Jump to content

Complacency, does it ever creep up on you?


Wiltshire Flyer
 Share

Recommended Posts

Posted by Biggles' Elder Brother - Moderator on 26/10/2014 17:21:3

Moral of the story? Never, ever, work on an electric model in the workshop with the prop on. That's why we always preach this. A moment's lack of thought - a secondary effect you haven't thought of - and wham, you suddenly have a big, potentially very serious, problem on your hands.

BEB

Means I'm not alone...thanks BEB

Futabaman Jo

Link to comment
Share on other sites

Have you ever thought about whether your model restraining system would work if the engine started backwards? I was running up a four stroke in the yard at home with a loop around the tailplane and a peg in the ground, with a couple of feet of line. It started backwards (using an electric starter) and ran back until the line came tight, luckily without any mayhem. However it was a very sobering moment. A four-stroke of course does not tend to run very long backwards, but could run long enough to cause problems.Two strokes will run much longer.

Meanwhile the restraints provided at our club only stop the model coming forwards....

John

Link to comment
Share on other sites

My 'workshop' was a spare upstairs bedroom a few years ago. I was busy soldering bullet connectors onto some new NiCd battery packs, putting two of the finished packs safely on the other bench behind me, out of harms way. My six year old daughter appeared and happily enquired 'What are you doing Daddy?' I showed her the batteries and the plugs and how they were soldered on. She seemed happy enough with the explanation but soon wandered off, as let's face it, soldering isn't very exciting! I had been aware that she had been quietly engrossed with something behind me before she skipped away down the hall but I was too engrossed in my soldering to bother. Shortly, I was aware of a pungent burning smell - electrical! I scanned my work bench thinking I had inadvertently melted something plastic with the hot iron. I switched the iron off but the smell was definitely getting stronger. There was smoke now. I whipped around on my swivel chair to see the two battery packs were erupting, billowing poisonous smoke from the split casings into the room. I grabbed the pair of pliers on my bench and hurled the red hot packs out of the window onto the gravel drive below.

Evidently my little daughter was impressed with how neatly the pretty gold connectors fitted together, before innocently leaving the room, unaware of the mayhem that ensued!

The moral of the story is that workshops are full of potentially dangerous things, so make sure that young children are properly supervised and that they don't have access if you are not there. My fault of course, but I learnt from this experience!

 

Edited By Piers Bowlan on 28/10/2014 07:40:52

Link to comment
Share on other sites

Posted by Peter Jenkins on 26/10/2014 18:40:05:

The key thing is to learn from these errors and not to repeat them. Repeating them is really very stupid!

Indeed, while it would be far better to be able to learn from other people's errors, sometimes you need to make the error yourself in order for it to be totally appreciated. I've done the whole Futaba throttle reversed thing, as I suspect have many many others, and although I knew beforehand that I should restrain the model, and I should take off the prop, and that I should reverse the channel, that knowledge isn't the same as fully appreciating. I think the fear factor: the several seconds of terror are probably required, in order to fully get the message home. I hear: I forget. I see: I remember. I do: I understand!

I'm not advising people to ignore advice and deliberately set out to make their own mistakes, it's just an observation on the way the mind works.

Edited By The Wright Stuff on 28/10/2014 08:46:02

Link to comment
Share on other sites

Posted by John Olsen 1 on 28/10/2014 05:45:30:

Have you ever thought about whether your model restraining system would work if the engine started backwards? A four-stroke of course does not tend to run very long backwards, but could run long enough to cause problems.Two strokes will run much longer.

John

LMAO! You just reminded me of a time many years ago, when I was riding an old Greeves trials bike. I rode up to the tip of a knife edge before a sort of crater in an old chalk pit. my intention was always to pause at the top. I didn't pull the clutch lever in as quickly as I should, but the engine had a relatively heavy brass flywheel, so it just coughed and kept running. Though I realized afterwards that it sounded slightly different. Yeap, when it coughed, it must have 'bounced' and gone back past top dead center, subsequently running backwards. I was ready to carry on into the crater, but the bike chickened out and shot backwards, depositing me and itself into the, thankfully long weeds at the side of the trail. face 20 face 20 face 20

Link to comment
Share on other sites

I think(!) I am fairy careful. My big embarrassment this year was when I fired up my Curare 25 at GreenAcres without checking that I had set the correct model on the transmitter. All controls worked in the correct order. All was OK until I fired it up - Idle= Full throttle - Engine Kill gave it full throttle plus 10% and no way of stopping it. IIRC, that nice Mr Hargreaves rescued me. I was holding the model steady and couldn't get round the other side to choke it.

Link to comment
Share on other sites

dsc_0110.jpgI got a new Futaba 14sg and was setting a model up outside on the bench, i had already run the motor without the prop, i disconnected everything and switched everything off, put the prop on switched the Tx on checked the throttle was off, as with the 14sg it wont come on if the throttle is on,

Connected the power and all hell broke loose the motor was flat out straight, away the model was off, without thinking i grabed the wing, and it flew round and bit me with this result, 75mm long 10mm wide and 5mm deap, and i did everything right, so be careful out there. sorry the pics came out in the wrong place

Tony

dsc_0104.jpg

Link to comment
Share on other sites

Hi Dave thats a good idea, but the little demon has gone to the bin bag now, it was something that i did not know at the time about Futaba reversing things, i learnt the hard way, i had just switched from Speky

It was only a 50" own design that bit me not some large monster, just shows electric models should be restrained at all times

Tony

Link to comment
Share on other sites

  • 7 months later...

Well, to continue on with this thread:

I had one of those brain fade moments yesterday. No physical injury at all but it certainly served as a timely reminder of the dangers of becoming complacent. I thought it would be worth sharing.

I have a low-wing model with an OS two stroke mounted upright - it's probably had about 50-60 flights. In the past, I have tinkered with different exhaust extensions to try to get the muck to go under the wing, but after trying a few different lengths of silicone pipe, I had basically decided it was largely fruitless without losing power, and over the winter, I removed the extension. At the same time, I rotated the silencer to point the exhaust away from the model and slightly upwards, away from the wing - settling on this configuration as the 'least worst' option.

Fast forward to this week, when I got it out and took it flying. I'd started the engine and had walked around the model to reach the needle valve from the rear. Automatically, as I'd done many times before, I adjusted the needle With my right hand, increased the revs a bit, and then reached across to remove the glow clip. The only difference on this occasion was that my normal hand position to remove the glow from the rear would have put my wrist in the exhaust flow, so to avoid getting oil on my hand, I automatically and subconsciously reached around it to remove it from the front. I caught myself just as my hand was about to disappear into the invisible prop - I was millimetres away. I subsequently managed a successful flight, but on landing and shutting off the engine, I had a sit down and a good long think about it.

The moral is (I think) to absolutely consider the effect of any changes you make to a model that might affect your usual routine in some way, or act as a distraction, however insignificant they might seem at the time...

Link to comment
Share on other sites

Complacency - Hmmm

Taildragger I hadnt flown for ages.... pre-flights , ok...

Placed on runway - powered up, little bit of up elevator and right rudder = vicious ground loop to the left- didnt take the hint

Placed back - took off goes to turn into the crosswind leg, that weird she's banking the right way but just not turning

Then it dawned on me - rudder reversed!!!!

Ok so now I have to think opposite rudder, so carried on and after 6 mins brought it down ok

Just goes to show things do change when you havent used a model for ages so double check and tripple check - I was lucky it was only the rudder so pretty easy to counter

Link to comment
Share on other sites

  • 2 months later...

Sunday afternoon, nice flying conditions, had four or five flights then loaded Fresh battery into Skybug, as I picked up my transmitter the neck strap caught on something and knocked the throttle open. The model ran into my foot and - see photo -

It took a while before I had the nerve to take the welly off. Luckily no damage other than ruined welly and dented pride.

Be careful out there.ouch.jpg

Link to comment
Share on other sites

I'm still relatively new to the hobby and my inexperience nearly got me into trouble last week. I'm still using a trickle charger to charge the TX and Rx batteries and I hadn't got around to buying a decent field charger or a battery checker.

We ( my instructor and I ) were about to get the third flight of the day out of my UNO WOT, and as we were walking out to the strip, the controls went dead. Now he had previously asked me if everything was charged up and I said yes which was a big Wopper. I had charged everything the day before and had already had one flight out of it. I just didn't give it a second thought.

When I realised what I had done and the possible consequences if it had happened during the previous flight, I was hugely embarrassed. I was very lucky to have got away with it, and began to see the benefit of having a field charger to keep everything topped up.

Guess what I bought over the weekend?

Link to comment
Share on other sites

Hi Dai,

being new, I will offer the advise of changing your batteries depending on what they are. If they are Nimh, a charge the day before and 1 flight to dead = dodgy pack IMO, and no matter how many top ups, they have warned you they are dodgy and so could give up at any point. Personally I wouldnt risk it, and get them changed.

There are many alternatives nowadays but that is for another occasion as not to complicate things.

Link to comment
Share on other sites

Posted by Mowerman on 15/09/2015 15:09:30:

Sunday afternoon, nice flying conditions, had four or five flights then loaded Fresh battery into Skybug, as I picked up my transmitter the neck strap caught on something and knocked the throttle open. The model ran into my foot and - see photo -

It took a while before I had the nerve to take the welly off. Luckily no damage other than ruined welly and dented pride.

Be careful out there.ouch.jpg

How about a new survey - have you experienced or witnessed an accident/incident involving neck straps? I suspect the majority of regular flyers will have...

...they are one reason that I'm very glad to be a transmitter holding thumbs pilot!

The incident that stands out most to me was of a model being started at the back of the pits (we have different procedures now!) on a busy day. The owner flicked the throttle open with his neckstrap as he was releasing his model from his restraint - happily for the rest of the members present he made a reflex grab for the model - unhappily for him it was the sharp whirling bit at the front that he caught!

I would suggest that i.c. tray and neckstrap users should adopt throttle locks if their radios support the facility (hopefully most e.p. flyers already do - and there's no reason why non-strap flyers shouldn't either) that will allow them to carry the model to the flight line relatively safely.

The majority of modern radios will either have it built in or a simple throttle to throttle mix can provide it.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...