Dec 29th

Practice Go-Arounds!

By Dave Schultz

Practice Go-Arounds!

Featuring Bob Martens

Mark: "We’re going to discuss the topic of go arounds. And this is a topic so basic, so fundamental. Why should we focus additional attention on the subject of go arounds?"

Bob: "Mark, I’ve always been a big advocate of the go around. I refer to it the most under utilized maneuver in aviation! Think about it. When was the last time you did an intentional go around without being required to? I’ll bet it’s been a while!

Now, think about how many of our awful landings might have been avoided had we exercised the good judgment to do a go around.

When I queried the NTSB data base to check out go-around accidents, there were over 1300 go-around accidents in the data base! That’s a lot of accidents. Clearly we have some work to do in this area."

Mark: "Why do we have so many go-around accidents, Bob?"

Bob: "While the go around is certainly not an inherently difficult maneuver, the fact that it is most often accomplished in close proximity to the ground cuts into our margin of error. Add to that the fact that the pilot is probably experiencing at least some degree of stress associated with the reason for the go around, and we start to understand the problem.

Now, factor in that the pilot has probably not done this maneuver in months, and we are now looking at a very serious problem. How can you expect to be good a something that you don’t practice regularly? Simply stated, you can’t!

The challenge of go arounds is that they must be performed instinctively, without hesitation, with precision. Far too many pilots are just not up to that challenge!"

Mark: "Bob, why is it that pilots fail to integrate go arounds into their training regimen?"

Bob: "Well Mark, first, and foremost, not enough pilots have a training regimen. I challenge all pilots to look into their log books and validate just how little time we spend on training. We all need to get back to basics, working hard on take offs and landings, heading to the practice area for stalls, steep turns and slow flight drills, and practicing emergency procedures. Integrated into this training must be go-around practice.

Any time we find ourselves out of sync with our airplane, go around and catch up! Far too often we find ourselves frantically chasing our airplane, hoping to catch up and make all the corrections before the airplane lands. That’s a dumb way to fly. Flying is like playing chess. We should be always looking several moves ahead, not playing from behind.

The go around is our tool to do just that. Far too many pilots perceive the go around as a negative procedure after a mistake. That is wrong! The go around demonstrates excellent judgment and has no down side! By practicing it and integrating it into our flying, we will be real good at go arounds and not hesitate to perform one at any time."

Full article at:

Dec 29th

Hey Gang! - New Ideas for TPSocial in 2012!

By Spencer Forman
I've been extremely excited to see how many quality video producers have "blossomed" here at TPSocial... awesome!

When I started this site back in 2001, there was no one publishing any video from trikes (at all)... and I was happy to put up postage-stamp sized low res vids.


Fast forward to 2012, and we now have HD resolution, and studio-quality production levels... all being done by passionate individuals with no formal training. WOW!


After trying some new things last year to expand our community offerings, it has become clear that the number-one most used feature on this site is the video hosting and commenting. As such, I'm going to "re-boot" the Trikepilot Pro side of the site in January by creating a "Featured Producer" section.

This new section will be for site members who have previously posted videos that demonstrate an incredible sense of style and production value. Once someone is invited to be a "producer" of videos on the pro-side, their videos will be featured in this new section and receive the voting of the community.

It is not my intention to be exclusionary, and no one will ever be prohibited from posting to TPSocial. Rather it is a way to focus the spotlight, and give some special attention, to those who demonstrate that they are really crazy-wild over making awesome videos. For everyone else, it is a way to have a more "cinematic" experience, with a curated menu of "top-notch" videos from which to view (if you so choose).

Let me know what you think about this idea?

Safe and Happy New Year!
Dec 27th

Training and proficiency for all pilots. How do we get better?

By Paul Hamilton
Here is the section 3 of the

Light Sport Aviators’ Model Code of Conduct

III. Training and Proficiency

   Pilots should:

a.      participate in training to maintain and improve proficiency beyond minimum legal requirements,

b.      participate in flight safety education programs,

c.       act with vigilance and avoid complacency,

d.      train to recognize and deal effectively with emergencies, and

e.       accurately log hours flown and maneuvers practiced to satisfy training and currency requirements.

Explanation:  Training and proficiency underlie avi­ation safety.  Recurrent training is a major component of flight safety.  Such training includes both air and ground training.  Each contributes significantly to flight safety and neither can substitute for the other.  Training sufficient to promote flight safety may well exceed what is required by law.

Sample Recommended Practices

q  Pursue a rigorous, life-long course of aviation study.

q  Use the manufacturer’s flight manual to deter­mine your aircraft’s performance and limita­tions, plan flights, properly secure cargo, determine fuel requirements and calculate weight and balance.

q  Follow and periodically review programs of study or training exercises to improve profici­ency.  Adhere to a training plan that will yield new ratings, certificates, and endorsements—or at the very least, greater flight proficiency.

q  Complete scenario-based training to supplement stick-and-rudder training with decision making and risk management skills.

q  Train for flight in unique environments such as over water or over remote, desert, or moun­tain­ous terrain.  Train for survival, and carry ade­quate survival equipment and drinking water.

q  Understand and use appropriate procedures in the event radio communications are lost.

q  Achieve and maintain proficiency in the operation of technology-intensive aviation equipment.

q  Know current aviation regulations and under­stand their practical application and rationale.

q  Spend time each month reviewing the aviation regulations and the Aeronautical Information Manual.

q  Understand and comply with the privileges and limitations of your pilot certificate.

q  Attend aviation training programs offered by industry organizations or the FAA.

q  Participate in the FAA Pilot Proficiency Award (WINGS) Program.

q  Seek out and study diverse and relevant aviation publications.

q  Study aviation weather, and develop a systema­tic approach to obtaining and evaluating aviation briefings and flight conditions.

q  Conduct a monthly review of recent or nearby accidents and incidents, focusing on probable causes.

q  Periodically demonstrate conformance to appli­cable practical test standards (PTS), and train to exceed minimum standards.

q  Obtain adequate training before flying an un­familiar aircraft, even if you have flown that type in the past.

q  Avoid practicing maneuvers near congested areas.

q  Seek to fly at least once every two weeks, in­clu­ding at least three takeoffs and landings.

q  Develop a practical understanding of the mecha­nical systems of each aircraft you fly.

q  Join a type club or support organization for the aircraft you fly to learn more about its operating limitations and performance capa­bilities.

q  Complete the equivalent of a Flight Review annually rather than every two years.

q  Maintain currency that exceeds minimum regu­latory requirements.

q  Register at <> to receive announcements of safety meetings and litera­ture, and to review appropriate safety courses online.



Dec 25th


By Dave Schultz

What You Need To Know

By Ron Alexander

The quality of our workmanship in building an airplane is very important. We all take the needed time and spend the necessary money to ensure we have a high quality airplane. We want it to not only look attractive, but also to be safe. But what about the materials that hold the airplane together the aircraft hardware? Do we try to cut expenses by using questionable bolts or used nuts? Is it really necessary to spend money on high quality aircraft hardware? Absolutely! The hardware used to assemble your airplane should be nothing but the best. Why take the time to build a perfect wing only to attach it to the fuselage with used hardware. It makes no sense. To quote the Airframe and Powerplant Mechanics General Handbook . . . "The importance of aircraft hardware is often overlooked because of its small size; however, the safe and efficient operation of any aircraft is greatly dependent upon the correct selection and use of aircraft hardware." Very well stated. The same book also provides us with a very good definition of aircraft hardware. "Aircraft hardware is the term used to describe the various types of fasteners and miscellaneous small items used in the manufacture and repair of aircraft."

The subject of aircraft hardware can certainly be confusing. Thousands upon thousands of small items are used on a typical airplane. What does the custom aircraft builder really need to know about hardware? Where do you find the information? What reference is really the end authority on proper installation? What do all of those AN numbers mean and do I have to know them? What types of hardware should I really learn more about in order to build my own airplane?

These questions will be answered in this series of articles on aircraft hardware. I hope to eliminate some confusion over what type of hardware to use and how to properly install it. To begin our discussion, it is absolutely imperative that you use nothing but aircraft grade hardware. Commercial grade hardware found in hardware or automotive stores is legal to use on an experimental airplane but should not be considered for even a moment. Why? Let's look at bolts as an example. Common steel bolts purchased from a hardware store are made of low carbon steel that has a low tensile strength usually in the neighborhood of 50,000 to 60,000 psi. They also bend easily and have little corrosion protection. In contrast, aircraft bolts are made from corrosion resistant steel and are heat treated to a strength in excess of 125,000 psi. The same comparison applies to most hardware items. So, use only aircraft quality hardware on your airplane. Save the other hardware for your tractor.

If aircraft hardware is special, then there must be a standard against which it should be measured and manufactured. That standard was actually developed prior to World War 11, but became more definitive during that war. Each branch of the military originally had its own standard for hardware. As time went on these standards were consolidated and thus the term AN which means Air Force-Navy (some prefer the older term Army-Navy). Later the standards were termed MS which means Military Standard and NAS which means National Aerospace Standards. Thus, the common terms AN, MS and NAS. Together they present a universally accepted method of identification and standards for aircraft hardware. All fasteners are identified with a specification number and a series of letters and dashes identifying their size, type of material, etc. This system presents a relatively simple method of identifying and cataloging the thousands and thousands of pieces of hardware. Several pieces of hardware will have both an AN number and an MS number that are used interchangeably to identify the exact same piece. A cross reference exists that compares these two numbers. So in the end, you are able to read your plans or assembly manual and identify, by number and letter, each piece of hardware on your airplane. You can then obtain that piece and properly install it in the right place. Imagine trying to do that without a system of numbers. The specifications for each piece of hardware also define the strength, tolerance, dimensions, and finish that is applied. If you would like further information on this numbering system, you can contact the National Standards Association in Washington, DC.

Out of all the thousands of hardware pieces manufactured, which ones are important to the custom aircraft builder? The following types and categories of hardware will be discussed:

  • Bolts
  • Nuts
  • Washers
  • Screws
  • Cotter pins and safety wire
  • Rivets
  • Turnlock fasteners
  • Miscellaneous items such as 0-rings, crush washers, etc.
  • Control cable hardware
  • Fluid lines and fittings
  • Electrical wiring and connectors

Where do you find information concerning aircraft hardware? Your aircraft plans or assembly manual should provide you with a general overview of hardware used on your project. Use the hardware the aircraft designer or kit manufacturer recommends. Do not substitute with your own ideas. This can be dangerous. The manufacturer has tested the design and its safety is dependent upon the proper pieces of hardware. FAA Advisory Circular 43-13-IA is an excellent reference source. The Airframe Mechanics General Handbook also has a very good section on the selection and use of hardware. These two books are considered the primary authority on the proper use of hardware. In addition, I would recommend two other small reference books: the Standard Aircraft Handbook and the Aviation Mechanic Handbook. Both of these provide a good reference source. The Aircraft Spruce & Specialty catalog also contains good reference material on hardware. If you have any doubts about the quality of the aircraft hardware you are purchasing, request a copy of the manufacturer's specifications. These specifications along with a specific manufacturer's lot number should be available.


Bolts are used in aircraft construction in areas where high strength is needed. Where this strength is not necessary screws are substituted. Aircraft quality bolts are made from alloy steel, stainless or corrosion resistant steel, aluminum alloys and titanium. Within our industry the first two are the most common. Aircraft bolts will always have a marking on their head. If you see no markings at all on the head of a bolt, do not use it. It is probably a commercial grade bolt. The markings on bolts vary according to the manufacturer. You should see an "X" or an asterisk along with a name, etc. If you purchase a corrosion resistant (stainless steel) bolt, the head of that bolt should have one raised dash. An aluminum bolt will have two raised dashes on its head. Aluminum bolts have limited use. They should not be used in tension applications or where they will be continuously removed for maintenance or inspection. A chart of typical bolt heads is presented in Figure 1. NAS bolts have a higher tensile strength (usually about 160,000 psi) and can be identified by a cupped out head. Close tolerance bolts are machined more accurately than general purpose bolts and they are used in applications requiring a very tight fit. Close tolerance bolts can be either AN or NAS and typically have a head marking consisting of a raised or recessed triangle.

The standard bolts used in aircraft construction are AN3 through AN20. Each bolt typically has a hexagon shaped head and a shank that fits into the hole. The shank is threaded on the end and the unthreaded portion of the bolt is termed the grip. The diameter of a bolt is the width of the grip. The shank of a bolt will be either drilled to accept a cotter pin or undrilled. Another option is to purchase a bolt that has the head drilled for the purpose of accepting safety wire. Clevis bolts are manufactured with a slotted head and are used for control cable applications. The size, material, etc. of a bolt is identified by an AN number. A breakdown of a typical bolt AN number follows:


  • AN means the bolt is manufactured according to Air Force-Navy specs.
  • 4 identifies the diameter of the bolt shank in 1/16" increments
  • 8 identifies the length of the shank in 1/8" increments
  • A means the shank of the bolt is undrilled (no letter here means a drilled shank)

So, this particular bolt is a 1/4 inch diameter AN bolt that is 1/2 inch long measured from just under the head to the tip of the shank. The bolt also has an undrilled shank which means it cannot accept a cotter pin. Also, bolt length may vary by +1/32" to -1/64". If the letter "C" follows the AN designation (ANC) that identifies a stainless steel bolt. The letter "H" after AN (ANH) identifies a drilled head bolt.

FIGURE 2: AN Aircraft Bolt Dimensions

In constructing you airplane, you will not encounter many bolts larger than an AN8 (1/2 inch diameter). To add a bit more confusion, if the dash number defining the length of the bolt has two digits, the first digit is the length in whole inches and the second number the length in additional 1/8" increments. In other words, an AN514 bolt would be I- 1/2 inches long.

Now that you are totally confused let me recommend a hand tool to simplify bolt selection and sizing. An AN bolt gauge is available that will assist you in identifying a bolt (click on the above link to Figure 2).

If you need to determine the proper size of a bolt, the length must be sufficient to ensure no more than one thread will be inside the bolt hole. This is the grip length of the bolt and it is measured from the underneath portion of the head to the beginning of the threads (see Figure 3 below). The grip length should be equal to the material thickness that is being held by the bolt or slightly longer. A washer may be used if the bolt is slightly longer. A piece of welding rod or safety wire can be used to measure the length of the hole. In his book titled Sportplane Construction Techniques, Tony Bingelis shows a simple tool that can be made for this purpose.

It is important that you do not "over tighten" or "under tighten" a bolt or the nut attached to a bolt. Under torque or under tightening results in excessive wear of the hardware as well as the parts being held. Over tightening may cause too much stress on the bolt or nut. The best way to avoid this is to use a torque wrench. AC43-13 presents a table of torque values for nuts and bolts. It shows fine thread and coarse thread series with a minimum and maximum torque limit in inch pounds. I recommend using a torque wrench whenever possible, at least until you get an idea as to the amount of force required. Of course, critical installations should definitely be torqued to proper values. A torque wrench is not that expensive and will be a worthwhile investment for a custom builder.

Basics of Bolt Installation

Certain accepted practices prevail concerning the installation of hardware. A few of these regarding bolt installation follow:

  1. In determining proper bolt length - no more than one thread should be hidden inside the bolt hole.
  2. Whenever possible, bolts should be installed pointing aft and to the center of an airplane.
  3. Use a torque wrench whenever possible and determine torque values based on the size of bolt.
  4. Be sure bolt and nut threads are clean and dry.
  5. Use smooth, even pulls when tightening.
  6. Tighten the nut first - whenever possible.
  7. A typical installation includes a bolt, one washer and a nut.
  8. If the bolt is too long, a maximum of three washers may be used.
  9. If more than three threads are protruding from the nut, the bolt may be too long and could be bottoming out on the shank.
  10. Use undrilled bolts with fiber lock nuts. If you use a drilled bolt and fiber nut combination, be sure no burrs exist on the drilled hole that will cut the fiber.
  11. If the bolt does not fit snugly consider the use of a close tolerance bolt.
  12. Don't make a practice of cutting off a bolt that is too long to fit a hole. That can often weaken the bolt and allow corrosion in the area that is cut.


Aircraft nuts usually have no identification on them but they are made from the same material as bolts. Due to the vibration of aircraft, nuts must have some form of a locking device to keep them in place. The most common ways of locking are cotter pins used in castle nuts, fiber inserts, lockwashers, and safety wire. The aircraft nuts you will most likely encounter are castle nuts, self-locking nuts, and plain nuts. Wing nuts and anchor nuts are also used.

Castle Nuts

AN310 and AN320 castle nuts are the most commonly used (see Figure 4). Castle nuts are fabricated from steel and are cadmium plated. Corrosion resistant castle nuts are also manufactured (AN310C and AC320C - remember, when you encounter a "C" it will designate stainless). Castle nuts are used with drilled shank bolts, clevis bolts and eye bolts. The slots in the nut accommodate a cotter pin for safetying purposes. The thinner AN320 castellated shear nut has half the tensile strength of the AN310 and is used with clevis bolts which are subject to shear stress only. The dash number following the AN310 or AN320 indicates the size bolt that the nut fits. In other words, an AN310-4 would fit a 1/4 inch bolt.

Self-Locking Nuts

Self-locking nuts, as the name implies, do not need a locking device. The most common method of locking is derived from a fiber insert. This insert has a smaller diameter than the nut itself so that when a bolt enters the nut it taps into the fiber insert producing a locking action. This fiber insert is temperature limited to 250-deg. F. The designation of these nuts is AN365 and AN364. This brings us to an example of a cross-reference MS number. An AN365 is also termed MS20365 with the AN364 being MS20364. Both of these nuts are available in stainless. The AN364 is a shear nut not to be used in tension.

An all metal locking nut is used forward of the firewall and in other high temperature areas. In place of a fiber insert, the threads of a metal locking nut narrow slightly at one end to provide more friction. An AN363 is an example of this type of nut. It is capable of withstanding temperatures to 550-deg. F.

The dash number following self-locking nut defines the thread size. Self-locking nuts are very popular and easy to use. They should be used on undrilled bolts. They may be used on drilled bolts if you check the hole for burrs that would damage the fiber. One disadvantage, self-locking nuts should not be used on a bolt that is connecting a moving part. Am example might be a clevis bolt used in a control cable application.

Plain Aircraft Nuts

Plain nuts require a locking device such as a check nut or lockwasher. They are not widely used in most aircraft. AN315 is the designation used for a plain hex nut. These nuts are also manufactured with a right hand thread and a left hand thread. The check nut used to hold a plain nut in place is an AN316. If a lockwasher is used a plain washer must be under the lockwasher to prevent damage to the surface.

Other Aircraft Nuts

There are a number of other aircraft nuts available. Wing nuts (AN350) are commonly used on battery connections or hose clamps where proper tightness can be obtained by hand. Anchor nuts are widely used in areas where it is difficult to access a nut. Tinnerman nuts, instrument mounting nuts, pal nuts, cap nuts, etc. are all examples of other types that are used.

Basics of Aircraft Nut Installation

  1. When using a castle nut, the cotter pin hole may not line up with the slots on the nut. The Mechanics General Handbook states "except in cases of highly stressed engine parts, the nut may be over tightened to permit lining up the next slot with the cotter pin hole." Common sense should prevail. Do not over tighten to an extreme, instead, remove the nut and use a different washer and then try to line the holes again.
  2. A fiber nut may be reused if you are unable to tighten by hand.
  3. At least one thread should be projecting past the fiber on a fiber nut installation.
  4. No self-locking nuts on moving part installations.
  5. Do not use AN364 or AN365 fiber nuts in areas of high temperature - above 250' F.
  6. Shear nuts are to be used only in shear loads (not tension).
  7. Plain nuts require a locking device such as a lockwasher or a check nut.
  8. When using a lockwasher, place a plain washer between the surface of the airplane part and the lockwasher.
  9. Shear nuts and standard nuts have different torque values.
  10. Use wing nuts only where hand tightness is adequate.


Finally, a hardware item that is simple. You are likely to encounter only a couple of different types of washers AN960 and AN970. The main purposes of a washer in aircraft installation are to provide a shim when needed, act as a smooth load bearing surface, and to adjust the position of castle nuts in relation to the drilled hole in a bolt. Also, remember that plain washers are used under a lockwasher to prevent damage to a surface.

AN960 washers are the most common. They are manufactured in a regular thickness and a thinner thickness (one half the thickness of regular). The dash number following the AN960 indicates the size bolt for which they are used. The system is different from others we have encountered. As an example, an AN960-616 is used with a 3/8" bolt. Yet another numbering system. If you see "L" after the dash number, that means it is a thin or "light" washer. An AN960C would be - yes, a stainless washer. I can tell you are getting more familiar with the system so I will throw another wrench into the equation - an AN970 washer has a totally different dash number system. I am not even going to tell you what it is. I will tell you that an AN970 is a larger area flat washer used mainly for wood applications. The wider surface area protects the wood.

There are other types of washers. I mentioned lockwashers that are made several different ways. They are often split ring, they are sometimes internal tooth and even external tooth (see Figure 5). You will also find nylon washers and finishing washers that usually have a countersunk head. So, as you can see, washers are not quite as confusing as other hardware even though we can make ft difficult if we wish.


The cotter pins mostly used on custom aircraft are AN380 and AN381. Cadmium plated cotter pins are AN380 and stainless are AN381. Cotter pins are used for safetying bolts, screws, nuts and other pins. You will normally use them with castle nuts. The MS number you may see is MS24665. The dash numbers indicate diameter and length of the pin. As an example, AN380-2-2 would be a cadmium plated pin 1/16" in diameter and 1/2" long. All supply companies will have charts showing the various sizes versus the reference number.

Safety wire is also widely used. The most used sizes in diameter are .020, .032 and .041 or small variations thereof. The material is usually stainless steel or brass. The easiest method of installation is acquired by using safety wire pliers (see Figure 6). The pliers are used to twist the wire. The wire is installed so that if the nut or bolt begins to loosen it will increase the tension on the wire. Be sure you do not overtwist the wire - doing so will weaken the safety wire. Leave about 36 twists and then cut off the excess wire and bend its end so you do not snag it with your hand at a later time.

I want to emphasize the major point of this article. USE ONLY AIRCRAFT QUALITY HARDWARE.

Do not assume the engineer role by using hardware types or sizes that are contrary to your plans or assembly manual. In future articles I will discuss the other hardware items including control cable installation, screws, rivets, turnlock fasteners, etc.

Full article and diagrams at:

About the Author, Ron Alexander

This article was written by Ron Alexander of Alexander SportAir Workshops.

Ron has been flying since the age of 16; he flew for the Air Force for five years (including one year in Vietnam) and started flying for Delta Airlines in 1969, where he now pilots the Boeing 767. He currently owns a J-3 Cub, C-3B Stearman, and a Beech 18. Ron started restoring antique airplanes in the early 1970's and could not find parts so he founded the Alexander Aeroplane Company which he operated for 17 years. He sold the company to Aircraft Spruce and Specialty in 1995 so that he could focus his efforts on providing education within the sport aviation industry.

Ron is currently president of Alexander SportAir Workshops, a series of "hands-on" workshops on building airplanes is presented throughout the country for education. For a schedule of locations and dates of upcoming workshops and information (prices, curriculum, etc.), call 800-967-5746 or visit their web site at

This article was first published in EAA's Sport Aviation magazine.

Dec 21st

Ultralight designer Mark Stull dies while test-flying new design

By Tony Castillo
This is very sad but I just read in EAA Light Plane World that Mark Stull died in an accident last November. My condolences to family and friends for this very tragic loss.

Mark was designing and testing a North Wing weight-shift  wing mounted in a fix-wing like frame, and incorporating a standard elevator/rudder configuration as a tail.

I have no idea how he was attempting to manage roll control as the weight-shift flexwing would be difficult to impossible to roll using just a rudder ... and I'm not aware there were any aileron type surfaces used or any weight shifting provisions in the carriage. Even pitch control is quite compromised in that configuration.

It's very sad story and for what I have read Mark was an accomplished pilot and quite susccessful designing and flying odd fix wing designs ... is sad to see that a weight-shift flexwing ultimately got to him. A wing that by design and controled per design is extremely safe and easy to control - in my oppinion. But then again Mark wasn't about "the standard" he liked to try non-standard. But I hardly see it possible or stable in the way Mark was trying to accomodate the controls for the weight-shift flex.

You can read more about in the EAA Light Sport Plane interent article:

There are also some interesting discussions in the yahoo groups where Mark was a very prolific and welcomed member.

Mark Stull ill fated prototype UL.jpg
Dec 17th

Evaluating a competent mechanic, and how do I recognize whether or not if I already have one?

By Dave Schultz

Written by  Rotax Owner

This can be a dynamic topic, but there are certainly some markers to look for in finding yourself a good mechanic that you can really trust to keep you in the air, safe and happy. You probably already have a mechanic, but the important thing is in recognizing if he has more than just the basic skills, but that certain something that gives you the confidence to trust life and limb to him. Let’s examine what the traits are that define “a good mechanic” and steps you can take to find one.

Let’s talk about looking for a good mechanic first. As in any profession, you’ll find varied degrees of competency. Just as in choosing a surgeon, you’ll want to avoid marginal competency and shoot for the elite, or as close to it as possible. Here are a few questions in the determination if whether a prospective mechanic is right for you. 

(In the interest of simplification and unencumbered continuity of thought, we will use the pronoun “he” as being asexual.)

  1. Does he come recommended by other aircraft owners?
  2. Do you hear from others that he does a satisfactory job?
  3. Does he have experience in your type aircraft and is he qualified to work on your Rotax engine with the proper iRMT ratings?
  4. Do you hear the prospects name brought up favorably in conversations?
  5. When you talk to the prospect, is he friendly, helpful and patient before the subject of fees is discussed?
  6. Ask the prospect if he has the service bulletins (SB’s) and all the manuals for your engine and fuselage on site?
  7. Is your prospect familiar with the tips, tricks and technical procedures for your Rotax Engine as shown on the Rotax Owner Videos.
  8. How many aircraft like yours has he worked on or inspected?
  9. Does he keep you abreast of issues he found and answer your questions knowledgably?
  10. What’s his philosophy regarding regular and preventive maintenance?
  11. Is he a self absorbed mechanic, or open-minded to your ideas, suggestions, concerns and will he research problems including Rotax Owner videos and forum?
  12. Does he use an inspection check list, discrepancy list and do accurate, detailed logbook label entries? (Possibly ask to see a couple of his labels and check lists)
  13. Does he document well? It’s for your benefit as well as his legal protection.
  14. Does he give you copies of the maintenance check list, or other documents for your personal file? This should be an absolute in case you need it for the FAA, insurance and the re-sale of your plane. You’re paying for the work, get it the way you want it not him.
  15. Does he seem to have the proper tools and education for your particular plane?
  16. Last, but not least and this item is not a real marker of the mechanic’s professionalism, but should be kept in the back of your mind. What is the charge? If the price sounds too good to be true then there may be a reason for it and you might get exactly what you paid for. Caveat emptor. Now I know this is not necessarily always true that’s why this is last consideration while looking for a mechanic that you have compatibility with and do the job that you expect and deserve.
  17. Ask the prospect if he has access to the Service Bulletins
 Your life might be in the hands of the mechanic. Strive for one who displays all or most of the attributes shown above.

  The mechanic’s motto should be: If there is a problem with your aircraft, major or minor, I’m going to find it. Your safety is priority one. 
Due to a plane’s wear and tear, loosening of attachment items or just sitting for extended periods things change and it’s your mechanics job to find these. He needs to be a skilled hunter of problems and an organized repairman for these items.

  You’re probably already use or have used, a mechanic. Use these questions, and your own, to determine if he is right for you. If there are some areas about which you wish your mechanic would do better then sit down with him and explain your issues and concerns. You’re the boss. The right mechanic needs to live up to your expectations.

Life is full of choices. We chose doctors, lawyers expecting them to be honest; to work in our best interests; to be receptive to our needs. You fully expect understanding and consideration of your input. Chose your mechanic in the same way.

Full article at:

Dec 16th

Throttle Body Injector: Guinea pigs needed

By Captain X
AeroConversions AeroInjector I was searching EAA for Rally information / rules and saw an add for this. It's not exactly a fuel injector, but similar. Now all we need is a Guinea pig to test some for us: $395.00 (I would guess that your would need two for a rotax 912) AeroInjector 32 shown above with flange mount and optional Intake Flange Adapter Simplicity in form and function! Utilizing what hydraulic and pneumatic engineers call the "perfect flow passage" the AeroInjector (formerly known as AeroCarb) achieves outstanding performance versatility! AeroInjector body parts are precision machined from solid 6061 aluminum billets. There are only two moving parts... no float bowls or secondary jets to complicate things. A fine adjustment metering needle provides clean burning, smooth running, outstanding response, and fuel economy. Spigot or flange mounts easily adapt to popular aircraft and auto conversion engines. AeroInjector's intake design accepts air filters or carb heat ducts. The AeroInjector is included as standard with all AeroVee engines, and is highly recommended to replace the Bing carb that ships with Jabiru engines. To read about AeroInjector performance and fuel economy with the Jabiru 3300 engine, read "The $35 Hamburger" by Sonex's own Kerry Fores, or check-out our AeroInjector FAQ's. See Fuel Burn and Econom FAQ: What do think? Got an E-LSA and wanna try it? They estimate it will pay for itself in 100 hrs (200 hrs for two) ;)
Dec 14th

Trikes in the US had a safe 2011

By Abid Farooqui
In looking at all monthly indexes for the accidents in 2011, very few accidents seemed to point to trikes. In the non-fatal accidents, pilot error (mostly judgement) was the main cause in ones with non-minor injuries. Pilots having these non-fatal accidents with injuries were either student pilots flying outside of their CFI's authorized airport or non-certificated flyer, flying with a passenger illegally.

Two of the troubling fatal accidents seem to come from Kauai, HI this year with two in mainland.

The mainland fatal accidents were to unrated (in category) pilots and one was in unregistered trike that was seemingly being flown under Part 103 though Saber trike would not qualify under Part 103 criteria and was originally a 2 seater when sold. The mainland accidents once again show that casual attitude towards training and not taking enough training or not following rules and regs and not waiting for your CFI to tell you when you should solo results in expensive accidents, serious injury or even death. We have seen this over and over but yet newer trike participants repeat the story without fail every year.

For accidents to S-LSA trikes and rated CFI's in Hawaii; although final reports are not out on them, they will most likely point mainly to operational issues and judgement lapses or according to some - possible sabotage-.

The mainland seem to have had no fatal accidents for trikes this year for rated in category pilots flying registered trikes.

Below are the links to NTSB reports of trike accidents in 2011:

1) N5628K (Crosswind pilot's failure to maintain clearance from obstacle on takeoff) - Non-Fatal

2) N5099A (The pilot’s failure to maintain directional control during landing.) Non-Fatal

3) N566RL (The pilot's failure to maintain control of the aircraft during take-off in a cross wind, which resulted in an inadvertent stall.) Non-Fatal

4) N705PM (Preliminary Information)  Fatal

5) N29EP (Preliminary Information) Fatal

6) N751EW (The simultaneous loss of engine and electrical power after takeoff for undetermined reasons.) Non-fatal

7) N4668L (The total loss of engine power during cruise flight, while operating in carburetor icing conditions). Non-fatal

8) No Registration, no pilot's license (1 serious injury, 1 minor injury). Struck electrical wires

Added based on comments
9) N94370 (non rated for category pilot flew the trike before getting signed off for solo, wanted to practice high speed taxi, found fatally wounded 500 feet off the runway to the left)

Comments: The above accident pilot was being trained at our facility in Zephyrhills. He was with Army core of engineers and a private airplane pilot and flew ultralight airplanes on private airstrip. The instructor was not even made aware that he had gone out and purchased a used 503 Aquilla trike, nor he had practiced any landings yet in 5 to 6 hours of dual and was definitely not ready to fly solo. His wife thought he was just going to do high speed taxi practice which is a dangerous thing to do for a student. The trike was damaged substantially on left side consistent with a stall

10) Unregistered Saber trike, No pilot's license - Fatal - (Robert Armond - FAA does not investigate unregistered ultralight crashes per story)

11) Unregistered Polaris FIB, No pilot's license - Fatal - Pilot seen looping the illegal aircraft, flown by an illegal unrated pilot

Dec 13th

4 Strokes (an informative article about 4 strokes).

By Rizwan Bukhari


With 4-stroke engine, we basically have to answer two major questions:

  1. Air-cooled vs water-cooled?
  2. Aero-engine or Auto-conversion (or Industrial engine)?

Air-cooled vs water-cooled
It all boils down to (excuse the pun – I couldn’t resist it) what is available.  The Spitfires (etc) during the war were all water-cooled – but since then, it seems that the only water-cooled engines available today are auto-conversions.  Aero engines almost exclusively rely on air cooling.

And the reasons for this are simply that air-cooled engines are lighter (no radiator) and simpler (no plumbing).  Water-cooled engines can have closer engineering tolerances, however, and are immune to such things as shock cooling.

Keeping a water-cooled engine cool
Simply having a radiator is insufficient.  Air has to be able to pass through the radiator fins.  And you’d be surprised at just how many builders seem to completely ignore this simple fact.  I’ve seen radiators shoved up hard against the firewall, with no POSSIBLE way air could pass out the back.  Placing the radiator out in the free stream of air is also not the solution.  Apart from extremely high drag, the fact is that air does not easily pass through radiator fins, and actually finds it easier to veer off to the sides and go round it.

So we need to place the radiator in such a place where it is out of the free stream of air (to reduce drag as much as possible), to slow the air down as much as possible (so that it can absorb the maximum amount of heat before escaping out the back) and finally, ensure that there is a good low-pressure at the rear (to suck the air through).  Here’s a schematic of the water-cooled Razorback F1

Keeping an air-cooled engine cool
Essentially, air passes through a system not because it is forced in (close the exit and you can force in as much air as you want – it won’t go in), but because it is sucked through.  Even a small opening – so long as there is a good suction at the exit – will allow in as much air as you need.  So what we have to identify is where the areas of high pressure are (the air wants to get IN) and where the LOW pressure areas are (ie a relative vacuum).

The pressure distribution on the cowl of an aircraft is a bit unexpected to be honest.  It looks like this…

Pressure distribution round cowling

Pressure distribution round cowling

Notice the arrow?  Arrows radiating OUTWARDS (eg: top of the cowl behind the spinner, top of the windshield, bottom rear of the cowl) indicate areas of relative LOW pressure – ie a suction.  The only two areas where air is trying to get IN are on the bottom of the cowl, and at the bottom of the windshield.

And so here’s the surprising thing.  By far the greatest suction is on top of the cowl just behind the spinner.  And it is HERE that we need to vent the warm air.

So if the Razorback were to have an air-cooled engine (eg the VW), here’s the best way to keep it cool:

Updraft cooling

Updraft cooling

Bottom line – if you opt for an auto-conversion, you are into radiators and if you choose an aero-engine (or industrial) you are wedded to air cooling.  So it’s really not that hard to decide.  So the REAL question is really….

Aero vs auto vs industrial

  • Purpose-built AERO engines:
    These come in two flavours.  Pre-war designs and modern engines.  I wouldn’t drive a car with an engine designed before the war, and neither will I fly a plane equipped with one of these engines.  Those in favour of these dinosaurs go on about how they have stood the test of time, how they are tried and true etc.  But I’m not convinced.  I wouldn’t put one in my car.  Bottom line.  What engines am I talking about here?  Your Lycomings and Continentals.  Besides, they cost a FORTUNE.  (Did you see the upper case letters in “fortune”?).  Like $28k  So, let’s not hear anything more about them.Fortunately, there are some excellent MODERN aero engines on the market today (also big bucks, but not horrendously so). HKS:
    In all my searching of the Internet, I have NEVER come across a single bad word about these engines.  Except, possibly their price (about $12k).  They come in normally aspirated (60hp, 121lbs complete with gearbox and exhaust) and the new turbo version, which costs considerably more, and doesn’t produce that much more power. Rotax
    Mmmm despite their much-vaunted reliability, I just don’t LIKE them.  They sound terrible (like little sewing machines whirring away), they are far too fiddly for my liking, and they cost almost as much as the Lycomings/Continentals of this world.  I think there are better engines than the 912 (80hp) and the 914 (100hp turbo).  About four times the cost of some other aero engines, like the VW conversions).Thunder Aero Engines:
    These little 4-stroke engines (850cc) offer outstanding value.  A true aero engine at a fraction of the price you’d expect.  And they are fuel injected and water-cooled, to boot.  The engine comes fully ready (ie exhaust, radiator, gearbox, starter etc) to bolt onto your airframe, add some gas, strap on a propeller and go flying.


    After an exhaustive search of everything from tiny industrial engines to large, powerful (120hp) auto-conversions, I have decided that this is the engine of choice for the little Razorback.  It is a perfect match for the airframe.

    Water-cooled, 121lbs, 80hp.  In-line twin only 9 inches wide.  In fact, you can thank the distinctive bump at the top of the Razorback cowl on this engine, which is much higher than it is wide.  I think this is the engine smaller aircraft have been waiting for.  Certainly I have…

    This Australian designed and built engine comes in 4 cylinder (85hp, 132lbs) and 6-cylinder (120hp, 178lbs) and is one of the engines of choice for the Sonex.  I’d take the 4-pot Jabiru over the Rotax any day of the week. But they are also not cheap.  (About twice the price of some other nice engines).

  • Smaller AUTO conversions (under 80hp)
    If you’re looking at smaller engines, there is only (in our opinion) one engine to consider:  the Geo/Suzuki G10


    Suzuki G-10 side view

    Suzuki G-10 side view

    Suzuki G-10 front view

    Suzuki G-10 front view


  • Raven Redrives are another source for this fine little engine.  They’re based in the US, and are very active on the small engine forum at Yahoo Groups.  Again, not a cheap option.

You can find them here:

  • Larger auto conversions (80 to 100hp)
    I know I’m going to be shot down in flames for this, but although there are literally scores of companies offering auto conversions of every description, from every manufacturer imaginable, for me it boils down to a single engine type – the tried and tested VW.  And there are only three places to get your VW conversion – again, my personal opinion.  The first is Aerovee (a subsidiary of Sonex Aircraft), the second is Revmaster, and the third is Great Plains Aircraft.




    This is a lovely engine, and in our opinion, the best on the market today for the home builder – bar none.  80hp, 161lbs.  You buy it in parts, and assemble it yourself, working from an assembly manual, and a video.  Even I can do it.

    Aerovee also offer all sorts of add-on goodies, like throttle quadrants, optional Nikasil Cylinder upgrade (saves 10lbs) and there is an active online support group at Yahoo Groups.  One of these will set you back about $6,500 (USD)

    Great Plains:
    Theyoffer three variants, so you get to choose between front drive, reduction drive and flywheel drive versions.  Prices, power and reputation about the same as Aerovee.  Only hassle is you can’t just buy an engine,  You have to work your way through their options and “build-up” your engine bits from all their options.  I found it quite confusing. Theyoffer three variants, so you get to choose between front drive, reduction drive and flywheel drive versions.  Cost?  About the same as the Aerovee.

    Not QUITE as pretty as the AeroVee, but this is a very sweet engine.  There is almost nothing of the original VW engine left in this built-from-the-ground-up aero engine.  Special crank, extra bearing at the prop hub, custom pistons, conrods, compression chamber etc etc.  AND you can use any prop you like, including composite or even metal props.  The more I think about it, the more I like this engine.  85hp take-off power, 80hp continuous.  170lbs.  Cost:  about $7,000 (USD)

    And a very fond word reserved for the BMW motorcycle conversions…
    Both the R1150 and R1200 series horisontally opposed engines are frequently used in aircraft.  Mainly because you just can’t break them.  They have dollops of torque, gobs of HP and they will run forever.

    The K-series engines are also great little powerplants.  The K-75 (750cc) weighs in at 185lbs fully oiled, and fitted with a Rotax gearbox.  It produces 73hp, and is just about bullet-proof.  Great engines to turbo, since they will take 8lbs of boost without blinking an eyelid, and suddenly you have a reliable turbo aero engine, capable of cruising at its full 110hp all the way up to 10k feet.  One of the problems with these motors is that they can’t be bought off the shelf.  These are all one-offs, and you need to know what you’re doing.  This is not an option if you want an easy solution.

  • INDUSTRIAL engines
    Now this is where it gets REALLY interesting.  If you don’t need a lot of power (ie under 40hp) then one of these might just do the trick.  The idea is relatively new, but there are already two companies which specialise in aero-converting these little workhorses.  (Valley Engineering (US-based) and Soloflight (in the UK).


    Soloflight Briggs aero conversion

    The 50cc Briggs and Stratton engine forms the basis of this conversion. 30kg, 40hp, 5 litres per hour cruise. Very tidy.

    Soloflight Briggs aero conversion - side view

    Soloflight Briggs aero conversion – side view

    Valley Engineering use the Generac 40hp engine in their conversion, which tips the scales at 112lbs (the included 8lb redrive brings the weight to 120lbs.  All for $4995 (USD) which includes a custom made prop, AND the PSRU.  Nice.  Very nice.

    And the latest development is that they now have a newly ground cam, together with high compression pistons enabling the engine to produce 50hp.  This costs an extra $750 – but I think this is a bargain.

    One of the nice things about the B&S or the Generac industrial engines is that these motors are designed to run flat out all day, taking terrible punishment.  They are simple, rugged and while not the most powerful engines for their size, make up for it with almost unrivalled reliability.  And low cost, of course.  You can buy a brand new engine for about $1,500 (USD).  An engine with redrive, and other mods to make it suitable for aircraft use will cost you more (about $5,000) from either Valley or SoloFlight.  But then it is a bolt-on-and-fly affair, and both of them produce lovely looking conversions.

    And it only drinks about 6 litres an hour.  That is under $7.50 for an hour’s flying.  Very impressive.

A new purpose-built aero engine from Verner
If you’re looking for something in the region of 40hp, then you have just GOT to check out the new Verner JCV-360.  It is a purpose-built aero engine, 4-stroke, water cooled boxer.  Weight = 26kg.  Wow!  Talk about a great pedigree.  At 35hp, however, it just doesn’t quite have the oomph I’m personally looking for, but if you can live with 35hp, then this one might be for you.  Cost?  Apparently (I have this 3rd hand, however…  2,600 Euro)

Here are some details from their web site:  (