Correction: The 2014 Nats coverage in the December 2014 “Control Line Scale” column incorrectly reported that Bob Whitney’s 1/2A Scale pond racer used .61 engines. The model was actually flown with .061 engines. That would have been one fast aircraft with a pair of .61 engines!
Bv 138 Flying Boat
Leroy Black’s model of the Blohm und Voss Bv 138 flying boat has three Norvel .061 engines. The 42-inch wingspan aircraft was entered in the Tucson 1/2A Scale contest in October 2014. The event was hosted by the Cholla Choppers Control Line (CL) club.
Flying boats are challenging because the full-scale aircraft has no wheels. One method for building a model flying boat that can fly from a hard surface is to bury half of the wheel in the fuselage, as shown in the photograph. The wheels allow the model to tip from side to side, so a small wheel on each wingtip is necessary to use throttle control to perform a taxi option.
CL Scale Rules Have Changed
If you plan to fly in an AMA-sanctioned CL Scale contest this year, you will need to read the updated 2015-2016 rules on the AMA website. If you are a contest director (CD), you also need to read the updated rules. If you don’t have Internet access, find someone to print them for you.
The CL Scale rules were completely rewritten. It is worth reading the entire set of rules so you know what to expect at the next contest.
We have several events that include Fun, Sport, Profile, and Team Scale. Designer Scale has been eliminated. Authentic Scale and 1/2A Scale have been added as official AMA events. The 1/2A Scale event has run for many years using club rules. If your club decides to continue to use club rules, make this clear on your contest sanction and advertising.
The 1/2A Scale event is judged 5 feet from the model. All other events are judged from a distance of 15 feet. The one exception is Authentic Scale, which is judged at 15 feet for outline and then up close for the details. Authentic Scale will require judges who have experience with Scale modeling and will require extra time for the static judging.
The maximum number of allowable documentation pages has also changed. Remember, the three-view only counts as one page regardless of how many pages it takes. Fun and 1/2A Scale allow a maximum of four pages. Sport, Profile, and Team can have up to eight pages of documentation, and Authentic Scale can have up to 12 pages of documentation.
It has long been unclear what weight should be used to calculate the pull-test requirements for electric-powered aircraft. The updated rules now require that the weight of the batteries be included in the weight of the model for pull-test calculations.
The minimum line diameters have also been revised, which will require most of us to make a new set of flying lines. The rule book has a diagram with line diameters based upon the model weight and the number of lines. For a model flown with two multistrand lines in the 4- to 8-pound range, the line diameter for this class was changed from .018 to .021 diameters. For aircraft weighing more than 12 pounds, the line diameter is now .027 with two multistrand lines.
Also, look at the line length requirements. Any model that weighs 8 pounds or more needs to use 65- to 70-foot lines. Bulk line material is available from MBS Model Supply. Brodak Manufacturing has lines available by length and diameter.
The taxi option can only be performed after the landing is complete under the new rules. Some CDs have allowed the taxi option to be accomplished before takeoff. The rules were written such that the model must come to a complete stop with the engine or motor idling before takeoff without help.
The rules also clarify that Profile Scale models can be entered in any event, but be prepared for outline downgrades if you enter the airplane in Sport or Authentic Scale. However, in Fun Scale you will not get any outline point deductions during static for a Profile Scale model.
The big change in the rules this year is the addition of Authentic Scale for the highly detailed models. This event is patterned after the international Fédération Aéronautique Internationale (FAI) F4B event, and allows the model and cockpit to be judged up close. Other CL Scale events do not judge the cockpit.
Authentic Scale raises the bar in terms of level of documentation and detail that is expected. As previously noted, the outline will be judged from 15 feet before the judges move in close for surface finish and other details such as panel lines and rivet detail. They cannot touch the aircraft.
One of the new items in Authentic Scale is the complexity score during static judging. The judges look at the full-scale aircraft in terms of the configuration and the paint job. An aircraft with two wings, lots of exposed details such as guns, exhaust pipes, and rigging wires, would earn a higher complexity score when compared to a homebuilt aircraft with one wing, smooth skins, and fewer exposed details.
The judges will look at the paint job for the complexity score. A World War II bomber with lots of lettering, other markings, and lots of colors, would receive a higher complexity score than an aircraft with a single color and few markings.
Retractable landing gear, surface details, exposed details, multiple wings, multiengine, and other features will raise your complexity score. Complexity is worth up to 10 points, so this will make a difference in the static scores. The complexity score is not judging the model, but the configuration of the full-scale aircraft.
If the full-scale aircraft had working flaps and retractable landing gear, during the flight portion, realism points will be lower if you don’t have retractable landing gear on the model.
Choosing a model for Authentic Scale is important. Make sure you can document the colors, markings, outline, cockpit, and the details to a higher level than you would for Sport Scale. Research the full-scale aircraft to figure out what maneuvers it can fly so you can duplicate them. Also consider what complexity score you might get based upon the configuration and paint scheme.
The CL Scale Nats will be held July 17-19. All other CL events will be held from July 13-18, so you can be a spectator at some of the other contests if you arrive early. FAI F4B will be replaced by Authentic Scale. The 1/2A Scale event will use the new AMA rules, so make sure you understand them.
If you have a Sport Scale model that is not currently being flown, consider entering it in Team Scale. This is where another person at the Nats pilots your model. Both the builder and the pilot have to register under Team Scale for the Nats.
I welcome contest reports, pictures, and any projects that you are building and flying. The deadline to send in your entry for the 2015 CL Scale Nats is June 19. Make sure you enter your 1/2A Scale model with the official AMA entry form. Entries sent in after the deadline will not be included in the head count to determine how many awards are required.