WPR22FA067

NTSB accident investigation · Vans RV6 · Show Low, AZ · December 22, 2021

Accident · FatalClass 3 · FieldFinal report
Date
December 22, 2021, 16:39 local (23:39 UTC)
Place
Show Low, AZ · Dry lake bed
Injuries
2 fatal
Damage
Destroyed
Phase of flight
Approach
Aircraft
N6000ZVans RV6
Defining event
Approach-VFR go-around: Loss of control in flight
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Western Pacific Region
Parties
FAA, Lycoming Engines
FAA report
20211222021919A
Case key
104437

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Probable cause

The pilot’s exceedance of the airplane’s critical angle of attack following an aborted landing approach, which resulted in an aerodynamic stall and loss of control at an altitude too low for recovery.

Findings · 5

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

Witnesses reported that a high-wing airplane and a low-wing airplane were on final approach for landing to the same runway, with the high-wing airplane ahead of and slightly below the low-wing airplane. An airport employee stated that the pilot of the high-wing airplane was making position reports over the airport’s common traffic advisory frequency (CTAF), but the pilot of the low-wing airplane was not. The employee transmitted via the CTAF that there were two airplanes on final approach, at which time the pilot of the high-wing airplane aborted the landing. That pilot reported that he never saw the other airplane. The pilot of the low-wing airplane (accident airplane) subsequently transmitted that he had been using the wrong radio frequency and aborted the landing approach, entering a right turn away from the runway at low altitude. Witnesses reported that, during the turn, the accident airplane entered a nose-low descent that continued until it impacted the ground. The airplane impacted terrain in a near-vertical, nose-down attitude. Postaccident examination of the airframe and engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. Based on the available information, it is likely that the pilot exceeded the airplane’s critical angle of attack while maneuvering away from the runway during the aborted landing approach, which resulted in an aerodynamic stall and loss of control at an altitude too low for recovery. It is possible that the high-density altitude conditions and the distraction of looking for conflicting traffic may have contributed to the accident.

Factual narrative

According to the FAA Airplane Flying Handbook (FAA-H-8083-3C): At the same gross weight, airplane configuration, CG location, power setting, and environmental conditions, a given airplane consistently stalls at the same indicated airspeed provided the airplane is at +1G (i.e., steady-state unaccelerated flight). However, the airplane can also stall at a higher indicated airspeed when the airplane is subject to an acceleration greater than +1G, such as when turning, pulling up, or other abrupt changes in flightpath. Stalls encountered any time the G-load exceeds +1G are called “accelerated maneuver stalls.” The accelerated stall would most frequently occur inadvertently during improperly executed turns, stall and spin recoveries, pullouts from steep dives, or when overshooting a base to final turn… Stalls that result from abrupt maneuvers tend to be more aggressive than unaccelerated, +1G stalls. Because they occur at higher-than-normal airspeeds or may occur at lower-than-anticipated pitch attitudes, they can surprise an inexperienced pilot…Failure to execute an immediate recovery may result in a spin or other departure from controlled flight. SOW is a publicly owned, nontower-controlled airport with a reported field elevation of 6,415 ft mean sea level. The airport was equipped with two asphalt runways. Runway 22 was 3,938 ft long, 60 ft wide, and had a left traffic pattern. On December 22, 2021, about 1639 mountain standard time, an experimental, amateur-built RV-6A airplane, N6000Z, was destroyed when it was involved in an accident near Show Low, Arizona. The pilot and passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. An airport employee reported that he saw two airplanes on final approach for landing; the airplane in front, a Cessna, was at a lower altitude than the accident airplane, which was descending toward the Cessna. The pilot of the Cessna was making radio calls on the airport’s common traffic advisory frequency. He did not hear any radio transmissions from the pilot of the other airplane (the accident airplane). The employee transmitted via radio that the two airplanes were about to collide, and the pilot of the Cessna aborted his landing and turned to the north. Shortly thereafter, the pilot of the accident airplane transmitted via radio that he was on the wrong frequency and aborted his landing to the north. The accident airplane continued its turn at low altitude and appeared to stall, immediately entering a “nosedive” toward the ground. Another witness reported that he also saw the two airplanes close to each other on final approach for landing, with the second airplane descending toward the first airplane. He then saw the first airplane turn north, and about five seconds later, the second airplane turned north. He saw the second airplane’s wing dip, and the airplane entered a nose-low descent toward the ground. The pilot of the Cessna reported that hedid not see the accident airplane, and aborted his landing when he heard the transmission that there were two airplanes on final approach. Based on the environmental conditions on the day of the accident, the density altitude at the accident site was estimated to be about 7,423 ft. The private pilot held a rating for airplane single-engine land. His most recent Federal Aviation Administration (FAA) second-class airman medical certificate was issued on May 5, 2015, without limitations. The pilot reported on his application that he had accumulated 5 total hours of flight experience, with 5 hours in the previous 6 months since the examination. The pilot’s logbooks were not located during the investigation. Examination of the accident site revealed that the airplane impacted terrain near the edge of a dry lakebed. The first point of impact displayed marks consistent with the wings and propeller hub in a near-vertical impact attitude. All major components of the airplane and most of the wreckage debris was contained within the main wreckage site. A post-impact fire consumed most of the airplane. Postaccident examination of the airframe and engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation.

Aircraft

Registration
N6000Z
Reported as
Vans RV6 (A)
Category
Airplane, amateur-built
Serial number
24142
Built
2001
Engine
Lycoming O-320 Series, 180 horsepower, reciprocating
Damage
Destroyed
Fire
On-Ground
Flight
Personal · Part 91
Airworthiness certificate
Special, Experimental (Special)
Departed
TYL · Taylor, AZ
Destination
Same as departure
Airport
SOW · Show Low Rgnl, runway 22, 3,938 × 60 ft, asphalt

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
40
Injuries
Fatal
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 2, Without waivers/limitations
Seat
Left
Toxicology
Performed
Flight hours
5 total

Weather

Conditions
Visual (VMC) · Day
Wind
210° at 7 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
55 °F, dew point 10 °F
Altimeter
30.16 inHg
Observed at
KSOW
METAR
KSOW 222335Z AUTO 21007KT 10SM CLR 13/M12 A3016 RMK AO2

Docket · 9

The files NTSB released with the investigation on May 3, 2023, on NTSB’s docket system: statements, records, photos and specialists’ reports. 2.5 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.

Other investigations on N6000Z · 1

Matched to the same aircraft by N-number and date.