Customers Comments

Here is a selection of what my customers had to say. Of course I only posted the nice ones :). Honestly, I have not received any negative ones!

 I love both of your books, very good info for pilots that are not mechanics and maybe also good for some mechanics. [Piston Engine Troubleshooting for pilots & Efficient Powerplant installations]

Thank you for the prompt delivery of the books I ordered last month. I am very impressed with the quality and the content of the books. They are easy to read, informative, and contain a wealth of information. They will certainly come in handy as I build my Zenith CH650. I’d like to purchase two more of the books listed on your website.
Thank you,
 Robert D. Johnson
Dear Sonja,
  I have been a certifiable airplane nut since about age 8.  I have been collecting books, plans, assembly instructions, articles, pamphlets, and brochures on composites over the past 7 or 8 years.  I have Lambe, Rutan, Zeke Smith, Marske, Strojnik, among others; plans for a number of aircraft; assembly manuals for Pulsar, Express, Lancair, and others; and numerous other documents.  Your composites book brought the immediate reaction of regret for having delayed ordering it for so long.  Though I have so far had time only for a rather superficial overview I am very pleased with your book, very much look forward to studying it thoroughly, and excited about how much there is to learn from it.
 Best regards,
 Jay B Swindle
Dear Sonja Englert,
 Recently I have finished your book (e-book)  TIPS AND TRICKS FOR AIRCRAFT HOMEBUILDER. In recent past, I also had the honor to read your another book COMPOST FACTS . Your another book BUILDING METAL AIRCRAFT is on my MUST read list.
All your books contains wealth of knowledge and a beacon of light in the composite world.
Warm Regards,
Hassan Bilal
 I have reviewed the composite horizontal tail files thoroughly and am very impressed with the detailed content. As with the wing design work, your services have not only been necessary without question but also a very good value. The work you have done exceeds my expectations in several ways. I would not have expected you to provide insight regarding aerodynamics, stability or alternate construction/assembly methods. Your suggestions have improved these components while accommodating my original vision. I am very appreciative of your efforts and look forward to working with you again.
Thank you very much!
 Rick Poe
“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.
 Michael McMahon“
Letter from a customer:
“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 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.
 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”
 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.
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).
John (Dreese)
DreeseCode Software”
 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?)
Jim Wixson“
„Hi Sonja,
 I read your ‘Building Metal Airplanes’ book (over 2 sittings); very well done!
 Tom Nalevanko”