Corey CIRRUS VK-30 N7033G

Summary

On 3 June 1996 at about 18:55 local time, a Corey CIRRUS VK-30 registered N7033G was involved in an accident near Lapeer, Michigan, 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

3 June 1996 at 18:55

Classification

Accident

Location

Lapeer, Michigan, United States

Coordinates

43.0390, -83.3195

Aircraft

Corey CIRRUS VK-30

Registration

N7033G

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Aircraft damage

Destroyed

Weather

VMC

Light

Not Reported

NTSB number

CHI96FA185

1 person died.

incomplete cure of the bonding material in the cruise flap, improper material in the cruise flap hinge, and improper welding of the cruise flap push rod end caps. Factors were delamination of the cruise flap, partial failure of the cruise flap hinge, and fatigue failure of the outboard cruise flap push rod.

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

Read the full NTSB narrative

According to witnesses, the accident pilot reported on Unicom that his 'flap bracket had broken.' A pilot who was on the ground near the accident site reported that he observed a 'violent flutter' on the right wing. Examination of the right flap revealed the inboard flap push rod was fractured at the end cap. The push rod welds exhibited 'porosity and secondary cracking indicative of poor welding techniques.' The inboard cruise flap push rod 'exhibited a thumbnail crack, which may have indicated failure by high stress, low cycle fatigue.' The outboard cruise flap hinge was fractured. Examination revealed the hinge was constructed entirely of composite material. The kit manufacturers drawings specify an aluminum core for the hinge. Differential scanning calorimetric analysis of the composite cruise flap skin revealed the vinyl ester matrix material was 'not fully cured.'

Quoted verbatim from the NTSB record.