Homebuilt Aircraft Frequently Asked Questions -

Last revised on October 6th.  Updated information on owner-maintenence.

This document attempts to answer common questions asked by newcomers to
the rec.aviation.homebuilt newsgroup, or those curious individuals
unfamiliar with the domain of homebuilt aircraft. It assumes that the
reader already possesses limited familiarity with aviation in general.
It is not meant to answer any and all questions, but it is intended to
give the reader a foundation upon which to learn more on their own. The
article is laced with the author's perception of "conventional wisdom",
which does tend to change as time passes.

The following questions are answered in this FAQ:

Q301: What is the Experimental category, and what types of aircraft are
       classified/operated in that category?
Q302: What is a kit airplane versus a plans-built airplane?
Q303: What separates a homebuilt from an ultralight?
Q304: Why would someone want to build and fly a homebuilt when perfectly
       good certified aircraft are available?
Q305: What is the 51% rule, and how does it affect me?
Q306: What are some common experimental types, kit-built or not?
Q307: What are the tradeoffs of metal vs wood vs composites?
Q308: What types of engines can I use?
Q309: Why do pilots get so upset over the choices between two and four
       stroke engines?
Q310: Can I use non-certified props?
Q311: How do I license my completed airplane, and what inspections are
Q312: How are registration numbers assigned, and can I choose one?
Q313: Can I type-certify my airplane?
Q314: If I sell the airplane, am I liable for it later?
|Q315: What operations are illegal in my homebuilt that might not be
       in a type-certified airplane?
Q316: What happens if I buy a homebuilt that I didn't build?
Q317: Can I insure a homebuilt airplane?
Q318: Am I safe flying a homebuilt airplane?
Q319: What health hazards might be involved while building?
Q320: What design should I choose?
Q321: Where can I see one of my choices, and can I fly one?
Q322: How long will it take to finish?
Q323: How do I know if I can afford it?
Q324: What tools and facilities will I need?
Q325: Will my marriage survive?
Q326: How do my maintenance costs compare to a certified airplane?
Q327: Who is the EAA, and what do they offer me?
       How can I join, and are there any local builder clubs?
Q328: Where can I find parts or materials for my project?
Q329: Can I find more written info?
Q330: [Deleted]
Q331: Is there anyone on Usenet who knows about the GarageRocket 432?
Q332: I'm having trouble with construction, where can I get help?
Q333: What financing is available for building a plane?
Q334:  Can I take lessons/get my license in my homebuilt?

The core of this FAQ was written by Steve Cornelius (formerly at
scornelius@ips.iacd.honeywell.com) with updates by Ron Wanttaja
(ron@wanttaja.com).  Comments, corrections, or suggestions always
welcome, please forward them to ron@wanttaja.com.

Vast helpful assistance and input was provided by:
scornelius@ips.iacd.honeywell.com (Steve Cornelius)
randys@cv.hp.com (Randy Stockberger)
charles.k.scott@dartmouth.edu (Corky Scott)
venky@bellcore.com (G A Venkatesh - "venky")


Subject: Legal category

Q301: What is the Experimental category, and what types of aircraft are
       classified/operated in that category?

A:    The Experimental category is essentially an "operating
       classification" that has a legal bearing on the operation of the
       aircraft, just like Normal, Utility, or Aerobatic categories have.
       There are several sub-classifications in the category, such as
       Amateur-built, Racing, Exhibition, Limited, R & D, and others.

       Experimental/amateur-built aircraft are the primary emphasis in
       this newsgroup. It refers to non-type-certified aircraft that are
       built, maintained, and flown by individuals, thus the term
       "homebuilt". Amateur-built aircraft are intended by the FAA to
       serve as educational "vehicles" for their builders and pilots.
      (sorry 'bout that pun...)

       The original justification for making the category legal was that
       it increased the pool of individuals knowledgeable in the area of
       aircraft production. Thus the nation had "experts" in aircraft
       production to draw upon in times of national emergency. Silly as
       this may sound today, it was taken seriously in the mid '50s when
       the category addition was being proposed.

       Note that a type-certified airplane may also be re-categorized as
       experimental if it's modified in a form such that the FAA will not
       approve on a standard 337. This is often the case for prototype/
       modified certified aircraft, or for highly specialized
       applications (although these are often categorized as "Restricted"


Subject: Kit Airplanes

Q302: What is a kit airplane versus a plans-built airplane?

A:    Kit airplanes are aircraft designs that are sold as a package of
       parts and subassemblies to be assembled by the owner. They are
       primarily a market response to the lack of new and affordable
       type-certified production aircraft. The kit attempts to strike a
       balance between those desiring a finished airplane, versus those
       wanting to build. They also allow people to build a new aircraft
       when they may not possess the time or ability to build from
       scratch. Cost of a kit airplane is generally higher than that of

       The "plans-built" aircraft is scratch built from a set of
       engineering drawings only, the builder makes most all of the parts
       from raw materials. This was the "original" form of homebuilding.
       These take longer to complete than a kit airplane, but can also be
       less expensive and more rewarding to those who enjoy building. For
       the popular designs, quite a few prefab parts do exist, especially
       the ones that are too difficult or costly to fabricate yourself.

       The term "kitplane" is commonly used for kit aircraft, but the
       term itself is trademarked by KITPLANES magazine.


Subject: Homebuilt .vs. Ultralight

Q303: What separates a homebuilt from an ultralight?

A:    Ultralights and Experimentals may both be built by the owner, but
       the ultralight may carry no passengers (except for instruction).
       It also has limits on weight, speed, and fuel, which the homebuilt
       has none of (outside of operating restrictions in part 91).

       Often, licensed ultralight owners have chosen to obtain
       airworthiness certificates so that they can overcome one or more
       of these restrictions. This reclassifies the ultralight as an
       experimental, and the pilot certificate, medical, and currency
       requirements become effective.


Subject: Homebuilt .vs. Certified

Q304: Why would someone want to build and fly a homebuilt when perfectly
       good certified aircraft are available?

A:    In a sense, Cessnas & Pipers can be compared to older Chevys and
       Fords, in that they attempt to be "all things to all people". Such
       compromises may be acceptable for most, but not all pilots.

       One of the remarkable things about homebuilts is the sheer
       diversity of designs & intended purposes. There are some compact
       aircraft that store in your garage and fly off of any short field.
       Right next to it might be another that carries 4 people 300mph at
       18,000 ft. Next to that one is one that cost less that $10K to
       build. Another could be flown in unlimited-class aerobatics.

       Note that your garden variety Skyhawk can't do any of these
       things, but it's still a quite a useful & desirable airplane. It
       all depends on what you want it to do.


Subject: FAA 51% Rule

|Q305: What is the 51% rule, and how does it affect me?

A:    In order for an aircraft to qualify as amateur-built, at least
       half the fabrication and assembly must be done for recreational
       and/or educational purposes.

       A common misconception is that a single *builder* must perform 51%
       of the work.  That is not the case.  To quote FAR 21.191, "...the
       major portion of which has been fabricated and assembled by
       persons who undertook the construction project solely for their
       own education or recreation."

       Note the plural..."persons."  You can buy a partially-completed
       project, finish it, and get it certified as amateur-built, even
       if you, yourself, didn't do 51% of the work.  However, you will
       still need to prove that "amateurs" did the majority of the work.
       If you buy a partially-completed project, get the previous
       builders' photos and builders log.

       The definition of "the major portion...fabricated and assembled"
       has been undergoing changes over the years.  Currently, the
       FAA has been taking more of a "task" orientation on this issue:
       The builder might have to construct a rib, for instance, to learn
       how to do that task, but the FAA is not currently requiring the
       builder to repeat that process on the remaining ribs.  This logic
       has resulted in the approval of a number of "quick build" kits
       that would have been unthinkable in the 70s or 80s.

       The original genesis of the "51% Rule" (the FARs don't define
       a percentage, they merely say "the majority."  The FAA interprets
       this as 51%) came back in the early days, when people would
       perform modifications to production aircraft and apply for
       certification as amateur-built.  Before the promulgation
       of the "majority" clause, you'd see J-3 Cubs converted to
       mid-wings, etc. certified as homebuilts.

       The first major update to the 51% rule came with the original
       Christen Eagle. An FAA official insisted that Frank Christenson's
       biplane kit was too complete, that the builder didn't need to do
       enough work.  Frank went to some length to prove to the FAA that
       this wasn't true.

       Now the FAA maintains a list of "approved" kits that have been
       proven to comply with the 51% rule. Note that a kit does *not*
       need to be on the list to be legally sold, it just serves as proof
       to the FAA that the type complies with the rule. Some kit
       suppliers opt not to put their products on the list, the reason
       being that once approved, any changes to the product require
       reapproval by the FAA. If your kit is not on the list, you will
       have to prove 51% compliance at inspection time.

       The inspector does his job based on a set of guidelines published
       in the "inspectors handbook" issued by the FAA to their field
       inspectors. The guidelines for the 51% rule are established in
       this handbook. All decisions made by the inspector are effectively
       determinations "by the Administrator" (if you're familiar with the
       FARs, you'll understand the phrase immediately :).

       You can download the list of kits approved under the 51% rule
       from http://av-info.faa.gov/dst/amateur/ama-kit.pdf.  This is
       an Adobe Acrobat file; free readers are available from a number
       of sources.

Subject: Types

Q306: What are some common experimental types, kit-built or not?

A:    Sorry, the list is just too long for the scope of a FAQ.

       Keep an eye on the many magazines which cater to homebuilders;
       any book magazine stand should carry a wide selection.  All
       run advertisements by both designers and builders, so try to
       follow them for a while.


Subject: Materials

Q307: What are the tradeoffs of metal vs wood vs composites?

A:    This can be a heated subject amongst builders, we'll try to
       approach the subject generally and gracefully.

       Metal construction has the widest acceptance by the non-aviating
       public. It is relatively simple to work with, and is inexpensive.
       A metal structure is strong and of moderate weight and cost. But
       with improper care it corrodes, and events (like the Hawaiian 737
       that lost its top) have reminded us that metal does have a finite
       fatigue life.

       Wood is the oldest aircraft structural material, but has a poor
       public acceptance. The strength-to-weight ratio and fatigue
       resistance of wood is excellent, the problem is simply its
       susceptibility to rot. Properly protected and stored, a wooden
       airframe will last decades. But if not cared for, it will be
       destroyed in a few short years. Wood also tends to be expensive,
       and the supply is erratic.

       Composites, "compost" jokes aside, have received much attention
       recently from private and commercial builders alike, largely due
       to work done a few years ago by Burt Rutan. Composite aircraft can
       be quite strong structurally, and be built at very reasonable

       The airplanes have very low drag figures and beautiful finishes.
       It is easy to work with. But there are concerns about longevity of
       the material. Most resins create an airframe that must be painted
       white to prevent excessive heat buildup in the sunshine, since
       epoxies and vinylesters soften significantly with an increase in

       All methods are perfectly viable. Which one you choose all depends
       on your preferences, abilities, and your needs for the airplane.


Subject: Powerplants

Q308: What types of engines can I use?

A:    Literally any! For years, homebuilders have relied on certified
       engines. But as the cost of these engines rises, alternatives have
       been found. Several companies are building specialty engines
       specifically for experimental use, and others are hard at work
       adapting automotive engines.

       The Rotax engines have received lots of attention. There are both
       two and four stroke geared engines for experimental use and most
       are water cooled. All are fairly reasonable in cost compared to
       their certified counterparts. These products develop power in the
       40 to 100hp category.

       Some builders are enthusiastic about auto conversions, some are
       not. Early on, a few builders were pulling engines out of junked
       autos with poor results. Untuned engines were not ready for such
       high-manifold pressure operations and suffered burnt plugs, blown
       pistons, etc. But other builders have taken the time to customize
       and tune auto engines to the application, and the results are
       improving. The all-aluminum small-block Chevrolet is becoming the
       poor-mans "Mini Merlin" and produces excellent power (not to
       mention sound!). Some are also experimenting with Wankel-type
       rotaries, as their power-to-weight ratio and physical compactness
       make them excellent candidates for aircraft use. Power in auto
       conversions can run from 80 to 400+ hp.

       Water-cooled engines aside, builders have used air-cooled
       Volkswagen conversions for years, and several companies are now
       producing parts and completed engines. One company
       actually had one of their VW Type IV engines certified in
       Australia. VW engines sound similar to their Lycoming or
       Continental counterparts but rev higher, in the 3100rpm range.
       Modified stock crankshafts seem to show a tendency to break, but
       the custom cranks do better (and cost more). Parts are usually
       reasonable (but notice I didn't say "cheap").

       If you are looking for an IFR cruiser to carry passengers, it may
       be best to stick with certified engines and swallow the cost. But
       if your purpose is a VFR weekend toy with good forced-landing
       options and you like to tinker with motors, you might consider a
       conversion. Again, your choice really depends on the mission.

       A word of warning: When choosing a certified engine, the engine
       must be equipped and maintained as it normally would be for a
       certified aircraft. This means that all AD and bulletins must be
       complied with. This can have some impact on your flight test
       period. If you make any mods to such an engine, it will be
       considered a non-certified engine for all intents and purposes by
       the FAA, which will increase the test period from 25 to 40 hours.
       It will also reduce the market value of an otherwise expensive


Subject: Powerplant types

Q309: Why do pilots get so upset over the choices between two and four
       stroke engines?

A:    The four-stroke air-cooled engine has been the mainstay of light
       aviation for over 50 years and this shows no immediate signs of
       change. Yet some two-stroke designs have attracted strong
       followings in recent years. Why has this happened?

       The two most obvious factors are probably cost and weight. A 65hp
       Rotax costs and weighs roughly 60% of its certified Continental
       A-65 counterpart. For the newer generation of "portable"
       lightplanes, this reduced weight is an obvious design advantage.
       The owners of these types often have to be conservative with their
       flying dollars as well, so the Rotax wins over many of them. When
       they consider that it can be majored by the owner in his garage
       for a few hundred dollars in an afternoon, the decision is easily

       Yet there are pilots out there who think of the idea of a
       "chainsaw" engine as anathema to a proper aircraft. Improper
       mixture control in a two-stroke can damage the engine quickly. The
       vibration through the airframe is of a higher pitch. The higher
       operating speed of the engine requires a geared speed reduction
       system. Probably the worst offense: the sound of two-stroke
       aircraft is simply unpleasant to some eardrums.

       The reliability questions of two-strokes may have some basis. Then
       again, it is often found that problems resulted from improper
       installation, operation, or maintenance. Possibly there is truth
       here, since the $10,000 certified engine understandably gets
       "fussed" over considerably more. Its care and feeding are well
       understood by most pilots since we are usually trained behind
       such engines anyway.

       Should you choose a two-stroke? Again, it all depends on your
       preferences and requirements. If you need more than 65hp, your
       decision is essentially made for now. But if it's a consideration
       for you, study your options and carefully evaluate your needs.
       Ride behind both and see if you're comfortable with them.


Subject: Propellers

Q310: Can I use non-certified props?

A:    Absolutely. You can use certified, original, or modified props.


Subject: Licensing

Q311: How do I license my completed airplane, and what inspections are

A:    You *did* document the construction, didn't you?

       Before you are issued an airworthiness certificate, an FAA
       inspector will require an inspection of the aircraft and all
       documentation of its construction. They used to require a
       "pre-cover inspection of the internal structure, but no longer.
       Now they prefer that in-progress inspections are done by an EAA
       Technical Counselor, and the inspector will look for his/her
       comments in the construction log. When the FAA inspector arrives,
       they expect the aircraft to be ready for inspection (all covers
       removed), all taxi tests done and logged, and all documentation
       ready for review.

       When the inspector is satisfied that your airplane is ready for
       inflight testing, they will issue a restricted airworthiness
       certificate that describes a test period and testing requirements
       (or they may insist on changes or repairs if deficiencies are
       noted). The testing period is usually 40 flying hours (often 25 if
       you use a certified engine & prop), and limits you to a fixed
       testing area, normally a 25 mile radius from the home airport and
       over unpopulated areas. Passengers are not allowed during the
       testing period. While testing, keep a *detailed* log of all
       activities, repairs, and changes.

       The inspector will evaluate your testing at the end of the
       test period, at which point he or she will issue a permanent
       airworthiness certificate.  At that point, you are free to carry
       passengers and fly most anywhere you like.

       If any major modifications or repairs are done later, the airplane
       may need a re-inspection and retest. Call your local FSDO before
       doing this to find out what they want to see.

       You can also be issued a Repairmans Certificate for your airplane
       only (*not* the type in general). This allows you to perform all
       repairs, inspections, annuals, etc. on the airframe, since they
       figure if you built it, you should be able to fix it. Note that in
       FAR part 45, an "annual" is referred to as a "condition check",
       which is legally different from an "annual inspection", even if
       both actions are intended to accomplish the same goal.

       Please note that the above information is valid only in the USA,
       other countries usually have very similar requirements, with some
       slight differences. Check with your local authorities before
       committing any large sums of money or time to a project.

       Also note that this procedure is the general case. It is entirely
       possible that you may experience variations in the procedure. For
       instance, one netter commented that his inspector waived the
       second inspection and allowed standard experimental privileges
       immediately after the test time was flown off and logged. As FAA
       policy often varies between regions, expect some slight


Subject: Registration

Q312: How are registration numbers assigned, and can I choose one?

A:    N numbers in the US are assigned by the FAA Aircraft Registry in
       Oklahoma City. You must get one assigned before you have your
       finished airplane inspected. It's sometimes suggested that you
       wait until about 6 months before estimated completion, since they
       will charge you an annual fee for reserving a number.

       Requesting an assigned number will cost $5. If you want to request
       a special number, it costs $10. If you request one, they suggest
       you submit a list of choices, like 5 or so in order of your


Subject: Certification

Q313: Can I type-certify my airplane?

A:    Not recommended. The costs are extremely prohibitive (which is
       often why the designers refuse to do it), and there is little
       benefit. Remember that the only major restriction on experimental
       operations is use of the aircraft for hire.


Subject: Liability

Q314: If I sell the airplane, am I liable for it later?

A:    Unfortunately, there is potential for a liability problem. Even
       though "free" legal advice is often available on the net, I advise
       you to contact your attorney if you find this issue troubling.

       Some advocate having the buyer sign a "release form", which
       would be promise not to sue if anything goes wrong.  These
       are essentially worthless... the buyer can't sign over his or
       her *spouse's* rights, nor those of any one he or she sells
       the airplane to.


Subject: Legal operations

Q315: What operations are illegal in my homebuilt that might not be
       in a type-certified airplane?

A:    Operations for hire are *expressly* forbidden - no paid cargo or
       passengers are permitted.  You cannot "lease back" the aircraft
       to a local FBO.

       This is not as restrictive as you might think. Often clubs are
       formed around homebuilt aircraft, and it is legal for you to pay
       an instructor to give you a checkout or BFR in your airplane.  The FAA
       also now allows homebuilt to be rented as part of a pilot checkout.

       Formerly, operations over "congested areas" was also forbidden, but
       the FAA is now issuing operating limitations that do not include
       this ban.

       So in general, you can do most anything with your homebuilt that
       you can do with normal private pilot privileges.


Subject: Purchase

Q316: What happens if I buy a homebuilt that I didn't build?

A:    You get poor, like all airplane owners :) Anyway, you will not
       be able to obtain a repairman certificate, since you didn't
       build the airplane.  The airplane can be inspected and maintained
       by an A&P... an Inspection Authorization is not required.  Also,
       if the original owner retains his or her Repairman Certificate,
       they can continue working on your plane...that is, if you can
       talk them into it.

       You, as the owner, are allowed to perform all the maintenance
       and repair of the aircraft.  Whoever performs the next condition
       inspection (the builder or an A&P) will essentially sign-off your
       work at that time.

       In other words, the A&P's annual inspection not only covers the
       inspection of the airplane, but it counts as the yearly signoff
       for work done by the owner in the past year.  An EAA article on
       this agreement can be found at


       Parts for kit airplanes may or may not be available depending on
       the source. For either kit or plans-built, one thing to insist
       upon is having the plans in your possession or available. This way
       should a part need to be fabricated later, you still have the
       specs to do it by.


Subject: Insurance

Q317: Can I insure a homebuilt airplane?

A:    Yes you can. The insurance company may have their own requirements
       above the FARs, but they normally will insure one. You may find
       lower limits on passenger liability coverage though.

       However, there is a growing problem with higher performance
       kit airplanes such as the Glasair III, Lancair IV, 320, and 235. A
       significant number of pilots have bought into these designs since
       they offer performance levels in excess of that available from
       Wichita. In an unfortunate few cases there has been poor
       construction, and little to no training in aircraft that fly far
       ahead of the average 172 or Cherokee pilot.

       One example of changes: Where fast kit airplanes are concerned, a
       major aviation insurance company is insisting on periodic
       construction inspections by company reps, and thorough checkouts
       in type (+10hrs) before they will underwrite a policy for that
       aircraft.  Check this out before you make a commitment.


Subject: Flight safety

Q318: Am I safe flying a homebuilt airplane?

A:    You are as safe as you want to be. Little definitive data exists
       comparing homebuilts to certified aircraft. One set of opinions
       holds that accident rates are about the same for both certified
       and homebuilt aircraft, once the test period for the homebuilt is
       complete. Certified aircraft seem to have more unintentional IMC
       accidents, while homebuilts fare worse in accidents resulting from
       over-stress from aerobatics, forced landings, etc.

       Safety is still a function of the pilots ability to make
       intelligent decisions, as with all aviation.


Subject: Builder safety

Q319: What health hazards might be involved while building?

A:    The most obvious hazards are those involved with common shop
       practices, such as wearing protective lenses, handling power tools
       properly, etc. Follow common sense in shop practice, and you
       should be just as safe as if you were building household

       However, a more subtle danger exists where chemicals are
       concerned.  Composite structures require handling of chemical
       resins that are more exotic that simple adhesives. Paint systems
       also require extra care. Epoxies and Polyurethane finishes pose
       the worst problem.

       Epoxies emit fumes that, while annoying, seem generally harmless
       at first. But after exposure, your body builds an allergic
       reaction to the substance. Once that threshold has been crossed,
       you will be "sensitized" for the rest of your life. The isocyanate
       content of polyurethane paint can trigger severe respiratory spasms
       once you become sensitized to them. Again, the reaction potential
       never goes away. Some paint and primer products also have
       carcinogenic potentials as well.

       The solution is skin and respiratory protection, and good
       ventilation of the shop. *All* paints require at least filter
       respiration, isocyanate based paints require a fresh-air system as
       well. Wear protective gloves and eyewear. Above all, put an
       exhaust fan in your shop and use it, so as not to affect the whole

       Before you open an unfamiliar substance, read *all* the supplier's
       warnings about protection. If you don't understand them, the
       supplier should be happy to explain the requirements. Whatever you
       do, *please* don't ignore those precautions.

       You may invest years and thousands of dollars in your airplane.
       Make sure you're still healthy enough to fly it when the time


Subject: Choosing a project

Q320: What design should I choose?

A:    It's all up to the individual, but I'd highly suggest that you pay
       particular attention to the following 2 items:

       (1) Your desired mission for your airplane.
       (2) Your available resources (money, space, ability, etc.)

       Once you've a realistic and unemotional (!) handle on these items,
       start checking out designs until you find 2 or 3 designs that fit
       your situation best. Then go ahead and start checking out
       differences between them. Don't dwell too much on factors like
      "I've never done any welding" since you're going to have to learn
       to do lots of things you never considered before. Also, designers'
       claims for performance are often "stretched" a bit, so wait to
       talk to owners before making any final decisions.

       When you're at this point, it's time to start checking out real
       aircraft. This is where the fun begins....


Subject: Evaluating types

Q321: Where can I see one of my choices, and can I fly one?

A:    Oshkosh is great place to see virtually everything side-by-side,
       but it's not the best place to take a ride because of traffic. If
       you do go to OSH, there will be builders' forums, dinners, and
       parties for type-specific gatherings. Make sure you take advantage
       of these. Same thing goes for Sun'n'Fun if you can make that

       Smaller fly-ins may be better for taking a ride *if* your favorite
       type shows up. If your pet design is a little more obscure, it may
       take some effort.

       Once you've expressed interest in a type (usually by buying the
       $10-$20 "info pack"), the seller may provide you with the
       addresses & phones of customers who are willing to demo. This is
       not as unusual as one might think - builders often love to show
       off their toys! But if the design is a single seater, forget the

       For most popular kit airplanes, the companies usually keep a
       demonstrator around. You will probably have to go to them unless
       they are "touring" your area giving demos.

       Some people do actually build and fly aircraft without ever having
       seen or ridden in one. But if there's a way to avoid that, do!


Subject: Completion time

Q322: How long will it take to finish?

A:    Always longer than you think! A well-known writer in homebuilt
       topics is often quoted as saying "Firewall-forward is half the
       work", and "The jobs you thought were simple take forever, and the
       jobs you thought were tough turn out to be easy".

       Designers often try to minimize their estimates of completion time
       for obvious reasons. And time varies significantly with builder
       skill and experience. So the best way to estimate this is to talk
       to other builders who have finished their projects.

       For simple fixed-gear kits, 500-1500 hours seems common. For
       complex kit airplanes (such as retractables) 1500-3000 is more
       realistic. For plans-built airplanes, anywhere from 1000-8000+
       hours are involved. All of these numbers are highly dependent on
       the type, and on builder skills.

       Don't be too dependant on "goal fixation", take the time to do the
       job right. Above all, don't push it to try and get finished for a
       major fly-in. The risks aren't worth it. Besides, the better
       attention you pay to small details will make you feel all that
       much better when you do fly it to a big event.


Subject: Completion cost

Q323: How do I know if I can afford it?

A:    Well, if you have to ask....

       The "nickel & dime" costs in construction can really add up fast.
       Generally, if the cost of a kit is already a real stretch, you
       have a problem. Sometimes the finished cost of a kit airplane will
       exceed twice the cost of the kit itself.

       Plan for this. Add up all the costs you can think of, then add 20%
       for the stuff you *didn't* know about. Plan for contingencies: if
       you make a mistake covering a wing, you may have to redo it (the
       price of learning how). Be realistic with your estimations.

       Scratch building is a little easier in that your expectations have
       to be lowered. You expect a certain monthly amount to be spent
       towards supplies, so you simply buy what you can afford, and hope
       that it stays ahead of your building speed. You know that you're
       trading time for money, and since completion is so far away it
       doesn't seem so obvious.

       Again, talk to other builders, and be honest with yourself about
       what you can afford. An awful lot of projects never get finished
       because the money supply ran out.


Subject: Builder requirements

Q324: What tools and facilities will I need?

A:    Many designers will specify the tools needed for construction in
       their particular case. Again (sorry!) other builders are also a
       good source.

       Every builder will need a set of basic mechanics tools. Nothing
       fancy, but cheap tools often cost you money and time too. Another
       shop accessory almost everyone needs is a small portable (or
       big :-) air compressor. For painting, to cleaning parts, to
       driving rivets, to general shop cleanup, compressed air is a
       welcome asset. A small variable speed power drill is another
       virtual necessity.

       A small grinder and a drill press are other useful items. For
       wood, a small table saw and bandsaw are indispensable. An orbital
       sander is needed for wood and composite finishing. Wood builders
       simply *never* have enough clamps, or so it seems. There are many,
       many other items which are often nice, but not necessarily

       Builders often get quite carried away with tools, and it's true
       they can make a job easier and faster. But if you're in a squeeze
       for a particularly expensive tool, think about how often you will
       use it. It's entirely possible that you're better off renting one,
       or borrowing one from a friend.

       It's often amazing to hear of the places airplanes have been
       created. One grand-champion airplane from the '92 season was built
       on the owners back patio! But the favorite shop by far is the
       ubiquitous suburban garage. Most airplanes can have the majority
       of the work done on components in the garage, usually moving to
       the hangar at the final assembly stage.

       Whatever space you use, make sure it's well lighted and
       ventilated. Composite aircraft may require winter heat in order
       for resins to cure properly. Above all, make sure you can get the
       assembly *out*of the shop before you start. More than one builder
       has had to "modify" his basement to extract a completed wing....


Subject: Marital discord

Q325: Will my marriage survive?

A:    This is too often the sad joke on the prop-tags at fly-ins: "Cost:
       $64000 plus Linda" or "Brenda's Nightmare" placarded on the panel.
       We've also heard of cases where a choice had to be made between
       the lover and the airplane, and the plane won. Such is the magnet
       of aviation....

       Discuss this at length with your significant other. Explain the
       commitment and be truthful. If they fly, great! But if not,
       seriously weigh the situation and enter with his or her blessing.

       Talk it over well with the kids too, if you have them. Some of
       them thrill at the idea of building "our very own plane". Others
       will think you've lost your mind. Kids can be great helpers too.
       What better way to prove to them the practical value of education?

       Consider establishing a planned work schedule. This does two
       things, it lets the family know when you will be available, and
       it helps keep your work habits consistent (keeping you on track
       to finish it).

       Once started, don't forget dinners out, long walks, helping the
       kids with homework, and bathing the dog. They all need you too.
       Have the number of the nearest florist on the shop wall, just in

       Then again, sometimes sanding the perfect finish on an elevator
       can make a lousy day disappear in a hurry...


Subject: Maintenance cost

Q326: How do my maintenance costs compare to a certified airplane?

A:    Probably lower for the homebuilt, but it's not an absolute
       guarantee. Parts prices will be far less, and if you're the
       original builder, labor cost is zero. But if your engine
       installation or wiring has problems, expensive parts can break in
       a hurry.

       Take care of it, and it should take care of you.


Subject: Experimental Aircraft Association

Q327: Who is the EAA, and what do they offer me?
       How can I join, and are there any local builder clubs?

A:    The Experimental Aircraft Association was formed in the '50s for
       the purpose of sharing information amongst homebuilders.
       Originally regional in scope, the EAA rapidly grew in later years.
       EAA headquarters in Oshkosh WI is the sponsor and site of the
       annual aviation party now known worldwide simply as "Oshkosh".
       The official term nowadays is "Airventure" but the term has been
       slow to take hold in the EAA rank-and-file.

       EAA's political involvement is somewhat different from the AOPA.
       AOPA was formed in support of all types of pilots, and tends to be
       more of a pilot aid and lobbying organization, while the EAA
       focuses more on building and flying for sport. This is not to say
       that they don't take a political stance for their membership,
       however. They have  been active in the area of simplified
       certification requirements for new training aircraft, and they had
       a part in the creation of auto-fuel STCs for certified light
       aircraft. Frankly, if you're a pilot, both organizations deserve
       your support.

       The foundation of EAA's membership support is through the
       organization of hundreds of local "chapters" where members get
       together on a routine basis.

       Some chapters have club-wide projects, some stress education, and
       some are only social in function. Most have at least one
       "Technical Counselor" that can help you with your project, or
       provide inspections. Involvement with a chapter is not a bad idea
       if you're just getting started.

       I can't stress the function of the Tech Counselor enough. If
       you're about to begin a project, you will need someone to check
       out your work and sign the construction log to effect. The
       sooner you get to know these people, the better off you'll be.

       The membership office is at (800)322-2412. The general office
       number is (414)426-4800. If you join, they will provide local
       chapter info upon request. Their address is:

       EAA Aviation Center
       P.O. Box 3086
       Oshkosh, WI 54903-3086


Subject: Parts and Supplies

Q328: Where can I find parts or materials for my project?

A.    Grab any homebuilder's magazine and scan the advertisements.
       There are plenty of outfits just itching to set you up.


Subject: Books

Q329: Can I find more written info?

A:    First, join the EAA.  Among other benefits, they have an
       extensive catalog of books covering homebuilding.  Anything
       written by Tony Bingelis is a good start.

       Available from the FAA (call your local FSDO) and suggested:

       AC 20-27D - Certification and Operation of Amateur-Built Aircraft.

       AC 90-89  - Amateur-Built aircraft Flight Testing Handbook.


Q330: [Deleted as obsolete]


Subject: Other builders

Q331: Is there anyone on Usenet who knows about the GarageRocket 432?

A:    A typical web search using Yahoo, Google, etc. will usually yield
       extensive information on any given type.


Subject: Finding Assistance:

Q332: I'm having trouble with construction, where can I get help?

A:    If you're having trouble with plans or type-specific details:

       The first place to check is with the kit or plans supplier. They
       may be able to assist over the phone, or direct you to someone in
       your area who has been through this before. This also allows the
       supplier to know where the weak spots in their documentation are
       so that it can be fixed later.

       The local EAA chapter may know of other builders of your type
       nearby, or there may even be a type club in the area. Check with
       these groups also, they'll be glad to assist.

       If you're stuck on construction technique (welding, painting, etc):

       Again, check with the local EAA chapter for someone who has some
       experience with the technique causing you trouble. All of us end
       up learning a few skills in the course of construction, so don't
       be afraid to ask for help when it's needed. Remember, you'll be
       trusting your life to the airplane, so learn to do it right.

       Certain skills will require practice, so please don't run right
       out and try things on a new airframe first. If you're learning to
       weld for instance, sacrifice some tubing and practice on it until
       the quality of your workmanship becomes acceptable. It will be
       cheaper and easier in the long run. Save the samples also, the
       inspector will feel better looking at a "destructible" sample.


Subject: Homebuilt Aircraft Financing

Q333: How can I finance my kit purchase?

A:   The best way is to select a kit that either builds from scratch
      or is available as subkits.  Financing increases your cost quite
      a bit.

      Netters have identified two companies which have financing
      available for homebuilders.  Here are some of their terms, as
      supplied in October, 1995:

      NAFCO/EAA Finance Plan
      (800) 999-3712

      $10,000 minimum loan, no maximum.  They'll fund 70% of the total
      cost for up to five years, then will extend the loan until aircraft
      completion.  Loan rate is based on the prime rate and the amount
      borrowed:  3% over prime for $10,000-$15,000, 2.5% over prime for
      $15K to $25K, 2% over prime for loans $25K to $50K, and prime +1.5%
      for over $50,000.

      Green Tree Financial Corporation
      (800) 851-1367 extension 3692

      $5,000 minimum, no maximum.  Finance 90% of the total cost for up
      to 15 years.  Interest rate for less than $25,000 is currently 13%,
      $25K< is 11%.

      Other options include:  Borrow from 401K finance plan
      signature loan from credit union (the current rate at my CU is
      11.75%), or home equity loan (~8.5%).
Q334: Can I take lessons/get my license in my homebuilt?

A.   Like so many things in aviation, the answer is, "Yes, but..."

      There is no regulations to prevent your taking lessons or your
      flight test in a homebuilt aircraft.  Your ability to do so will
      depend on finding an instructor willing to instruct in a homebuilt,
      as well as an Examiner willing to administer the test in the
      aircraft.  Neither is automatic, and you'll have little recourse if
      they refuse.

      If you would like to take lessons in your homebuilt, ask around at
      your local EAA chapter.  Many EAA members are instructors, and
      would probably be more willing.  My local chapters, for instance,
      include several CFIs who administer BFRs in members' homebuilts.
[end of rec.aviation.homebuilt FAQ]

Return to Sea and Sky Aviation Page