Customer’s Comments
“Homebuilt Aerodynamics and Flight Testing” customer:
“Dear Sonja,
Thanks for the prompt delivery. Your books arrived in good condition. Very enjoyable to read-I like the way you wrote them. I like the "cut the engine" prior bail out. Will add that in my bailout-section! Very interesting to read on SB-13.
Best Regards
Dieter Reisinger”
“Tips and Tricks for Aircraft Homebuilders” customer:
“You are my new idol! I looked at more of your past projects last night, incredible stuff. .. Thanks again for the book, I am looking forward to reading it this weekend. I haven't been so excited about a new book in a while.
Best,
Michael McMahon“
Letter from a client:
“I am rebuilding a
Legacy that was crashed a while ago and had some spar damage. The dilemma
was to find someone who could properly engineer the repair and make sure they
were properly done. We talked to many “composite” engineers over the last
year try to find one that was competent and willing to write a proper repair
schedule. No luck, until;
The other day I was
googling something and ran across Sonja Englert’s web site http://www.caro-engineering.com/
and contacted her. She was willing to come over to Denver
to look at the project and for a very reasonable fee engineer the repairs.
I can’t tell you how
fantastic she is as an engineer and knows composites inside and out. She
spent the day measuring and preparing the repair schedule with obvious
knowledge of her trade. When I queried how long she had be involved with
composites and this type of work she indicate she had been doing this since her
teen years as an apprentice in a sail plane factory in Germany. Quality
and craftsmanship!
After she returned
home, she prepared a 20 page repair document with pictures, lay up schedules
and drawings showing how precisely to do the repairs and what materials and
post curing procedures to use. Absolutely top professional by anyone’s
standards!
If anyone has need of
any aeronautical engineering services, I recommend her highly and I will not
hesitate to fly this repaired aircraft as I know it has been done with quality
and safety of design.
She has also written
some wonderful books for homebuilders.
Thanks,
David Williams,
Fahren Corporation”
“Sonja Englert, Tim's German Engineer friend is now doing some friendly consulting.
Her new book..."EFFICIENT POWERPLANT INSTALLATION...piston engines" is full of goodies. It can be ordered on-line from her or Amazon and is a very good read. It's worth the $$.
Will Stout”
“Sonja
I test flew the aircraft on
the weekend. Success is the reader's digest answer.
I am sourcing the
temperature strips to confirm temperatures but very little heat was radiating
into the cabin area. The rudder pedals were not heating. Many thanks for your
help. I would have been trying to insulate and keep the heat near the turbo
instead of shielding it without your suggestions.
Cheers..............Phil”
This book review was printed in “Kitplanes”, March 2008:
Engine Installation Tips from a Pro
Many
readers would covet the author’s day job. An aero engineer responsible for
engine cooling designs at Columbia Aircraft, Sonja Englert is also the
company’s experimental test pilot.
Englert
flies her Pulsar and is building a motorglider she has designed. She has
written four books of interest to homebuilders. Sensing a lack of detailed
information on engine installation in kit aircraft instructions, she wrote this
one to fill the gaps. Photos, drawings and charts are clear and helpful.
Readers
without a strong technical or aviation background will understand her writing,
and there’s enough meat here for practical application by any homebuilder.
Those who
have not yet built will find value in the sections on firewalls (appropriate
materials and how to use them), safe penetrations through the firewall, and on
engine mounts. There are sections on air filters, carburetors and exhaust
systems. Fuel systems, Englert says, may be the most important element in
engine installations. Fuel lines, valves, return lines (for some fuel-injected
engines), drain valves and fuel tanks come in for special attention. There’s a
chart on the recommended distance between supports for both aluminum and steel
fuel lines forward of the firewall and tables of torque limits for connecting
flared metal tubing, both aluminum and steel. Every new homebuilt should be
tested for fuel flow before it flies, and Englert tells how to do it.
Oil system
components and engine electrical systems including battery capacity calculation
are detailed as are sections on ignition types and advantages. As might be
expected, material on engine cooling and cowlings – Englert’s forte – is
especially useful and interesting. Air pressure differential between the top of
the properly baffled engine (the inlet side on the usual downdraft airflow) and
the bottom, she notes, determines the efficiency of the cooling system.
Properly designed and built, the system minimizes cooling drag, and engine cooling
is optimized. Englert shows how to calculate the size of the air inlets and
notes that several of her projects resulted in reducing the size of air inlets
for best efficiency. Before and after photos show how she treated the inlets on
a Mooney and on her own Pulsar homebuilt. Both cooled better and achieved
higher top speeds (4 knots in the Mooney’s case). Another successful project
was changing the cooling of the rear engine on a Cessna Skymaster from
downdraft to updraft, which increased efficiency considerably.
Using a
simple temporary water U-tube manometer, one can measure the engine inlet
plenum/outlet air pressure differential in flight, Englert says, but it’s
important to ensure that the tubing used in the engine compartment won’t melt.
Liquid-cooled
engines such as the Rotax 912 are covered, as are propellers and how to size
them. She also notes that it is dangerous to use a metal propeller unless it
has been certified for operation with the specific engine. There is no way for
a homebuilder t know if a non-certified engine/prop combination will avoid
catastrophic (prop-breaking) resonances, Englert says.
Most of the
information in the book may be available from other sources, but much of what a
homebuilder needs to know about these systems has been combined in this well
written and nicely illustrated package, which sprinkles a lot of useful
technical information with personal experience, insight and touches of humor.
“Hello
Sonja:
I received
your books today. Hard to put them
down. I will be ordering a couple more
to give to my friend who is helping me. They are excellent, and easy to read.
Thank you, Colin”
“Hi Sonja,
Your books are fantastic; they show a true practical
understanding of the material that is absent from many other books available
(author names withheld).
Thanks,
John (Dreese)
DreeseCode Software”
jdreese@dreesecode.com
“Sonja,
Thank you for the engine book, which I have devoured.
There are many things which I would like to discuss
(sometime) with you.
One of them is tuned induction - for example, when
calculating the
scavenging effect in exhaust manifolds, do you suppose that
the "low
pressure wave" travels to the collector, then back up
the pipe of the
just-opening valve?
Or that the same phase of the pressure wave occurs
simultaneously in all pipes of the manifold? (Who figures these things out?
Where to find out more?)
Hochachtungsvoll,
Jim Wixson“
„Hi Sonja,
I read your ‘Building Metal Airplanes’ book (over 2
sittings); very well done!
Tom Nalevanko”
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