CONTROL LINE NAVY CARRIER
Author / Contact
Dick Perry 427 Live Oak Ln. NE, Albuquerque NM 87122 E-mail: [email protected]
This month
This month I will write about the exciting events planned for this summer, some expanding activities in Nostalgia Carrier, and include a bit of technical information about tailhook placement.
World Championships — Muncie, IN (July)
Be sure to make plans to go to Muncie, Indiana, in July. The United States is hosting the CL World Championships this year at AMA’s International Aeromodeling Center. Although there is no FAI Navy Carrier event, two demonstration events will be flown during the contest.
- Saturday, July 10 (the last day of the World Championships): The Navy Carrier Society (NCS) will sponsor AMA Profile Carrier and AMA Class I Navy Carrier.
- Profile Carrier will be flown according to AMA rules.
- Class I will use AMA rules with 10% fuel supplied by the contest sponsor.
With the 10%-nitromethane limit and mufflers allowed, the NCS hopes to encourage Carrier modelers attending the World Championships to bring their Class I models and enter the demonstration event. We anticipate having awards that will be appropriate for an international event.
This is a good opportunity for US Carrier modelers to come a little early, enjoy the CL World Championships, fly an extra Carrier contest, and have three days for practice and for watching other CL events before the Nats Navy Carrier competition.
Nationals Navy Carrier schedule (July 15–17)
The Nationals Navy Carrier events will be flown Thursday, Friday, and Saturday, July 15–17.
- Wednesday evening: Processing for AMA Profile.
- Thursday: AMA Profile events lead off. The NCS will sponsor Sportsman Profile Carrier as an unofficial event; Sportsman will be flown with AMA Profile on Thursday. Sportsman contestants are encouraged to process Wednesday evening, though processing on Thursday is allowed on a noninterference basis with the AMA event.
- Friday: Class I and Class II.
- Saturday: Nostalgia Carrier (all three classes), .15 Carrier, and Skyray Carrier.
The NCS annual meeting and awards banquet will be held Friday evening.
Volunteers / Contact for events
We are seeking volunteers to officiate and support the Carrier demonstration at the World Championships and the Nationals Carrier events. Please contact:
- Dick Perry (address above)
- Bill Calkins, 317 Snow St., Sugar Grove IL 60554; Tel.: (630) 466-1531; E-mail: [email protected]
Contact either of us for full details about any of the Carrier events or to volunteer to help.
Nostalgia Carrier activity
Nostalgia Profile Carrier was flown at the Northwest Skyraiders Tailhook 2003 event in Tacoma, Washington, in August. There were four entries; all flew Nostalgia-period aircraft, and all but one used loop-scavenged engines. D. Salter won the event with a Bill Melton Guardian powered by a SuperTigre ST-35. Other models included a Super MOHO, a Midwest Skyraider, and a GS Bearcat.
Nostalgia was also flown at the Southwest Regionals in Tucson, Arizona, in January, but I’m unable to provide details of that contest because my deadline for this column is before it takes place. Check the NCS’s High Low Landings newsletter for results.
Others building Nostalgia models for this season include Bob Heywood (Dayton, OH) and Jim Dross (Tulsa, OK). I’d appreciate hearing from those of you who have new models for the 2004 season. I can always use photographs to include in the column. You can contact me at the address in the column header.
Central Arizona contest — in-flight breakup and newcomers
I attended the Central Arizona Control Line Club’s contest in November and had a wonderful time—with the exception of witnessing a spectacular in-flight breakup, probably caused by the loss of a propeller blade at high speed. One of the highlights was getting to meet Dave Dawson (Burbank, CA). He was competing in his first Carrier contest, flying a Bill Bischoff Sniper design in .15 Carrier. Dave has been flying Carrier with Ron Duly’s encouragement and help, and judging from Dave’s smile he apparently had a great time. I’m sure we’ll be hearing more about him in the future. Welcome aboard, Dave!
The result of the in-flight breakup I mentioned is shown in one of the photos. The model went from about 110 mph to pieces, fluttering to earth in an instant. Fortunately the largest mass (engine and nose) stayed attached to the bellcrank, and the inboard wing, although separated from the fuselage, stayed on the lines as well, forming an effective airbrake. The lighter pieces landed near the point of the breakup.
Propeller safety and airframe design
If you haven't experienced the loss of a propeller blade in flight, you don't want to. We stress our propellers a great deal during landings when they often hit the deck. Even at low throttle, the “sudden stoppage” is hard on propellers. Nicks and scratches on the blades are potential initiation points for cracks, as are contact points from thrust washers, propeller washers, or spinners if they touch the blades.
- Discard any propeller that is damaged or that has had a sudden stoppage, even if no damage is apparent to the eye. I knew of no damage history on the particular propeller I was using, and it still came apart. If you lose a propeller blade, there is nothing you can do but watch.
- For added safety, design models so that the bellcrank mount is tied to an engine mount; therefore, the engine will stay in the flight circle during an accident.
Tailhook placement
I received a letter from a Carrier modeler asking if there was a “best” place to put the tailhook on our models. His problem was a tail-heavy aircraft, and he wanted to try moving the hook forward to a point under the wing to help move the balance point forward.
There isn’t a single answer. As a general rule, the pivot point for the tailhook should be near the rear of the model. That location helps avoid potential problems of tipping the model’s tail up when it is arrested, but almost any location can be made to work as long as you are careful.
When a model’s tailhook catches the arresting line, physics is the dominating factor. The faster the model is moving on landing, the more powerful the forces acting on it. During the arrested landing, the model’s CG tries to continue moving forward, and the force of the arresting line acts on the tailhook in the opposite direction.
An often-ignored factor is the tendency for the hook end, the tailhook pivot point, and the model’s CG to form a straight line. You can see this straight line if you hang the model from the tailhook with no spring on the tailhook: the hook, the pivot point, and the CG will line up vertically.
What that means during the arrested landing is that a hook pivot that is lower on the fuselage than the CG will tend to rotate the model’s tail up to achieve the straight-line alignment. With the pivot nearer the rear of the fuselage, the tail-up angle to achieve that straight line is minimal. If the tailhook pivot is closer to the CG—e.g., under the trailing edge of the wing—the tail-up attitude to achieve the straight line can be quite pronounced. In the extreme, the model could be tipped up on its nose, reducing the landing score.
That's it for now. See you at the Nats! MA
Transcribed from original scans by AI. Minor OCR errors may remain.
