This is just to educate our beginner modelers about the very real dangers associated with electric RC aircraft. (thank you to whomever stickied it!!)

Without making things here too graphic or naming names, a fellow club member I fly with on the weekends had to go to the hospital today with very deep and serious lacerations to his left forearm from just a simple mistake. Just casually putting his still powered up model onto the workbench and began chatting with another club member when he switched his transmitter off with the airplane still powered up.

Now, I do not know if his receiver even has failsafe capabilities in it (it's an inexpensive chinese receiver being guided by a Futaba FASST 7C transmitter) but the moment he switched the transmitter off the motor sprang to life and went right into his arm, cutting him up very badly (I have not spoken to him but I am certain there will be a lot of stitching needed- very messy even with a few gauze pads still, lots of blood to cleanup (thankfully some of us have walked a similar path before so we were well prepared for the inevitable)). Somehow the propeller and hub assembly popped off of the spinning motor and rendered the airplane harmless at this point so I could grab it and unplug the battery. 47 stitches to seal the wounds up.

The airplane in particular was an E-flite Carbon-Z Yak 54 3X PNP, so it had some power in it. A common airplane around most clubs (for the curious minds, the airplane was undamaged).

These electric airplanes might seem harmless enough, especially as you become more and more accustomed to being around them, but make absolutely no mistake- they can be VERY dangerous and cause SERIOUS injury with just a simple and unconscious decision like switching the transmitter off accidentally during a conversation. It only takes one second for a propeller to slice you up and cut through a major artery- these thin electric propellers are like razor blades at the tips (I've actually used a propeller as a knife on the occasion). As such, I thought it would be a good idea to make a post about the SAFE way to handle your airplane. These are some simple steps to follow that will help keep you safe.

• ALWAYS POWER YOUR TRANSMITTER ON FIRST, OFF LAST!
  
• Utilize a THROTTLE LOCK on your transmitter- most modern radio systems will be capable of doing this one way or another. Get into the habit of turning it on before you power up your model to keep you from bumping the throttle stick.
  
• Whenever the power system is LIVE, always keep well clear of the propeller. These thin electric propellers will cut through you like a hot knife through butter, even smaller power systems.
  
• Keep everybody else clear of the propeller while the power system is powered up, even while it is arming. Do not stand in front of the model without the model being restrained.

And for those who do fly in a club setting, you should already have some basic safety rules established so consult your club safety officer(s) for specific details. I have a feeling that my clubs rules may be altered slightly to ensure a safer environment for electrics.

Whenever working on your model on the workbench:

• ALWAYS DISCONNECT POWER FROM YOUR POWER SYSTEM FIRST! Ensure that no matter what it will not power up on you.
• Always remove the propeller! If the motor spools up for some reason, no harm no foul without the prop on. Alternatively, you can disconnect the motor from the ESC.
• Never remove or install a propeller on a powered up model with the motor plugged in. Remove all power or disconnect the motor.
• Whenever bench testing a power system, ensure bystanders are well clear of the propeller, and ensure the model is sufficiently restrained- always stand behind the prop!

Please, please do get into the habit of SAFELY handling your electric aircraft! It is much more enjoyable doing so and will benefit you in the long run. Do pass this information along to your fellow modelers, an educated modeler is a safe modeler.

And as always, if you have any suggestions to add, please do post them. If you have any questions whatsoever, do feel free to ask them. The only stupid question is the one you haven't asked

Lets keep this thread relatively clean, no graphic images with bodily fluids!

As an addendum, I would suggest taking a basic first aid class. Basic first aid is very simple and easy to do and it's a very important and vital skill to have. Especially for those of us who fly in a club setting and may have that one modeler who you're always questioning (we all know who they are, so lets not talk about it ). And having some supplies with you doesn't hurt either- I have a 2'x2' gauze pad and some gauze wrap tucked inside of my electric flight box out of the way, and at the ready in the event of a mishap. Maybe even have an instructor teach a basic first aid class at your clubs next meeting so everybody is up to speed.

Having a first aid kit at your club would also be a good idea as well. My club has a kit that we have bolted to our shed just for the inevitable. It's inside of a sturdy electrical box that's sealed around the edges for protection against the elements. It's always a good idea to have one around.

Apart from assigning, and using, a throttle cut switch, the modeller should be sure that the fail-safe has been set correctly. With Futaba FASST sets the throttle fail-safe is whatever position the transmitter throttle stick is at at the time of binding.

Unfortunately, with Futaba sets the throttle needs to be reversed for all ESCs that I know of, so when a new receiver is bound to a transmitter with a new model memory selected, chances are the throttle won't have been reversed yet, so chances are the throttle fail-safe will be set, by default, to full throttle So, after binding the receiver, and reversing the throttle channel, you then need to go back and re-bind the receiver with the throttle stick at zero.

Good post Express, we can all benefit from a good safety reminder on occasion. One second of not following the rules can really ruin your day!

Hi Xpress
A great article and a good alert. I believe most people believe that electric planes are safer than engine drive planes. In many ways, just the opposite is true. Another good safety measure is to always remove the propeller prior to connecting the battery, if you are "checking things", or adjusting controls.

Originally Posted by villapilote

Hi Xpress
A great article and a good alert. I believe most people believe that electric planes are safer than engine drive planes. In many ways, just the opposite is true.

I concur. Fuel powered engines are a lot more predictable with they aren't running

Another good safety measure is to always remove the propeller prior to connecting the battery, if you are "checking things", or adjusting controls.

I've updated the list to include workbench testing

All true, you need to be aware of what can happen. And even so, we are human, and we will screw up on occasion. Sometimes it gives a heck of a scare, sometimes it can get real ugly.
And for those that get to experience such, it usually makes one heck of a reminder, be it mental or physical.

As an example, I always walk around my truck before I leave, old habit of looking for something amiss. Had I not this morning I wouldn't have seen the nail in the right rear tire.
Got it fixed, but what could have happened if I had not seen it. Maybe I'd have had to have changed to the spare and bought a new tire or worse it could have left go at 70 mph.

Originally Posted by Xpress..

Always remove the propeller! If the motor spools up for some reason, no harm no foul without the prop on. Alternatively, you can disconnect the motor from the ESC.

This reminds me of an old post...

Sometimes you don't even know that you are about to make an EPIC mistake. That is why it is crucial to remove those props before doing major adjustments.

A couple years ago, I put a new receiver in a twin engine plane. I was ready to bind the plane to the receiver. This is the one time where your're SUPPOSED to connect the battery before turning on the Tx.

Unknown to me, I put the bind plug where the throttle goes and the throttle plug where the bind plug goes!

Beep, Beep, WHIRRRRRRRR! The two motors screamed to life and one of the props hit my finger which started bleeding a moment later. I held onto the fuse in sheer panic with one hand while my other hand went for the Tx. NOTHING HAPPENED! I had no control over the throttle! Did I mention that I was doing this on the kitchen table? Well, I had a tiger by the tail and no way to stop it. It went on this way for several minutes as I contemplated my options. I was only trying to bind the reciever, so the battery pack was not mounted inside the fuse. No, it was dangling by its wires outside the fuse, right between those two spinning props! I carefully (???) managed to grab the battery pack and give a yank. Fortunately, the EC3 connectors separated and beast was tamed.

I must admit that I too am a victim of carelessness around electric aircraft. I was setting up a Phase 3 Fidget biplane that used a 2s power system and a 9x4.7SF propeller. During my initial setup I accidentally bumped the throttle on my transmitter which let the airplane go right into my hand. Thankfully, it wasn't more than 1/4 throttle and my hand stopped the motor pretty quickly but the damage was done. A nice section of skin was separated from my right hand at the base of my thumb.

That was the only time I've ever been injured in the workshop. Another time I was attempting to catch a 3D biplane (no landing gear, hover landing) when a small gust of wind popped out of nowhere and blew the plant back at me, giving me a small slice in my hand. That may have been avoidable but since then I've never been hit like that again.

All it takes is one time (okay, maybe 2-3 times for others) to realize just how dangerous these can really be. They're still toys (in the sense that a motorcycle or a jet ski is a toy), but that doesn't mean you shouldn't exercise safety precautions.

Originally Posted by Xpress..

I must admit that I too am a victim of carelessness around electric aircraft. I was setting up a Phase 3 Fidget biplane that used a 2s power system and a 9x4.7SF propeller. During my initial setup I accidentally bumped the throttle on my transmitter which let the airplane go right into my hand. That was the only time I've ever been injured in the workshop.

You mean you never enjoyed a self-inflicted cut with an X-acto blade? Hard to believe. Personally I never try to set up an electric plane without removing the prop. I just won't do it.

TP

Originally Posted by Tepid Pilot

You mean you never enjoyed a self-inflicted cut with an X-acto blade? Hard to believe. Personally I never try to set up an electric plane without removing the prop. I just won't do it.

TP

Well, injured by an airplanes power system. I have been on the receiving end of my own hobby knife and drill bits more than one occasion

I personally only setup electric aircraft without the prop installed now- that's the last step.

holy crow! i hope your friend gets better soon. please be safe

Originally Posted by PeteLev

holy crow! i hope your friend gets better soon. please be safe

I spoke to his son today, he's sore but doing just fine. I think he'll recover just fine

I've seen a guy with his plane on a work stand activate the retracts for a test, and one of the gear pushed the throttle stick up. He caught the plane before it left the table but the wood flew from the table as the prop bit into it and the plane was damaged in the melee. No one hurt fortunately.

Also heard a story at our field a couple of years ago from a young man who had an incident, when I asked about all the bandages on his hand, forearm, and leg. Seems he flew one plane and when he was done, set it on a table and turned off his tx. (Didn't unplug battery. ) He went to fly another plane later and was kneeling over it when he turned his tx on to change models. The plane on the table came alive and was headed for his face. He blocked it with his arm and after a few slices the prop stopped, stuck in his arm, so he started shaking his arm to get it off. It came off, the prop started up again and did a number on his leg. I don't know how he finally stopped it.

Every little detail counts. Be careful out there and think of what you're doing every step of the way.

Originally Posted by xmech2k

I've seen a guy with his plane on a work stand activate the retracts for a test, and one of the gear pushed the throttle stick up. He caught the plane before it left the table but the wood flew from the table as the prop bit into it and the plane was damaged in the melee. No one hurt fortunately.

Also heard a story at our field a couple of years ago from a young man who had an incident, when I asked about all the bandages on his hand, forearm, and leg. Seems he flew one plane and when he was done, set it on a table and turned off his tx. (Didn't unplug battery. ) He went to fly another plane later and was kneeling over it when he turned his tx on to change models. The plane on the table came alive and was headed for his face. He blocked it with his arm and after a few slices the prop stopped, stuck in his arm, so he started shaking his arm to get it off. It came off, the prop started up again and did a number on his leg. I don't know how he finally stopped it.

Every little detail counts. Be careful out there and think of what you're doing every step of the way.

Yikes!!

This is why it's always a good idea to form good habits. The first thing I do when I land is I lock the throttle in the idle position and then unplug the battery. I don't even think about it, it's just so habitual that I instinctively know to do it right away.

This is why it's wrong to think of these as toys!

The image toys conjures doesn't include something with the potential to maim or kill.

I treat all my planes like I'd treat any gun, as if were always loaded.