MIA99LA130

NTSB accident investigation · Zemp Avid Catalina · Sebring, FL · April 14, 1999

Accident · Minor injuriesLimited investigationFinal report
Date
April 14, 1999, 17:00 local (21:00 UTC)
Place
Sebring, FL
Injuries
2 minor
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N9224TZemp Avid Catalina
Weather
Visual (VMC) · Day
Status
Completed · report March 31, 2000
Report
Approved by Office Director
FAA report
19990414003519A
Case key
46122

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

The in-flight separation of one of the propeller blade's and one of the engine's exhaust pipes causing the engine to vibrate until it stopped running. A related factor was the unsuitable terrain for the forced landing.

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/malfunctionCruise
Exhaust system,manifold/pipe - crackedCause
Exhaust system,manifold/pipe - separationCause
Propeller system/accessories,blade - separationCause
Powerplant - vibration
Forced landingEmergency descent/landing
Terrain condition - none suitableFactor
In flight collision with terrain/waterEmergency landing
Terrain condition - high vegetation
Terrain condition - rough/uneven
Terrain condition - loose gravel/sandy

Analysis

The pilot reported that during cruise flight, at 1,000-feet agl, his experimental, pusher engine, hull configured amphibian sustained a propeller blade(s) separation and when he reduced power to alleviate the extreme vibration, the engine quit. The pilot's only option was to attempt an emergency landing to a clear spot in an abandoned orange grove. The aircraft collided with sand furrows and high vegetation sustaining heavy damage to the airframe. Examination of the wreckage revealed that 2 of the 3 composite propeller blades were missing as well as the engine's left/front exhaust pipe. All that remained of the missing exhaust pipe was its attaching hardware to its exhaust port and a short stub revealing a 360-degree circumferential crack.

Factual narrative

On April 14, 1999, about 1700 eastern daylight time, an experimental Zemp Avid Catalina, N9224T, registered to Microlite Jet Engines, Inc., operating as a 14 CFR Part 91 personal flight, crashed following an in-flight propeller blade(s) separation near Sebring, Florida. The amphibian aircraft was substantially damaged, and the private-rated pilot and a passenger sustained minor injuries. The flight originated from Avon Park Municipal Airport (AVO) about 1 hour before the accident.

According to the pilot's statement, the flight was at 1,000 feet agl, in cruise, when he heard a "bang", experienced severe vibration of the whole airframe, and when he reduced power, the engine stopped running. The pilot and his passenger determined their only option was to try a forced landing to a clear area within an old citrus grove. As the touchdown area emerged clearer in the pilot's view, he decided to leave the main landing gear up on the hull configured airplane due to the uneven terrain. Upon landing, the right pontoon collided with a small tree/sand dune, and the airplane ground looped and came to rest inverted.

Additionally, according to the pilot, postcrash examination of the airplane by he and the passenger revealed two of the three composite propeller blades of the pusher configured engine were missing except for about 10-inches from the hub, outward. Also missing was the engine's front/left side exhaust pipe. The stub of the exhaust pipe remaining shows a 360-degree circumferential crack. An engineering drawing supplied by the pilot detailing the failure is included in this report under, "Other Pertinent Forms and Reports".

According to the FAA inspector, the pilot and his passenger, both Swiss nationals, were in this country for only a short time during the 1999 Sun 'N' Fun EAA Convention at Lakeland, Florida. Before the inspector could personally examine the wreckage, the pilot had removed the engine, sold it at Sun 'N' Fun, stored what was left of the airframe in a "T" hangar of a friend at AVO, and returned to Switzerland. Statements made by the friend are included in this report under, "Other Pertinent Forms and Reports".

Aircraft

Registration
N9224T
Reported as
Zemp Avid Catalina (AVID CATAL)
Category
Airplane, amateur-built
Serial number
155AB
Airframe hours
100
Engine
Rotax 912UL, 80 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Adrian M. Zemp
Registered owner
Microlite Jet Engines Inc
Airworthiness certificate
Special, Experimental (Special)
Last inspection
Annual · April 13, 1999 · 1 hours before
Departed
AVO · Avon Park, FL

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
35
Certificate
Private
Airplane ratings
Single-engine sea, Single-engine land
Medical
Class 3, Valid Medical--no waivers/lim.
Seat
Left
Flight hours
185 total · 100 in this make and model · 142 as pilot in command · 1 in the last 90 days · 1 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
140° at 12 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
86 °F, dew point 63 °F
Altimeter
29.00 inHg
Observed at
ORL, 60 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.