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51% rule

Posted By:
Richard Lowe
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#1 Posted: 3/17/2011 21:03:31

Is there a list of ELSA kits that meet the 51% rule?



Jeff Point
Vintage Aircraft Association MemberYoung Eagles Pilot or VolunteerHomebuilder or CraftsmanAirVenture Volunteer
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#2 Posted: 3/18/2011 02:12:02

Richard,

Welcome to the forums.  I'll take a stab at your question.  The short, technical answer- there is no such thing as an ELSA that meets the "51% rule".  These are actually two distinct and mostly exclusive ways of building and licensing a homebuilt.

An ELSA is a kit aircraft that meets the LSA rules (top speed, weight, etc.) and is an exact copy of a factory built design (SLSA.)  In order to be licensed as an ELSA, it must be built as an exact copy of the factory ship.  You can paint it a different color, but beyond that not much customization is allowed.  The up side is that there is no "51%" rule and you can legally hire others to perform most of the construction work for you.

The "51% rule" applies to Experimental- Amateur Built aircraft.  E-AB (the traditional way to license a homebuilt) requires that the majority of the construction be done by the builder for their own "education and recreation," ie. the 51% rule.  The upside to this over E-LSA is that there are not the same restrictions of speed, weight, etc., and that you can customize the design to your heart's content.

Now, their are E-AB designs out there (both kits and plans-built) that meet the speed and weight requirements of ELSA aircraft and can be flown on a Sport Pilot license, but there are not ELSAs.  And, to split hairs, there are some ELSA kits out there that could be shown to meet the major portion requirements to be registered as an E-AB, but that would be up to the individual builder to document and prove to the FAA.  For example, the RV-12 from Van's was recently approved by the FAA to meet the major portion rule.  So, you could build an RV-12, for example, with an O-200 instead of the standard Rotax, but at that point it is no longer an ELSA, because it does not conform to the original design.

Clear as mud?

It might help us help you a bit if you could clarify what you are looking for.  Are you looking for E-AB designs that can be flown as a Sport Pilot?  Or an ELSA that could be modified and licensed as an E-AB?

Sorry for the long answer to a short question.



Dave Prizio
Young Eagles Pilot or VolunteerHomebuilder or Craftsman
118
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#3 Posted: 3/18/2011 12:28:03

I assume what you actually want the list of approved kits for experimental amatuer built airplanes that the National Kit Evaluation Team has reviewed and agreed that they meet the rule. Here is a link to the most current list:

http://www.faa.gov/aircraft/gen_av/ultralights/amateur_built/kits/media/amateur_built_kit_listing.pdf

Just because a kit is not on the list does not mean that it can't be built in compliance with the so-called 51% rule, but it does mean that you will have to do some additional work to convince a DAR that you have met the intent of the rule.



Richard Lowe
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#4 Posted: 3/20/2011 21:49:38

I am in the market of a E-AB kit that meets the 51% rule that I can fly as a Sport Pilot.

Just curious who makes the call on the gross take off weight of an airplane that I build. Or the stall speed and airspeed limit of the sport pilot rules.

Thanks for the list.



Dave Prizio
Young Eagles Pilot or VolunteerHomebuilder or Craftsman
118
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29
#5 Posted: 3/21/2011 12:43:30

For a guide to who makes kits that can be flown by a Sport Pilot you might check out KITPLANES magazine buyers' guide.  Here's a link:  http://www.kitplanes.com/aircraftdirectory/

As for the gross weight of an experimental amateur-built (E/AB) airplane, it is up to the builder to determine that. Usually the recommendations of the kit manufacturer or plans designer are followed, but it is possible to use a higher or lower number if you choose to do so, although we hope that you have some good reason for doing this based on sound engineering. 

Stall speed and maximum cruise speed are determined by the designer, but there are cases where a too-fast plane can be slowed down a bit to fit within the rule. The thing is, when you get an airworthiness cert on an E/AB airplane, no one cares if you comply with the LSA rules. It is simply not part of the process.  Ultimately it is up to you to deternime if your plane complies with the rule, but if something ever goes wrong you can be sure that the FAA will want to know just how you decided that your plane was in compliance if you only have a Sport Pilot license.



Rick Girard
Homebuilder or Craftsman
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#6 Posted: 3/25/2011 13:14:41

Jeff, You are correct about an E-LSA being in conformance to its qualifying S-LSA but this is only true at the time the aircraft is presented to the FAA inspector or a DAR for the issuance of its airworthiness certificate. The only modifications allowed would be those accompanied by a Letter of Authorization from the holder of the S-LSA's certificate of compliance. Once the certificate is issued an E-LSA is no different from an Experimental Amateur Built aircraft, any modification the owner wishes to do that doesn't violate the LSA definition is just another part of the "experiment".

In Jeff's proposed RV-12 with an O-200, the builder could literally have the O-200 on the hook of his hoist and the 912 installed on the aircraft when the DAR arrives. Once the A/W certificate is in hand, off comes the 912 and on goes the O-200. No Letter of Authorization would be required then. The aircraft would not have to fly with the 912, or even start it up. The owner would only have to comply with the portion of the aircraft's operating limitations as applies to major changes and fly off the hours required to complete phase one testing.

Rick Girard

EAA 597933



Jeff Point
Vintage Aircraft Association MemberYoung Eagles Pilot or VolunteerHomebuilder or CraftsmanAirVenture Volunteer
94
Posts
65
#7 Posted: 3/30/2011 02:03:14

Rick,

You are of course technically correct.  However, as a practical matter, I don't see too many people spending $20K and up for a 912 just for a "dummy" engine to show to the inspector to qualify as an E-LSA.  Much more practical to build an E-AB that meets sport pilot requirements.