Brodak .25, OS .25FP proposed for NWSR engine list
Northwest racing fliers are being asked to consider adding two more engines to the list of those allowable for Northwest Sport Race.
Current rules allow the Fox .35, O.S. .35LS and ASP .25. The proposal would add the Brodak .25 and the O.S. .25FP to the list.
The proposal is offered by John Thompson and Mike Hazel.
If approved by a vote of Northwest racing participants, the amended rule would take effect in 2019.
Northwest Sport Race began in the 1970s as a simplified racing event, and since has undergone an evolution. Beginning in 1980, the only engine allowed was the Fox .35 Stunt. In 2014, the O.S. .25 LA was added to the list of allowable engines. The ASP was added in 2018. This rule change would bring the number of legal engines to five.
With the passage of time, all of the engines currently allowed for Northwest Sport Race have become difficult to obtain. The Brodak .25 also is available intermittently, but its addition to the list would expand the options for potential NWSR contestants. The O.S. .25FP is an obsolete engine from the 1970s, but it can often be found at swap meets and online sales sites.
Here are the specifics of the change:
Amends rule No. 3 by adding "the Brodak .25. and the O.S. .25FP."
A thread is open for discussion of this topic on the Northwest CL Forum. After a one-month discussion period which will end in early January 2019, voting will be opened.
Proposed 2019 Northwest Sport Race rules
New language in red; deleted language in
RULES FOR NORTHWEST SPORT RACE
1. Purpose: It is the intent that that this event will provide
the novice competitor a beginning racing event, racing with other competitors
using similar equipment which is readily obtainable and operates in a basic
2. All pertinent rules from AMA unified racing rules shall apply,
in regard to safety and conduct of races, except as follows.
3. Engines: The only allowed engines shall be the Fox Stunt .35, and the O.S. LA .25, the ASP .25, the Brodak .25 and the O.S. .25FP, all of which shall operate on suction feed and be in stock, unmodified condition except as follows:
a. Stock is defined as absolutely unmodified but making exceptions for needle valve assemblies, engine assembly bolts, gaskets, prop nut, and prop washer(s). Additionally, intake venturi must maintain original factory stock dimension.
b. No exhaust extensions are allowed except bona fide mufflers that do not increase engine performance.
c. Other: The Fox Manufacturing Co. hemi/stuffer kit modification is prohibited. The O.S. LA .25 may have the rear needle valve assembly post removed, and may also use a substitute backplate. The RC version of the O.S. LA .25 engine may be used, by fixing the throttle in one position. The ASP .25 may have the rear needle valve assembly post removed. The RC version of the ASP .25 engine may be used, by fixing the throttle in one position. The ASP .25 may have the RC carburetor replaced by a control-line style venturi with a bore not larger than the original RC carburetor (6mm or .236").
4.1. Aircraft: The model shall be built from, or an exact duplication
of, a commercially manufactured kit. In the case of obscure or rare kits,
some documentation, such as a set of plans, may be required by the contest
director for confirmation of the airplane's kit status. Kits need not be
in current production or distribution to qualify.
4.2. Models must be of profile fuselage type, and must conform to
the general profile definition. The model must have a minimum fuselage length
of 24" when measured from the propeller thrust washer face to the leading
edge of the movable elevator surface.
4.3. The minimum wing area shall be 300 square inches. The wing must
have a minimum thickness of 1 inch when measured at any point along the
span, with the exception of the last two inches before each wingtip.
4.4. All models must have a canopy, horizontal stabilizer, elevator
and vertical fin. Models must have a fixed landing gear with a minimum of
one wheel, 2 inches in diameter or larger.
4.5. Modifications: Major changes to the kit design such as
clipped wings, shortened fuselage, partial omission of the tail assembly,
etc., are prohibited. Reinforcement of the nose and engine mount areas is
permitted. Landing gear location and construction are entirely optional
from what may be included in the kit, except as specified in section 4.4.
5. Fuel tank: The fuel tank shall be fully external and forward
of the wing leading edge, and located on the outboard side of the fuselage.
The tank may not be designed so as to cowl the engine. All tank vents are
limited to a maximum size of 1/8-inch outside diameter. The tank may not
be pressurized, but the vents may be directed forward into the airstream.
6. Prohibited equipment: The following equipment and devices standard to full-race
aircraft are prohibited: pressure refuelers,
fast-fill systems, "hot glove" electrical contact systems, and
centrifugal carburetor switches.
7. Pull test: The plane and entire control system shall undergo
a pull test of 35 pounds.
8. Lines shall be of a minimum .018-inch diameter, and lines shall
be of the stranded type, with a length of 60 feet measured from the handle
grip to the fuselage, plus or minus 6 inches.
9. Races: Preliminary heats shall be of 70 laps duration, with
one pit stop minimum required. Feature races shall be of 140 laps with two
pit stops minimum. All races shall be flown with at least two entrants,
and not more than four entrants. At contestants where entrants fly preliminary
heats to determine finalists, at least three entries shall proceed to the
final races. The decision on the number of final entries shall be made by
the event director and made in advance before the start of any preliminary
10. It is assumed that the usual sportsmanship of Northwest modelers
will prevail in this event. The event director may disqualify any entrant
that is not in keeping with the spirit or intent of this racing event.
For a complete copy of the Northwest Sport Race rules (without the annotations above), and for an explanation of how the Northwest control-line rules process works, see the Northwest Rules page.
This page was upated Dec. 3, 2018