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Stop: The design of the Hall type airspeed indicator involves using a ram air
versus static pressure differential to raise a disc in a tapered tube against the
force of the weight of the disc. Because of this the ASI has certain operating
limitations:
a) It is only accurate in one G flight. If you are turning at a bank angle of more than 30
degrees, the ASI will read artificially low as a result of the G loading of the turn. Reliance on
the ASI for limiting airspeeds in high banked sustained spiral maneuvers will likely cause you
to exceed the placarded speed limitations of the glider and will compromise your safety.
b) It is only accurate when within 15-20 degrees of the vertical orientation.
USING THE VG SYSTEM
The RamAir VG system uses a 7:1 reduction system of pulleys to allow for up to a 4.75"
(4.0" on the 146) rearward adjustment of the crossbar center and up to a 2.7 degree in-
crease in the airframe nose angle. Tightening the VG increases the spanwise tension which
the airframe places on the sail, reducing the spanwise twist and the sail elasticity. The result
is an increase in L/D performance and a reduction in roll control authority and roll control
response.
The VG is activated by pulling laterally on the VG rope and then setting the rope in the
basetube cleat. The relatively short throw of the rope (about three feet) makes it possible to
adjust from full VG loose to full VG tight in one pull. However, it is easier to make adjust-
ments of no more than half that amount at one time. The recommended procedure for in-
creasing VG tension is to grasp the rope firmly at the cleat, and pull straight across behind
the basetube.
Two different types of VG cleats are used on the RamAir. Early models have a traditional
jam cleat mounted to the top of the basetube, Later models use a V cut knife edge cleat
mounted to the back of the basetube pulley bracket. With the early cleat, when the desired
degree of pull is achieved, move your hand up and over the basetube and then down to drop
the rope into the cleat. With the late model, simply move your hand straight aft under your
body to engage the cleat. In either case, as you release tension on the rope, the cleat will
secure it in the desired position.
When using the basetube mounted cleat, your first attempts may seem just slightly awkward
due to the rope not being captive in the cleat. However, with a little practice you will find it
easy to set the VG quickly, exactly where you want it.
Like the HP AT, and unlike some other gliders, the full loose setting of the VG on the
RAMAIR is intended to be used. This setting does not represent a degraded performance
tuning configuration. VG full loose is a very useful configuration for maximizing control ease
and response while retaining excellent performance. It is the recommended VG setting for
working lift when any degree of turbulence is present, or when you are in proximity to terrain
or other aircraft.
Between VG full loose and VG one third, the glider retains good ease of control and control
response. Tighter than VG one third, the glider’s roll pressures increase markedly and the
