page=2 ## The whole list in SQL Runs in DuckDB 1.2 or later on the release's Parquet files over HTTPS: ```sql SELECT c."ntsbNumber", c."eventDate", c."eventType", c."eventCity", c."eventStateOrRegion", a.n_number, a."aircraftMake", a."aircraftModel", c."highestInjuryLevel", c."totalFatal", c."completionStatus", c.report_url FROM 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' c LEFT JOIN 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' a ON a.case_mkey = c."mKey" AND a.position = 1 WHERE c."mKey" IN (SELECT f.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_findings.parquet' f WHERE starts_with(f."findingCode", '010229')) ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC ``` This list as a web page: https://openairdocs.org/ntsb-findings/010229/cases --- 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.