20070630825939I

Incident · Minor damage

FAA incident report · Tlultr STINGSPORT · Germantown, WI · June 30, 2007

Date: June 30, 2007 · 10:37 local
Place: Germantown, WI
Phase of flight: Normal Cruise
Operating rules: General operating rules (Part 91)
Damage: Minor damage
Aircraft: N646N
Reported as: Tlultr Stingsport
Reported engine: ROTAX ROTAX912ULS
People aboard: 1
Fatal injuries: 0
Pilot’s certificate: Student
Pilot’s flight hours: 117 total35 in this make and model13 in the last 90 days

N646NRegistered now · TL Ultralight Sro STINGSPORTS/N TLUSA 139 · Built 2006 Airframe modelTL Ultralight Sro STINGSPORT Engine modelRotax 912ULS series4 cycle

From the FAA’s Accident/Incident Data System (AIDS), through its Aviation Safety Information Portal, as reported. The NTSB investigates accidents separately, and its record of an accident is the fuller one. The aircraft is matched to the registry by N-number and event date, checked against the reported make and model; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

What happened

The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.

(-23) Aircraft departed timmerman airport (mwc) at 10:11 am CDT. During cruise flight at 3,000 feet AGL the pilot felt strange jerking in controls and engine RPM increased. He noticed the aircraft was sinking at 500 fpm rate and realized the propeller had come off. He landed in a soybean field without further damage at 10:37 am CDT. The propeller departed the aircraft due to failure of the 6 mounting bolts. The propeller was not recovered, however one partial bolt and nut were recovered from the engine cowling. Examination of the propeller mounting flange and partial bolt indicates all the mounting bolts loosened and eventually failed due to fatigue cracking and overload.

As the FAA filed it

(-23) AIRCRAFT DEPARTED TIMMERMAN AIRPORT (MWC) AT 10:11 AM CDT. DURING CRUISE FLIGHT AT 3,000 FEET AGL THE PILOT FELT STRANGE JERKING IN CONTROLS AND ENGINE RPM INCREASED. HE NOTICED THE AIRCRAFT WAS SINKING AT 500 FPM RATE AND REALIZED THE PROPELLER HAD COME OFF. HE LANDED IN A SOYBEAN FIELD WITHOUT FURTHER DAMAGE AT 10:37 AM CDT. THE PROPELLER DEPARTED THE AIRCRAFT DUE TO FAILURE OF THE 6 MOUNTING BOLTS. THE PROPELLER WAS NOT RECOVERED, HOWEVER ONE PARTIAL BOLT AND NUT WERE RECOVERED FROM THE ENGINE COWLING. EXAMINATION OF THE PROPELLER MOUNTING FLANGE AND PARTIAL BOLT INDICATES ALL THE MOUNTING BOLTS LOOSENED AND EVENTUALLY FAILED DUE TO FATIGUE CRACKING AND OVERLOAD.