TECHNICAL BULLETIN
Wills Wing Inc 500 West Blueridge Ave Orange, CA 92865 Ph/Fax (714) 998-6359/0647
Bulletin #: TB940501 RamAir Pitch Stability Modification
Date: 5/25/94
Page 1 of 3
Revised 6/1/94 Destroy all previous copies
Introduction
On May 12, 1994 Wills Wing issued a temporary grounding order for the RamAir 154. This order was issued following a turbu-
lence induced tumble and subsequent structural failure in Germany, and reports of three other turbulence induced upsets without
structural failure. Because of these incidents, both the DHV and Wills Wing retested the RamAir 154 on their test vehicles. In both
cases, areas of noncompliance were found at some intermediate VG settings. As of the date of this bulletin, no incidents or
problems have been reported on the RamAir 146.
Wills Wing has since developed a retro-fittable modification. This modification has been tested and shown to substantially
increase the RamAir 154's and RamAir 146's margin of compliance with U.S. H.G.M.A. standards and also improve some qualitative
handling characteristics. The modification includes a new bridle set, a bridle compensator adjustment, the addition of reflex to the
profile root area battens and a CG/hang loop adjustment. The parts are available free of charge through Wills Wing dealers world
wide. Installation instructions follow.
Batten Reflex Modification
The 154 has reflex added to 4 battens: no. 8 through no. 11, the 146 has reflex added to 3 battens: no. 8 through no. 10. Refer to
figure no. 1. Measure and mark each batten at distance "A". Bend each batten in a smooth radius over a 3 inch length centered on
the mark. Verify the reflex specification "B" using the replacement batten chart available from Wills Wing. Use the X's, and the
unchanged root and #7 battens to align the overlays to the chart. Use care to keep the reflex bend in the same plane as the nose
area camber. You will achieve better quality results if you work on a large flat unobstructed surface.
Batten
#8
#9
#10
#11 (154 only)
Distance A
12 in [30.5 cm]
13 in [33 cm]
14 in [35.5 cm]
15.5 in [40 cm]
Distance B RamAir 154
1 in [2.5 cm]
1-1/2 in [3.8 cm]
1-3/4 in [4.5 cm]
2-1/8 in [5.5 cm]
Distance B RamAir 146
1-3/8 in [3.5 cm]
1-3/4 in [4.5 cm]
2-1/4 in [5.7 cm]
NA
Figure no. 1
Bridle Installation
Remove the original bridle set from the #4, #6 and #8 batten stations. Save the 6 bridle balls. Install the retrofit bifurcated bridle
set at the #4, #5, #6 and #7 stations. Install the cable loops through the original bridle anchor grommets at the #4 and #6 stations,
and through the outboard of the two batten tension grommets at the #5 and #7 stations. Refer to figures no. 2 and no. 3. Check that
