----- Original Message -----
From: Ben
Subject: switchable landing gear
Switchable Landing Gear
I have finally completed the undercarriage conversion on my Europa. It
all works beautifully and enables one to change undercarriage
configuration either in flight or on the ground. It's possible to select
any one of three configurations; a standard mono-wheel, a conventional
tailwheel or a trigear with little more than the flick of a switch and a
little bit of trimming. At present the nosewheel and tailwheel remain
fixed (but I am working on that). All the main undercarriages are, of
course, fully retractable.-no more of that unsightly monowheel bulge!!
While flying one simply selects, by means of a pneumatic switch, which
particular gear is required. This is then lowered hydraulically. Next, a
simple electric fuel pump is activated to move fuel between two tanks as
necessary to achieve an appropriate Cof G to suit the type of gear
selected. The location of the second tank will depend on the original
aircraft's landing gear type but on tri-gears it is envisaged that it
will be located about midway between the original tank and the tail fin.
Experience has shown that the amount of fuel transferred is not overly
critical to the handling characteristics.
The undercarriage change lever can be operated on the ground but it is
best done only while stationary until familiarity with the system
develops. Early tests have indicated that there can be some minor
handling problems if activated during high speed taxiing or immediately
prior to rotation. This is particularly noticeable in strong crosswinds
(20+ kts) and on unmade strips. Similarly it is recommended that the
desired landing configuration is selected well before touch down. Low
hours pilots are advised to stick to one configuration for the first few
flights and then to gain experience of configuration changes in the air
before attempting any high-speed ground changes.
The PFA are very supportive of the modification and have only
requested some very minor additional testing before full approval is
given. They believe some annunciator lights may be helpful to remind
pilots as to which particular gear they have selected. Also, while
impressed with my innovative system, they have suggested an alternative,
and perhaps simpler, method of Cof G adjustment which obviates the
necessity of an additional fuel tank. Their proposal requires a heavy
weight being moved on rails along the length of the inside of the
fuselage by means of a small electric, or manual, winch. Both systems
have obvious merits and the decision as to which one to adopt will
depend largely on personal preference and range requirements.
Europa Aviation are especially enthusiastic about this system unlike
some of the other, cruder, developments that have been suggested and
discussed on this forum. As a result Andy and the "team" have undertaken
to supply all the necessary components at very reasonable prices.
However I am advised that there may be difficulties in shipping the
weight overseas. Therefore overseas customers who opt for the "weight
shift" system may have to have the weight manufactured under local
arrangements. However it is possible that the battery(with suitable
extending leads) could be used to fulfill this function (subject to size
and to PFA approval).
Obviously there are slight weight penalties. Pilots who are prone to
adiposity or those who carry passengers that are similarly challenged
may wish to consider the modification only in conjunction with a VP
prop, a larger engine (or perhaps a change of diet!).
Demand is yet to be fully assessed, but initial reactions have been
very encouraging
A limited number of stage by stage building instructions and copies of
the supplementary handling notes are already available from the Factory.
Happy landings
Ben!!
Just what we need! I've been waiting for news of this mod
for weeks now, ever since Frank mentioned it.....
What I have done in the meantime is stop-gap but meets
local regs here. I have taken the dry protion of the pigment used in the
polyurethane coatings and had it collandered down to 5 micron size. It's
tricky, and the supervisor is not keen to do this too often.
Since 5 micron is below the visible spectrum and is wetted
out priuor to application, and the carrier (wet) portion is colourless,
this renders the entire mix to below the visible protion especially
after careful drying.
Thus the trigear and tailwdragger mains are not readily
visible, so the mod looks Mark I, but the aircraft is multi-capable. The
only restriction comes from Transport Canada - that flagged notices must
be used on all tie-downs to permit conspicuity of unseen containment.
Best regards of the day,
Ferg
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