CHI98FA244

NTSB accident investigation · Stubbe-Kitfox Classic · Traer, IA · July 12, 1998

Accident · FatalField investigationFinal report
Date
July 12, 1998, 10:03 local (15:03 UTC)
Place
Traer, IA
Injuries
1 fatal, 1 serious, 1 minor
Phase of flight
Maneuvering
Aircraft
N494SStubbe-Kitfox ClassicN70035Vultee BT-15
Weather
Visual (VMC) · Day
Status
Completed · report October 13, 2000
Report
Approved by Office Director
Case key
43075

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 failure of the pilot of the Kitfox to maintain flying speed (Vs).

the failure of the pilot of the Kitfox to maintain flying speed (Vs).

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 - in flightManeuvering
Airspeed(vs) - not maintainedPilot in commandCause
In flight collision with objectDescent - uncontrolled
Object - aircraft parked/standing
In flight collision with terrain/waterDescent - uncontrolled
Miscellaneous/otherStanding - engine(s) operating
Object - aircraft parked/standingFactor
Airspeed(vs) - not maintainedPilot of other aircraftCause

Analysis

The experimental Kitfox had departed and according to a witness, 'The Kitfox was slow and had a definite nose-up pitch. My very first thought when I saw the Kitfox was that the pilot was, for some reason, demonstrating slow flight. But almost as quickly, I recognized an impending stall was about to happen. The wings of the Kitfox were rocking back and forth and the nose was yawing. The Kitfox then stalled and collided with the BT-13 hitting the BT-13 in the front cockpit area and right wing before impacting the ground. ... The Kitfox came to rest inverted and burst into flames immediately after impact.' According to the pilot of the BT-13, 'I was being directed by [ground personnel] who was on the ground. The Kit Fox had departed on runway 17 and stalled overhead at 50-65 feet and struck my airplane. My prop slashed through the wreckage of the airplane and then slammed the Kit Fox to the ground where it exploded.'

The experimental Kitfox had departed and according to a witness, 'The Kitfox was slow and had a definite nose-up pitch. My very first thought when I saw the Kitfox was that the pilot was, for some reason, demonstrating slow flight. But almost as quickly, I recognized an impending stall was about to happen. The wings of the Kitfox were rocking back and forth and the nose was yawing. The Kitfox then stalled and collided with the BT-13 hitting the BT-13 in the front cockpit area and right wing before impacting the ground. ... The Kitfox came to rest inverted and burst into flames immediately after impact.' According to the pilot of the BT-13, 'I was being directed by [ground personnel] who was on the ground. The Kit Fox had departed on runway 17 and stalled overhead at 50-65 feet and struck my airplane. My prop slashed through the wreckage of the airplane and then slammed the Kit Fox to the ground where it exploded.'

Factual narrative

See the narrative for CHI98FA244A.

History of flight

On July 12, 1998, at 1003 central daylight time (cdt), a Stubbe-KitFox Classic, N494S, piloted by a private pilot, was destroyed by collision forces and fire when it collided with a Vultee BT-15, N70035, while maneuvering during its initial climb out following takeoff from Runway 17 (2,550' X 100', dry sod) at the Traer Airport, Traer, Iowa. Visual meteorological conditions prevailed at the time of the accident. The personal flight was operating under the provisions of 14 CFR Part 91, and was not operating on a flight plan. The pilot was seriously injured in the accident. The passenger was fatally injured. The pilot of N70035 reported minor injuries.

The pilot of N494S had previously attempted to fly, but aborted the takeoff. According to a witness, the pilot said that "he didn't like the way the engine was missing, so he had scrubbed the takeoff...Back at the hangar, [the pilot] removed the cowling from the engine area. I watched as he did this. Obvious problems with the engine were looked for and nothing was found."

"I came back a few moments later and observed that [the pilot] was starting the Kitfox engine. The runup was brief and from my position sounded smooth and normal. While I was absent, I learned that [the pilot] had pulled a spark plug(s), found some fouling of a plug, had cleaned it, re-installed it and the subsequent runup was A-OK."

While the maintenance was being performed on N494S, the other aircraft, N70035, had landed and was taxing to park. According to the pilot of N70035, "I landed on 17 using a 3 pt landing and taxied to the south end of the airport where I was about to turn into a parking place. I was being directed by [ground personnel] who were on the ground. The Kit Fox had departed on 17 and stalled overhead at 50-65 feet and struck my airplane. My prop slashed through the wreckage of the airplane and then slammed the Kit Fox to the ground where it exploded. At that time I did not know what had happened. I remember screams that 'it' was on fire. I was bent over still strapped in. I released my seat belt and exited the airplane. Upon hitting the ground I passed out again. The next thing I remember was the ambulance 3-4 blocks from the hospital."

According to a witness, "I was focused on watching the BT-13 (N70035) taxi in when a "Kitfox" airplane, (N494S) apparently on its take-off departure, appeared into my view. I would estimate the altitude of the Kitfox to be between 60 - 100 ft. agl. (feet above ground level) I did not see the Kitfox begin its take-off nor did I see where the Kitfox began its take-off run. When I saw the Kitfox, it had departed from the airport runway centerline and was over the taxiway. The Kitfox was slow and had a definite nose-up pitch. My very first thought when I saw the Kitfox was that the pilot was, for some reason, demonstrating slow flight. But almost as quickly, I recognized an impending stall was about to happen. The wings of the Kitfox were rocking back and forth and the nose was yawing. The Kitfox then stalled and collided with the BT-13 hitting the BT-13 in the front cockpit area and right wing before impacting the ground. I do not recall which wing of the Kitfox dropped first. The Kitfox came to rest inverted and burst into flames immediately after impact. I saw one individual crawl from the Kitfox wreckage. I did not see how the pilot of the BT-13 got out nor did I see who or how the BT's engine was shut down...The flames were not controlled until the Traer Fire Department arrived on scene."

Damage to aircraft

N494S came to rest on its back and was subsequently destroyed by the post accident explosion and fire.

N70035 received substantial damage to the forward part of the canopy and the right wing from the impact. The right wing of the aircraft had white paint on the outboard half of the wing. There was a piece of the leading edge damaged between the landing light and the right main landing gear strut. The forward half of the canopy was missing from the aircraft. There was impact damage ahead of the cockpit, and the area had white paint marks on it. The propeller was marked with white paint. See attached photographs of damage.

Personnel information

The pilot of N494S, born December 20, 1960, was the holder of a private pilot certificate with airplane single engine land privileges. Federal Aviation Administration (FAA) records indicate that the pilot's last aviation medical examination was performed on October 13, 1997. The pilot possessed a current third class medical with the limitation, "must have available glasses for near vision" at the time of the accident.

The pilot's logbook indicated that he had flown 282 hours prior to the accident flight, 107 of which were in the accident airplane.

The pilot of N70035, born February 9, 1929, was the holder of a commercial pilot certificate with airplane single engine and airplane multiengine land privileges, and an instrument airplane rating. The pilot also held an airframe and powerplant mechanic certificate. FAA records indicate that the pilot's last aviation medical examination was performed on November 18, 1997. The pilot possessed a current second class medical with the limitation, "must wear corrective lenses" at the time of the accident.

The pilot's logbook indicated that he had flown 1,260 hours prior to the accident, of which 150 were in the accident airplane.

Aircraft information

N494S, serial number C9404-0019, was a kit built, monoplane with fixed landing gear in a tail-wheel configuration. The aircraft can accommodate a pilot and a single passenger. The aircraft was certified as an experimental amateur built on January 21, 1998.

The engine was a Subaru, model A/B.

N70035, serial number 11453, was a low wing monoplane with fixed landing gear in a tail-wheel configuration. The aircraft can accommodate a pilot and a single passenger.

The engine was a Wright, model number 975E&F-2&3.

Meteorological information

A weather observation facility, located at Waterloo, Iowa, 25 statute miles on a 007 degree magnetic bearing from the accident site reported the weather approximately 6 minutes before the accident as:

Observation Time: 0954 cdt Wind: 170 degrees at 7 knots, variable direction between 140 degrees and 210 degrees Visibility: 9 statute miles Sky Condition: Scattered clouds at 3,200 feet agl, broken clouds at 4,200 feet Temperature: 24 degrees centigrade Dew Point Temperature: 21 degrees centigrade Pressure: 30.02 inches of mercury

Wreckage and impact information

Both aircraft came to rest next to each other, with N494S on its back, on the Traer airport. N70035 was pushed back to aid in the emergency response to N494S.

N494S was destroyed by the impact with the other aircraft and the subsequent post accident fire. A post accident examination of the engine could not be completed due to fire damage.

N70035 received substantial damage to the right wing and canopy areas of the aircraft. The right wing of the aircraft had white paint on the outboard half of the wing. There was a piece of the leading edge damaged between the landing light and the right main landing gear strut. The forward half of the canopy was missing from the aircraft. There was impact damage ahead of the cockpit, and the area had white paint marks on it. The propeller was marked with white paint. See attached photographs of damage.

Survival aspects

In a written statement, the pilot of N70035 stated, "I am alive today because I was wearing a USAF (United Stated Air Force) flight helmet. The wing of the Kit Fox hit the back of my helmet and broke through the exterior shell. I was also wearing a nomex flight suit and nomex gloves."

Additional information

The wreckage of both aircraft was released to the Traer airport manager.

Aircraft · 2

Registration
N494S
Reported as
Stubbe-Kitfox Classic
Category
Airplane, amateur-built
Serial number
C9404-0019
Engine
Subaru MDL A/B, 65 horsepower, reciprocating
Damage
Destroyed
Fire
On-Ground
Flight
Personal · Part 91
Registered owner
Kenneth D. Stubbe
Airworthiness certificate
Special, Experimental (Special)
Departed
8C6
Destination
8C6
Airport
8C6 · Traer Municiple, runway 17, 2,550 × 100 ft, grass/turf

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.

Registration
N70035
Reported as
Vultee BT-15
Category
Airplane
Serial number
1142
Airframe hours
2,067
Engine
P&W R985AN1, 450 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
John Bryan Ruyle
Registered owner
Great Plains Aero, Inc.
Airworthiness certificate
Standard, Normal
Last inspection
Annual · March 2, 1998 · 11 hours before
Departed
IOW · Iowa City, IA
Destination
8C6
Airport
8C6 · Traer Municiple

Flight crew · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot, aircraft N494S
Age
37
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, Valid Medical--w/ waivers/lim
Seat
Left
Flight hours
282 total · 107 in this make and model · 225 as pilot in command · 41 in the last 90 days · 14 in the last 30 days
Role
Pilot, aircraft N70035
Age
49
Certificate
Commercial
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Front
Flight hours
1,260 total · 150 in this make and model

Weather

Conditions
Visual (VMC) · Day
Wind
170° at 7 knots
Visibility
9 statute miles
Lowest ceiling
None
Temperature
75 °F, dew point 70 °F
Altimeter
30.00 inHg
Observed at
ALO, 25 nm away

FAA reports on this event · 2

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