# NTSB NYC07LA170: Learjet 25, N70SK, St. Augustine, FL, July 21, 2007 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 21, 2007, 14:10 local (18:10 UTC) - Place: St. Augustine, FL - Coordinates: 29.959999, -81.339996 - Nearby events: https://openairdocs.org/map.md?lat=29.9600&lon=-81.3400&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report September 26, 2008 - Report: Approved by Office Director - Parties: Nordam, Learjet, FAA/FSDO, SK Logistics, Inc. - NTSB case key (mKey): 66267 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC07LA170 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/66267/pdf - Page: https://openairdocs.org/ntsb/NYC07LA170 ## Probable cause A loss of power on both engines for an undetermined reason. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, descent - all engines - reason for occurrence undetermined - Forced landing, emergency descent/landing - Hard landing, emergency descent/landing ## Analysis About 5 miles from the destination airport, the flight was cleared by air traffic control to descend from its cruise altitude of 5,000 feet for a visual approach. As the first officer reduced engine power, both engines "quit." The captain attempted to restart both engines without success. He then took control of the airplane, and instructed the first officer to contact air traffic control and advise them that the airplane had experienced a "dual flameout." The captain configured the airplane by extending the landing gear and flaps and subsequently landed the airplane on the runway "hard," resulting in substantial damage to the airframe. Both engines were test run following the accident at full and idle power with no anomalies noted. Examination of the airplane revealed that it was equipped with an aftermarket throttle quadrant, and that the power lever locking mechanism pins as well as the throttle quadrant idle stops for both engines were worn. The power lever locking mechanism internal springs for both the left and right power levers were worn and broken. Additionally, it was possible to repeatedly move the left engine's power lever directly into cutoff without first releasing its power lever locking mechanism; however, the right engine's power lever could not be moved to the cut off position without first releasing its associated locking mechanism. The right throttle thrust reverser solenoid installed on the airplane was found to be non-functional, but it is not believed that this component contributed to the accident. No explicit inspection or repair instructions were available for the throttle quadrant assembly. Other than the throttle quadrant issues, no other issues were identified with either the engines or airframe that could be contributed to both engines losing power simultaneously. ## Factual narrative HISTORY OF FLIGHT On July 21, 2007, about 1410 eastern daylight time, a Learjet 25, N70SK, operated by SK Logistics Inc., was substantially damaged during a hard landing following a dual engine flameout while on approach to St. Augustine Airport (SGJ), St. Augustine, Florida. The certificated airline transport pilot captain and the certificated commercial pilot first officer were not injured. Visual meteorological conditions prevailed, and the airplane was operating on an instrument flight rules flight plan. The positioning flight, which departed Gainesville Regional Airport (GNV), Gainesville, Florida, at 1354, was conducted under the provisions of 14 Code of Federal Regulations Part 91. During an interview, the captain stated that while inbound to their home airport, St. Augustine, they were cleared to descend from their cruise altitude of 5,000 feet for a visual approach to runway 31. As the first officer reduced engine power, both engines "quit." The captain attempted to restart both engines without success. He then took control of the airplane, and instructed the first officer to contact air traffic control and advise them that the airplane had experienced a "dual flameout," and that they would land on runway 13. The captain configured the airplane by extending the landing gear and flaps and subsequently landed the airplane. He stated that the landing was "hard, but not that hard," and that he normally would have used power to slow the rate of descent right before touchdown. After landing, they "turned everything off" and exited the airplane. During a separate interview, the first officer stated that on their final leg to St. Augustine, cruising at 5,000 feet, they switched radio frequencies in preparation for landing. There was congestion on the frequency, and they "had a hard time checking in." With the airport in sight, the first officer began a descent by reducing power and slowing the airplane when the engines "quit." He stated that the power reductions were very subtle, and he never reduced power all the way to idle. The first officer responded by energizing the igniters, turning on the starters, and transferring control of the airplane to the captain. The first officer called out the airplane's speed throughout the descent, and they landed on runway 13. The airplane touched down on runway 13 near the threshold. Both main tires blew out and the airplane came to rest on runway 13 just short of taxiway A3. PERSONNEL INFORMATION The captain held several certificates and ratings including an airline transport pilot certificate with a rating for airplane multiengine land, and an LR-JET type rating. He reported 4,620 total hours of flight experience, 250 hours of which were in the accident airplane make and model. His most recent Federal Aviation Administration (FAA) first-class medical certificate was issued on March 1, 2007 with no limitations. The first officer held several certificates and ratings including a commercial pilot certificate with a rating for airplane multiengine land, and a LR-JET second-in-command type rating. He reported 2,453 total hours of flight experience, 368 hours of which were in the accident airplane make and model. His most recent FAA first-class medical certificate was issued on June 20, 2007 with no limitations. AIRCRAFT INFORMATION The accident airplane was a transport category, twin turbojet airplane manufactured by the Gates Learjet Corporation in 1970. The accident airplane was powered by two GE CJ610-6 engines, rated at 2,950 pounds of thrust each. The airplane's maximum gross weight was listed as 15,000 lbs. The airplane was maintained in accordance with the manufacturer's inspection program and had accumulated 15,812 hours in service at the time of the accident. Engine No. 1 had accumulated a total of 13,433 hours, with 4,385 hours since the last overhaul. Engine No. 2 had accumulated 7,989 total hours, with 4,681 hours since the last overhaul. The engines had each accumulated 274 hours of service since the most recent inspection, performed on June 28, 2007. METEOROLOGICAL INFORMATION The weather conditions reported at SGJ, at 1402, included calm winds, 10 statute miles visibility, clear skies, temperature 82 degrees Fahrenheit, dewpoint 72 degrees Fahrenheit, and an altimeter setting of 29.97 inches of mercury. AIRPORT INFORMATION SGJ was located at an elevation of 10 feet and its layout was comprised of 3 intersecting runways. Runway 13-31 was 7,996 feet long and 150 feet wide, with an asphalt surface. The control tower was in operation at the time of the accident. FLIGHT RECORDERS Although the accident events were captured on the cockpit voice recorder (CVR), the audio did not offer any additional information that had not been obtained through other sources in the investigation. Therefore, no CVR transcript was prepared. WRECKAGE AND IMPACT INFORMATION A postaccident inspection of the airplane by an FAA inspector revealed that the airplane had incurred substantial damage to the wings and fuselage during the landing. On July 23, 2007, the SK Logistics Director of Maintenance started both engines on the accident airplane. The engines were operated to full power and throttles were repeatedly closed to the idle position, but the flameouts could not be duplicated. An inspection conducted on August 8, 2007, by National Transportation Safety Board investigators revealed that the left and right sides of the fuselage over the wings, 31 inches forward of the wings' trailing edges, were buckled. The left side of the fuselage was buckled between the top of the wing and 12 inches above the wing. The right side of the fuselage was buckled between the top of the wing and 13 inches above the wing. There was no other apparent damage to the fuselage. The left wing did not have any apparent damage, and the underside of the wingtip fuel tank was not scraped. The right wing had a 9-inch long by 7 1/2-inch wide tab lifted off the upper surface of the wing over the right main landing gear strut. The tab was lifted approximately 1 ½ inches at the rear. The underside of the right wingtip fuel tank was not scraped. The upper surface portion of the right main landing gear strut was protruding slightly above the upper wing surface. An 'O' ring from the top of the landing gear strut was lying on top of the wing and was cut. The right main landing gear outboard wheel rim was broken 360 degrees around from the hub. The right main landing gear outboard tire was deflated. The right main landing gear strut door was buckled. The nose and left main landing gear did not appear to have any damage. The left and right engines were still in place on the airplane and did not have any indications of an uncontainment, case rupture, or fire. The left and right engines' rotors could be rotated with slight finger pressure and the compressor and turbine blades rotated concurrently. There was no apparent damage to the compressor or turbine blades. Fuel samples were taken from the left and right wing tank sumps and tested for density, flash point, and water content. All of the samples were found to meet the requirements for Jet A fuel, and the fuel tanks contained more fuel than the minimum useable. A total of four fuel filters were removed from the engines, two from each high pressure fuel pump and two from the fuel control on each engine. None of the filters displayed any visible contamination or debris. Examination of the throttle rigging revealed that when the cockpit throttle levers were in the cutoff position, idle stop, or maximum power, the throttle pointer was in the appropriate position on each engine. The original throttles of the Lear 25 were designed that when pulled back to the idle position, their motion was stopped by a detent. A lock pin then needed to be raised to allow the throttle levers to continue back to the cutoff position. ## Aircraft - Registration: [N70SK](https://openairdocs.org/deregistered/N70SK-2008-09-11), registration cancelled 2008-09-11, S/N 049, built 1970 (OpenAirDocs) - Reported make and model: Learjet 25 - Registry model: [Learjet 25](https://openairdocs.org/model/learjet-25) (registry code 5170506) (OpenAirDocs) - Registry engine: [GE CJ610-5&6](https://openairdocs.org/engine/ge-cj610-5-6) (registry code 30013, turbo-jet) (OpenAirDocs) - Category: Airplane - Serial number: 049 - Airframe hours: 15812 - Engines: General Electric CJ610-6 2950 lbs thrust turbo jet - Damage: Substantial damage - Flight: Positioning, Part 91 - Registered owner: SK Logistics Inc - Airworthiness certificate: Standard, Transport - Last inspection: Condition, June 1, 2007 - Departed: GNV, Gainesville, FL - Destination: SGJ, St. Augustine, FL - Flight plan: IFR - Airport: SGJ, St. Augustine Airport, runway 13, 7,996 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 40; injuries: none; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review May 1, 2007; seat: left; flight hours: 4,620 total, 250 in this make and model, 2,500 as pilot in command, 160 in the last 90 days, 55 in the last 30 days, 3 in the last 24 hours - Pilot; age 22; injuries: none; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review December 1, 2006; seat: right; flight hours: 2,453 total, 368 in this make and model, 1,647 as pilot in command, 244 in the last 90 days, 89 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 82 °F, dew point 72 °F - Altimeter: 29.96 inHg - Observed at: SJG, 1 nm away ## 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 20070721018079A](https://openairdocs.org/incident/20070721018079A), Jul 21, 2007: Lear 25, St Augustine, FL, Substantial damage. (-23) On July 21, 2007, at approximately 1415 EDT, a Learjet 25, N70SK, serial #049, was substantially damaged during a hard landing at st. Augustine airport,… 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.