SEA97FA120

NTSB accident investigation · Piper PA-32-301T · Bend, OR · May 24, 1997

Accident · FatalField investigationFinal report
Date
May 24, 1997, 12:20 local (19:20 UTC)
Place
Bend, OR
Injuries
2 fatal
Damage
Destroyed
Phase of flight
Enroute
Aircraft
N83211Piper PA-32-301T
Weather
Instrument (IMC) · Day
Status
Completed · report April 24, 1998
Report
Approved by Office Director
FAA report
19970524011809A
Case key
42503

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

Overload of the airframe structure. Thunderstorms and turbulence were factors.

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.

Airframe/component/system failure/malfunctionDescent - normal
Weather condition - turbulence(thunderstorms)Factor
Airframe - overloadCause

Analysis

The last radio communications from the pilot indicated that they were in instrument meteorological conditions and experiencing updrafts and picking up ice on the structure. Widely scattered thunderstorms and rain were reported in the area. Light to occasional moderate rime and mixed icing in the precipitation was reported from the freezing level to 12,000 feet. Moderate turbulence was reported for the entire state. Witnesses on the ground heard the sound of the engine but could not see the airplane. The witnesses reported that a 'pretty nasty looking cloud' with the sounds of thunder was in the area when they heard a sound similar to a sonic boom. After this sound, the aircraft's engine was no longer heard. Evidence at the accident site indicated that the aircraft broke-up in flight. The left wing separated at the root, the right wing separated about 109 inches from the root. Both the horizontal stabilizers and the vertical stabilizer separated from the empennage. Metallurgical examination of the fractured components were typical of overstress separations. Both the wings and the horizontal stabilator failed in a downward loading condition.

Factual narrative

History of flight

On May 24, 1997, about 1220 Pacific daylight time, a Piper PA-32-301T, N83211, operated by the pilot as a 14 CFR Part 91 personal flight, experienced an inflight break-up near Bend, Oregon. Instrument meteorological conditions prevailed at the time and an instrument flight rules flight plan was filed. The airplane was destroyed and both instrument rated private pilots were fatally injured. The flight had departed from Concord, California, earlier in the day and was en route to Redmond, Oregon.

Witnesses on a nearby golf course reported that the airplane's engine was heard clearly but that they could not see the airplane. The witnesses reported that they were actually looking at "a pretty nasty looking cloud" at the time. The witnesses reported that thunder was heard but they did not see any lightning. Shortly after this, a sound described as a "sonic boom" but not as loud was heard. After this sound, the airplane noise was no longer heard.

Personnel information

At the time of the accident the pilot held a private pilot certificate for single-engine land aircraft and an instrument rating. The pilot's flight logbook and records found among personal effects at the accident site indicated that the pilot had accumulated a total flight time of approximately 660 hours in all make and model aircraft. Approximately 220 hours had been accumulated in the accident aircraft.

The pilot-rated passenger held a private pilot certificate for single-engine land aircraft and an instrument rating. At the time of the accident, this pilot had accumulated a total flight time of approximately 892 hours, with about 220 hours in the accident aircraft.

Meteorological information

At 1216, the Redmond Airport was reporting 5,000 feet scattered, with 10 miles visibility. The wind was from 300 degrees at 10 knots, gusting to 15 knots. The temperature was 52 degrees. Rain was reported in the area.

Widely scattered thunderstorms and rain were reported in the Willamette Valley. An Airmet for the state of Oregon reported light to occasional moderate rime and mixed icing in the precipitation from the freezing level up to 12,000 feet. The freezing level was reported at around 7,000 feet. Another Airmet reported moderate turbulence for the state of Oregon.

Communications

At 1106, the pilot made contact with Seattle Center and reported in at 12,000 feet.

At 1133, the controller gave the pilot the current Klamath Falls, Oregon, altimeter setting.

At 1135, the pilot notified the controller that they were climbing to 13,000 feet to get above the clouds. The controller responded that he noticed the climb and instructed the flight to maintain 13,000 feet.

At 1140, the pilot requested to deviate about five miles to maneuver around clouds. The controller approved the deviation to either side of the flight course, and to rejoin the airway when able.

At 1154, the pilot requested to descend to 12,000 feet. The controller approved the flight to descend and maintain 12,000 feet.

At 1202, the pilot informed the controller that they were at 12,300 feet and descending to 12,000 feet.

At 1206, the controller asked the pilot for her altitude. The pilot responded that they were at 12,800 feet and getting an updraft in the clouds. The pilot informed the controller that they were going to stay on top of the clouds for a few more minutes. The controller inquired as to how the pilot would classify the updraft, as the radar was showing the flight at about 13,200 feet. The pilot responded that it was better now and requested to descend to 10,000 feet. The controller stated that 12,000 feet was the lowest that he was able to give them at the time. The pilot responded that since they could not descend, then they wished to remain at 13,000 feet. The controller instructed the pilot to descend to 12,000 feet at pilot's discretion. The controller then inquired again as to the classification of the updraft. The pilot responded that it was a 500 feet per minute updraft.

At 1214, the pilot informed the controller that they were diverting "a little bit" for clouds and asked if they could descend to 10,000 feet. The controller responded that the flight could not descend to 10,000 feet due to terrain, and asked the pilot which way they were diverting. The pilot responded "to the right." The controller stated that deviation to the right was approved and to descend to 10,000 feet.

At 1215, the controller asked the pilot what the flight conditions were. The pilot responded that there was slight icing in the clouds and freezing rain.

At 1218, the controller inquired about the type of approach the pilot wanted for landing. The pilot responded that she wanted to descend now because she was picking up ice. The controller instructed the pilot to turn right to a heading of 40 degrees and descend and maintain 8,000 feet. The pilot responded to the instructions.

There were no further communications received by the flight after 1219.

Wreckage and impact information

The wreckage was scattered over an area of 1,400 feet by 800 feet. The terrain was heavily wooded and low bush covered the ground. The ground was level, wet and rocky. The elevation at the accident site was approximately 4,400 feet.

The point of origin for wreckage measurements was taken from the location of the fuselage. The debris field was located due west of the fuselage. The fuselage was positioned with the nose of the airplane pointing to 320 degrees. The fuselage was laying on its left side and appeared to have collided with the terrain in a nearly level attitude. The structure was flattened. Fire consumed the fuselage and destroyed the cockpit and cabin area. Approximately 35 inches of the rudder remained attached to the empennage at the lower hinge. The engine remained attached at the firewall and was laying with the left side partially buried in the soil. The engine sustained severe heat distress which destroyed the accessory section. The propeller hub remained attached to the crankshaft. All three propeller blades displayed slight bending deformation. The inboard 109 inches of the right wing remained partially attached to the fuselage. The right flap was positioned in place with the right wing and sustained fire damage to the inboard section.

The entire left wing separated from the fuselage at the wing root. The left wing was found approximately 800 feet northwest of the fuselage. Both the aileron and the flap remained attached at their respective hinges. The left main landing gear remained attached. The control cables had been pulled to separation and partially cut through the lower skin of the wing. Minor leading edge tip damage was noted to the wing. The fuel tank remained intact.

The outboard section of the right wing was located approximately 500 feet to the northwest of the fuselage and about 300 feet southeast of the left wing. The aileron had separated from the hinges and was found in two pieces about 400 feet due south of the wing and about 300 feet due west of the fuselage.

The entire vertical stabilizer had separated from the fuselage at the base and was found approximately 800 feet west of the fuselage. The leading edge plastic covering was missing. The vertical stabilizer was bent slightly to the left.

The right side stabilator separated near the root and was found about 1,300 feet due west from the fuselage and about 500 feet southwest from the vertical stabilizer. The trim tab separated at the hinges and was located in the debris field about 400 feet southeast of the horizontal section. The stabilator was creased and bent from the inboard leading edge aft and outboard.

The left side stabilator separated near the root and was found about 1,100 feet northwest of the fuselage and about 400 feet to the north of the right side stabilator. The trim tab had separated from the hinges an

Aircraft

Registration
N83211
Reported as
Piper PA-32-301T
Category
Airplane
Serial number
32-8124006
Airframe hours
2,839
Engine
Lycoming TIO-540-S1AD, 300 horsepower, reciprocating
Damage
Destroyed
Fire
On-Ground
Flight
Personal · Part 91
Operator
Suzanne A Isaacs
Registered owner
William C. Isaacs
Airworthiness certificate
Standard, Normal
Last inspection
Annual · February 3, 1997 · 40 hours before
Departed
CCR · Concord, CA
Destination
RDM · Redmond, OR
Flight plan
IFR

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
54
Certificate
Private
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 3, Valid Medical--w/ waivers/lim
Seat
Left
Toxicology
Performed
Flight hours
660 total · 220 in this make and model · 6 in the last 90 days · 3 in the last 30 days

Weather

Conditions
Instrument (IMC) · Day
Wind
300° at 10 knots, gusting 15
Visibility
10 statute miles
Temperature
52 °F, dew point 36 °F
Altimeter
29.00 inHg
Observed at
RDM, 21 nm away

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 N83211 · 1

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