GAA16CA090

NTSB accident investigation · Stinson 108 · Portales, NM · December 19, 2015

Accident · No injuriesData collectionFinal report
Date
December 19, 2015, 14:00 local (21:00 UTC)
Place
Portales, NM
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N97411Stinson 108
Defining event
Landing-aborted after touchdown: Loss of control on ground
Weather
Visual (VMC) · Day
Status
Completed · report April 5, 2016
Report
Approved by Office Director
NTSB office
General Aviation Accidents
Parties
Lubbock FSDO (FAA)
FAA report
20151219022179A
Case key
92503

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 receiving instruction's improper brake application during the flight instructor's aborted landing, which resulted in a loss of directional control and a runway excursion. Contributing to the accident was the flight instructor's decision to perform flight training in an airplane without dual-equipped wheel brakes.

Findings · 4

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.

Action: unnecessary actionPersonnel issues › Action/decision · Student/instructed pilotStinson 108: 1 caseAll aircraft: 52 casesProbable cause
Performance/control parameters: directional controlAircraft › Aircraft oper/perf/capability · Not attained/maintainedStinson 108: 5 casesAll aircraft: 3,958 casesProbable cause
Info processing/decision: decision making/judgmentPersonnel issues › Action/decision · Instructor/check pilotStinson 108: 4 casesAll aircraft: 3,098 casesProbable cause
Wind: crosswindEnvironmental issues › Conditions/weather/phenomena · Effect on equipmentStinson 108: 2 casesAll aircraft: 1,008 cases

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 flight instructor, seated in the right seat, was providing tail-wheel flight instruction in an airplane equipped with wheel brakes only accessible to the pilot in the left seat. The flight instructor reported that he demonstrated the first landing to the pilot receiving instruction in the left seat. During the landing roll, he reported that he began to lose rudder effectiveness and the airplane started to veer to the right, so he applied full power to abort the landing. The flight instructor further reported that during the aborted landing, the pilot receiving instruction applied both toe brakes at the moment full power was applied. The flight instructor attempted to maintain directional control, but the left wing impacted the runway and the airplane veered off the runway to the left. The flight instructor reduced the power to idle and the airplane stopped in the terrain adjacent to the runway. The left wing and left aileron were substantially damaged. The pilot receiving instruction reported that he remained clear of the flight controls and brakes during the landing roll. He reported that he applied brakes only after the runway excursion to the left, after the flight instructor had reduced power to idle during the aborted landing. The flight instructor and pilot receiving instruction reported there were no mechanical malfunctions or failures with the airplane that would have precluded normal operation. Postaccident photos revealed deceleration skid marks leading off the runway first to the right, and additional deceleration skid marks about 550 feet further down the runway leading off to the left into the grass. The flight instructor reported the automated weather observing system about the time of the accident reported wind from 220 degrees true at 10 knots, which resulted in a 5 knot crosswind.

Factual narrative

The flight instructor, seated in the right seat, was providing tail-wheel flight instruction in an airplane equipped with wheel brakes only accessible to the pilot in the left seat. The flight instructor reported that he demonstrated the first landing to the pilot receiving instruction in the left seat. During the landing roll, he reported that he began to lose rudder effectiveness and the airplane started to veer to the right, so he applied full power to abort the landing. The flight instructor further reported that during the aborted landing, the pilot receiving instruction applied both toe brakes at the moment full power was applied. The flight instructor attempted to maintain directional control, but the left wing impacted the runway and the airplane veered off the runway to the left. The flight instructor reduced the power to idle and the airplane stopped in the terrain adjacent to the runway. The left wing and left aileron were substantially damaged. The pilot receiving instruction reported that he remained clear of the flight controls and brakes during the landing roll. He reported that he applied brakes only after the runway excursion to the left, after the flight instructor had reduced power to idle during the aborted landing. The flight instructor and pilot receiving instruction reported there were no mechanical malfunctions or failures with the airplane that would have precluded normal operation. Postaccident photos revealed deceleration skid marks leading off the runway first to the right, and additional deceleration skid marks about 550 feet further down the runway leading off to the left into the grass. The flight instructor reported the automated weather observing system about the time of the accident reported wind from 220 degrees true at 10 knots, which resulted in a 5 knot crosswind.

Aircraft

Registration
N97411
Reported as
Stinson 108 (1)
Category
Airplane
Serial number
108-411
Built
1946
Airframe hours
1,868.3
Engine
Franklin 6A4-150-B3, 150 horsepower, reciprocating
Damage
Substantial damage
Flight
Instructional · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
Annual · March 8, 2015
Departed
PRZ · Portales, NM
Destination
PRZ · Portales, NM
Airport
PRZ · Portales Muni, runway 19, 5,700 × 60 ft, asphalt
Equipment
None

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
72
Injuries
None
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, Without waivers/limitations
Seat
Left
Restraint
Lap only
Flight hours
80 total · 15 in this make and model
Role
Flight instructor
Age
22
Injuries
None
Certificates
Flight instructor, Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Last flight review
May 18, 2015
Seat
Right
Restraint
Lap only
Flight hours
350 total · 3 in this make and model · 310 as pilot in command · 35 in the last 90 days · 5 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
240° at 18 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
63 °F, dew point 16 °F
Altimeter
30.11 inHg
Observed at
KCVS, 14 nm away

Docket · 3

The files NTSB released with the investigation on March 10, 2016, on NTSB’s docket system: statements, records, photos and specialists’ reports. 4.3 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.