SEA04LA115

NTSB accident investigation · Piper PA-20 · Deer Park, WA · June 23, 2004

Accident · No injuriesLimited investigationFinal report
Date
June 23, 2004, 09:45 local (16:45 UTC)
Place
Deer Park, WA
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N699DSPiper PA-20
Weather
Visual (VMC) · Day
Status
Completed · report October 28, 2004
Report
Approved by Office Director
Parties
Federal Aviation Administration
FAA report
20040623014129A
Case key
59546

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 flight instructor's delayed remedial action. Factors include the owner/pilot's failure to maintain directional control during the landing roll, and a warped/realigned fuselage that contributed to the sensitivity of the aircraft's response to pilot rudder inputs.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of control - on ground/waterLanding
Directional control - not maintainedPilot in commandFactor
Remedial action - delayedPilot in command(cfi)Cause
Fuselage - warpedFactor
Main gear collapsedLanding - roll
Landing gear,main gear - overload
On ground/water encounter with terrain/waterLanding - roll
Terrain condition - ground

Analysis

The pilot/owner had previously received a tail wheel endorsement, but had not utilized it for a number of years. He was therefore working with an instructor to regain his proficiency, but the flight instructor chose to fly in the left seat because the airplane only had brakes on that side, and it had been awhile since he had instructed in a tail wheel aircraft. On the second touch-and-go of the day, the owner made an approach with the intent to do a three-point landing, but inadvertently allowed the airplane's main wheels to contact the ground first, resulting in a bounce. The airplane then touched down in a three-point attitude and began to swerve to the left. The owner applied right rudder, but could not stop the turn. Seeing that the owner was having difficulty, the flight instructor took control of the airplane and attempted to correct the situation by applying "full" right rudder, right brake, and left aileron. The instructor did not take corrective action in time to arrest the left turn, and subsequently, the right main gear collapsed, and the airplane came to rest on the runway. It was ultimately determined that although the aircraft was responding correctly to pilot inputs, a realignment/warping of its fuselage due to a number of previous repairs caused it to be very sensitive to any rudder inputs. Although the aircraft was responding correctly to the pilot's inputs, its degree of sensitivity made it difficult for the owner to control from the right seat, and required quicker than normal remedial action by the flight instructor.

Factual narrative

On June 23, 2004, approximately 0945 Pacific daylight time, a Piper PA-20, N699DS, was substantially damaged following a main gear collapse while landing at Deer Park Airport, Deer Park, Washington. The private pilot, who is the registered owner of the airplane, and his flight instructor were not injured. The local 14 CFR Part 91 instructional flight, which departed the same airport about 30 minutes earlier, took place in visual meteorological conditions. No flight plan had been filed, and there was no report of an ELT activation.

According to the pilot/owner, he had previously received a tail wheel endorsement, but had not utilized it for a number of years. He said that he was currently working with an instructor to regain his proficiency, but that the flight instructor chose to fly in the left seat because the airplane only had brakes on that side, and it had been awhile since he had instructed in a tail wheel aircraft. On the second touch-and-go of the day, the owner made an approach with the intent to do a three-point landing, but inadvertently allowed the airplane's main wheels to contact the ground first, resulting in a bounce. The airplane then touched down in a three-point attitude and began to swerve to the left. The owner applied right rudder, but could not stop the turn. Seeing that the owner was having difficulty, the flight instructor took control of the airplane and attempted to correct the situation by applying "full" right rudder, right brake, and left aileron. The instructor was unable to arrest the left turn, and subsequently, the right main gear collapsed, and the airplane came to rest on the runway.

The pilot said that there did not appear to be any malfunctions or anomalies in the flight control or rudder systems, but that the aircraft was very sensitive to control inputs during landing and takeoff. He said that flying from the right side of the aircraft, which was something he had not done before, made it harder for him to effectively control the aircraft. He said that after he purchased the aircraft, he flew for about two hours with other instructors, both of whom mentioned that the aircraft was very sensitive to rudder inputs. He therefore had the aircraft's wheel toe-in checked. During that inspection it was determined that the toe-in on one wheel was incorrect, so the owner had the setting corrected. About the same time, the alignment of the wings to the fuselage was checked and found to be within acceptable limits. During this same alignment check, it was also determined that one main gear axle was set about one inch aft of the other, but its toe-in and camber were correct. The student and CFI then accumulated about five hours of instructional flight time in the aircraft after the alignment and toe-in check. It was the opinion of the owner that the aircraft was responding correctly to pilot inputs, but since it had both the standard "narrow" gear and a STOL (short takeoff and landing) kit installed, that it was just much more sensitive than the other tail wheel aircraft he had experience with.

The FAA inspector who responded to the scene said that the aircraft had been damaged and repaired a number of times before, and that the realignment/warping of the fuselage due to these repairs had created a situation where the wing lift strut attach fitting adjustments where set to their limits (one at its retracted limit and one at its extended limit). It was his opinion that this realignment contributed to the sensitive nature in which the aircraft responded to pilot inputs. Except for the fuselage being out of alignment, the inspector did not find any other anomalies that he felt would have contributed to the sequence of events that lead to the accident.

Aircraft

Registration
N699DS
Reported as
Piper PA-20
Category
Airplane
Serial number
20-951
Engine
Lycoming O-320, 150 horsepower, reciprocating
Damage
Substantial damage
Flight
Instructional · Part 91
Registered owner
David L Varnam
Airworthiness certificate
Standard, Normal
Departed
DEW · Deer Park, WA
Destination
DEW · Deer Park, WA
Airport
KDEW · Deer Park, runway 16, 6,100 × 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
Flight instructor
Age
71
Injuries
None
Certificates
Flight instructor, Commercial
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 3, Valid Medical--w/ waivers/lim
Last flight review
October 25, 2003
Seat
Left
Flight hours
7,800 total · 32 in this make and model · 7,200 as pilot in command · 121 in the last 90 days · 38 in the last 30 days · 5 in the last 24 hours
Role
Pilot
Injuries
None
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, Valid Medical--no waivers/lim.
Last flight review
June 18, 2004
Seat
Right
Flight hours
282 total · 5 in this make and model · 8 in the last 90 days · 8 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
50° at 5 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
77 °F, dew point 52 °F
Altimeter
29.96 inHg
Observed at
DEW

FAA reports on this event · 1

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