Saturday, June 15, 2019

Aerodynamic Stall / Spin: Cessna 172N Skyhawk, N251CH, fatal accident occurred November 04, 2017 near Hatch Municipal Airport (E05), Dona Ana County, New Mexico


Anthony DeRamus, pilot

Christopher Howell

Malcolm Watkins and Kanequa Chancellor

The National Transportation Safety Board traveled to the scene of this accident.

Additional Participating Entities:

Federal Aviation Administration / Flight Standards District Office; Albuquerque, New Mexico
Textron Aviation; Wichita, Kansas
Lycoming; Chandler, Arizona

Aviation Accident Factual Report - National Transportation Safety Board: https://app.ntsb.gov/pdf


Investigation Docket - National Transportation Safety Board: https://dms.ntsb.gov/pubdms

http://registry.faa.gov/N251CH




Location: Hatch, NM
Accident Number: CEN18FA024
Date & Time: 11/04/2017, 1630 MDT
Registration: N251CH
Aircraft: CESSNA 172N
Aircraft Damage: Substantial
Defining Event: Aerodynamic stall/spin
Injuries: 4 Fatal
Flight Conducted Under: Part 91: General Aviation - Personal 

On November 4, 2017, about 1630 mountain daylight time, a Cessna 172N airplane, N251CH, sustained substantial damage when it impacted terrain near Hatch Municipal Airport (E05), Hatch, New Mexico. The pilot and three passengers received fatal injuries. The airplane was owned by Caribbean Paradise LLC and was being operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal flight. Day visual meteorological conditions prevailed, and no flight plan was filed for the flight, which departed from E05 between 1630 and 1730 and was destined for El Paso International Airport (ELP), El Paso, Texas. 

The flight departed ELP earlier in the day and landed at E05 about 1300. The pilot and passengers went to a local restaurant in Hatch and had lunch; they were driven back to the airport around 1600. The exact departure time is unknown and there were no witnesses to the accident. The airplane impacted rugged desert terrain about 0.56 nautical mile west of the departure end of runway 29 (4,110 ft by 60 ft, asphalt) at E05. The flight did not return to ELP as expected, and a Federal Aviation Administration (FAA) Alert Notice was issued. The wreckage was not located until about 1700 on November 5, 2017. 

Pilot Information

Certificate: Private
Age: 57, Male
Airplane Rating(s): Single-engine Land
Seat Occupied: Left
Other Aircraft Rating(s): None
Restraint Used: 3-point
Instrument Rating(s): None
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: Yes
Medical Certification: Class 3 With Waivers/Limitations
Last FAA Medical Exam: 08/25/2016
Occupational Pilot: No
Last Flight Review or Equivalent: 09/23/2016
Flight Time:  140 hours (Total, all aircraft) 

The 57-year-old pilot held a private pilot certificate issued on September 23, 2016, with a single-engine land rating. On the application for that certificate, he reported 139.6 total hours of flight experience. The pilot's logbook was not obtained during the course of the investigation. He held a third-class FAA airman medical certificate that was issued on August 25, 2016.



Aircraft and Owner/Operator Information

Aircraft Make: CESSNA
Registration: N251CH
Model/Series: 172N
Aircraft Category: Airplane
Year of Manufacture: 1978
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: 17271075
Landing Gear Type: Tricycle
Seats: 4
Date/Type of Last Inspection: 11/01/2016, Annual
Certified Max Gross Wt.: 2550 lbs
Time Since Last Inspection:
Engines: 1 Reciprocating
Airframe Total Time: 5538 Hours as of last inspection
Engine Manufacturer: LYCOMING
ELT: Installed, not activated
Engine Model/Series: O-360-A4M
Registered Owner: CARIBBEAN PARADISE LLC
Rated Power: 180 hp
Operator: On file
Operating Certificate(s) Held: None

The four-seat, single-engine airplane, serial number 1727105, was manufactured in 1978. It was equipped with a 180-horsepower Lycoming O-360-A4M engine, serial number L-31715-36A, per Supplemental Type Certificate (STC) SA4428SW. The STC engine installation increased the engine horsepower from 160 to 180 horsepower. STC SA2196CE increased the gross weight of the airplane from 2,300 lbs to 2,550 lbs. The engine powered a two-bladed, metal Sensenich propeller.

The estimated weight of the airplane at takeoff was 2,526 lbs, given the following estimated weights:

Aircraft Empty Weight: 1,513 lbs

Pilot/Front Pax: 450 lbs

Rear Pax: 385 lbs

Baggage: 5 lbs

Fuel: 180 lbs (30 gallons x 6 lbs; Total fuel capacity is 40 gallons)

Minus Start/Taxi/Runup Fuel: -7 lbs 



Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: KLRU, 4456 ft msl
Distance from Accident Site: 27 Nautical Miles
Observation Time: 1635 MDT
Direction from Accident Site: 148°
Lowest Cloud Condition: Clear
Visibility:  10 Miles
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: 15 knots / 18 knots
Turbulence Type Forecast/Actual: /
Wind Direction: 220°
Turbulence Severity Forecast/Actual: /
Altimeter Setting: 30.05 inches Hg
Temperature/Dew Point: 23°C / 6°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Hatch, NM (E05)
Type of Flight Plan Filed: None
Destination: El Paso, TX (ELP)
Type of Clearance: None
Departure Time: 1630 MDT
Type of Airspace:

At 1635, the surface weather observation at Las Cruces International Airport (LRU), Las Cruces, New Mexico, located 27 nm south of the accident site, included wind from 220° at 15 kts, gusting to 18 kts; 10 miles visibility; clear skies; temperature 23°C; dew point 6°C; altimeter 30.05 inches of mercury.

On November 4, 2017, sunrise at Hatch, New Mexico, was at 0729 and sunset was at 1815. At 1730, the solar azimuth was 245.54° and the solar elevation was 8.1°.

The elevation at E05 was 4,456 ft. The calculated density altitude at 1635 was 6,371 ft. 



Airport Information

Airport: Hatch Municipal Airport (E05)
Runway Surface Type: Asphalt
Airport Elevation: 4129 ft
Runway Surface Condition: Dry
Runway Used: 29
IFR Approach: None
Runway Length/Width: 4110 ft / 60 ft
VFR Approach/Landing: None

Wreckage and Impact Information

Crew Injuries: 1 Fatal
Aircraft Damage: Substantial
Passenger Injuries: 3 Fatal
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 4 Fatal
Latitude, Longitude: 32.666389, -107.214444 

The on-site examination of the wreckage revealed that the airplane impacted terrain in a steep, left-wing-low, nose-down attitude on a 110° heading. A piece of the left wingtip and red navigation lens was found near the initial impact point. The step from the left strut was found 17 ft to the right of the left wingtip's initial impact point. A depression in the sand stretched from the initial impact point to a 5-ft-by-4-ft depression in the sand that was located near the left step. Pieces from the nose of the airplane and engine cowling were found in the depression. A 25-ft skid mark stretched across the sand from the depression to where the engine and propeller were located in front of the main wreckage. The nose of the airplane was aligned on a 020° heading. First responders reported that the tail of the airplane was initially found in a near-vertical position, but it had fallen back down and was resting on the ground.

The left wing exhibited aft crushing of the outboard section of its leading edge. The left wing was buckled and broken about mid-span and the left wing strut was buckled. The left wheel was separated from the left landing gear. The aileron and flap remained attached to the wing. No fuel was found in the left fuel tank and the fuel lines were broken at the wing root. The 25-gallon fuel tank exhibited hydraulic deformation, with the forward section of the fuel tank bulging out and the rear of the tanks sucked in. There were no apparent fuel stains on the sandy soil. 

The right wing exhibited aft crushing of the wingtip. The rest of the wing, including the strut, remained largely intact. The right wheel remained attached to the right landing gear and did not exhibit any impact damage. The aileron and flap remained attached to the wing. No fuel was found in the right fuel tank and the fuel lines were broken at the wing root. The 25-gallon fuel tank exhibited hydraulic deformation, with the forward section of the fuel tank bulging out and the rear of the tanks sucked in. There were no apparent fuel stains on the sandy soil. 

The empennage remained attached to the fuselage and no impact damage was evident to the vertical and horizontal stabilizers or their control surfaces. The airplane's tail was found buckled aft of the rear passengers' seats and offset to the left of the cabin and fuselage. 

The examination of the cabin and engine compartment revealed extensive downward and aft buckling and crushing of the airframe structure. The engine remained attached to the firewall and engine mount. Numerous fractures were observed that were consistent with overload fractures. The engine firewall was bent aft and down. The cockpit exhibited damage consistent with downward and aft crushing and buckling. The fuel strainer was intact. The fuel strainer bowl and screen were clean; however, a light blue rubbery material (similar to RTV blue silicone gasket sealant) was observed around the top of the fuel strainer screen.

The examination of the cockpit revealed that the ignition switch was in the BOTH position, and the master battery and alternator switches were on. The fuel selector handle was found in the BOTH position. The fuel selector valve was found in the off position; however, the shaft for the fuel selector valve exhibited impact damage and was bent. The throttle was found in the full-power position and the throttle cable was still connected to the carburetor. The mixture was in the full-rich position, but the mixture cable was separated at the carburetor. The carburetor heat was in the cold position, but the carburetor air/heat box was crushed from impact forces. Most of the instruments were destroyed; the airspeed indicator needle indicated 46 kts, the altimeter indicated 5,800 ft, the vertical speed indicator indicated a 300 ft-per-minute descent, and the altimeter Kollsman window displayed 29.95. The engine tachometer indicated 300 rpm and displayed 1,232.5 hours of operation.

The elevators, rudder, and flaps exhibited control continuity from the cockpit controls to the control surfaces. Aileron control continuity was established to the left aileron. The right aileron push/pull rod from the wing bellcrank to the aileron was separated, and the rod end was bent and displayed a fracture surface consistent with overload. The flap indicator in the cockpit was in the extended position, but the flap actuator was found in the retracted position.

The engine was separated from the airframe and the propeller was removed from the engine. The crankshaft was rotated by hand utilizing the vacuum pump drive, and thumb compression was obtained in proper firing order. Mechanical continuity of the drivetrain was established during the rotation of the crankshaft. Each of the valve rockers moved in normal order. Cylinder borescope examination revealed no evidence of foreign object ingestion or detonation to any of the cylinders. The left and right magnetos remained secure at their respective mounting pads. The magnetos were removed and produced spark at each lead during hand rotation of the drive. The Champion REM-40E spark plugs remained secure at each cylinder with their respective lead attached. The top spark plugs were removed and exhibited no mechanical damage at each electrode. The coloration was consistent with normal operation. The carburetor was separated from the engine at the mounting flange. The fuel filter inlet screen was free of visible contaminants. The carburetor was opened for examination. The plastic floats remained undamaged and securely mounted. There was no fuel observed, and there were no visible contaminants observed in the bowl. The air filter was crushed. There were no foreign objects observed in the carburetor air passage.

The propeller remained attached to the crankshaft flange. The flange exhibited impact damage and was bent, and the metal spinner was crushed. The blades remained intact. One propeller blade exhibited significant leading-edge damage, chordwise striations, trailing edge "S" bending and torsional twisting. The opposing blade exhibited leading edge damage and moderate chordwise striations. The signatures were consistent with rotational energy at the time of impact. 

Medical And Pathological Information

The Office of the Medical Investigator, Albuquerque, New Mexico, performed an autopsy of the pilot. The cause of death was from multiple blunt force injuries. The autopsy identified moderate coronary artery disease without angina with 3 stent placements.

Toxicology testing performed at the FAA Forensic Sciences Laboratory detected no carbon monoxide in blood and no ethanol in vitreous. The testing indicated 2.206 (µg/mL, µg/g) desmethylvenlafaxine (O-) in the liver; 0.856 (µg/mL, µg/g) desmethylvenlafaxine (O-) in the blood; 0.575 (µg/mL, ug/g) venlafaxine in liver; and 0.252 (µg/mL, µg/g) venlafaxine in blood. Venlafaxine is an antidepressant medication. Desmethylvenlafaxine is a metabolite of venlafaxine. 

Additional Information

According to the Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25B) Chapter 10, Weight and Balance, excessive weight reduces flight performance in almost every respect. Some of the most important performance deficiencies of an overloaded aircraft include higher takeoff speed, longer takeoff run, reduced rate and angle of climb, and higher stalling speed.

FAA Pamphlet 8740-2, Density Altitude, states that an increase in density altitude results in increased takeoff distance and reduced rate of climb. Additionally, at density altitude above 5,000 ft, it is necessary to lean normally aspirated engines for maximum takeoff power; otherwise, the excessively rich fuel/air mixture is another detriment to overall performance.

1 comment:

Anonymous said...

As was expected... chubby pax not from 1960s where the average weight of an american was a mere 170 lb + almost full fuel + 6300 ft density altitude = disaster.

My first encounter with density altitude was in TX and my C172 chewed up the whole runway with a density altitude of 6000 ft and 90 degrees temp.

I was alone and weigh 160 lb!!! and the airplane climbed at 150 ft/min for a good 2-3 minutes until it reached colder air and resumed a less knuckle scaring 500 ft/min.

Density altitude is a thing and one's first encounter with it always scary AF.