WPR19TA037

NTSB accident investigation · Scottish Series 100 MDL 101 · Lake Pleasant, AZ · November 17, 2018

Accident · Minor injuriesClass 3Final report
Date
November 17, 2018, 13:00 local (20:00 UTC)
Place
Lake Pleasant, AZ
Injuries
2 minor
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N82696Scottish Series 100 MDL 101
Defining event
Maneuvering-low-alt flying: Inflight upset
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Western Pacific Region
Parties
Federal Aviation Administration
FAA report
20181117022699A
Case key
98730

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

Impact with a lake for undetermined reasons.

Findings · 3

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.

Not determinedNot determined › Not determined · Unknown/Not determinedAll aircraft: 2,247 casesProbable cause
Performance/control parameters: altitudeAircraft › Aircraft oper/perf/capability · Not attained/maintainedAll aircraft: 1,310 casesProbable cause
Terrain: waterEnvironmental issues › Physical environment · Contributed to outcomeAll aircraft: 97 casesProbable cause

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.

Inflight upsetManeuvering-low-alt flyingAll aircraft: 74 casesDefining event

Analysis

The pilot reported that during a pleasure flight over a lake, about 700 ft above ground level, the engine started to shake and subsequently lost all power. The pilot attempted to restart the engine by turning the auxiliary fuel pump on, and he dove the airplane toward the water so that the windmilling propeller would help to restart the engine. The engine started, but the pilot estimated that it was only producing about 50% power. The pilot thought that he might be able to maintain or gain some altitude to reach a nearby runway; however, during the climb, the engine lost all power again. The pilot then initiated a forced landing to the lake. Witnesses around the lake reported seeing the airplane flying at low altitude. One witness stated that the engine sounded normal but that the airplane was flying erratically. Another witness saw the airplane about 40 ft above the water. He did not hear any unusual noises emanating from the engine. The airplane and engine remained submerged in the lake for about 3 weeks before recovery. The right wing was not recovered. Cursory examination of the engine revealed continuity to the accessory drive when the propeller was rotated by hand; however, the examination was insufficient to determine whether or for what reason a loss of engine power may have occurred.

Factual narrative

On November 17, 2018, at 1300 mountain standard time, an experimental Scottish Aviation Series 100 MDL 101 airplane, N82696, was substantially damaged when it was involved in an accident near Lake Pleasant, Arizona. The pilot and passenger received minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that after takeoff he departed to the north toward a lake for a sightseeing flight. While over the lake at 700 ft above ground level (agl), the engine started to shake and subsequently lost power. The pilot attempted to restart the engine by turning the auxiliary fuel pump on and he dove the airplane toward the water in hopes of the wind milling propeller would help in restarting the engine. The engine started but the pilot estimated that it was only producing about 50% power. The pilot noted a glider port just south of the lake and thought that he might be able to maintain or gain some altitude to make it to the glider port. The pilot initiated a climb, however the engine subsequently lost power again. The pilot then initiated a forced landing to the lake. After touchdown, the pilot and passenger exited the airplane before it sank. Witnesses from different locations around the lake, reported seeing a low-flying airplane in the area. One witness reported that the airplane came over the hills at a low altitude and made a sweeping right turn toward the north. It then gained altitude, where the witness lost sight of it as it disappeared into a canyon. The witness stated that the engine sounded normal, but that the airplane was flying erratically. Another witness at a boat ramp saw the airplane traveling in a westerly direction about 40 ft above the water. He did not hear any unusual noises emanating from the engine. Finally, another witness, traveling in his jet boat reported that the airplane crashed about 20 ft in front him. The airplane was in a nose down attitude. According to the pilot, the engine was rebuilt about 2 years ago and had about 100-150 hours in service. The mixture was about one-half inch lean and the auxiliary pump was in the ON position as he was flying low. The airplane was recovered from the lake 23 days after the accident and transported to a storage facility. An examination of the airplane was performed by Federal Aviation Administration (FAA) inspectors. The engine cowling and right wing were not recovered from the lake. The propeller blades were bent aft. The crankshaft was manually rotated verifying accessory section continuity. The oil dipstick was removed, and several quarts of oil were observed. A visual inspection of the engine oil revealed no debris and it was free of metal shavings. The fuel feed lines at the wing roots were inspected and showed extensive wear to the outer lining; it was frayed, and the inner lining displayed dry rot. Fuel staining was present on the gascolator bowl. The amount of fuel on board was not determined due to water inthe left-wing tank and the separation of the right wing.

Aircraft

Registration
N82696
Reported as
Scottish Series 100 MDL 101 (100 101)
Category
Airplane
Serial number
128
Built
1971
Engine
Lycoming IO360 SER, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Special, Experimental (Special)
Departed
DVT · Phoenix, AZ
Destination
DVT · Phoenix, AZ
Equipment
None

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
63
Injuries
Minor
Certificate
Private
Airplane ratings
Single-engine land
Seat
Left
Flight hours
0 total · 0 in this make and model

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
None
Temperature
70 °F, dew point 25 °F
Altimeter
30.03 inHg
Observed at
KDVT, 17 nm away

Docket · 4

The files NTSB released with the investigation on October 9, 2020, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.7 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.