WPR12LA135

NTSB accident investigation · Cook Smith AVN Replica SU · St. Johns, AZ · March 13, 2012

Accident · Minor injuriesLimited investigationFinal report
Date
March 13, 2012, 09:50 local (16:50 UTC)
Place
St. Johns, AZ
Injuries
1 minor, 1 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N712AZCook Smith AVN Replica SU
Defining event
Landing-landing roll: Loss of control on ground
Weather
Visual (VMC) · Day
Status
Completed · report January 31, 2013
Report
Approved by Office Director
NTSB office
Western Pacific Region
Parties
Federal Aviation Administration
FAA report
20120313006169A
Case key
83130

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

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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 anomalies that would have precluded normal operation.

Findings · 2

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: directional controlAircraft › Aircraft oper/perf/capability · Not attained/maintainedCook Ron SMITH AVN REPLICA SU: 1 caseAll aircraft: 3,958 casesProbable cause
Landing gear system: brakeAircraft › Aircraft systems · Not specifiedCook Ron SMITH AVN REPLICA SU: 1 caseAll aircraft: 297 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 had recently purchased the airplane and was receiving instruction in it. The pilot reported that the day before the accident, during landing, the left brake became less responsive than the right, and the airplane veered off of the runway but incurred no damage. The pilot and his flight instructor then bled the brake lines. This was followed by taxi and touch-and-go landing checks with no anomalies noted. The following morning the brakes were tested again and were operational. During the fourth landing that morning, the right brake locked up, and the airplane swerved to the right and nosed over. Although the flight instructor indicated that he had signed off the pilot for his tailwheel endorsement the day of the accident, he did not hold a current airman medical certificate. Additionally, the instructor reported that he did not remain on the flight controls with the pilot during the landings. Postaccident examination of the brake system revealed no evidence of a mechanical malfunction or failure that would have precluded normal operation.

Factual narrative

On March 13, 2012, at 0950 mountain standard time, an experimental Cook Smith Aviation Replica SU, N712AZ, veered from the runway during landing at St. Johns Municipal Airport, St. Johns, Arizona. The private pilot sustained minor injuries and the certified flight instructor (CFI) was not injured. The airplane was substantially damaged. The pilot was operating the airplane under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed. According to the pilot, he purchased the airplane on March 12, and was ferrying it from Arizona to Texas. The CFI was providing flight instruction to the owner during the flight. While landing for fuel at St. Johns on March 12, the pilot discovered that the left brake was less responsive than the right. The airplane veered off of the runway, but incurred no damage. The pilot indicated that the brakes were not operating on either the right or left side. The pilot and CFI then decided to bleed the brake lines. The brakes were successfully tested during taxi tests, followed by touch-and-go takeoffs and landings, and the pilot and CFI remained overnight in St. Johns. The following morning, the brakes were tested again, and found to be operational. The winds were calm. The pilot and CFI departed to practice touch-and-go takeoffs and landings. During the fourth landing, the left brake was not as responsive as the right brake. The pilot reported that the right brake locked up and the airplane swerved to the right, skidding off of the runway, and the airplane came to rest inverted. The certified flight instructor (CFI) was interviewed following the accident. He reported that he was flying with the aircraft owner from Arizona to Texas. They had landed at St. Johns the previous day and encountered a problem with the brakes in the airplane. The airplane departed the runway surface but resulted in no damage. They elected to bleed the brake system and completed post maintenance checks on the airplane. No problems were noted. The following morning they completed three landings successfully. On the fourth landing, the brakes locked up and the airplane veered off into a gully. The CFI was not on the flight controls at the time, but indicated that the left brake failed. The CFI stated that the pilot had about 10 hours in a similar make and model airplane as the accident airplane. He gave the pilot his tailwheel endorsement the morning of the accident; however the CFI did not hold a current airman medical. 14 CFR Part 61.31 states, in part, "...no person may act as pilot in command of a tailwheel airplane unless that person has received and logged flight training from an authorized instructor in a tailwheel airplane and received an endorsement in the person's logbook from an authorized instructor who found the person proficient in the operation of a tailwheel airplane." The FAA accident coordinator examined the airplane following the accident. Nomechanical anomalies were identified with the braking system.

Aircraft

Registration
N712AZ
Reported as
Cook Smith AVN Replica SU
Category
Airplane, amateur-built
Serial number
04076
Airframe hours
125
Engine
Mattituck TMX O-360, 180 horsepower, reciprocating
Damage
Substantial damage
Flight
Ferry · Part 91
Operator
Clayton McMartin
Registered owner
Freedom Group, Inc.
Airworthiness certificate
Special, Experimental (Special)
Last inspection
Annual · March 1, 2012 · 19 hours before
Departed
SJN · St. Johns, AZ
Destination
SJN · St. Johns, AZ
Airport
SJN · St. Johns Industrial Air Park, runway 14, 5,322 × 75 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 · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
48
Injuries
None
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, Without waivers/limitations
Last flight review
December 1, 2010
Seat
Front
Flight hours
257 total · 12 in this make and model · 28 in the last 90 days · 2 in the last 24 hours
Role
Flight instructor
Age
62
Injuries
None
Certificates
Flight instructor, Commercial
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Last flight review
May 15, 2010
Seat
Rear
Flight hours
5,000 total

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
None
Temperature
52 °F, dew point 9 °F
Altimeter
30.12 inHg
Observed at
SJN

Docket · 7

The files NTSB released with the investigation on November 28, 2012, 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 N712AZ · 1

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