Author: B. Boss
Edition: Model Aviation - 1988/04
Page Numbers: 67, 164, 165
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Control Line: Scale

Bill Boss 77-06 269th Street New Hyde Park, NY 11040

URGENT!

I am sure that by the time you read this column you will have the 1988–1989 Competition Regulations book in hand. Please review the many rules changes pertaining to our CL Scale events — several significant changes affect general rules, static judging, flight operations, and in some cases are clarifications of previous wording.

Statistics from the rules-change cycle

  • 44 Scale proposals were submitted.
  • 38 proposals made the Final Vote.
  • 26 proposals passed in the Final Vote; 16 (about 60% of the 26) pertained to CL events.
  • The remaining 10 passed proposals were spread among Indoor and RC events (including Helicopter).

These numbers emphasize the large number of CL rules affected for the coming two years. I urge all competitors to read the new rules; the summary below is intended to help clarify the major changes.

General rules changes

Weight limits

  • Sport Scale (single- or multi-engine): model weight limit increased to 20 lb. (See CL Sport Scale rules, Event 509, Para. 25.)
  • Precision Scale: no change; the weight limit remains 20 lb.

Lead-out guides

  • Removable lead-out guides are now permitted to be removed for static judging (for a cleaner appearance) and reinstalled for flight. (See Para. 55e in the Sport Scale section and Para. 5.g in the Unified Scale Judging Regulations (USJR) for Precision.)

Dummy pilots

  • CL Precision Scale (Event 508, Para. 2 General) now requires all flight models to have dummy pilots installed during flight.
  • A pilot figure may be removed for static judging if the contestant wishes; the rules indicate this removal does not affect static scoring.

Proof of Scale and documentation changes

  • Clarification: "three-view drawings" may include three or more views. This avoids rejecting drawings that include more than three views. (See Para. 4.2a in CL Sport Scale and Para. 4.5 in the USJR.)
  • Maximum size for three-(or-more)-view drawings in Precision/Sport (where allowed): up to 24 x 36 in.
  • Documentation limits for Precision events:
  • Up to 25 pages single-sided, maximum 11 x 14 in.
  • The contestant's declaration listing components not made by him does NOT count against the documentation page limit for Precision.
  • Proof of Scale page limits (Sport):
  • Increased from 6 to 8 pages (see Para. 4.5).
  • In Sport Scale, the contestant's declaration of components not made by him IS counted as one of the eight pages.
  • Plastic model used as Proof of Scale:
  • New rule (Para. 4.2c): a plastic model counts as one page of the eight allowed (previously it counted as two pages).

Oversight on drawing-size proposal

  • Proposal SC-88-15 (increase max size of three-(or-more)-view drawings in Sport Scale to 24 x 36 in.) passed but the published rule book omitted the intended wording. Para. 4.2a should read:
  • "A single-sheet, three- (or more) view drawing (line, tone, or color) of up to a maximum of 24 x 36 in. is permitted."
  • This oversight has been referred to AMA Headquarters and the Scale Board Chairman for correction.

Flight and operational rules changes

Multiengine operation

  • Para. 8.a (Precision) and Para. 9.4 (Sport): ALL power plants on multiengine models must contribute significantly to the model's performance to receive multiengine points.
  • Points shall not be awarded simply because a power plant is present if it does not contribute noticeably.
  • A suitable demonstration should be arranged between contestant and judge(s) to show the contribution of each power plant. Example demonstration: show that the model can taxi under reasonable control and speed using only the smaller or "diverse-type" power plant(s).

Engine starting bonus

  • The 10-point "Engine Starting" bonus has been removed from the CL Precision Scale Bonus Points (Para. 9). This anticipates entries of all-electric-powered models and reflects the common use of electric starters.
  • Because the rules book was not fully updated in every place, the starting bonus was inadvertently not removed from the Flight Score section (Para. 11, "Official Score"). The correct maximums should be:
  • Maximum single Flight Score: 215 points.
  • Maximum possible Official Score: 665 points.
  • This inconsistency has been referred to Headquarters for correction.

Operational features and timing

  • CL Precision Scale rule 8.g: preflight or post-flight operations (e.g., unfolding wings, opening/closing canopies) may now be demonstrated and awarded operational feature points.
  • One caveat remains: no points are given for any operation unless the feature is demonstrated in accordance with Para. 8.a (i.e., the operation must be demonstrated and verified by the judges as required).

Flap operation

  • Para. 8.c: flap operation must be independent of throttle control to receive maximum points. This change aligns model flap operation more closely with full-scale aircraft.
  • Independent flap control can be achieved using available servo and electronic solutions.

Example: independent flap control (from Bill Oldham, Hangar Talk, Choppers Club)

Bill Oldham provided sketches and notes for an electric motor-driven gearbox and microswitches to control flap extension and travel limits. Summary:

Materials suggested

  • Three subminiature DPDT lever switches (Radio Shack part #275-016)
  • One or two 1.5 V batteries (may be Ni-Cads)
  • A small light spring
  • A small geared motor with a light gear train
  • Associated wiring and mounting hardware
  • A small motor-driven gearbox and limit microswitches

Operation description

  • The auxiliary flap switch (operated by the pilot) routes power to the motor and through limit microswitches.
  • The motor drives the geartrain until a limit microswitch trips at the Up or Down position, then the motor is deenergized.
  • The auxiliary switch is used to select flaps Up or Down at the required time (in flight or upon landing).
  • Battery pack (Ni-Cd) can be mounted in the fuselage as a small shrink pack rather than a separate external pack.

Bill also suggests that an independent servo/electronic system can be used to accomplish the same control. This simple electromechanical arrangement is a practical method to meet the new independence requirement for flap operation.

Closing

My thanks to Bill Oldham for his notes and sketches, and to those who worked on the rules clarifications. I hope this review helps clarify the rule changes and provides useful information for anyone planning to compete in CL Scale this season.

Bill Boss

Transcribed from original scans by AI. Minor OCR errors may remain.