Indoor models

Double Whammy

Double Whammy

The Double Whammy was designed by Chuck Markos, who published plans in AMA’s Model Aviation magazine in November 1999.  It is so-called because it may be converted to a more competitive plane with simple modifications. The original version has a flat plate wing, and is used by the Bong Eagles in a best of three rounds contest called the “Cash Bash”.  The propeller that comes with the AMA Cub, a 5 3/8 inch diameter plastic one, is required.   Wingspan is 17 inches and wing area is 64 square inches. 

P-18  –  An AMA Beginner Class

P-18 planes resemble Double Whammy planes in size and complexity, and have been added to the AMA Indoor Free Flight Rule Book for Competition. (

The Big Smash by Bud Romash is a good example of this type. A file of the tiled plan and construction notes are attached.

Comet Phantom Flash

Comet Phantom Flash

The Comet Phantom Flash is a simple rubber powered plane which may be flown indoors or out, at least on calm days.  It was originally designed by Comet, but is now available from many sources as a kit or plans. A kit with laser cut main parts is available from An indoor flight lasting over 1.5 min was posted on YouTube by sandfac of Glastonbury CT on 1/10/2016.  Decorations were inspired by the popular Phantom comic strip. Wing span is 16 inches. 

Delta Dart – AMA Cub

Delta Dart or AMA Cub

The Delta dart is a very simple aircraft with a stick for a fuselage and flying surfaces with thin graph paper covering over a framework of 1/16 X 1/8 inch balsa sticks. A 5 3/8 inch diameter plastic propeller comes with the kit. The Bong Eagles fly them in “Mass Launch” = last down wins contests both indoors and out.


Simple Bostonian

Bostonians are simple sport cabin planes limited by AMA Rules to 50 square inch wings, and requiring a cabin of a designated size. They are usually flown indoors, and must take off from the floor. This simple one was designed using Turbo CAD. The airframe weighs 12.5 grams with nose weight added, and total weight is 14.5 grams with 2 grams of rubber.  This is heavier than the 9 gram minimum weight set by AMA rules.

No Cal – Profile Scale

No Cal or Profile Scale planes are built with a simple framework showing the side view of the aircraft they represent, attached to a motor stick which carries the propeller bearing and the rear motor hook. The wing is covered on one side and usually has cambered “sliced” balsa ribs. This splendid example represents the “Chambermaid” pylon racer and was flown at a 2010 Meet at Racine’s Memorial Hall, There are a wealth of plans available for such planes, either in “Model Aviation” or in the Flying Aces Newsletter archives. Short kits are available at retrorc or Volare Products.

Film Covered Planes

There are a large variety of very low wing loading planes covered usually with a plastic film that are described in the AMA free flight rule book. A “ministick” is shown flying in the cover photo for this page. Minimum weights vary, but the Penny planes have a minimum weight based on the old copper penny, about 3 grams,

Limited Penny Plane/LPP

Limited Penny Plane at Rantoul 2015

Limited Penny Plane competition is flown under AMA rules and is one of the “entry” levels to film covered indoor flying. Limitations on the propeller used, such as no variable pitch mechanism and solid blades, make these planes easy to spot. The close FAI equivalent F1M has a 460 mm maximum wingspan, and must be a monoplane. Minimum airframe weight is 3 grams, and maximum motor weight is 1.5 grams. Any covering, even tissue, is allowed but not “microfilm”.


F1L Plane flying at Rantoul

An F1L class film covered plane is the near equivalent to the AMA’s EZB, but follows rules of the FAI (Federation Aeronautique Internationale) Sporting Code. It also is an “entry” level plane. Maximum wingspan is the metric equivalent of 18 inches and maximum wing chord is 3 inches. Minimum air frame weight is 1.2 grams


A Ministick catches the light inside the dome at West Baden. Photo by Mike Kirda.
A Ministick catches the light inside the dome at West Baden. Photo by Mike Kirda.

Ministick’s are smaller versions of the Limited Penny Plane.


A6 was the last class that required condenser paper as a covering material. Due to the covering weight, getting the model down to weight was quite difficult for a ‘beginner’ class. With the rule change to allow film coverings, building to the 1.2 gram minimum weight is much simpler now. The best flying A6’s use extremely long thin motors and many thousands of turns to keep these up in the air for upwards of ten minutes.


“Ez-bee” is a misnomer – There is nothing easy about this class. The AMA rules specify no minimum weight, so competitive models are normally sub-400 milligrams in weight. The hardest part of this class is finding the right wood. Very light wood is rare enough, but very light AND stiff wood is extremely rare. That is exactly what is needed to make these models. These are known to do 20 minutes in category 2 ceiling heights.

F1R aka 35cm

There is only one rule in this class: A maximum wingspan of 35cm. Known as a miniature F1D, competitive models often weigh in the area of 400 milligrams. Microfilm covering and braced wings are not uncommon. This is a very interesting and challenging event with flight times similar to F1D models.


Nick Ray getting ready to fly his F1D. Photos by Jeff Annis and Mike Kirda

This class is the most challenging of the film covered planes, with film covered variable pitch propellers only one of the sophisticated means used to reach 20 minute flights indoors. Wing span maximum is 550 mm (21.7 inches) and wing chord maximum is 200 mm (5.1 inches). Minimum weight is 1.4 grams for the airframe. Motor maximum weight is 0.4 grams. Wing loading for the 0.77 square foot wing would be 0.083 ounces per square foot, and cube loading would be a gossamer 0.094 ounces per cubic foot.

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