LAX94FA048

NTSB accident investigation · Beech V-35 · Shaver Lake, CA · November 12, 1993

Accident · FatalField investigationFinal report
Date
November 12, 1993, 11:17 local (19:17 UTC)
Place
Shaver Lake, CA
Injuries
4 fatal
Damage
Destroyed
Phase of flight
Maneuvering
Aircraft
N630AWBeech V-35
Weather
Instrument (IMC) · Day
Status
Completed · report September 13, 1994
Report
Approved by Office Director
FAA report
19931112042859A
Case key
28506

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

An in-flight breakup of the airplane following the pilot's continued VFR flight into IMC conditions during which directional control of the airplane was not maintained, and the design limits of the airplane were exceeded. The pilot's inadequate evaluation of the weather conditions that consisted of mountain wave activity and standing lenticular clouds were factors in the accident.

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
Weather condition - mountain waveFactor
Weather condition - cloudsFactor
Preflight briefing service - not obtainedPilot in command
Weather evaluation - inadequatePilot in commandFactor
Vfr flight into imc - continuedPilot in commandCause
Aircraft control - not maintainedPilot in commandCause
Airframe/component/system failure/malfunctionDescent - uncontrolled
Design stress limits of aircraft - exceededPilot in commandCause
Wing - separation

Analysis

During a cross-country flight, the aircraft crossed high mountainous terrain where areas of rain and snow showers were reported. Airmets had been issued for turbulence, mountain obscuration, and icing conditions. Satellite images revealed the presence of standing lenticular clouds. A weather briefing was not obtained and no flight plan was filed. No voice communications were received from the aircraft and no in-flight services were being provided by the FAA. Radar data indicated that the airplane made several maneuvering turns and a rapid descent before radar contact was lost. The airplane experienced an in-flight breakup and was scattered over a 3/4-mile area. A trajectory study indicated that the location of the separated airplane components was consistent with a breakup altitude of 14,000 feet.

Factual narrative

History of Flight

On November 12, 1993, about 1117 hours Pacific standard time, a Beech V-35, N630AW, registered to and operated by the pilot, experienced an in-flight breakup, about 25 miles northeast of Shaver Lake, California. The airplane was destroyed. The certificated private pilot and three passengers received fatal injuries. The airplane was being operated as a visual flight rules (VFR) cross-country personal flight to Death Valley Monument Airport when the accident occurred. Instrument meteorological conditions prevailed in the accident area at the time. A flight plan was not filed.

The flight originated at Reid-Hillview Municipal airport, San Jose, California, about 0951 hours. After departure, the pilot was given a frequency change as he exited the airport traffic area. There was no further voice communication with the pilot. The flight was expected to arrive in Death Valley about 1100 hours. On November 13, 1993, the flight was reported as overdue.

National Track and Analysis Program (NTAP) radar data from the Oakland Air Route Traffic Control Center (ARTCC) was reviewed and a plot of the accident area was prepared by the Federal Aviation Administration (FAA). The airplane was not radar identified and the pilot was not receiving traffic advisories from the FAA. Radar data in the vicinity of the accident site was plotted from 1101:41 to 1121:40 hours. Radar data points from 1110:17 to 1117:38 hours were consistent with the location of the accident airplane.

At 1110:17 hours, the airplane was at 15,700 feet. The radar track was oriented on a northeasterly heading. As the flight continued to the northeast, the altitude continued to climb to 17,300 feet, and the radar track indicated a "U" turn toward the west. At 1117:26 hours, the NTAP indicated an altitude of 17,100 feet and the airplane turned back to the northwest. At 1117:38 hours, the last radar return indicated an altitude of 16,500 feet.

Search personnel located an emergency locator transmitter (ELT) signal from the airplane on November 15, 1993. The wreckage was located at about 1545 hours, about 10,000 feet mean sea level (msl).

The accident occurred during the hours of daylight at latitude 37 degrees 20.9 minutes N and longitude 118 degrees 51.2 minutes W.

Crew Information

The front seats of the airplane were both occupied by certificated pilots. No evidence was found that indicated who was manipulating the aircraft controls at the time of the accident.

The occupant of the left front seat (first pilot) held a private pilot certificate with an airplane single-engine land rating. The most recent third-class medical certificate was issued to the pilot on September 10, 1991, and contained no limitations. A third-class medical certificate is valid until the end of the 24th month of the date of issuance.

No personal flight records were recovered for the first pilot, and the aeronautical experience listed on page 6 of this report was obtained from a review of the FAA airman records on file in the Airman and Medical Records Center located in Oklahoma City. On the pilot's application for an FAA medical certificate on September 10, 1991, the pilot reported having accrued 600 flight hours, with 100 hours accumulated in the previous 6 months.

The occupant of the right front seat (second pilot) also held a private pilot certificate with a single-engine land rating. The most recent third-class medical certificate was issued to the pilot on January 6, 1993, and contained no limitations.

No personal flight records were recovered for the second pilot and the aeronautical experience listed in Supplement E of this report was obtained from a review of the FAA airman records on file in the Airman and Medical Records Center. On the pilot's application for an FAA medical certificate on January 6, 1993, the pilot reported having accrued 140 hours. No flight hours were indicated in the previous 6 months.

Aircraft Information

The airplane was originally manufactured as a model V-35TC which had a Continental TSIO-520-D engine installed as original equipment. On February 28, 1984, the airplane had accumulated 2,616.7 hours and, on that date, the engine was removed and replaced with a Continental IO-520-BA. The original logbooks were lost and a new record was initiated when the engine was changed. With the engine change, the airplane reverted to a model V-35. The manufacturer reported that the service ceiling for a model V-35 is 17,500 feet.

Examination of the maintenance records revealed that the airplane had accrued a total time in service of 3,207.95 flight hours. On February 5, 1992, the airplane was given an annual inspection and found to be unairworthy. The unairworthy items were listed as a fuel leak in the left wing, unsafe rudder and aileron rigging, ruddervator cable chafing, pitot heat inoperative, and a deteriorating induction inlet coupler duct. On April 1, 1992, the unairworthy items were repaired and the airplane was returned to service. At that time, the airplane had accrued 3,070.69 flight hours, 76.34 hours before the accident.

The engine had accrued a total time in service of 2,778.51 hours of operation. The maintenance records note that a major overhaul was accomplished on February 28, 1984, 591.51 hours of operation before the accident. An annual inspection was accomplished on the date specified above for the airframe.

Meteorological Information

The closest official weather observation station is Mammoth-June Lakes Airport, elevation 7,128 feet msl, which is located 16 nautical miles north of the accident site. At 1147 hours, a surface observation was reporting in part:

Sky condition and ceiling, estimated 1,500 feet overcast; visibility, 8 miles; temperature, 30 degrees F; dew point, 20 degrees F; wind, 210 degrees at 8 knots; altimeter, 29.98 inHg; remarks, mountain tops obscured all quadrants.

An automated weather observation station (AWOS) is also located at the Mammoth-June Lakes Airport. At 1101 hours, the AWOS was reporting:

Temperature, 31 degrees F; dew point, 20 degrees F; wind 240 degrees at 12 knots; altimeter, 29.79 inHg.

Bishop, California, elevation 4,145 feet msl, is located 23 nautical miles east of the accident site. At 1050 hours, a surface observation was reporting in part:

Sky condition and ceiling, estimated ceiling, 2,000 feet overcast; visibility, 10 miles in light snow; temperature, 36 degrees F; dew point, 32 degrees F; wind, 020 degrees at 15 knots; altimeter, 29.79 in Hg.

A National Transportation Safety Board meteorologist conducted a study of the accident area weather conditions. At 1000 hours, a surface weather map prepared by the National Weather Service (NWS) depicted a center of low pressure over southeastern Nevada. A cold front extended from the low, southwest to the San Diego, California area. A secondary trough extended from the low westward to the vicinity of Paso Robles, California. The weather system was moving eastward and extended across the central portions of California and Nevada.

An Aviation Area Forecast, valid until 1600 hours, was reporting extensive low clouds and precipitation across California. For the San Joaquin Valley scattered clouds at 1,500 feet, overcast skies at 4,000 feet, with visibility 3 to 5 miles in fog were expected. Widely scattered light rain showers, thunderstorms with light rain showers, were forecast, possibly in lines and/or clusters. Mountain areas were forecasted to have skies of 8,000 feet scattered, 12,000 feet broken, occasionally 8,000 feet overcast. Scattered light rain showers and/or snow showers were expected with the tops of the clouds layered to 24,000 feet.

Additionally, the area forecast was reporting that from Vandenberg Air Force Base to China Lake to 60 miles northwest of Bishop, California, widely scattered areas of light rain showers and thunderstorms, possibly in lines and/o

Aircraft

Registration
N630AW
Reported as
Beech V-35
Category
Airplane
Serial number
D-8500
Airframe hours
3,208
Engine
Continental IO-520-BA, 285 horsepower, reciprocating
Damage
Destroyed
Flight
Personal · Part 91
Operator
Gary L. Mc Coy
Registered owner
Gary L. Mc Coy
Airworthiness certificate
Standard, Normal; Standard, Utility
Last inspection
Annual · February 5, 1992 · 76 hours before
Departed
RHV · San Jose, CA
Destination
L06 · Death Valley, CA

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
40
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, Valid Medical--no waivers/lim.
Seat
Left
Toxicology
Performed
Flight hours
136 total

Weather

Conditions
Instrument (IMC) · Day
Wind
210° at 8 knots
Visibility
8 statute miles
Lowest ceiling
1,500 ft overcast
Temperature
30 °F, dew point 19 °F
Altimeter
29.00 inHg
Observed at
MMH, 16 nm away

Docket · 56

The files NTSB released with the investigation on August 11, 1995, on NTSB’s docket system: statements, records, photos and specialists’ reports. 6.7 MB in all.

Supplement AItem 1 · .PDF · 182 KBSupplement BItem 2 · .PDF · 255 KBSupplement EItem 3 · .PDF · 469 KBSupplement KItem 4 · .PDF · 1.2 MBSupplement SItem 5 · .PDF · 61 KBWeather Factual ReportItem 6 · .PDF · 354 KBChart No. 1Item 7 · .PDF · 57 KBChart No. 2Item 8 · .PDF · 55 KBChart No. 3Item 9 · .PDF · 65 KBChart No. 4Item 10 · .PDF · 81 KBChart No. 5Item 11 · .PDF · 78 KBChart No. 6Item 12 · .PDF · 106 KBChart No. 7Item 13 · .PDF · 63 KBChart No. 8Item 14 · .PDF · 46 KBChart No. 9Item 15 · .PDF · 51 KBChart No. 10Item 16 · .PDF · 52 KBRadar and Trajectory StudyItem 17 · .PDF · 750 KBMaps of Accident AreaItem 18 · .PDF · 590 KBFAA NTAP PlotItem 19 · .PDF · 291 KBNTAP Graphical Plot of List 3 DataItem 20 · .PDF · 77 KBStatus of Investigation Letter to EstateItem 21 · .PDF · 58 KBStatement of Party Representatives to NTSB InvestigationItem 22 · .PDF · 221 KBToxicological Report (CAMI)Item 23 · .PDF · 56 KBStatement of Party Representatives to NTSB InvestigationItem 24 · .PDF · 62 KBRelease of Aircraft Wreckage, NTSB Form 6120.15Item 25 · .PDF · 72 KBPhoto No. 1 View of inverted aft bottom section of fuselage.Item 26 · .PDF · 45 KBPhoto No. 2 View of aft fuselage floor. Note rear seats still attached to seat rails.Item 27 · .PDF · 44 KBPhoto No. 3 View of upper portion of fractured right wing carry-through.Item 28 · .PDF · 29 KBPhoto No. 4 View of lower end of fractured right wing carry-through.Item 29 · .PDF · 34 KBPhoto No. 5 View of upper portion of fractured left wing carry-through.Item 30 · .PDF · 33 KBPhoto No. 6 View of left side of fuselage and empennage.Item 31 · .PDF · 46 KBPhoto No. 7 View of bottom of fuselage where aft floor section of the aircraft separated. Note shearing of the rivets at the fuselage to floor seam.Item 32 · .PDF · 55 KBPhoto No. 8 View of right stabilizer and elevator lying along the top portion of the fuselage.Item 33 · .PDF · 42 KBPhoto No. 9 Close-up view of right stabilizer leading edge cuff attach point.Item 34 · .PDF · 37 KBPhoto No. 10 View of separated right stabilizer spar attach points.Item 35 · .PDF · 41 KBPhoto No. 11 Close-up view of forward right stabilizer spar.Item 36 · .PDF · 35 KBPhoto No. 12 View of tail and left stabilizer. Note aft curling of leading edge of the stabilizer.Item 37 · .PDF · 47 KBPhoto No. 13 Another view of aft and upward curling of the left stabilizer.Item 38 · .PDF · 43 KBPhoto No. 14 View of exposed forward stabilizer bulkhead.Item 39 · .PDF · 52 KBPhoto No. 15 Closer view of tearing around the left spar attach point at the stabilizer bulkhead.Item 40 · .PDF · 44 KBPhoto No. 16 View of left spar to bulkhead attach point.Item 41 · .PDF · 40 KBPhoto No. 17 View of underside of left wing.Item 42 · .PDF · 35 KBPhoto No. 18 Close-up view of separated area of aft wing carry-through attach point.Item 43 · .PDF · 40 KBPhoto No. 19 View of separated inboard end of left wing.Item 44 · .PDF · 37 KBPhoto No. 20 Close-up view of upper end of wing spar.Item 45 · .PDF · 40 KBPhoto No. 21 Close-up view of lower end of wing spar and spar web.Item 46 · .PDF · 38 KBPhoto No. 22 View of front portion of engine.Item 47 · .PDF · 50 KBPhoto No. 23 View of front portion of engine.Item 48 · .PDF · 52 KBPhoto No. 24 Another view of propeller blades. Note "S" bending and heavy gouging of one blade.Item 49 · .PDF · 41 KBPhoto No 25. View of fractured control yoke, instruments, and attitude instrument gyro rotor case recovered from rock crevice.Item 50 · .PDF · 42 KBPhoto No. 26 Close-up view of attitude gyro rotor case. Note rotational scoring on inside of case.Item 51 · .PDF · 36 KBPhoto No. 27 View of right wingItem 52 · .PDF · 34 KBPhoto No. 28 View of inboard end of right wing.Item 53 · .PDF · 51 KBPhoto No. 29 View of scoring adjacent to control collum pin.Item 54 · .PDF · 40 KBPhoto No. 30 View of orientation of control yoke.Item 55 · .PDF · 50 KBPhoto No. 31 View of wreckage at recovery yard.Item 56 · .PDF · 46 KB

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 N630AW · 2

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