Heal SONERAI-I N4227N

Summary

On 23 June 1991 at about 20:48 local time, a Heal SONERAI-I registered N4227N, operated by R.w. Leonard, was involved in an accident near Davenport, Iowa, United States. One person was on board and one died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

23 June 1991 at 20:48

Classification

Accident

Location

Davenport, Iowa, United States

Nearest airport

Davenport Muni (DVN)

Coordinates

41.5204, -90.5690

Aircraft

Heal SONERAI-I

Registration

N4227N

Category

Airplane

Engines

1

Operator

R.w. Leonard

Operating rule

Part 91: General Aviation

Purpose of flight

Unknown

Phase of flight

Not recorded

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

CHI91DCD01

1 person died.

FAILURE OF THE WING SPAR STRAPS, AS THE AIRCRAFT WAS BEING MANEUVERED AROUND A PYLON IN AN AIR RACE.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

THE PLT WAS PARTICIPATING IN A PYLON AIR RACE FOR FORMULA V RACERS. ABT HALF WAY THRU THE RACE, AS HE WAS MNVRG PAST THE #2 PYLON, THE LEFT WING BGN TO SEPARATE. THE WING THEN FOLDED OVR THE TOP OF THE ACFT. THE WING & PIECES OF THE CANOPY FELL TO THE GND. AS THE WING SEPD, THE ACFT BGN A VIOLENT ROLL & FLWD A TRAJECTORY PATH TO THE GND. INV REVEALED THE INNER PORTION OF EACH WING WAS DESIGNED WITH BOX SPAR CONSTRUCTION, SECURED TO A FUSELAGE CARRY-THRU CONFIGURATION. THE OUTER WING SPARS CONSISTED OF A SERIES OF UPPER & LOWER STRAPS. THESE WERE SECURED TO A SHEET METAL WEB WITH RIVETS. THE 4 LOWER SPAR STRAPS HAD FAILED; 2 HAD FAILED AT THE 1ST RIVET HOLE OUTBOARD OF THE BOX SPAR CONFIGURATION; ONE FAILED AT THE 1ST BOLT HOLE NEAR THE OUTBOARD END OF THE BOX SPAR & THE 4TH FAILED FLUSH WITH THE OUTBOARD END OF THE BOX SPAR.

Quoted verbatim from the NTSB record.