British Gliding Association Aircraft Inspection
Recommended

Number:
050/05/2010
Date: 10 May 2010

Issue:
1

Subject:

Slingsby Capstan Inspection guidelines for inspection of wing fittings

Applicability:

Slingsby T49 Capstan

Accomplishment: Annual inspection

Reason:

Crack found in centre lamination of wing main spar to fuselage attachment with loose bushing

Instructions:

1/ Remove both wing root fairing panels to expose the wing to fuselage fittings.

2/ With the wings still rigged to the fuselage, but the root fairing panels removed, have 2 assistants push upwards fairly hard on both wing tips, whilst watching (or feeling with a finger) the root fittings closely for any movement. There should be zero movement between the steel bush and the aluminium plates of either the wing half of the fitting, or the steel bush and aluminium plates of the fuselage half of the fittings. There may be a small amount of movement between the rigging pin and the steel bush, which is normal wear and tear, but zero movement between the steel bushes and aluminium plates. Look at both top and bottom fittings, but pay particular attention to the lower fittings.

3/ Visually inspect the fittings, (with the wings removed for better access), paying particular attention to the area around the lower main spar rigging pin, (as that is the fitting under tension in normal flight loads). On the damaged fitting found, the crack was visible on the centre of the 3 laminations of the wing part of the fitting, roughly opposite the centre-line of the rigging pin (i.e. the thinnest, most highly stressed part of the fitting)

Issued by - The British Gliding Association Ltd, Kimberley House, Vaughan Way, Leicester, LE1 4SE, U.K. Note: Mandatory inspections must be recorded in the aircraft log book, unless specified, and certified by an appropriately rated BGA inspector.
Optional inspections should be entered into the D.I. book or log book as appropriate. Optional inspections may be certified by a BGA Pilot. Alternative methods of compliance will be considered providing an equal level of safety is accomplished. Contact BGA for authorisation.

Findings: there was about 30 thou movement between the steel bush and the aluminium plates in the wing half of the lower fitting, which should have been obvious, even if the crack had been missed.
Approved By Jim Hammerton, Chief Technical Officer
Issued by - The British Gliding Association Ltd, Kimberley House, Vaughan Way, Leicester, LE1 4SE, U.K. Note: Mandatory inspections must be recorded in the aircraft log book, unless specified, and certified by an appropriately rated BGA inspector.
Optional inspections should be entered into the D.I. book or log book as appropriate. Optional inspections may be certified by a BGA Pilot. Alternative methods of compliance will be considered providing an equal level of safety is accomplished. Contact BGA for authorisation.