GAA19CA034

NTSB accident investigation · Just Just Aircraft (Highl · Monroe, WA · October 12, 2018

Accident · No injuriesData collectionFinal report
Date
October 12, 2018, 09:30 local (16:30 UTC)
Place
Monroe, WA
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N488VGJust Just Aircraft (Highl
Defining event
Approach-VFR pattern final: Fuel starvation
Weather
Visual (VMC) · Day
Status
Completed · report June 5, 2019
Report
Approved by Office Director
NTSB office
General Aviation Accidents
Parties
FAA
FAA report
20181012019859A
Case key
98535

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 pilot's improper engine modification and operation, which resulted in a total loss of engine power due to fuel starvation, and the pilot's failure to maintain an adequate approach path, which resulted in the airplane landing short of the runway.

Findings · 5

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.

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.

Analysis

The pilot of the tailwheel-equipped, experimental, amateur-built airplane, who was also an airframe and powerplant mechanic, reported that, during approach to a sandbar, he side-slipped the airplane and that the engine then lost power because he was "too aggressive with the throttle and pulled it enough to bend the [carburetor] idle stop screw bracket." The engine was normally quiet, the airplane was sound proofed, and the pilot also used a noise-cancelling headset, which prevented him from being aware of the power loss until he attempted to add power to no avail. He did not have enough time to restart the engine, so the airplane settled onto the water about 15 to 20 ft short of the sandbar. Subsequently, the airplane hydroplaned and then came to rest on the sandbar inverted. The pilot reported that the reason he was aggressive with the throttle was because of a lean mixture that tended to overheat the engine during takeoff or cruise on hot days. The airplane sustained substantial damage to the left wing lift strut, left wing, and rudder. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The Federal Aviation Administration inspector reported that the pilot had modified the number and position of the last hole in the fuel spray bar. By doing so, the pilot was able to get the engine to "barely run" to perform short-field landings. During the accident landing, it "must have cut off the flow of fuel enough to make the engine quit." That pilot reported that he had previously attempted to mechanically enrich the mixture by drilling holes in the fuel spray bar but had drilled a hole "at the location where the engine wanted to idle," meaning that, if the hole was open, the engine would idle high, and if the hole was closed, the engine would "die." He added that it was not a problem unless he was trying to land short.

Factual narrative

The pilot of the tailwheel-equipped, experimental amateur built airplane, who was also an airframe and powerplant mechanic reported that, during approach to a sandbar, he side-slipped the airplane and the engine lost power because he was "too aggressive with the throttle and pulled it enough to bend the [carburetor] idle stop screw bracket." Because the engine was normally quiet, the airplane was sound proofed, and he used a noise-cancelling headset, he was unaware of the power loss until he attempted to add power, to no avail. He did not have enough time to restart the engine, so the airplane settled onto the water about 15 to 20 ft short of the sandbar. Subsequently, the airplane hydroplaned and came to rest on the sandbar inverted. The pilot reported that the reason he was aggressive with the throttle was because of a lean mixture that tended to overheat the engine during takeoff or cruise on hot days. Previously, he had attempted to mechanically enrichen the mixture by drilling holes in the fuel spray bar, but had drilled a hole "at the location where the engine wanted to idle", meaning that if the hole was open, the engine would idle high and if the hole was closed, the engine would "die." He added that it was not a problem unless he was trying to land short. The airplane sustained substantial damage to the left wing lift strut, left wing, and rudder. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The Federal Aviation Administration (FAA) inspector reported that the pilot had modified the number and position of the last hole in the fuel spray bar. By doing so, the pilot was able to get the engine to "barely run" to perform short field landings. During the accident landing, it "must have cut off the flow of fuel enough to make the engine quit."

Aircraft

Registration
N488VG
Reported as
Just Just Aircraft (Highl (No Series)
Category
Airplane, amateur-built
Serial number
JA214-08-10
Built
2010
Airframe hours
975
Engine
Jabiru 3300, 120 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Special, Experimental light sport (Special)
Last inspection
Annual · February 3, 2018
Departed
S50 · Auburn, WA
Destination
Monroe, WA
Equipment
Onboard weather, ADS-B, Electronic primary flight display

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
67
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land, Single-engine sea, Multi-engine land
Instrument ratings
Airplane
Last flight review
July 20, 2018
Seat
Left
Restraint
3-point
Flight hours
7,000 total · 974 in this make and model · 7,000 as pilot in command · 20 in the last 90 days · 10 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
4,900 ft broken
Temperature
52 °F, dew point 48 °F
Altimeter
30.13 inHg
Observed at
KPAE, 12 nm away

Docket · 3

The files NTSB released with the investigation on March 21, 2019, on NTSB’s docket system: statements, records, photos and specialists’ reports. 6.3 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.

Other investigations on N488VG · 1

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