I have had email
discussions with the test pilot who undertook some of the test flying on the
Lancair which resulted in the recommendation to enlarge the
tail.
I quote from the email I
received from one him on 20 September 2007:
.When the
first example (a 320 I think?) was evaluated, it was found to have 2 major
design problems/defects. First the aft CG condition was unrealistic (in
excess of 30% MAC), and the horizontal stabiliser was too small.
Combined these resulted in neutral or negative stick free longitudinal
stability. Also manoeuvre stability (stick force per G) was at best
measured in ounces per G. Standard comment from then owners was"I like
it like that because it has fighter like feel." These pilots had
obviously never flown a fighter, at least not one built since about 1920,
which all have positive long stab, and minimum stick forces of about 7
lb/G.
CASA insisted
(under the good/bad old 101.28 rule) that stability be improved. I think
the aft CG limit was moved forward (not sure how much) and bigger tails were
required. The bigger tails (2 local REG 35 solutions by Graham Swannel
and Dave Simons) produced adequate solutions, but the practicalities of
keeping CG forward remained.
Very quickly
the manufacturer of kit X came out with a bigger tail (about 50% bigger!), and
some advice on how to fix the CG problem. Lancair eventually
did the same
Hopefully this will help, if
not cause the usual broad-ranging hackles raising.
Cheers,
Dom Crain
VH-CZJ
Melbourne
Not Florida