For those of you who missed extensive discussions in the past on cleaning up the
Europa to get the performance you desire, lets reflect.
In some previous writings I gave a summary of projects to improve the Europa
Trigear
speed kit and how I make my custom speed kits. See attachment below. I
also summarized how I get maximum potential out of my own and customers
aircraft.
Again, it is somewhat detailed.
For those of you who expect to just clip on a bit of fiberglass and some rattle
can paint and get huge jumps in performance, you will be sadly disappointed.
Aerodynamic efficiency comes from hours of work, fairing, study and testing.
Gary Leinberger has commented recently and to add to the discussion points I
have the following comments on his N388SG:
1. The aircraft is a high top, wide body, fully IFR, full leather
interior, dual
autopilot, 912S equipped, Airmaster AP332 with my full Custom Flight Speed Kit
(including hand done fairing) but with the wheel pants set higher than my 1.5
inch standard height for some grass strip operations. Empty weight was just
over 1000 pounds.
2. The paint job is very smooth and even the exterior lighting is as small
and
clean as was available in 2006. The cooling drag improved somewhat following
my Cooling 101 guidance.
3. We tried using an oil thermostat but in the hot Pennsylvania summers it
was
not allowing sufficient cooling. It was removed and a simple air dam butterfly
was used to block oil/glycol airflow in the duct during taxi out and winter
time cruise. I also has the hot water carb heat on full time.
4. The aircraft is well maintained, kept clean and polished, and its
engine well
serviced and repaired of any discrepancy.
Performance is more than adequate for a 912S. Especially considering its
weight.
I have found at approximately 6500 MSL at 5000 RPM and about 24 inches MP
the plane was flying at 126KTAS, 5.4 GPH, without any leaning or modifications
to the Bing carbys such as the HAC Man. If the HAC Man or similar was used we
would get a bit of a boost. At high cruise at 5500RPM, and 26+ inches the
aircraft
edged up to just below 140 KTAS at 2500MSL and due to running a bit rich
only about 135 at 6500. Above 7500 MSL one expects that 75% power can no longer
be maintained. It has a somewhat inefficient carb air box arrangement where
about 1 of Hg is lost.
What Garys aircraft has is an aircraft built with much attention to detail. It
is well rigged/trimmed and frankly fussed over to keep it in top shape. His
learning curve to maintain that has been quite high.
The 914/Airmaster equipped trigear aircraft benefit from turbocharging and
cruise
at or near 10,000 MSL is a comfortable 140 to 145 KTAS depending on weight
and attention to detail following my speed kit, trimming, and cleanup guidance.
This guidance was not discovered by me or my clients. It is tried and true
research
and development carried out through wind tunnel tests years ago. If you
want to make a fixed gear airplane cleaner you must pay attention to details:
1. Seal the gaps in the wing to root fairing. Tape is ugly, sticky and
messy.
Learn how to do it with gap sealing filler strips of weatherproof foam tapes
and rigging and sealing is fast and repeatable.
2. Wheel pants alone do not add performance. Installation of a pant to be
as low
as practicable and each transition from pant to leg to fuselage must be made
smooth and well faired. On my first LSA aircraft my original hack at my custom
speed kit increased speed by 17 knots and added only 8 pounds total. (40
extra hours of work though then paint on top of that.)
3. Cooling drag is a big deal. Most aircraft drag is from poor duct
sealing and
flow control. Cooling 101 is my start on how to improve your cooling drag.
4. Trim is essential. Weight and balance should be near the center at
about 60
inches. Too nose heavy and the stabilator will be creating a lot of downforce
and drag. Balance the aircraft. Roll and rudder trim is essential.. Engine
offset, proper wing incidence and trim tabs that are large enough to limit
grossly
large deflections help. I have papers on my website on how I do trimming,
as well as on The Europa Club Website.
5. A clean smooth painted surface that is well polished will increase
speed considerably.
6. Keep the engine at its full potential. If the engine is not running
right or
compressions are dropping, fix it. If you have tinkered with the induction
system, and are seeing very low manifold pressure at full throttle (below 28
inches)
you have an inefficient inlet system. Mufflers create back pressure.
The Classic muffler has a bit too much and as a result the original 80 HP
aircraft
suffer a bit. But since the Classic is lighter, one doesnt notice it as
much. The XS has the CKT exhaust which is lighter and has less backpressure.
7. A constant speed propeller will gain you additional cruise at a weight
and cost
penalty. However, following the golden rule: If it adds weight and it must
increase performance, is definitely at play here, it is a performance and safety
enhancer.
8. Get the weight down. Weight is the main performance penalty to many
very nicely
built aircraft. Old vacuum instruments, heavy gyros, non-solid state radios,
antiquated storm scope and navigation heads are no longer necessary or even
cost effective. The vacuum pump also robs horsepower from the engine. Old
heavy and draggy Whelen lights were high amperage units, and the wire was nearly
a pound a foot. Thats 12 unnecessary pounds with todays LED tip lights alone.
Super heavy (but comfortable) cushions decrease payload and are somewhat
easy to change out to our new fabrics and foams. Get rid of the golf cart
batteries
and put in lighter gel cell batteries, or even consider Lithium ion type
batteries.
Following these basic rules is not easy or fast. Often it will require
extensive
rebuild of a used or already built aircraft. But if you have an older aircraft,
and it is down for maintenance, tackle one or more of the above and in a
few years, the plane will be like a new aircraft. I just takes a few minutes
to review TheEuropaClub website to download more info and please look at the
references for more ideas.
Bud Yerly
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=500762#500762
Attachments:
http://forums.matronics.com//files/custom_flight_speed_kit_installation_2020_152.pdf
http://forums.matronics.com//files/techniques_for_increasing_europa_performance_2020_394.pdf
http://forums.matronics.com//files/custom_flight_trimming_101_126.pdf
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