Edition: Model Aviation - 1990/07
Page Numbers: 133, 134, 135, 136, 137, 138, 139, 140
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COMPETITION NEWSLETTER

A Note From the Technical Director

Bob Underwood

Let's skip all that preliminary stuff this month and cut right to the chase! There are lots of new things to report.

The FCC has allowed the transmitter narrow-banding petition to surface. I have put off doing this column as long as possible in the hope that the actual text and technical aspects would be available, but that hasn't happened. What we have received is a news release indicating that it will soon be in the comment stage.

The timing involved in the order is interesting. After March 1, 1992, the present FCC regulations concerning the manufacture or importation of RC equipment will no longer be in effect, with March 1, 1993 as the last date such equipment may be sold. This allows a period of one year for the pipeline to be cleared. From that point on it will be illegal, by FCC regulation, to sell any non-narrow-band equipment.

Beyond the question of what the actual technical specifications will be, there are two important questions that will be on the minds of most members. The first concerns whether a grandfather period is included for present transmitters in the field. I guess it is appropriate to leave that hanging until next month's publication, since this is the end of the TV year and the winter shows are over until the next season. Until we get the actual document, we do not know for a fact. As soon as the answer is known we will mail the information to all publications and get the word into the first available communication channel, such as the AMA National Newsletter, which operates on a shorter lead time than this publication.

The second question centers around what this does to the 1991 phase-in of the odd channels. The answer is: Nothing. Radio manufacturers and importers have been voluntarily doing for several years what the FCC regulation will require. Granted, there are still a few transmitters being produced that are not narrow-band. Some very basic, entry-level units may not be 55 dB down at 20 kHz out. However, most transmitters meet that requirement now.

National Records Monthly Update

The following new National Records were processed during the month of April 1990:

Indoor

  • Category II
  • R/C Stick Open — 13:09 — Stan Chilton — 3/10/90

New CL Speed Pull Test Added

Safety: The Control Line Contest Board has approved a safety proposal submitted by CLCB Chairman Vic Garner. The proposal notes that current National Records in 1/2A Speed, B Speed and Open result in centrifugal force generated by the model exceeding the required pull test. This is considered undesirable from a safety standpoint. The proposal increases pull tests to:

  • 40G for 1/2A Speed
  • 52G for B Speed and Open

The Contest Board approved the change for immediate enforcement.

Contest Board procedures require this notice be published at the earliest possible date, followed six weeks later by a ratifying ballot. The six-week period after publication allows interested modelers to make their opinions known. AMA district CL Contest Board members' names and addresses are published in the Competition Directory section of the Competition Newsletter. The rule change is in effect until the Contest Board has approved the forthcoming ratification ballot; the result of that ballot will be published as soon as possible after the vote has been tabulated.

FF Coupe d'Hiver Rules Interpretation

The Free Flight Contest Board has voted to substitute FAI Class F1G rules for the AMA Coupe d'Hiver rules in the 1991 rule book. The measure was approved by a vote of six to two. Therefore, effective with the issuance of the 1991 AMA Competition Regulations, the existing AMA rules will be removed from the table of contents and event number 154, F1G* Coupe d'Hiver, will be added. Also, on page 16, section 2, Classes: F1G class will be inserted. Contest Directors may run Coupe contests under either AMA or FAI rules.

World & U.S. Aviation/Space Records Book Available

From NAA: AMA's parent organization, the National Aeronautic Association (NAA) of Reston, VA 22090, has just published a book of World and U.S. aviation records. It is available to AMA members for $10. To order, send to NAA, 1763 R St. NW, Washington, DC 20009; however, your AMA number must be included with the order to receive the special low price. Cover price of the book is $13.95.

Indoor World Champs Attract Entrants

The 1990 Indoor FAI Class F1D World Championships are scheduled to be held June 4–6 in Johnson City, TN. As of April 25, the following nations indicated they intended to have fliers competing: Argentina, Canada, Finland, France, FRG, Japan, Switzerland, United Kingdom, United States and Hungary. The U.S. team is composed of Cezar Banks, Larry Cailliau and Robert Randolph (defending World Champion); also, U.S. flier Jim Richmond is entered.

FAI Approves Major Rules Changes — Noise Reduction

John Worth: At the April 6, 1990 meeting of the Fédération Aéronautique Internationale's Committee (CIAM), new noise rules were approved. Control Line Scale and Radio Control Aerobatic events, along with Free Flight Power, RC Helicopter and RC Pylon Racing categories, were given rules changes aimed at noise reduction. These changes are significant and the direction being taken by FAI-CIAM is now clear: noise reduction for internal-combustion-engine classes will shift focus to engine/prop combinations for future international competition.

FAI Noise Reduction (continued)

CIAM officers and subcommittee appointments included:

  • (Slovakia), Second Vice President
  • Werner Groth (F.R. Germany), Third Vice President
  • Tony Aarts (The Netherlands), Technical Secretary
  • John Worth (U.S.A.), Secretary
  • Pierre Chaussebourg (France), Assistant Secretary
  • Ian Kaynes (England), Free Flight
  • Rolf Girsberger (Switzerland), RC Thermal Soaring
  • Rich Ruisink (The Netherlands), RC Electroglider
  • Dennis Thompson (England), Scale

The 1991 schedule for aeromodelling World Championships was approved:

  1. Free Flight classes F1A/B/C — Yugoslavia
  2. RC classes F3A/C/D — Italy
  3. RC class F3D — The Netherlands
  4. F1E Slope Soaring class F1E for Juniors and Seniors — Romania
  5. CL World Championships for Juniors (first ever) — U.S.S.R.

Romania, suspended last year for nonpayment of FAI dues, has been reinstated following back dues payment. Romania was approved to host the 1991 European Indoor Power Championship and the Junior/Senior Slope Soaring event, and made offers to host future European championships.

The April 1990 FAI-CIAM meeting was the largest ever for this annual meeting. One hundred seven people were registered, representing 33 countries. Attendance was not greatly affected by the current political problems of Eastern Europe; several attendees noted they came at their own expense as previous government funding was no longer available.

U.S.A. representation was supported financially by the AMA budget, continuing a long-standing policy to participate and provide expertise for international aeromodelling categories. Such participation enables AMA members to compete in World Championships, set world records, and occasionally host World Championships in the U.S.A. AMA President Don Lowe was the current U.S.A. Voting Delegate.

Additional technical experts from the U.S.A. serving on subcommittees included:

  • George Xenakis, Free Flight
  • Terry Edmonds, RC Thermal Soaring
  • Cal Ettel, RC Electriflight
  • Bob Wisher, Scale

A new milestone in FAI-CIAM communications was the first issue of the CIAM FLYER newsletter, produced by Art Schroeder, chairman of the Information and Education Subcommittee. Copies were distributed and sent to aeromodelling publications worldwide.

Looking ahead to 1992:

  • Another Free Flight World Championships for Juniors was approved for Czechoslovakia.
  • Poland made a tentative offer to host the Indoor World Championships.
  • The Netherlands was approved (instead of Australia) to host the RC Electroglider World Championships.
  • The U.S.A. was approved to host the Spacemodels World Championships.
  • The U.S.A. made a tentative offer to host the 1992 Scale World Championships (Oshkosh hoped as site).
  • No offers yet for the 1992 Control Line World Championships.

New to FAI and scheduled for France in 1991 (September) are the first-ever World Air Games, FAI's effort to hold Olympics-type events for sport aviation. CIAM approved a proposal to include aeromodelling categories (Large Scale models, RC Pylon Racing, RC Helicopters, CL Combat) for potential inclusion in the Games. Final acceptance will depend on the World Air Games sponsors.

Highlights from CIAM decisions:

  • All applicable subcommittees to give priority to improving standards for judges and judging performance.
  • A proposal to reinstate a previous ban on RC in Free Flight competition was rejected as premature.
  • The Control Line Speed pull test was returned from 60G to 50G (immediate).
  • The battery definition rule for RC Thermal Soaring winches was retained for now, with a planned change in 1993.
  • Specific new noise reduction rules were approved for all CL classes, RC Aerobatics and Scale.
  • The newly added (1989) CL Aerobatics Maneuver (Triangular Loops) was rescinded (to take effect 1993).
  • Normalizing for RC Aerobatics scoring was approved (1993).
  • No landing arresting devices allowed for RC Soaring (immediate).
  • For RC Duration records, assistant pilots are permitted (1993).

The noise-reduction rules approved by the April 6, 1990 FAI-CIAM Plenary meeting were:

A) Control Line — Effective January 1, 1993:

  • F2A (Speed): A silencer is compulsory. Minimum internal volume 50 cm3. Maximum tailpipe internal diameter 6 mm. An effective engine shutoff is compulsory, but the time duration at high noise level can be limited to 20–30 seconds per flight.
  • F2B (Aerobatics): A silencer must be used except on four-stroke engines. In either case the noise limit will be no higher than 96 dB, as is current practice.
  • F2C (Team Race): Maximum cylinder exhaust projected area to be 60 mm2. The piston face at the exhaust outlet shall not be visible from the exterior of the model when side- or front-exhaust engines are used.
  • F2D (Combat): Glow engines shall use a simple chamber silencer of minimum internal length 40 mm, minimum diameter 20 mm, and maximum tailpipe internal diameter 8 mm. Any other shape of the same volume (4 cm3) is acceptable. Compression-ignition engines may remain unsilenced.

B) Radio Control (F3A Aerobatics) — Effective January 1, 1992:

  • Change maximum noise level from 98 dB to 96 dB when measured over concrete or macadam.
  • Change from 96 dB to 94 dB when measured over bare earth or short grass.

C) Scale (F4C Radio Control and F4B Control Line) — Effective January 1, 1991:

  • Maximum noise level of 96 dBA at three meters will apply, with the exception of ducted-fan models, which should not exceed 100 dBA; however, ducted-fan models must comply with 96 dBA by January 1, 1993.

Competition Newsletter

The rule about a magnetically operated switch (solenoid) was passed last year along with a rule prohibiting electronic devices from being used to boost winch power. Apparently it was not the intention of the proposer to ban mechanical switches; thus the correction. This will not come into effect until 1993.

Rule changes and clarifications:

  • 5.3.2.2.a(2) (page 70). Change to: "The power source shall be a 12-volt, lead/acid battery. The maximum cold cranking ampere capability shall not be more than:
  • 275 Amperes DIN, or
  • 310 Amperes IEC, or
  • 460 Amperes SAE."

The proposer mentioned possible battery resistance measurements in cases of batteries without type-plates or suspected type-plate tampering. Batteries would have to be at least 5.4 milliohms (6 milliohms minus 10%). The U.S.A. opposed this rule, favoring the original rule of maximum linear measurements of the battery case, because it is easier to check. After the CIAM meeting it was noted the wording of the new rule did not have any provision for resistance measurements. The cold cranking ampere method will be simple if resistance measurements are not involved. Note the IEC amps differ from current rule books. This rule will be effective in 1993.

  • 5.3.2.4.a(2) Task B (page 72). Replace "After the 4 minutes' flight time expires the model can land anywhere." with: "For a model which lands within the 4 minutes' flight time, only the full 150 m will be counted. For models still in the air when the 4 minutes' flight time or 7 minutes expires, whichever is first, only the completed laps at that moment will be taken into account." The original wording did not accord with the minutes of the 1984 CIAM Plenary Meeting. The new wording will have immediate implementation.
  • 5.3.2.6.a Partial Scores (page 73). Replace the first sentence "For each task the winner ...." with "For Task C the winner ...." This was an editorial error in the 1989 Sporting Code. This will be effective immediately.
  • Annex 5C Test Method. New wording: "A first measurement is taken in order to check the correct functioning of the measuring arrangement. This first measurement is discarded. Three following measurements should be made with an interval of about 30 seconds. The total internal resistance of the motor is the average of these three results. This procedure is repeated once if the average is less than 15.0 milliohms. The motor is declared in accordance with the rules if its total internal resistance (first or second average, if necessary) is above or equal to 15.0 milliohms. If the measurements show that there is a decreasing resistance, more measurements should be done. The accuracy of the measuring equipment (shunt included) shall be better than or equal to ±2%."

This provides a better definition of the measurement method and will be in effect in 1993.

Another item brought to the attention of the subcommittee was a problem with permissible modifications to a winch motor. With many motors it is necessary to modify the end flanges to accommodate mounting to the winch frame. The matter did not surface soon enough to get on the agenda for the 1990 meeting, nor was there time at the Technical Meeting to discuss it.

Several subcommittee members agree the rules are unclear, but that it is generally accepted to modify end flanges for mounting. It has also been suggested that all motor restrictions be removed with only the 15 milliohm rule applying. This matter will have to wait until next year's meeting and probably could not be changed until 1993.

It was discovered that the F3J rules published in the Supplement to the FAI Sporting Code, Section 4, 4a, are not the correct version. Copies of the correct rules were not available to AMA as of May 2, 1990.

Competition Newsletter — Opinions & Proposals

"Competition Newsletter" will present, from time to time, constructive and thought-provoking ideas or criticisms of AMA rules and policies that affect competitors. When an issue has two sides, CN will endeavor to print all viewpoints submitted—within limits of space, uniqueness, constructiveness, timeliness, and good taste. Determination of appropriateness for publication rests most of the time with the publisher.

The thoughts presented are those of the author and should not necessarily be construed as those of AMA HQ, AMA officers, or the publisher. Publication here of a rules-change or policy-change idea does not necessarily mean the specific proposal has been presented to a Contest Board, the Executive Council, or an appropriate committee; such action is the responsibility of the author or anyone else interested in obtaining official action.

Proposed Change in AMA Noise Recommendation

George F. Abbott, Raleigh, NC

The current AMA-recommended noise standard is 90 dBA at 9 ft., measured over a hard surface, on the exhaust side of the airplane. The "A" in dBA means "A" weighting, which measures summed noise power over a frequency spectrum roughly from 30 to 8,000 Hz, adjusted to match human ear sensitivity. Inexpensive noise meters (e.g., Radio Shack) commonly include "A" weighting.

Experience over almost two years shows two things:

  • Few engines in the .40-and-up category meet 90 dB @ 9' with stock mufflers.
  • Four-cycle setups that do not sound objectionable also frequently do not meet the 90 dB @ 9' criterion.

This illustrates that objective A-weighted measurements do not always reflect subjective impressions. The goal is to minimize annoyance to neighbors while minimizing impact on modelers, encouraging voluntary compliance by hobbyists and manufacturers. Perceived reasonableness of criteria is key to voluntary compliance.

The "A"-weighted measurement is broadband, while annoyance often relates to narrow frequency bands. For example, Figure 1 in the November 1987 issue of Model Aviation ("Sound Related to Flying Sites") showed that for a noise rating number of 30 (expected to result in no complaints), there is a differential of about 8 dB over the octave of 125 Hz to 250 Hz. A two-cycle model engine at 12,000 rpm produces a fundamental at ~200 Hz; a four-cycle at the same rpm produces a fundamental at ~100 Hz, which could be 8 dB greater for the same perceived rating. This helps explain why four-cycles often sound less offensive even if the A-weighted measurement is similar.

A need exists for research into noise spectrum analysis of model engine noise. In view of perceptions and field experience, I propose the following recommended noise objectives:

  • 90 dBA @ 9 ft. for two-cycle engines
  • 98 dBA @ 9 ft. for four-cycle engines
  • 98 dBA @ 9 ft. for any engine at less than 7,000 rpm

The 90 dBA objective for two-cycles is challenging for current equipment. The 98 dBA objectives recognize the lower-frequency spectrum of four-cycles and practical field experience. These objectives can still be measured with readily available A-weighted meters, are as easy to administer as current ones, would better reflect public reaction, and would reward use of less offensive equipment.

Racing should be recommended.

As acting chairman for the F3C class, I was asked to bring this subject up at the F3C Technical Meeting the following day. The Sporting Code discussion raised more questions, but it was noted that if the World Air Games modeling events could be held early in September, pilots participating in the World Championships in Italy in late August could extend their stay in Europe to participate in the Games without significant additional travel expense.

The Italian delegate (Mr. Fontana) and Mr. Giulianetti (organizer of the Open International F3C contest scheduled for August 1990 in Milano) attended the F3C TM to discuss changing the contest to an official FAI F3C European Championship event. The SC felt Mr. Giulianetti had a good chance because two firm offers from Austria and France to sponsor the 1990 European Championships were withdrawn just prior to the December 1989 CIAM Bureau meeting deadline, leaving little time for alternate plans.

Normally contest details such as FAI Jury members and judges must be firm and presented at the December Bureau meeting. It was suggested that if the FAI Jury were selected by the end of the Plenary session, approval chances would be good. The SC prepared a list of candidate judges and suggested three FAI Jury members accepted by the contest organizer. Unfortunately, just prior to a vote the Italian delegate asked for 10 more days to finalize plans, and the FAI President made it clear the FAI Jury had to be finalized by the end of the present Plenary session. Consequently, there will be no 1990 F3C European Championships.

Firm offers from Australia and Japan to host the 1993 F3C World Championships were considered. The Australian offer included F3A and F3D (aerobatics); the Japanese offer was for F3C and F3D. Material for these events was not yet in the hands of the SC. Mr. Honda (Japanese delegate) stated that the Japanese Model Aeronautic Association had strong support from industry and an automobile company. He was reluctant to submit a firm offer when he learned the Australians were bidding for the fourth Aerolympics.

The F3C Subcommittee Chairman was again unable to attend the CIAM meeting, and the Belgian delegate did not nominate Mr. De Potter for the F3C Chairman position. I was nominated for and accepted the position of chairman. As chairman I plan to increase membership to include all countries with an active interest in the F3C class.

If you have suggestions for improving the FAI F3C rules, please forward them to me at the address provided in the Competition Directory section of this edition of the Competition Newsletter. If you need a direct response, include a SASE.

Members of the F3C Subcommittee attending the meetings included J. Amacher.

CIAM Report

F3D RC Pylon Racing

Bob Brown, Subcommittee Chairman

The 1990 FAI meetings resulted in no rule changes for the 1991 FAI Pylon (F3D) season.

The Italian bid for the 1991 Pylon World Championship was accepted. The site is Milan, and the dates are August 17–26, 1991. Approximately 15 countries are expected to send full teams, and worldwide enthusiasm should produce the most competitive world championship in history. The United States' continued superiority in F3D will only continue if the team produces the ultimate effort.

A new event, the World Air Games, is being created by the FAI. The modeling events proposed include Pylon, Scale, Helicopters, and CL Combat. The 1991 Games would be held in Toulouse, France during September. The Pylon competition would take place approximately one week after the Italian World Championships. At present the entire modeling portion is tentative, subject to approval by involved organizations. The proposed Pylon event would be by invitation only and include the top 21 Pylon pilots and callers worldwide, with invitations including transportation and accommodation expenses. The F3D Subcommittee is expected to generate the invitation list. U.S. competitors should aim to place in the top ten positions of the U.S. team selection race to have the best chance for invitation.

Australia generated a bid to host the 1993 World Championships for Pylon, Pattern, and Helicopters.

The FAI CIAM mandated in 1989 that by January 1991 all categories must produce specific sound restraints. Pylon competitors worldwide opposed this mandate, arguing speed events should not be subject to such rules. That position is not in agreement with broader political bodies. The FAI Bureau delayed the edict for one additional year; at next year's CIAM meeting Pylon must propose methods to restrict sound. Possible approaches include muffled tuned pipes, different propellers, enclosing the pipe in the fuselage, and other minor modifications. Reducing current sound levels (around 115 dBA) to an acceptable level (about 105 dBA) should be possible within a short period. Suggestions are requested immediately.

The 1991 U.S.A. Pylon team will need additional funds for its competitive effort. Contributions should be forwarded to AMA Headquarters, specifically marked for the 1991 U.S. FAI Pylon team. Thank you for all contributions!

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