WPR20LA180

NTSB accident investigation · Bellanca 7KCAB · Renton, WA · June 12, 2020

Accident · Minor injuriesClass 3 · LimitedFinal report
Date
June 12, 2020, 10:00 local (17:00 UTC)
Place
Renton, WA
Injuries
2 minor
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N36339Bellanca 7KCAB
Defining event
Initial climb: Loss of engine power (total)
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
20200612019609A
Case key
101432

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

Maintenance personnel’s inadequate post-maintenance inspections that resulted in the total loss of engine power due to a blockage in the air intake.

Findings · 2

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.

Power plant: air intakeAircraft › Aircraft power plant · Inadequate inspectionBellanca 7KCAB: 1 caseAll aircraft: 50 casesProbable cause
MaintenancePersonnel issues › Task performance · Maintenance personnelBellanca 7KCAB: 1 caseAll aircraft: 143 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.

Analysis

The airplane had recently undergone an annual inspection, and the accident flight was the first flight since being out of maintenance. After making a normal departure and touch-and-go landing, the pilot receiving instruction applied full power. As the airplane reached an altitude of about 400 feet above ground level (agl), the engine abruptly stopped producing (total) power. The airplane could not maintain level altitude and during the subsequent off-airport landing, the airplane was substantially damaged when it collided with a tree. Postaccident examination revealed that the air induction box contained a piece of bunched up paper that likely restricted the inlet cavity. As part of the annual inspection, a repair person completed a small fiberglass patch and painting on the lower cowling. He could not recall the specific repair on the airplane but said he often placed paper in the induction to prevent debris from entering the engine. After the maintenance, the airplane sat for a day with the lower cowling not fastened but maintenance personnel did not recognize the blockage. They also did not find the paper during the post-maintenance inspections and returned the airplane into service with an unsafe condition.

Factual narrative

On June 12, 2020, about 1000 Pacific daylight time, a Bellanca 7KCAB Citabria airplane, N36339, was substantially damaged when it was involved in an accident near Renton, Washington. The certified flight instructor (CFI) and pilot receiving instruction sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The airplane had recently undergone an annual inspection and the accident flight was the first flight since being out of maintenance. The operator, Boeing Employees Flying Association, required that a test flight be performed following annual inspections and the CFI was authorized to perform those flights. The CFI elected to take the pilot receiving instruction for the test flight since she was working on obtaining her tailwheel endorsement. The test flight protocol provided an extended checklist including an elongated preflight and runup. The CFI added 10 gallons of fuel in each wing tank and the engine start and runup were all normal. With the pilot receiving instruction positioned in the front seat, she performed the initial takeoff from runway 16 and they remained in the traffic pattern with the intention of performing touch-and-go takeoff practice and landings. After making an uneventful three-point landing, the pilot receiving instruction applied full throttle and the airplane accelerated reaching an altitude of about 400 feet above ground level (agl). At that time, the engine abruptly stopped producing (total) power, although the propeller continued to rotate. The CFI opted to land on an access road. During the off-airport landing, the airplane sustained substantial damage to both wings and the fuselage when it collided with a tree before coming to rest in a vacant construction company storage area. The CFI stated that the airplane was too low for him to look at the instruments or perform troubleshooting steps and from the rear seat he did not have good visual access to the engine gauges. The pilot receiving instruction stated that immediately following the power loss, the CFI asked her what was happening. She confirmed that the throttle was fully forward, the mixture was rich, and the fuel selector valve and boost pump were both in the ON position. During a postaccident examination, investigators discovered the air induction box contained an approximate two by three feet piece of bunched up paper that was white and had a plastic type coating. The paper appeared to have mostly restricted the inlet cavity (see figure 1). Figure 1: Picture of Air Induction The lead mechanic who performed the annual inspection before the accident stated that as part of the annual inspection, the airplane needed a repair concerning a hole near the exhaust on the lower cowling. He hired a local repair person he normally uses to complete the fiberglass work and painting. After the maintenance, the airplane sat for a day with the lower cowling/ air filter off. After the work was completed andthe lower cowling was reinstalled, the mechanic completed a final inspection followed by a post-inspection run-up, with no discrepancies noted. The were no other anomalies found during the postaccident examination.

Aircraft

Registration
N36339
Reported as
Bellanca 7KCAB
Category
Airplane
Serial number
388-73
Built
1973
Airframe hours
5,961
Engine
Lycoming IO-320-E2A, 150 horsepower, reciprocating
Damage
Substantial damage
Flight
Instructional · Part 91
Operator
Boeing Employees Flying Assoc Inc
Registered owner
Boeing Employees Flying Assoc Inc
Airworthiness certificate
Standard, Normal; Standard, Aerobatic
Last inspection
Annual · June 11, 2020 · 0 hours before
Departed
RNT · Renton, WA
Destination
RNT · Renton, WA
Airport
RNT · Renton Municipal Airport, runway 16, 5,382 × 200 ft, concrete
Equipment
ADS-B

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 · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
89
Injuries
Minor
Certificate
Flight instructor
Airplane ratings
Single-engine sea, Multi-engine land
Instrument ratings
Airplane
Medical
BasicMed
Last flight review
May 29, 2020
Seat
Rear
Restraint
None
Flight hours
7,387 total · 1,100 in this make and model · 7,320 as pilot in command · 38 in the last 90 days · 22 in the last 30 days · 2 in the last 24 hours
Role
Student pilot
Age
59
Injuries
Minor
Certificate
Private
Airplane ratings
Single-engine land
Medical
BasicMed
Last flight review
June 11, 2020
Seat
Front
Restraint
5-point
Flight hours
293 total · 46 in this make and model · 100 as pilot in command · 10 in the last 90 days · 8 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
180° at 8 knots
Visibility
10 statute miles
Lowest ceiling
3,900 ft overcast
Temperature
59 °F, dew point 48 °F
Altimeter
29.98 inHg
Observed at
KMT

Docket · 6

The files NTSB released with the investigation on April 20, 2022, on NTSB’s docket system: statements, records, photos and specialists’ reports. 31.4 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 N36339 · 1

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