An explanation of both the RC and FF 1/2A Texaco events
By
Bob Angel | [email protected]
1/2A Texaco is a good starting point for any aspirant to Old-Time (OT) flying, and it is also one of the most popular events among seasoned fliers and contestants. It began life as a Society of Antique Modelers (SAM) RC special event and later graduated to a basic event flown at each annual SAM Championships.
At the 2006 SAM Champs, 41 people entered 1/2A Texaco. Although only 31 flew, it was still the most popular among the 27 RC or 27 FF categories. The FFers picked up on the 1/2A Texaco event too and put their own spin on it, with slightly different rules from those in RC. It’s still a special event for FF, which means that it’s often flown in local contests but may or may not be flown at the SAM Champs. The 1/2A Texaco event wasn’t offered for FF at the 2006 SAM Champs; a couple of similar special categories—Nostalgia 1/2A glow and Nostalgia 1/4A glow—were flown instead.
RC 1/2A Texaco: basics and rules
The simplicity of the RC 1/2A Texaco rules and of the aircraft themselves is mainly responsible for the event’s popularity.
Key RC requirements and typical practice:
- Engine: Cox reed-valve .049 required, using an integral 5.1 cc tank mount such as that supplied on the Cox Texaco Jr. or Babe Bee.
- Radio: Two-channel (two-servo) radio for elevator and rudder.
- Operation: Fill the tank, start, launch, and try for a 15-minute max flight. The engine runs until the fuel is exhausted, similar to the way most CL models are flown.
- Scoring: Best two of three allowed flights are scored; winners are usually determined by a flyoff if two or more fliers max.
- Aircraft: Any pre-1943 powered designs allowed and may be scaled to any size. Most are built in the range of 288–350 sq in wing area, use 6- to 8-inch propellers, and run 5% to 15% nitro fuel.
- Weight: Minimum required weight is 8 ounces per square foot of planform wing area.
There are two basic approaches to flying the event:
- Use a small, light model with the maximum-allowable 8-inch propeller and low-nitro fuel while shooting for a four-minute or longer engine run. The engine tends to lug with that propeller, which eats up flight time toward the 15-minute max while the model climbs slowly.
- (Author’s preference) Use a larger and heavier model, a 6-inch propeller, and higher-nitro fuel and go for maximum altitude during a 2.25- to 3-minute engine run. The smaller prop allows for higher RPM, better fuel draw, and steadier running.
Cox reed-valve engines can be extremely frustrating to operate; they often suffer speed changes and flameouts during the run and are much less tolerant of any dirt, especially in the fuel supply.
Engine maintenance and fuel cleanliness
Bill Schmidt recently wrote an excellent article about 1/2A engine operation for SAM Speaks. It can be summarized: be a fanatic about filtering and maintaining clean fuel.
A few practical tips and anecdotes:
- I prefer the old open-exhaust engines, but they can present more cleanliness problems than the newer two-slot exhaust types. If you kick up the tiniest speck of dirt on the piston side, you’re in trouble until it’s gone.
- Years ago I started wrapping a paper towel around my engine, supposedly to keep it clean between runs. Mistake! My wife reminded me about the fibers in those paper towels. Reliability returned when I abandoned that practice.
- It was a little embarrassing because I had designed super-clean rooms for working on Atlas and other missile hydraulic steering actuators. When a speck of fiber or lint can bind a large, high-pressure ram used for steering an ICBM, what can you expect from a little .049 engine?
FF 1/2A Texaco: differences from RC
The FF rules for 1/2A Texaco have a few notable variances from RC and follow historical Texaco-event practices more closely:
- Models: Older designs from the Antique category (pre-1939).
- Flight time: Unlimited (no max).
- Weight: No minimum weight requirement.
- Engines and fuel: Slightly larger glow engines up to .051 displacement and more modern rotary-valve designs are allowed in FF. Also permitted is 15 cc of fuel—nearly three times the allotment for RC models—which can result in fairly long chases.
I haven't spent much time observing that particular event, but the combination of larger engines and more fuel would seem to encourage very long flights and chases.
Spread-spectrum radios and ignition interference
The old and the new are represented by an OT RC airplane flown with a new spread-spectrum 2.4 GHz radio. Early tests at my home flying field indicate much-improved rejection of spark-ignition noise, which often causes radio glitching. We had several models develop ignition interference problems that were becoming frustrating to solve.
Examples from our field:
- Steve Remington bought a Futaba FASST system and replaced his Futaba FM receiver in a Super Cyke-powered model. The new system cured the problem, so he ordered a second receiver, which immediately cured the same problem in his Ohlsson & Rice-powered Playboy.
- I followed suit and replaced my Futaba FM receiver with a FASST receiver. I chose Futaba because it allowed me to keep the same servos and its small size fit the available space. After getting the same immediate cure of glitches, I took it a step further.
Most RC spark-ignition aircraft use a 10K-ohm resistor in the high-tension lead for radio-noise suppression. After testing progressively smaller resistors, I'm flying the Anderson Spitfire-powered model with a 1K-ohm resistor. I wasn't quite able to eliminate the resistor completely.
Safety items and practical precautions with 2.4 GHz systems:
- Continue to use frequency pins or follow AMA frequency-control habits even with spread-spectrum radios, since you’ll sometimes use multiple systems (old and new) at the same field.
- Always check antenna configuration. One flier switched immediately from flying a 2.4 GHz model to another model using a standard FM transmitter and forgot to extend the FM antenna. His model took off, he lost control at about 100 feet, and the crash followed.
Discus launch in OT FF glider flying
Discus launch will be finding its way into OT FF glider flying. The question arose whether discus launch would be allowed at a recent SAM Champs. FF CD Gene Wallock pronounced it okay, citing precedence in allowing various kinds of grips permitted on OT gliders. He also suggested it might save some muscle cramps and kinks in aging arms.
There was also a cautionary note about careful practice and perhaps keeping the discus launch to a single revolution to prevent pilot error and crashes.
Omahawks club and outreach
Richard Behrens of the Omahawks club (Omaha, Nebraska) sent a nice letter and pictures of his OT group. With a limit of three pictures in the column I couldn't include all the photos I received, but as a reward for being one of the first contributors I’ll acknowledge the group.
Most, if not all, appear to be genuine old-timers—not just 29-year-old “wanna-bes.” Richard mentioned that they have mostly stayed away from SAM competition because of a perceived complexity in the events and a lack of experience, especially with ignition engines, and he offered some opinions about rules to entice beginners.
I hope the 1/2A Texaco rules outlined here might inspire the group members to give that event a try. I’ll bet that if one or two 1/2As showed up at the field, by next year they might have enough participation to join one of the annual 1/2A Texaco postal events.
Let's meet here again in a couple of months.
Transcribed from original scans by AI. Minor OCR errors may remain.
