The recent comments regarding the Small v. Big tail draw my attention to the fact that on a recent visit to the wide brown land up over, LML lister Angier was privileged to see two examples of large tail Lancair's. One belonging to me (didn’t build it), and the other being the example quoted in the attached letter to Rob Wolf’s post “A look at Lancair 360 Handling Qualities”. Now owned by another lister here.
The only Lancair’s I have handled in the air were all large tail versions, with one exception, that being N5ZQ in the States. Bill will undoubtedly recall that I was – let’s say “ropey” – to say the least. While I am prepared to accept that is my lack of skill, and I reflect long and hard on this after each flight I have made over forty odd years, I do come to the conclusion that there is a distinct improvement in stability and handling of the Lancair with the large tail.
Over the past few months –almost a year actually, there has been a slow but steady approach to the improvement of training of, and understanding by, Lancair pilots here up over, brought on by the historical global accident rate, and highlighted by two fatals within six days in Australia, 20 months ago.
A Lancair Pilot Group has been established, and having been asked to be involved, I have sought advice from various sources regarding their views on the matter of Lancair training and opinions on handling.
In this process 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. The Lancair 235/230/360 models also have negative lateral sideslip stability; with a low wing and no dihedral the predominant rolling force in a sideslip is due to the rudder. This characteristic is rarely seen, and is disturbing when deliberately sideslipping during cross wind approaches. For IFR approval, CASA insisted this be fixed and a rudder/aileron interconnect was developed (I think by Dave Simons) which produced apparent lateral sideslip stability and hence predictable handling qualities in sideslip.
The kit manufacturer was not amused by these criticisms of his creation and refused to have anything to do with them. However, shortly after CASA came the heavy, Aviation Consumer magazine in the US conducted some flight tests on the Lancair, and another fast plastic of similar size and shape, and concluded their findings with some not very flattering remarks along the lines of ......... how dare you foist on the unsuspecting public expensive machines with such bad design features........ - I was very pleased to hear this as it vindicated the position taken by CASA and other professional Test Pilots who had flown the machines.
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……”
CASA is the current name for the old CAA here up over. Under a Labour Government, the name changes every few weeks to create jobs. Although the quote uses the current term CASA, at the time of testing the authority was called CAA.
Hopefully this will help, if not cause the usual broad-ranging hackles raising.
Cheers,
Dom Crain
VH-CZJ
Melbourne
Not Florida