How to safely land 75% of an RC airplane
Dave Gee | [email protected]
The incident and initial reactions
A reader sent me an amazing video filmed during an RC aerobatics competition. The models were giant-scale replicas of modern aircraft, and the pilot was so spectacularly skilled that I felt like a complete doofus by comparison.
The crowd reactions were audible as he guided the airplane through incredible maneuvers—stunts no full-scale pilot could survive. I assumed the high-powered aerobatic model must be extremely strongly built to withstand such twists and turns. It wasn't.
A wing tore off in mid-roll. The model began to fall as the racing engine pulled it into a spin. The crowd gasped. The soundtrack captured a comment that a pilot this good might somehow save his aircraft. That point sparked a lengthy e-mail debate with my friend.
In the video the pilot proved his skill. The camera stayed on the airplane and it was clear he was trying to regain control. The other flying surfaces remained intact, the RC system was working, and he was able to stabilize the spinning aircraft into something approaching controlled flight.
The decision under pressure
Now came another debatable decision. Some would say the model should be guided far from the crowd and planted where it could do no harm. A few might suggest attempting the landing strip, which is much closer to the crowd. A damaged airplane that is not under full control shouldn't be flown toward people, right?
The video showed the pilot turning his model away from the crowd, getting it somewhat stabilized, and testing the controls to see what options he had. The crippled aircraft was descending rapidly, but at the last moment it flared and made an astounding three-point landing. The crowd went wild!
The model landed in a dirt area on the far side of the runway. I counted the steps of the guys who walked to the airplane and verified there was a great deal of distance between the onlookers and the spot the pilot had selected. That flier's quick thinking showed his judgment under pressure matched his flying skill. He handled each stage of the emergency in a way that ultimately allowed him to save his aircraft without endangering the audience.
Thoughts and preparedness
My correspondent and I watched the video several times. It's not fair to second-guess someone after the fact; we were seeing the event in leisurely slow motion and did not have to deal with the surprise and urgency.
I tend to handle a crisis with immediate panic. My friend thought it would have been best to crash the damaged airplane immediately and as far from people as possible. He softened a bit when we saw how far away the landing spot was, but the issue is a good one for discussion.
What would you do in such circumstances? It's useful to think these things through beforehand. In an emergency there is no time to ponder options. Perhaps a bench-flying session with friends would be the right time to hash it out.
Most of us will experience some type of in-flight emergency someday. Full-scale pilots practice and plan for everything possible to go wrong, so they already know what to do. If you talk about this at your club meeting, please let me know how it went and what points were made. My e-mail is in the column header and an address for paper letters is at the end.
Flying Under the Influence (FUI)
Another Internet discussion with readers raised questions about drinking and flying. Let's use the term "Flying Under the Influence," or FUI, since it covers alcohol, drugs (prescription and other), and any other substance that might impair a pilot's judgment.
The latest version of the AMA Safety Code reads, "I will not operate my model while under the influence of alcohol or while using any drug which could adversely affect my ability to safely control the model."
That sounds ironclad, but there has been debate about improving the wording and how to enforce it. Club leadership at the RC field are not law-enforcement officers or medical professionals and are therefore unqualified to determine who is "chemically impaired" and who is not. Airline pilots must abstain from alcohol for a set number of hours before flight. That is easier to enforce because it requires only a clock—not a blood test—though it seems less applicable to RC flying.
Many hobbyists have enjoyed a cool one in the pits after a flying session, but problems arise when the beverage (or whatever) was enjoyed before a flight. The social situation at some fields complicates matters: we're with pals who think like we do, and friends might look the other way as we all bend the rules together. Who is going to step forward and ruin the moment?
That's why the Safety Code exists—to provide impartial standards we can use instead of subjectively deciding that our buddy should get a pass because he's a great guy. I'm afraid this is one of those non-compromise issues. I think the Safety Code wording is proper and enforceable, and I endorse the concept of abstinence until after flying.
Why push the matter? Someone who insists they cannot enjoy a flying session without chemical enhancement before or during flight might have a deeper problem. After the airplanes and helicopters are safely landed (or in my case retrieved), we'll all sit down together for some beverages and storytelling. Make mine a root beer, please.
Bolt markings and fastener grades
Have you ever seen that chart in florists' shops that tells the meaning of various flowers? It gets specific. Those flower charts look simple compared to the markings found on the heads of hardened steel bolts.
There are several code systems worldwide, with markings to indicate material, hardness, strength, and manufacturer. You can use the Internet to track down the "grade" of a bolt you have or find what type you need for a particular use. Certain markings might indicate an extremely strong bolt, but sometimes they can be brittle or have other limitations.
The code is often marked as radial lines cast into the bolt head. Their arrangement has meaning, as do the numbers and letters you might see. Regular hardware-store bolts will likely have no markings because they are standard "Grade 2" fasteners. If a part came out of a box of assorted nuts and bolts from the dollar store, odds are you have a low-quality part.
This subject came up in an e-mail from an experienced modeler who had an engine test-stand failure. The rig was old, heavily built, and used for many years. One day the oversized bolts decided it was time to break, and they did.
We tend to be trusting of our old, reliable tools; their failure can be quite a shock, especially if it involves a screaming gas engine. Who would have thought to inspect those bolts for microscopic cracks?
I'm not smart enough to read the coding and tell the particular steel alloy of a bolt, what treatments it has had, or if it is Grade 2, 4, or 8. Nor can I calculate the proper part for a given usage. For this reason, I tend to overengineer things with a much stronger fitting than is needed. At least that way I hope the system will fail elsewhere before my bolt breaks. Still, the original story indicates it's not a bad idea to occasionally inspect our tools and equipment for problems.
One photo shows a few coded bolts I found in my workshop, along with a dollar-store cheapo pack of questionable-quality nuts and bolts. These have their uses, but not on anything that moves or flies. Our engine mounts deserve the best.
Photos and field incidents
Another picture shows Karl Gies launching his Lanzo Duplex, which won the Four-Ounce Wakefield event at the 2009 SAM Champs. This event took place in inhospitable conditions in the middle of the desert. Karl is no newcomer to FF (free flight) and is decked out in serious protective clothing for a long day in the sun. Nothing ruins a triumphant awards ceremony like a painful sunburn. Wonder if he brought that stylish straw pith helmet all the way from Missoula, Montana.
The last photo is an attention-grabber. Here in California we have a nearly year-round brushfire season, broken only by our two-week-long winter flood-and-mudslide season. Ted Davis witnessed the crash of a jet model into some dry grass and photographed the aftermath. The aircraft went in right after takeoff, so it had a full load of fuel, which ignited. Local modelers were unable to control the fire.
This field is located close to a big fire department helicopter base, so air support soon arrived to help the ground units. The burn area was small because of the rapid response, but it is a black eye for local RC fliers nonetheless.
Sources
Dave Gee Box 7081 Van Nuys, CA 91409
Transcribed from original scans by AI. Minor OCR errors may remain.
