# NTSB ERA16LA323: Learjet 25, San Juan, PR, September 22, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 22, 2016, 18:20 local (22:20 UTC) - Place: San Juan, PR - Coordinates: 18.4575, -66.096107 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=18.4575&lon=-66.0961&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report March 18, 2019 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 94070 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA16LA323 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94070/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94070 - Page: https://openairdocs.org/ntsb/ERA16LA323 ## Probable cause The pilot’s improper decision to land the airplane on a wet runway, in heavy rain, with tires worn beyond safe limits, which resulted in a hydroplaning condition and subsequent loss of directional control. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: tire casing](https://openairdocs.org/ntsb-findings/01023244): Aircraft › Aircraft systems · Not serviced/maintained (probable cause); cases with it: [All aircraft, 36 cases](https://openairdocs.org/ntsb-findings/01023244/cases.md) - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Ceiling/visibility/precip: rain](https://openairdocs.org/ntsb-findings/03035035): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [All aircraft, 56 cases](https://openairdocs.org/ntsb-findings/03035035/cases.md) - [Runway/land/takeoff/taxi surface: wet surface](https://openairdocs.org/ntsb-findings/03023010): Environmental issues › Physical environment · Effect on operation; cases with it: [All aircraft, 141 cases](https://openairdocs.org/ntsb-findings/03023010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) - [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094); cases with it: [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis The airline transport pilot reported that rain was intensifying as the airplane approached the runway and that the runway appeared to be wet. After landing smoothly and while decelerating through 80-90 knots, the airplane hydroplaned and departed the left side of the runway. An 8-knot crosswind from the left prevailed. The left main landing gear collapsed, and the airplane came to rest in the grass about 180° from the runway heading, which resulted in structural damage to the left main gear well. Postaccident examination of the main landing gear tires revealed that three tires had no measurable tread, and the fourth tire had only 1.17 mm of tread. The tire manufacturer stated that tires should be removed if tread wear reached the base of any groove. White skid marks were found on the runway, indicative of a hydroplaning condition. Witnesses reported heavy rain and standing water on the runway at the time of the accident. ## Factual narrative On September 22, 2016, about 1820 Atlantic standard time (AST), a Learjet 25D, Venezuelan registration YV1738, was substantially damaged during a runway excursion while landing at Fernando Luis Ribas Dominicci Airport (TJIG), San Juan, Puerto Rico. The foreign-certificated pilot, co-pilot, and one passenger were not injured. The airplane was operated by WMG Techno-Logistic, C.A. under the provisions of 14 Code of Federal Regulations Part 91 as a business flight. Day, visual meteorological conditions prevailed at the time, and an instrument flight rules flight plan was filed. The flight originated from Punta Cana, Dominican Republic (MDPC) about 1750 AST. The pilot reported that the runway appeared to be wet as they were cleared to land. There was light rain on the windshield, and the rain intensified as they approached the runway. After a smooth landing on runway 9, as the airplane decelerated through 80 to 90 knots, the airplane began to hydroplane, and departed the runway surface to the left, into the grass. As the airplane crossed the intersecting taxiway, the left main landing gear collapsed, the airplane completed a 180-degree turn, and came to rest in the grass. The crew and passenger egressed the airplane and were met by first responders. The pilot later reported that there were no mechanical anomalies or malfunctions that would have prevented normal operation of the airplane. An inspector with the Federal Aviation Administration responded to the accident site and examined the wreckage. The left main landing gear actuator support beam was structurally damaged. The left wing tip fuel tank was scraped on the lower side. Rudder control continuity was confirmed. Runway 9 was 5,539 feet long and 100 feet wide. The runway surface was noted as "asphalt, in good condition." The runway was not grooved. FAA inspectors observed tire skid marks from all three landing gear on the runway, leading to the resting position of the wreckage. The skid marks were white in color. A subsequent examination of the main landing gear tires revealed that three of the four tires were worn to the point where no measurable tread remained. The number 4 (right, outboard) main tire measured 1.17mm tread remaining. The main landing gear tires installed at the time of the accident were approved by the airplane manufacturer. The Goodyear aircraft tire maintenance manual stated, regarding treadwear, "Inspect treads visually and check remaining tread. Tires should be removed when tread has worn to the base of any groove at any spot, or up to 1/8 of the tire circumference." The weather at TIG at 1820 included wind from 350 degrees at 8 knots, 2 statute miles visibility in thunderstorms, overcast ceiling at 2,000 feet, and altimeter 29.94 inches of mercury. A U.S. Customs agent reported that there was heavy rain at the time of the accident. The passenger on the airplane reported that there was 2 to 4 inches of water on the taxiway and runway and it was "raining profusely." ## Aircraft - Registration: YV1738 (not matched to a registry record) - Reported make and model: LEARJET 25 (D) - Category: Airplane - Serial number: 363 - Year built: 1983 - Airframe hours: 5330 - Engines: General Electric CJ-610-8A 2950 lbs thrust turbo jet; General Electric CJ-610-8A 2950 lbs thrust turbo jet - Damage: Substantial damage - Flight: Business, Part 91 - Operator: WMG Techno-Logistic C.A. - Registered owner: WMG Techno-Logistic C.A. - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, September 6, 2016 - Departed: MDPC, Punta Cana - Destination: TJIG, San Juan, PR - Flight plan: IFR - Airport: TJIG, Fernando Dominicci Airport, runway 09, 5,539 × 100 ft, asphalt - Equipment: Stall warning system, Data recorder, Auto-pilot, Angle of attack indicator ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 33; injuries: none; foreign, airline transport, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review June 30, 2016; seat: left; restraint: 5-point; flight hours: 2,200 total, 1,400 in this make and model, 1,700 as pilot in command, 125 in the last 90 days, 40 in the last 30 days, 2 in the last 24 hours - Co-pilot; age 48; injuries: none; foreign, airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review March 31, 2016; seat: right; restraint: 4-point; flight hours: 6,800 total, 25 in this make and model, 6,600 as pilot in command, 90 in the last 90 days, 32 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Instrument (IMC), Day - Wind: 350° at 8 knots - Visibility: 2 statute miles - Lowest ceiling: 2,000 ft overcast - Temperature: 77 °F, dew point 75 °F - Altimeter: 29.94 inHg - Observed at: TJIG ## Docket (14 files) The files NTSB released with the investigation on November 29, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94070. 13.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 7.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468658&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - FAA Record of Conversation and Pilot's Written Statement (item 2, .PDF, 508 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468659&FileExtension=.PDF&FileName=FAA%20Record%20of%20Conversation%20and%20Pilot%27s%20Written%20Statement-Master.PDF - FAA Record of Visit (item 3, .PDF, 219 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468660&FileExtension=.PDF&FileName=FAA%20Record%20of%20Visit-Master.PDF - FAA Record of Telephone Calls (2) (item 4, .PDF, 427 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468661&FileExtension=.PDF&FileName=FAA%20Record%20of%20Telephone%20Calls%20(2)-Master.PDF - FAA Inspector Statement (item 5, .PDF, 170 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468662&FileExtension=.PDF&FileName=FAA%20Inspector%20Statement-Master.PDF - Goodyear Aviation Tire Data (item 6, .PDF, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468663&FileExtension=.PDF&FileName=Goodyear%20Aviation%20Tire%20Data-Master.PDF - Goodyear Maintenance Manual Excerpts (item 7, .PDF, 250 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468664&FileExtension=.PDF&FileName=Goodyear%20Maintenance%20Manual%20Excerpts-Master.PDF - NTSB Memorandum for Record - Bombardier (item 8, .PDF, 98 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468665&FileExtension=.PDF&FileName=NTSB%20Memorandum%20for%20Record%20-%20Bombardier-Master.PDF - TJIG Weather Data (item 9, .PDF, 107 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468666&FileExtension=.PDF&FileName=TJIG%20Weather%20Data-Master.PDF - Aircraft Trajectory Diagram Provided by FAA (item 10, .PDF, 1 photo, 124 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468667&FileExtension=.PDF&FileName=Aircraft%20Trajectory%20Diagram%20Provided%20by%20FAA-Master.PDF - Runway Skid Marks Diagram from FAA (item 11, .PDF, 1 photo, 220 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468668&FileExtension=.PDF&FileName=Runway%20Skid%20Marks%20Diagram%20from%20FAA-Master.PDF - Photo Array (item 12, .PDF, 6 photos, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468669&FileExtension=.PDF&FileName=Photo%20Array-Master.PDF - Cockpit Voice Recorder - Specialist’s Factual Report (item 13, .PDF, 36 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468670&FileExtension=.PDF&FileName=Cockpit%20Voice%20Recorder%20-%20Specialist%E2%80%99s%20Factual%20Report-Master.PDF - Evidence Control Form (item 14, .PDF, 198 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468671&FileExtension=.PDF&FileName=Evidence%20Control%20Form-Master.PDF 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.