GAA16CA281

NTSB accident investigation · American Champion 8KCAB · Black Diamond, WA · June 4, 2016

Accident · Minor injuriesData collectionFinal report
Date
June 4, 2016, 10:30 local (17:30 UTC)
Place
Black Diamond, WA
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N244SFAmerican Champion 8KCAB
Defining event
Landing-flare/touchdown: Abnormal runway contact
Weather
Visual (VMC) · Day
Status
Completed · report August 31, 2016
Report
Approved by Office Director
NTSB office
General Aviation Accidents
Parties
FAA
FAA report
20160604004049A
Case key
93319

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 abnormal runway contact during the landing flare, which resulted in a porpoise, aerodynamic stall, impact with terrain, and nose over.

Findings · 3

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.

Performance/control parameters: landing flareAircraft › Aircraft oper/perf/capability · Not attained/maintainedAmerican Champion 8KCAB: 1 caseAll aircraft: 1,285 casesProbable cause
Performance/control parameters: angle of attackAircraft › Aircraft oper/perf/capability · Capability exceededAmerican Champion 8KCAB: 3 casesAll aircraft: 990 casesProbable cause

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

The pilot of the tailwheel equipped airplane reported that during touchdown the airplane porpoised and drifted off the runway to the right. The pilot further reported that he initiated an aborted landing procedure, but the airplane aerodynamically stalled, impacted the ground, and nosed over. The airplane sustained substantial damage to the empennage. According to the pilot there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. The Federal Aviation Administration has published the Airplane Flying Handbook FAA-H-8083-3A (2004). This handbook discusses aerodynamic stalls and states in part: The key to stall awareness is the pilot's ability to visualize the wing's angle of attack in any particular circumstance, and thereby be able to estimate his/her margin of safety above stall. This is a learned skill that must be acquired early in flight training and carried through the pilot's entire flying career. The pilot must understand and appreciate factors such as airspeed, pitch attitude, load factor, relative wind, power setting, and aircraft configuration in order to develop a reasonably accurate mental picture of the wing's angle of attack at any particular time. It is essential to flight safety that a pilot takes into consideration this visualization of the wing's angle of attack prior to entering any flight maneuver. Stall accidents usually result from an inadvertent stall at a low altitude in which a recovery was not accomplished prior to contact with the surface. The Federal Aviation Administration has published the Airplane Flying Handbook FAA-H-8083-3A (2004). This handbook discusses porpoising and states in part: In a bounced landing that is improperly recovered, the airplane comes in nose first setting off a series of motions that imitate the jumps and dives of a porpoise—hence the name. The problem is improper airplane attitude at touchdown, sometimes caused by inattention, not knowing where the ground is, mistrimming or forcing the airplane onto the runway. Ground effect decreases elevator control effectiveness and increases the effort required to raise the nose. Not enough elevator or stabilator trim can result in a nose low contact with the runway and a porpoise develops. Porpoising can also be caused by improper airspeed control. Usually, if an approach is too fast, the airplane floats and the pilot tries to force it on the runway when the airplane still wants to fly. A gust of wind, a bump in the runway, or even a slight tug on the control wheel will send the air plane aloft again. The corrective action for a porpoise is the same as for a bounce and similarly depends on its severity. When it is very slight and there is no extreme change in the airplane's pitch attitude, a follow-up landing may be executed by applying sufficient power to cushion the subsequent touchdown, and smoothly adjusting the pitch to the proper touchdown attitude.

Factual narrative

The pilot of the tailwheel equipped airplane reported that during touchdown the airplane porpoised and drifted off the runway to the right. The pilot further reported that he initiated an aborted landing procedure, but the airplane aerodynamically stalled, impacted the ground, and nosed over. The airplane sustained substantial damage to the empennage. According to the pilot there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. The Federal Aviation Administration has published the Airplane Flying Handbook FAA-H-8083-3A (2004). This handbook discusses aerodynamic stalls and states in part: The key to stall awareness is the pilot's ability to visualize the wing's angle of attack in any particular circumstance, and thereby be able to estimate his/her margin of safety above stall. This is a learned skill that must be acquired early in flight training and carried through the pilot's entire flying career. The pilot must understand and appreciate factors such as airspeed, pitch attitude, load factor, relative wind, power setting, and aircraft configuration in order to develop a reasonably accurate mental picture of the wing's angle of attack at any particular time. It is essential to flight safety that a pilot takes into consideration this visualization of the wing's angle of attack prior to entering any flight maneuver. Stall accidents usually result from an inadvertent stall at a low altitude in which a recovery was not accomplished prior to contact with the surface. The Federal Aviation Administration has published the Airplane Flying Handbook FAA-H-8083-3A (2004). This handbook discusses porpoising and states in part: In a bounced landing that is improperly recovered, the airplane comes in nose first setting off a series of motions that imitate the jumps and dives of a porpoise—hence the name. The problem is improper airplane attitude at touchdown, sometimes caused by inattention, not knowing where the ground is, mistrimming or forcing the airplane onto the runway. Ground effect decreases elevator control effectiveness and increases the effort required to raise the nose. Not enough elevator or stabilator trim can result in a nose low contact with the runway and a porpoise develops. Porpoising can also be caused by improper airspeed control. Usually, if an approach is too fast, the airplane floats and the pilot tries to force it on the runway when the airplane still wants to fly. A gust of wind, a bump in the runway, or even a slight tug on the control wheel will send the air plane aloft again. The corrective action for a porpoise is the same as for a bounce and similarly depends on its severity. When it is very slight and there is no extreme change in the airplane's pitch attitude, a follow-up landing may be executed by applying sufficient power to cushion the subsequent touchdown, and smoothly adjusting the pitch to the proper touchdown attitude.

Aircraft

Registration
N244SF
Reported as
American Champion 8KCAB (NO SERIES)
Category
Airplane
Serial number
855-2000
Built
2000
Airframe hours
1,203.5
Engine
Lycoming AEIO-360-H1B, 180 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Aerobatic
Last inspection
Annual · May 21, 2016
Departed
TIW · Tacoma, WA
Destination
51WA · Black Diamond, WA
Airport
51WA · Evergreen Sky Ranch, runway 34, 2,600 × 75 ft, grass/turf
Equipment
Handheld GPS, Stall warning system

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
80
Injuries
Minor
Certificate
Airline transport
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 3, With waivers/limitations
Last flight review
July 14, 2014
Seat
Front
Restraint
5-point
Flight hours
3,123.3 total · 255 in this make and model · 3,050 as pilot in command

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
None
Temperature
73 °F, dew point 59 °F
Altimeter
30.11 inHg
Observed at
KPLU, 13 nm away

Docket · 2

The files NTSB released with the investigation on August 17, 2016, on NTSB’s docket system: statements, records, photos and specialists’ reports. 871 KB 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.