Emergency Aborts

[Tom Luciano]

  I want to get out in front of this and take a proactive approach to something at least I have overlooked especially in high stress situations like our National championships.

  The incident at the nationals with the armed airplane in the pits was mine. I feel we all can learn from the events that happened that day.  First, I will explain exactly what went down and where we as a team failed and how we will proceed forward.
  Pitman and I arrived at the field at 6:20am to make sure we were first in line to get a practice flight. Prior to practice flights a group of us decided to pull test our airplanes for our officials. Pitman flew first so we could get him a needle in case we had to get him up again. I followed, lets realize that I haven’t been to my handle since the plane was pulled. I retrieved Pitman’s plane, placed it in the pits and grab mine while he did the same with the handles. Pitman takes a knee, ready, ready, arming plug in, switch on. Walk my line out safety thong on and look at my clips. There I see one strand of four strand lines dancing in the air. A few seconds to process and I yell to Pitman “SHUT IT DOWN, SHUT IT DOWN! Pitman didn’t hear me, repeat and he heard me. As he was reaching for the switch the plane started to spool up, Pitman was able to shut the switch off but was visibly a bit shaken, rightfully so. I assumed (always a mistake) Piman pulled the plug, however, he didn’t. We proceeded to the pits. At some point, possibly when he lifted the plane, he inadvertently put the switch back on. Putting the switch back on restarts the esc/timer and we have 30 seconds to spool up! We walked backed to the pits and Pitman places the plane down and within seconds it spools up. I was actually still at the handle investigating what happened to my line. The plane lunges forward and proceeds to start gobbling up Pitman’s plane. This could have been so much worse if. there was any delay getting back to the pits it would have spun up while pitman was carrying it. This would have ended with a trip to the ER and I’m sure multiple cuts to his hand, arms and face. Think about how we carry a stunt ship. Left hand on the prop, right hand either by fuselage belly or fuselage mounted gear.
  Pitman and I have been pitting for each other since I started flying electric in 2016. In those 6 years we have never had an abort such like that or any for that matter. Clearly, I’m the pilot and I take ownership of my plane and responsibility for it. I could have simply verified if the plane was disarmed by the arming plug. The issue here is we got totally taken out of our routine and it could have been devastating. This could happen to you!
 Moving forward it has made me think on our routine at home and especially on contest day when we always help each other out. Not different then glow guys going over a starting procedure especially when starting inverted. We need to use universal terminology. It could be something as showing the plug or yelling “off” like we do in R/C when turning of a receiver. Most importantly prior to anyone launching the pilot needs to point out where the activating/deactivating switch is and where the disarming plug is. Some of us try to make them inconspicuous.
  I have pitted for multiple top level flyers at the Nats and other contests, at no point did we ever go over a just in case scenario. I have picked up planes at the Nats not knowing or visibly seeing the arming plug.
We need to be prepared for the “Emergency Abort.”

Thanks,
Tom

[Motorman]

My wife and I practice normal operations and emergency situations all the time. She has knowledge of how the system works and what the controls will do/won't do and a strong awareness of where the arming plug is at all times. Also, we only have two hand signals, launch and shut it down.

Motorman

[CircuitFlyer]

Pehaps you should bring this incident up with your timer manufacturer.  This could have been prevented by better programming.  An aborted flight has to be taken seriously and should not allow a restart without cycling the power first. This forces you to take a second and start over from the beginning of your normal procedure. 

[Tom Luciano]

Hi Circuitflyer,
  I understand your concern and I will have a private conversation but, I bear the responsibility and will not publicly pass blame or criticize the manufacturer. This is the exact reason for the arming plug. We can't assume that any timer is completely shut down unless the power is cut off.
Tom

[Motorman]

I guess you were lucky he didn't hear you the first time. If you hit the switch before it spools up it does not stop the count down. At least not on the FM9.

[Brett Buck]

Hi Circuitflyer,
  I understand your concern and I will have a private conversation but, I bear the responsibility and will not publicly pass blame or criticize the manufacturer. This is the exact reason for the arming plug. We can't assume that any timer is completely shut down unless the power is cut off.
Tom

   Right - and it's even worse than just the timer. There are at least *dozens* of "states" stored in he controller that could either start the timer, start the motor at full power, stop it in flight, etc, if they glitch on or off. And there have been numerous cases where it did just that.

   These sorts of glitches are part of the inherent nature of low--level logic states  (i.e. stored "bits" in some sort of processor, computer chip, or other signal that has extremely high impedance and low voltages). That's essentially everything that is a logical circuit, rather than the high-power output section.

     These glitches cannot be avoided entirely, they will happen, and the more sophisticated the processor or circuit, the more of them there are and the more prone they are to it. You computer wouldn't run 10 minutes without a glitch, and if a single glitch stopped it, it would be completely unusable. In your computer there are methods to correct for these glitches in most of the places they occur - look up EDAC or "error correcting code" to find more.

    As noted, this phenomenon is inherent and essentially unavoidable, and this is the reason this rule is worded the way it is - remove primary power to the motor with a mechanical connector/plug, etc. It guarantees that it cannot spool up unexpectedly. there is no power to make it run, whether it's a glitch, inadvertent poke of the start switch, a failure of the circuit itself, etc

    It was pointed out during the awards ceremony that this was a classic case of "abnormal procedure", where something unplanned and unpracticed happened, and a step was skipped in the aftermath (i.e. plug remained in). But, like most accidents, it required a second failure before anything happened - also accidentally hitting the switch. The rule and idea behind it was to protect us from a single failure, This was actually two, and if you start looking at combinations of failures, it rapidly becomes impractical, so, this was a rare case of a dual nearly simultaneous failure that led to a serious issue.

   After having 36 hours watching the fine North American scenery rolling by to think about it, I think this is one of those cases of "random failure, no action required", and I can't think of anything reasonable in rules/guidelines to preclude this sort of situation.
 
   Brett

[Paul Taylor]

Tom
Thanks for sharing. This is something that I as a new electric pilot have not thought about.
Going to make sure my pitman knows how to disarm my junk. 👍🏼

[Tim Wescott]

<snip>

   After having 36 hours watching the fine North American scenery rolling by to think about it, I think this is one of those cases of "random failure, no action required", and I can't think of anything reasonable in rules/guidelines to preclude this sort of situation.
 
   Brett

I dunno -- officially, no I don't think any rulz action is required.

Unofficially, I think I'm going to start training myself to check that the thing is unplugged before I take my hands off of the plane.

[Peter in Fairfax, VA]

Tom,

Thanks for sharing this incident report.

Yes, as you suggest, hold the arming plug high in the air and show it to the pilot and, if during a contest flight, also show the officials.

Peter

[Ken Culbertson]

Tom,

Thanks for sharing this incident report.

Yes, as you suggest, hold the arming plug high in the air and show it to the pilot and, if during a contest flight, also show the officials.

Peter

This is our practice in practice!  One thing mentioned earlier about carrying a plane by it's prop.  DON'T do it with electric.  They look so sweet and innocent when just sitting there but that electric motor's real name is Chucky.

Ken

[Dwayne Donnelly]

When flying in a contest or even practicing with a helper, the helper holds the plane and the pilot should be the one to pull the plug and always remove it fully from the plane.

[Peter in Fairfax, VA]

> When flying in a contest or even practicing with a helper, the helper holds the plane and the pilot should be the one to pull the plug and always remove it fully from the plane.

Hmm.  Not sure that is local contest practice.  Our practice is the pilot must have the handle held until the pit man disarms.

[EricV]

I don't fly electric but I've partnered with pilots flying electric plenty. So, I have a thought.

Old sayings are still said for a reason... core value. Out of sight out of mind is one that comes to mind here.

Arming plugs are tiny things we shove in our pocket. What if we standardized on an arming plug lanyard with a female side of the plug on the end that we all wear around our necks in plain sight?  Even your flying partner can look at you and say hey, where is your plug?, when he sees it vacant from your lanyard. You can reach for it and feel its not there yourself, and if you're OCD you can check over and over, heh. Plus it keeps you from loosing it constantly, which is also something ive noticed. If your flying partner retrieves your plane, either he or you wear the lanyard by prearranged agreement, and stick with it. At a contest I would suggest the pilot assume responsibility for the plug, as the onus of safety is more on him.

Just a thought.
EricV

[Dwayne Donnelly]

> When flying in a contest or even practicing with a helper, the helper holds the plane and the pilot should be the one to pull the plug and always remove it fully from the plane.

Hmm.  Not sure that is local contest practice.  Our practice is the pilot must have the handle held until the pit man disarms.

If the pitman has full control of the model would it not be the same as a pitman holding a running glow plane while the pilot walks to the handle? As long as the pitman is holding the plane I don't see why the pilot can't walk in and pull the plug. If that's the rule at the Nats then perhaps it needs to be revisited. It would eliminate things like this from happening. Imho. 

[Ken Culbertson]

If the pitman has full control of the model would it not be the same as a pitman holding a running glow plane while the pilot walks to the handle? As long as the pitman is holding the plane I don't see why the pilot can't walk in and pull the plug. If that's the rule at the Nats then perhaps it needs to be revisited. It would eliminate things like this from happening. Imho. 

Takes too much time in a crowded environment.  We routinely have 5-6 flyers in a session.  If everything goes perfectly you get a flight every 45 minutes or so. We land as close to the pits as possible, next up or a helper takes your plane to it's parking space with you at the handle.  You set your handle down and pick up his handle (in my case usually after a reminder ) then move him onto the circle.

There is nothing wrong with the rules or the procedures we use now as long as you do it.  I will admit, after 60 years of "fly and forget" IC it took me a while to remember the plug.  The biggest problem for me comes just after putting in the battery I normally arm the plane to make sure everything is working then hit the kill switch and pull the plug.  That is my place for most likely forgetting the plug.  Our IC diehards are as up on E-safety as we are so if someone forgets the plug, we get a reminder.  Our biggest safety problem is slipping on their pipe puddles!     

ken

[john e. holliday]

Electric flying does have its problems.  But, in my years of flying and competing I have seen Glow plug engines start with out a battery attached.  Especially in hot weather.  Seen guys just barely hanging on to a plane and flip the prop just to feel compression and have the engine go.  So safety should be foremost in all of our flying.  Glad no one got hurt except for their pride.

[Bob Hunt]

I don't fly electric but I've partnered with pilots flying electric plenty. So, I have a thought.

Old sayings are still said for a reason... core value. Out of sight out of mind is one that comes to mind here.

Arming plugs are tiny things we shove in our pocket. What if we standardized on an arming plug lanyard with a female side of the plug on the end that we all wear around our necks in plain sight?  Even your flying partner can look at you and say hey, where is your plug?, when he sees it vacant from your lanyard. You can reach for it and feel its not there yourself, and if you're OCD you can check over and over, heh. Plus it keeps you from loosing it constantly, which is also something ive noticed. If your flying partner retrieves your plane, either he or you wear the lanyard by prearranged agreement, and stick with it. At a contest I would suggest the pilot assume responsibility for the plug, as the onus of safety is more on him.

Just a thought.
EricV

Wow! Electric flier bling jewelry! 

Bob Hunt

[Scott Richlen]

Hanging things around our necks is not a good idea.  Say you have your stopwatch on a cord around your neck, start your engine and then lean forward to adjust the needle valve (or for some other purpose.)  If the prop catches that cord, mayhem will ensue...

[Bob Hunt]

Hi Scott:

I agree that hanging anything around your neck at the field is probably not a good thing, but an electric flier inserts the arming plug, hits the start button and is then anywhere from 60 to 70 feet from the model when it starts. Conversely, many, many fliers have made trips to the hospital after having a propeller attached to a glow engine do massive damage to their hands after they have started the engine. The issue here is total safety awareness whenever we are at the flying field, or in our shops, in all regards. Its not about electric system safety, or glow starting procedure safety, or awareness of where we are walking in respect to the edge of the circle, or the integrity of the control system by virtue of a pull test (and how many contests have you gone to recently where the pull test is not given, or a lower than rule required pull test is administered?), or any other single issue. As we spend more and more years in this pastime, we also naturally become complacent (or forgetful) about a lot of things; safety is one of them. Perhaps it is time for a cold hard look at all our practices in regard to safety. It's not about electric safety; it's not about glow safety; it's not about circle awareness safety; it's about all aspects of safety when we are engaging in our beloved hobby/sport. There are many inherent dangers with all model airplanes. If there wasn't, we wouldn't have the need for insurance... 

Tom's Nats accident was just that - an accident. I understand that a couple of fliers got injured by sticking their hands into spinning props - also accidents. No one intentionally does something that causes an accident; but accidents still happen. Finger pointing has begun. We should be pointing the finger at ourselves.

Bob Hunt   

[Scott Richlen]

Bob:

I was actually thinking of the i.c. guys who hang their stopwatch around their neck  But as you say, we tend to become complacent - familiarity breeds contempt - but contempt in the form of laxity and not respecting just how powerful our little power systems have become.

Here's an interesting thing for me: every time I hold one of my flying buddies electric planes for launch I am always impressed by the power output.  I don't necessariy think the electric systems are more powerful than i.c. but because they don't generate the noise of i.c. there is a dissonance of expectation.  Because of this, I am always very careful in handling an electric powered plane (and where that prop is in relation to any part of my body) - there is no noise to warn me of danger.  It doesn't seem make a lot of logical sense, but it is true for me.

[Ken Culbertson]

Scott:

I had the same experience when I switched.  I had always thought of them as toys and since all of the electric types around here, including me, use unassisted takeoff I had never felt the brute force that these tiny motors put out till I bench ran my first.  Lucky that I survived!  What is even more fantastic is that we run them at well below their potential maximum power.  A Cobra 3520/12 for example is *capable* of putting out over 8lbs of thrust on a 5s battery.  We don't use anywhere near that.  Can you match that with an IC?  Probably but how big and how heavy would it be.  Still, within the envelope we fly in the power issue is moot.  Both produce more than we can use.  I just think that IC is messy and full perplexing problems.  Perhaps that is why I miss it but would never go back.

Ken

[Brett Buck]

Here's an interesting thing for me: every time I hold one of my flying buddies electric planes for launch I am always impressed by the power output.  I don't necessariy think the electric systems are more powerful than i.c. but because they don't generate the noise of i.c. there is a dissonance of expectation.

   The other issue is that it is spinning much faster than an IC engine would with the same prop, maybe 800 rpm faster, since it doesn't unload to any great degree. That's about 25% more power on hte ground.

     Brett

     

[Ken Culbertson]

That's about 25% more power on the ground.

     Brett

   

One of the main reasons I went to unassisted takeoff's and a slow spin up.  At full power is like releasing the pinch on a balloon full of air.  The plane wants to leap off of the ground.  Some folks like that, not me!

Ken

[Tom Luciano]

As I read through this and as Brett initially said. We don't need any changes in rules etc. I will say I wanted to create awareness and promote diligence. For my own benefit as I handle someone elses plane,  I'll have that 20 second conversation as pilot or pitman. Where is the arming plug ,where is the switch, and how I want to abort a flight. My case I  would prefer to shut the switch off wait the 4 seconds for the system to shutdown. Trying to pull the arming plug at full song might be a little dangerous. It can be done but a deans type doesnt come out that easy.
Tom

[Bruce Shipp]

On the airliner flight deck we practice VVM, verbalize verify and monitor. Anytime a switch position is changed the pilot making the change verbalizes it, the other pilot verifies it, then the change is made and both pilots monitor.

This arming switch accident is very similar to full-size aircraft pilots forgetting to turn the magneto/ignition switch off after flight. The common practice in maintenance shops and airshow flight lines is for another mechanic or the ground crew to confirm that the magnetos/ignition are turned off prior to the pilot leaving the cockpit. The consequences are quite similar.  An airplane engine with hot magnetos can start with the slightest movement of the propeller.

It would be appropriate if we began the practice of verbalizing and verifying that the arming switch has been pulled after a flight. This can be pilot to pit man, pit man to pilot, and also other people in the pits when an airplane  is brought back to the pits.

No offense is meant by asking and no offense should be taken by being asked. Just another layer of safety which is easy and painless to implement.

[Steve Helmick]

In case I missed it, where was the arming plug mounted? Some guys are mounting them in the belly of the plane, which I think is a mistake from a safety standpoint. It should be visible at a glance, IMO. This makes it easier to deal with for a launcher/retreiver that isn't familiar with every airplane on the field.

I have also seen a few instances of fliers looking for their arming plug when getting ready for their next flight. It was usually in the right front pants pocket of the last guy that retreived their model for them. A lanyard attaching the arming plug to the model makes much sense to me.    Steve

[Ken Culbertson]

On the airliner flight deck we practice VVM, verbalize verify and monitor. Anytime a switch position is changed the pilot making the change verbalizes it, the other pilot verifies it, then the change is made and both pilots monitor.

This arming switch accident is very similar to full-size aircraft pilots forgetting to turn the magneto/ignition switch off after flight. The common practice in maintenance shops and airshow flight lines is for another mechanic or the ground crew to confirm that the magnetos/ignition are turned off prior to the pilot leaving the cockpit. The consequences are quite similar.  An airplane engine with hot magnetos can start with the slightest movement of the propeller.

It would be appropriate if we began the practice of verbalizing and verifying that the arming switch has been pulled after a flight. This can be pilot to pit man, pit man to pilot, and also other people in the pits when an airplane  is brought back to the pits.

No offense is meant by asking and no offense should be taken by being asked. Just another layer of safety which is easy and painless to implement.

This may be a good idea.  We sort of do that now but not enough to call it a procedure.  It makes sense at a contest, but I would be more inclined to let the CD decide how to go about it.  I don't think we need a rule change, but I have no clue how you would enforce it without one. 

Ken
     
Let me respond to Steve so I don't have to do a new post:  The nose of a typical electric is a pretty crowded place.  On most of my planes the Arming Switch ended up where it fit.  Most of the time it was in plain sight.  There is only one place it can go in the wiring, and it has to still allow the ESC to be removed.  That means a plug, two bullets some wire and solder none of which bends very well.  One of our local fliers uses two bullets and a wire connecting them.  This way only one has to be pulled and the other stays with the plane. 
                                                                                                                                                                             

[Bruce Shipp]

This may be a good idea.  We sort of do that now but not enough to call it a procedure.  It makes sense at a contest, but I would be more inclined to let the CD decide how to go about it.  I don't think we need a rule change, but I have no clue how you would enforce it without one. 

Ken
     
                                                                                                                                                                             

No rule change required an not a procedure  that needs to be “enforced”. Simply another tool our community can use to check each other’s “six”.

I’ve been asked countless times if my mags are off, never been offended or annoyed, and they have still been on more often than I care to admit. 

Let’s work together to have each other’s backs.

[Brett Buck]

No rule change required an not a procedure  that needs to be “enforced”. Simply another tool our community can use to check each other’s “six”.

I’ve been asked countless times if my mags are off, never been offended or annoyed, and they have still been on more often than I care to admit. 

Let’s work together to have each other’s backs.

  Exactly, not everything needs a rule. This was a classic "dual simultaneous failure" where two independent failures happened to combine. There's generally nothing to be done about these, and the incidence is low enough that it is safe enough.

  Brett

[Tom Luciano]

Bruce,
  Excellent comment. We where in Philadelphia yesterday and did exactly that. Verbally communicating the arming plug is out. This is our best practice principle.

Steve,
The inboard side of my ship

[Steve Helmick]

Bruce,
  Excellent comment. We where in Philadelphia yesterday and did exactly that. Verbally communicating the arming plug is out. This is our best practice principle.

Steve,
The inboard side of my ship

Wow, that's on the pit man, IMO. Cannot make it much more obvious. Of course, the flier should also have checked that immediately upon arriving in the pits. Don't rely on the other guy...."trust but verify" is always good SOP.  Steve

[Bruce Shipp]

Wow, that's on the pit man, IMO. Cannot make it much more obvious. Of course, the flier should also have checked that immediately upon arriving in the pits. Don't rely on the other guy...."trust but verify" is always good SOP.  Steve

No Steve, it is definitely not on the pit man.  It is on everyone.  It is on anyone.

The motor quits and the pilot lands.

The “pit man” walks out to the airplane to carry the plane back to the pits. As he bends to pick it up, the pilot says “please remove the arming plug.”  The pit man removes the plug, shows it to the pilot and an unarmed plane is returned to the pits.

Or:  the pitman reaches to pick up the plane, but first removes the arming plug.  He holds it up to show the pilot and says “you’re plane is safe, the arming plug is removed”.  The pilot says thanks and a unarmed plane is returned to the pits. 

Or: after one of countless distractions occur during the post flight procedures and neither of the above scenarios occur, the plane is returned to the pits. Another pilot is in front of the space where the pit man is about to set the plane. He looks at the nose and does not see a cylinder, carb, muffler or pipe.

“Is that plane electric?”

“Yes”

“Has the arming plug been removed?” Two possible response here.

“No”. Pit man removes the plug. “Thanks for asking.”

Or the preferred and most common response “yes, I safed the motor before we returned to the pits. Thanks for asking.”

In a perfect world, the first scenario where the pilot directs the pit man to remove the arming plug happens every time.  But, we do not live in a perfect world.  Distractions happen.  The pilot finds a broken line before launch. Your launcher gets called to fly on the other circle and a complete stranger walks out to carry your plane to the pits. A part falls off your airplane during landing and confusion ensues (this happened to me at my first NATS..also my first contest). In these scenarios there are least two, likely three and often countless people who can simply ask, “is your arming plug removed?” 

This is on no one. It is on every one.  It is on any one.

[Teodorico Terry]

I also happen to fly R/C pattern and the helper will generally walk up to the plane to retrieve it after landing, pull the arming plug off and hold his arm up for a second or two; this lets the pilot know that the plug has been pulled. When getting ready for take off, the helper will also raise his arm to let the pilot know that the plane is armed.  This is not something that is written anywhere but the group that I normally fly with do this by default which I think is good practice.

A few months ago I made an accidental discovery regarding Castle controllers which I think is useful.  When setting up the over current protection I generally set it to sensitive (60A on a 50A ESC) or very sensitive (50A on a 50A ESC) with a hard cut-off. The hard cut-off is important as it will shutdown the ESC if the current limit is exceeded and it will not reset itself until the throttle signal is cut and started up again. In essence, it will ignore the throttle signal from the timer if the time has not run out.  I had a prop strike in the spring due to the ground being a little too soft and mushy and the motor stopped without damaging anything and it stayed that way giving me time to walk up to the plane, disarm it, and check it out.  I always use a stooge to make sure that the plane is released when I want to and not before and I also use a relatively slow spool up to make the take off more gradual.  Since I fly from grass, I also plant a stake near the center of the circle which allows me to tie the handle's safety tong to it when not flying.  If the plane happens to get away from me by accident, once the lines become tight the handle will give down elevator keeping the model from becoming airborne.  Even with my glow planes I used to do this. The stake also keeps the handle and lines off the ground when I am walking the plane back to the starting point after a flight.

Teo

[Dennis Adamisin]

My starting procedure is different than most folks and is in part focused  around finding & avoiding the consequence of the kind of failure that Tom encountered.

In a nutshell, my flying buddy (Wesley Dick) and I use a procedure by which the Mechanic presses the START button but only after being directed to do so by the Pilot.  In a normal flight (practice or official) we wait until the launcher is in position, then the pilot plugs in the arming plug.  As part of the last step of the pre-flight inspection (applies to glow or electric) the pilot examines his line clips at the leadout end (clips secure, not turned over, etc.) then walks out the lines.  At the handle end he makes sure the lines are unwound, examines the clips at that end and if all is well assumes his position for take-off.  Only then does the Pilot shout "CONTACT".  The mechanic presses the start button (zero delay needed) and launch proceeds.  Key thing is that the final starting procedure does not proceed until the pilot is ready to fly.

If there is a problem the pilot does not assume his take-off position and waves off, shouts or in some other way alerts the mechanic to stop.  The mechanic first gets the visual cue that the pilot is NOT ready to fly body position and that (plus the pilot shouting/waving) alerts the mechanic to disarm the system - pilot witnesses/if needed shouts out for verbal confirmation.  I will also point out that Wes & I are both very hard of hearing and may not fully understand wordy directions from 60+ feet away, yet we do not have any problem communicating a GO/NO-GO situation.  Trust me on this, when working with near deaf folks like us, any verbal communication should be simple unambiguous 1-word instructions.  The universal "throat slashing" motion is a pretty clear cut-off signal too!

In Tom's case his airplane was armed, and the 30 second (?) starting countdown was in progress.  When he discovered his issue with the lines he and his mechanic were literally "against the clock" - something that should always be avoided when possible.  I surmise (perhaps incorrectly) that if the START sequence had never been activated in the first place then the accidental unintended re-start also might not have happened?


BTW, as an aside, I use a simple plug style arming device, mounted in a visible location, usually o/b side just above the leading edge. It is easy to see and ANYONE can disarm if/when needed.  If flying with a new mechanic I also make sure they know where the plug is.  I'm not fast enough to be the ONLY one who can run out & disarm my airplane in case of a crisis!

[Tom Luciano]

Dennis,
  Really great response and some great practices. It may be an approach I might take. Rather then a 30 second delay make it a 7 second delay using the on /off switch.

Edit;
  On second thought there is a caveat. This would require me to adjust delay times between  practice and contest day. If I forget to put my delay back to 30 seconds on practice day it would result in a lost airplane. I spike my thong in the ground when flying alone.

Tom

[Dennis Adamisin]

Exactly correct, won’t help you when you fly alone.  However if the delay is zero then you get immediate feedback and shutdown & reset the delay. If the delay is set long and you have a helper present then at worst you apologize for wasting those 30 seconds of his time.  I did this once on the practice field this year.

Given that MOST of the time I am lucky enough to practice with a helper that has not been much of an issue for me.  However, my helper is 90 and showing signs of slowing down - I see more solo practice sessions in my future…

[Teodorico Terry]

Question - I fly using the relatively simple timers available through Brodak and as part of their start-up they will slowly spin the prop for a couple of revs after the button is pushed. After that the motor will not spin until the delay time has gone by.  At the end of the flight and after the motor stops the timer becomes inactive; you can push the button as many times as you would like and nothing will happen.  To reset, you have to unplug the battery and plug it back in.  If you decide to abort the flight pushing the button will stop the motor and the timer will become inactive.  The only way to reset the timer is to unplug and plug the battery.  Seems like a sensible design. Pushing a button seems simpler than pulling an arming plug as well.  Do the other timers work differently?

Teo

I only use the timer to provide a throttle signal; I use Castle ESC's to actually set the RPM, start-up, etc.

[Ken Culbertson]

Question - I fly using the relatively simple timers available through Brodak and as part of their start-up they will slowly spin the prop for a couple of revs after the button is pushed. After that the motor will not spin until the delay time has gone by.  At the end of the flight and after the motor stops the timer becomes inactive; you can push the button as many times as you would like and nothing will happen.  To reset, you have to unplug the battery and plug it back in.  If you decide to abort the flight pushing the button will stop the motor and the timer will become inactive.  The only way to reset the timer is to unplug and plug the battery.  Seems like a sensible design. Pushing a button seems simpler than pulling an arming plug as well.  Do the other timers work differently?

Teo

I only use the timer to provide a throttle signal; I use Castle ESC's to actually set the RPM, start-up, etc.

They are quite nice but hitting the start button to stop the timer does not accomplish the complete disconnect from the power source.  Timers fail, not very often, but they do.

Ken

[Steve Helmick]

The closest I've come to an "emergency abort" was when launching Bruce Hunt's new (and first electric) Skylark. The motor hit WFO almost instantly and torqued itself free from the nose of the plane. Motor GONE. It shutdown all on its own when the wiring came loose. I casually reached forward, pushed the red button and pulled the arming plug. These things put out buckets of instant torque, if you let them.    Steve

[Ken Culbertson]

The closest I've come to an "emergency abort" was when launching Bruce Hunt's new (and first electric) Skylark. The motor hit WFO almost instantly and torqued itself free from the nose of the plane. Motor GONE. It shutdown all on its own when the wiring came loose. I casually reached forward, pushed the red button and pulled the arming plug. These things put out buckets of instant torque, if you let them.    Steve

Been there, Done That!  I liked the new nose better.
I learned that lesson early.  You need a slow ramp-up.  Mine doesn't reach flight RPM till about a quarter lap.

Ken