Rigging Instructions for Grob Acro II (GDEWP)
Introduction:
Coming from the Astir
“family” the Grob Acro 2 (EWP) has similar rigging components and,
like Astirs, needs to be properly set up and aligned in order to facilitate a smooth and
expeditious rig. This guide is a distillation of the things learnt from previous rigs and will
hopefully provide a useful guide to anyone rigging this glider in future.
1. Preparing to Rig:
1.1 Pick an area of ground, to do the rigging, that is relatively level. Slope and uneven
surfaces present a significant challenge when rigging this glider. This is because the
tolerances on the spigots and sockets at the root end of the wings are extremely tight
and both wings must be lined up such that each wing aligns perfectly with the other in
terms of horizontal and vertical planes where the respective spigots/sockets engage.
1.2 Wind the jockey wheel up such that the two lugs on the rear of the trailer rest on the
ground. The aim is to get a straight, gentle slope along the rails. Slide the fuselage out
of the trailer making sure to have a couple of helpers to carry the rear fuselage far
enough for the tail wheel to touch the ground without the underside of the fuselage
scrapping on the trailer rear edge. A double-handled strap has been provided to
facilitate this (Figure 1). Wrap it once round the rear fuselage just forward of the fin and
use the handles to easily lift the rear out and back until the tail wheel is safely on the
ground.
1.3 Keep the fuselage on the belly dolly in the upright position so that the main wheel
remains clear of the ground thus minimising the likelihood of unwanted fuselage rotation
in the dolly. Hold the fin, look to the front for reference and straighten up the fuselage if
required.
1.4 Remove all loose objects and accessories (total energy/pitot probes, parachutes,
cushions, batteries, etc.) from the rear cockpit and baggage area.
1.5 Open the access panel on the floor of the baggage compartment. Remove rear seat
back centre pad using a standard screwdriver by unlocking the Dzus fasteners. Unlock
the Dzus fastners on the seat pads either side and pull the pads forward from the top to
enable access to the wing-fuselage fittings. There are two fittings on either side of the
fuselage under to baggage deck (rear fittings) and two fittings on either side of the
fuselage behind the rear seat pads (front fittings).
1.6 For each fitting, slide the locking nut (threaded) inboard, push the locking sleeve
outboard, then rotate so that it stays in the unlocked position (pins not in slots). Note
these should all be in the correct position to start with but it is worth checking (Figure 2).
1.7 Ensure that the airbrake arms and control rods under the aft baggage deck are in the
proper position. It will be impossible to rotate them to the proper position once the wings
are installed.
