# NTSB CEN17LA096: Cook Smith Aviation Repli, N712AZ, Justin, TX, January 31, 2017 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: January 31, 2017, 15:00 local (21:00 UTC) - Place: Justin, TX - Coordinates: 33.08472, -97.295829 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.0847&lon=-97.2958&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor - Status: Completed, report November 6, 2018 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA North Texas FSDO, Continental Motors - NTSB case key (mKey): 94677 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN17LA096 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94677/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94677 - Page: https://openairdocs.org/ntsb/CEN17LA096 ## Probable cause A total loss of engine power due to fuel starvation as the result of a disruption in fuel flow. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Cook Ron SMITH AVN REPLICA SU, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=056262R), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Cook Ron SMITH AVN REPLICA SU, 1 case](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=056262R), [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Simulated/training event](https://openairdocs.org/ntsb-events/600); cases with it: [Cook Ron SMITH AVN REPLICA SU, 1 case](https://openairdocs.org/ntsb-events/600/sequence.md?model=056262R), [All aircraft, 173 cases](https://openairdocs.org/ntsb-events/600/sequence.md) - [Maneuvering-low-alt flying: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Cook Ron SMITH AVN REPLICA SU, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=056262R), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cook Ron SMITH AVN REPLICA SU, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=056262R), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The private pilot reported that he departed in the experimental, amateur-built airplane with 10 gallons of fuel in the left fuel tank and 15 gallons of fuel in the right fuel tank. He had flown for about 15 minutes in straight and level flight, then he conducted a simulated forced landing to a wheat field. During the recovery from the practice maneuver, he turned off the carburetor heat, applied full engine power, and raised the nose to a steep pitch attitude of about 35° to 40° nose up. He stated that the engine experienced a total loss of power in the climb about 200 to 500 ft above ground level. He pushed the control stick full forward to maintain airspeed and chose to land straight ahead. The engine started to "sputter" and regain power about the time that the airplane struck the trees, which resulted in substantial damage to the wings and fuselage. Examination of the accident site revealed that no fuel was present; however, the airplane's fuel system was largely compromised by impact damage. There were no apparent fuel stains on the fabric-covered wings. Based on the temperature and dew point about the time of the accident, the conditions were not favorable for carburetor icing at any power setting. The engine was installed on an engine test stand and operated through a range of engine power settings between 1,200 to 2,700 rpm, and at idle. Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The airplane had a 180-hp engine installed that was not equipped with an engine-driven fuel pump or electric fuel boost pump. The airplane's gravity feed fuel system had 24-gallon fuel tanks installed in each overhead wing, but there was no fuel header tank installed. Leading edge slats were installed along the entire span of the right and left wings, which allowed the airplane to be flown at a very high nose-up pitch attitude. It was possible for the airplane to climb at a very steep angle, which could put the carburetor higher than the wing tanks. With inadequate fuel pressure to deliver fuel to the carburetor, it is possible that a gravity feed fuel system might experience a disruption of fuel flow in high nose-up pitch attitudes; given the lack of any mechanical anomalies with the engine, it is likely that the loss of power was the result of a disruption of fuel flow during the climb. ## Factual narrative On January 31, 2017, about 1500 central standard time, an experimental, amateur-built Cook Smith Aviation Replica SU airplane, N712AZ, sustained substantial damage when it struck trees and impacted terrain during a forced landing after a loss of engine power near Justin, Texas. The pilot received minor injuries and the passenger received serious injuries. The airplane was registered to Clear Blue Marketing, Inc., and was operated by the pilot under the provisions of the Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which was not operating on a flight plan. The flight departed from the Northwest Regional Airport (52F), Roanoke, Texas, about 1440 on a local flight. The pilot reported that he departed with 10 gallons of fuel in the left fuel tank and 15 gallons of fuel in the right fuel tank. He had flown for about 15 minutes in straight and level flight when he flew a practice forced landing to a wheat field. He stated that during the recovery from the practice maneuver, he turned off the carburetor heat, applied full power, and raised the nose to a steep pitch attitude of about 35° to 40° nose up. He stated that the engine experienced a total loss of power in the climb about 200 to 500 ft above ground level. He pushed the stick full forward to maintain airspeed and he chose to land straight ahead. He stated that the engine started to "sputter" and regain power about the time that the airplane struck the trees, which resulted in substantial damage to the wings and fuselage. The pilot and passenger were able to exit the airplane. The pilot stated that he turned the fuel selector to the OFF position and disconnected the battery cable. The 52-year-old pilot held a private pilot's certificate with airplane single-engine land and airplane single-engine sea ratings. He held a third-class medical certificate issued on January 1, 2016. The pilot reported that he had 1,054 total flight hours with 176 flight hours in the make and model of the accident airplane. The experimental, amateur built Cook Smith Aviation Replica SU, N712AZ, serial number 30-6, was manufactured in 2008. The high-wing airplane was a two-place tandem seat airplane equipped with the 180-horsepower TMX Mattituck O-360 engine and had a maximum gross weight of 2,400 lbs. Leading edge slats were installed along the entire span of the right and left wings, which allows the airplane to be flown at a very high nose up attitude. The fuel system was a gravity feed system to the carburetor. Each wing had a 24-gallon metal fuel tank, but there was no header tank installed. The 3/8-inch diameter fuel lines went from the fuel tanks to the fuel drain located in the belly of the airplane aft of the engine firewall. Then the fuel lines were then connected to the fuel selector before being routed to the carburetor through a fuel transducer which measured the fuel flow. The airplane was not equipped with an electric fuelboost pump. Airplane maintenance records indicated that the airplane was previously involved in a nose over accident. Maintenance was performed to bring the airplane into an airworthy condition, which was completed on November 3, 2016. At the time of the inspection, the maintenance logbooks indicated that it had 124.60 hours total time on the airframe, and the tach read 0.0 hours. The pilot reported that at the time of the accident, the engine had a total time of 145 hours and 21 hours since the last inspection. Figure 1 - View of the airplane wreckage at the accident site A Federal Aviation Administration inspector examined the airplane at the accident site. He reported that the left wing had impacted the trees and remained lodged in the branches. The left-wing fuel tank was separated from the wing and was found lying on the ground. It exhibited minor impact damage. The fuel cap was off, and no fuel was found in the tank. The main airplane wreckage was located about 40 ft from the tree that was struck by the left wing. The fabric-covered right wing was found with the main wreckage, but it was broken and fractured at numerous places. The right-wing's metal fuel tank's leading edge was crushed about 12 inches, which was consistent with an impact with a tree. The fuel tank was compromised, and the fuel cap was off. The inspector reported that the carburetor bowl plug was removed, and no fuel drained from the bowl. There were no apparent fuel stains on the fabric covered wings. The propeller did not exhibit rotational damage. The engine was shipped to the Continental Motors facility at Fairhope, Alabama, for examination and engine run. The engine was installed on an engine test stand and an engine run was conducted. The engine operated through a range of engine RPMs between 1,200 to 2,700 RPMs, and at idle. The engine was not equipped with an engine driven fuel pump. At 1454, the surface weather observation at the Fort Worth Alliance Airport (AFW), Fort Worth, Texas, located 6 nautical miles southwest of the accident site, was: wind 190 at 6 kts; 10 miles visibility; sky condition few clouds at 25,000 ft; temperature 26° C; dew point -4° C; altimeter 29.88 inches of mercury. The Smith Aviation Replica SU airplane kit is no longer in production; however, Backcountry Super Cub manufactures a similar airplane kit. The owner of Backcountry Super Cub reported that all their engines are equipped with engine driven fuel pumps, and he recommends that aircraft builders install electric fuel boost pumps to ensure adequate fuel flow to engines that demand more fuel at high power settings. He reported that the slats on the leading edge of the wing allow for a very high nose up attitude, about 40-50 degrees up, which could possibly cause fuel starvation unless there is adequate fuel head pressure to deliver the fuel to the carburetor. ## Aircraft - Registration: [N712AZ](https://openairdocs.org/deregistered/N712AZ-2019-06-18), registration cancelled 2019-06-18, S/N 04076, built 2008 (OpenAirDocs) - Reported make and model: COOK Smith Aviation Repli - Registry model: [Cook Ron SMITH AVN REPLICA SU](https://openairdocs.org/model/cook-ron-smith-avn-replica-su) (registry code 056262R) (OpenAirDocs) - Registry engine: [Mattituck TMX-360](https://openairdocs.org/engine/mattituck-tmx-360) (registry code 59602, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 04076 - Year built: 2008 - Airframe hours: 124 - Engines: TMX Mattituck O-360 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, November 3, 2016, 21 hours before - Departed: 52F, Roanoke, TX - Destination: 52F, Roanoke, TX - Equipment: Handheld GPS, Electronic primary flight display, Electronic multifunction display, Auto-pilot ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 52; injuries: minor; private; airplane ratings: single-engine sea, single-engine land; medical: class 3; seat: front; restraint: 4-point; flight hours: 1,054 total, 176 in this make and model, 38 in the last 90 days, 12 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 190° at 16 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 25 °F - Altimeter: 29.87 inHg - Observed at: AFW, 6 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 20170131016489A](https://openairdocs.org/incident/20170131016489A), Jan 31, 2017: Cook Ron SMITH AVN REPLICA SU, Northlake, TX, Destroyed. On January 31, 2017, at 1528 CST, a smith aviation super cub kit, N712AZ, registered to clear blue marketing, inc, lost power to the engine and collided with a… ## Other investigations on N712AZ (1) 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. - [NTSB WPR12LA135](https://openairdocs.org/ntsb/WPR12LA135), Mar 13, 2012: Cook Smith AVN Replica SU (N712AZ), St. Johns, AZ, substantial damage. Probable cause: The pilots’ failure to maintain directional control when the right brake locked up during the landing roll for reasons that could not be determined because postaccident examination did not reveal any… ## Docket (10 files) The files NTSB released with the investigation on March 28, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94677. 6.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 750 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461366&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - NTSB Record of Conversations (item 2, .PDF, 111 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461367&FileExtension=.PDF&FileName=NTSB%20Record%20of%20Conversations-Master.PDF - Record of Conversation with FAA Inspector (item 3, .PDF, 55 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461368&FileExtension=.PDF&FileName=Record%20of%20Conversation%20with%20FAA%20Inspector-Master.PDF - Aircraft Maintenance Records (item 4, .PDF, 2.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461369&FileExtension=.PDF&FileName=Aircraft%20Maintenance%20Records-Master.PDF - Aircraft Weight and Balance (item 5, .PDF, 49 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461370&FileExtension=.PDF&FileName=Aircraft%20Weight%20and%20Balance-Master.PDF - Engine Run Results (item 6, .PDF, 503 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461371&FileExtension=.PDF&FileName=Engine%20Run%20Results-Master.PDF - Carburetor Icing Chart (item 7, .PDF, 107 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461372&FileExtension=.PDF&FileName=Carburetor%20Icing%20Chart-Master.PDF - Investigation Photos (item 8, .PDF, 12 photos, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461373&FileExtension=.PDF&FileName=Investigation%20Photos-Master.PDF - NTSB Party Form (item 9, .PDF, 68 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461374&FileExtension=.PDF&FileName=NTSB%20Party%20Form-Master.PDF - NTSB Wreckage Release (item 10, .PDF, 416 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461375&FileExtension=.PDF&FileName=NTSB%20Wreckage%20Release-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.