20040523015629A

Accident · Substantial damage

FAA accident report · Amtr Skybolt · Altus, OK · May 23, 2004

Date: May 23, 2004 · 13:00 local
Place: Altus, OK
Airport: Altus Municipal Airport
Phase of flight: Descent
Operating rules: General operating rules (Part 91)
Damage: Substantial damage
Aircraft: N25BM
NTSB investigation: NTSBFTW04LA148
Reported as: Amtr Skybolt
Reported engine: Lycoming IO540*
People aboard: 2
Fatal injuries: 0
Pilot’s flight hours: 3,200 total30 in this make and model30 in the last 90 days

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) During aerobatics maneuvers the pilot noticed the fabric of the top wing right side coming loose and departing the aircraft. The pilot reduced power, lowered his airspeed and altitude and returned to Altus Municipal Airport without further problems. Investigation by an FAA, aviation safety inspector, revealed that 1.7 ounce fabric was used to cover this aircraft. The wing rib stitching had failed, allowing the wing fabric to come loose, tear, and about five feet of fabric on top of the top right wing and about three feet of fabric on the bottom of the top right wing departed the aircraft. One rib was damaged, and two trailing edge ribs were missing. The trailing edge tube had about five feet missing. Inspection of the left top wing revealed broken wing stitching, but the fabric had not yet failed.

As the FAA filed it

(-23) DURING AEROBATICS MANEUVERS THE PILOT NOTICED THE FABRIC OF THE TOP WING RIGHT SIDE COMING LOOSE AND DEPARTING THE AIRCRAFT. THE PILOT REDUCED POWER, LOWERED HIS AIRSPEED AND ALTITUDE AND RETURNED TO ALTUS MUNICIPAL AIRPORT WITHOUT FURTHER PROBLEMS. INVESTIGATION BY AN FAA, AVIATION SAFETY INSPECTOR, REVEALED THAT 1.7 OUNCE FABRIC WAS USED TO COVER THIS AIRCRAFT. THE WING RIB STITCHING HAD FAILED, ALLOWING THE WING FABRIC TO COME LOOSE, TEAR, AND ABOUT FIVE FEET OF FABRIC ON TOP OF THE TOP RIGHT WING AND ABOUT THREE FEET OF FABRIC ON THE BOTTOM OF THE TOP RIGHT WING DEPARTED THE AIRCRAFT. ONE RIB WAS DAMAGED, AND TWO TRAILING EDGE RIBS WERE MISSING. THE TRAILING EDGE TUBE HAD ABOUT FIVE FEET MISSING. INSPECTION OF THE LEFT TOP WING REVEALED BROKEN WING STITCHING, BUT THE FABRIC HAD NOT YET FAILED.

NTSB investigation

The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.

NTSB FTW04LA148Accident · No injuriesLimited investigationFinal reportAltus, OKThe partial in-flight separation of the wing fabric and rib structure due to an inadequate material installed by the airplane builder.May 23, 2004 · Substantial damage