|Steve Colman||20/05/2016 22:02:45|
743 forum posts
Last Tuesday, after what must have been the slowest assembly in history, I finally got round to maidening my Staufenbiel Cheetah. All went well but my power set up was pulling too many amps and I felt that the CG needed some tweaking too.
Having some free time this morning, I swapped the prop for a smaller one, hooked up the watt meter and things were now well inside the limits. So far so good.
Next I attached the wings and removed some weight I had added beforehand to move the CG back by a couple of mm.
With the two small tweaks completed I put the model in the car without removing the wings. Later, in the afternoon it proved to be perfect weather for a test flight so off I drove to the club field at around 6pm. After 15 minutes a couple of friends arrived and we set to enjoying what had become a beautiful evening for flying.
So, a battery was duly placed in the Cheetah and she was readied for a flight. A flat hand launch from a friend ensued and within two seconds my previously pristine model was a broken mess on the ground a few metres ahead after torque rolling "uncontrollably" to the left.
Note the word "uncontrollably"
For some insane reason, what little brain cells I have must have parted from my brain, and my normally extremely fastidious set up and model check routine just did not register.
So what went wrong you may ask?
After recovering the model from it's sad, fractured state upon the ground, I removed the wings only to discover.....................................
............................... aileron leads not connected to the Rx !
When I attached the wings to the fuselage at home for the CG adjustment I hadn't connected them, And, for some mad moment of total insanity and loss of brain function at the field my mind just failed to register and undertake the most basic of pre flight checks that I have been so meticulous in completing up to this point.
Now, whilst the model can be repaired, my utter stupidity in this sorry little tale will serve as a reminder for the future. I've always taken pride in my model set up and pre flight check routine, and believe that I've had very few failures/crashes as a result.
Today has been a sorry reminder, that sometimes, even when we try with with the best will we can muster, only a thin line separates success from disaster.
|Biggles' Elder Brother - Moderator||20/05/2016 22:21:10|
15748 forum posts
Oh dear - sorry to hear about that Steve. But you are so right - the one time you depart from your tried and test routine is always the one time it bites you! Hope the repair goes well and isn't too much of a problem.
|Jon - Laser Engines||20/05/2016 22:26:47|
|5086 forum posts|
Your aren't the first and wont be the last. Shows how easy it is to make a mistake though
|Stephen Jones||20/05/2016 23:31:09|
2765 forum posts
I did some thing similar many many years ago when i was in my twenties .
I had not long passed my A cert and i had bought a Pilot QB25s and could flew it very well , I had arranged to meet a friend at a local field and fly together .
Well another friend of mine wanted to come along and watch as he had not seen me fly before.
I arrived at the field first , and quickly got setup and in my excitement wanted to show my none flying buddy how well i could fly before my flying buddy turned up.
I fueled up the model switched on the radio checked all control surfaces worked correctly , then started up the engine , checked my engine was running ok then off i went.
The model was not in the air long before i lost control of it and it came crashing to the ground .
I pick up the bits and walked back to my car just as my flying buddy turned up .
So what happened , well in my hast to get the model in the air i forgot to un-coil the aerial .
|2836 forum posts|
|Even been known to happen in the world of full size aviation....but with fatal results.|
Don't beat yourself up over it though, there's not one of us with a few years flying under our belts who hasn't done something similar. Often you'll get away with it, sometimes you won't
Edited By Cuban8 on 20/05/2016 23:47:03
2002 forum posts
You need a Taranis - every single time I arm the throttle mine reminds me to carry out the pre-flight check. Has already saved at least 2 models from inflight failures in 3 years (one unglued aileron horn, another reversed control surface)...
|Former Member||21/05/2016 01:32:55|
|3578 forum posts|
[This posting has been removed]
485 forum posts
So many things (maybe a dozen or so) have to be done right for a successful flight and you can get it right 500 times, but just one slip up can catch you out.
I have had heaps of oops moments and often they have been caused by getting out of routine by being distracted. A while back I bungy launched a glider without turning on the power as I was in a park with some mates and a member of the public had come up and I had been talking to them while setting up. It was the sixth launch of the day and there was a slight cross wind - I have never felt so helpless watching the glider perform a graceful arc and do a lawn dart still attached to the tow rope.
A friend of mine had a couple of high powered (1500w) electric pylon racers and was flying at a meet last year. He had completed a race, got talking to some other competitors, and then put the model on the back seat of his (brand new) car and picked up the second model. Did his preflight checks, but didn't run the motor up as the set up had a limited run time. Duly launched, when there was an immediate commotion from the peanut gallery and people started yelling at him to land! He powered off and glided in to find people pointing at his car. There in the back was a thoroughly destroyed model and back seat. He had forgotten to turn the model off and it had powered up to full noise when the second one was launched. Cost was the airframe, plus ESC, plus a full recover of the back seat - $1,800NZ.
The best you can do is just try to maintain "situational awareness" and be particularly careful when out of your normal environment. Sometimes, it can also help to just take a moment, don't rush and think things through.
|Rich too||21/05/2016 08:00:42|
3057 forum posts
At first I thought don't you check the surfaces every time? Then I remembered, my worst one, was launching a glider on a bungee - I'd forgotten to turn the receiver on! Doh! Luckily it flew well and I had the address in the fuselage. I collected it from a house a few miles alway. Mind you, I was only about 14 at the time
More recently, and posted on this forum, I started a petrol powered model, didn't restrain it, forgot to turn the receiver on, and watched it race across the field into a fence post.
I feel you're pain, you are not alone!
|Frank Skilbeck||21/05/2016 08:12:11|
4573 forum posts
I did that with my Easy Glider, it did 4 or 5 circuits and landed in the next field , mind you I was only about 56 at the time.............................
|Rich too||21/05/2016 08:15:34|
3057 forum posts
|David Davis||21/05/2016 10:43:54|
3528 forum posts
Some years ago, when I was still importing the Telemasters, I organised a fly-in for vintage and Telemaster models. Hardly anyone turned up as it was blowing a gale but one bloke flew a half-sized electric powered Rudder Bug and feeling that noblesse oblige, I cranked up the "works" eight-foot ARTF Senior Telemaster (STM) as seen in my avatar, and I flew that. The flight wasn't very steady but I put that down to the wind conditions. Shortly afterwards some guests arrived with free-flight vintage models. One of these was launched and disappeared rapidly downwind where it was eventually retrieved without damage. Feeling obliged to fly again, I launched the STM for a second time. This time the flight pattern became more and more uncontrollable so I cut the motor and landed it in an adjacent field without damage. I put the problem down to the wind conditions until I checked the model over once I'd retrieved it.
It's unstable flight pattern was due to my not having connected the ailerons but unlike Steve, I had flown the model twice! In my defence I would like to say that I am in the habit of using both sticks when flying a model and I hadn't noticed that I was using much more rudder than I normally do. Nice stable trainer the Telemaster!
I have also launched a Chris Foss Uno Wot without switching on the receiver. It flew very well in free flight mode until it gently dropped it's starboard wing and hit the ground. Both its flight characteristics and its strength are a credit to its designer.
Edited By David Davis on 21/05/2016 10:44:58
Edited By David Davis on 21/05/2016 10:47:31
|Mike Etheridge 1||21/05/2016 11:19:17|
|1536 forum posts|
There is a routine on Epsom Downs enforced by those responsible for the A and B tests. On every visit to the Downs, prior to flying any model a range check has to be carried out in the usual way with aerials lowered on 35 mhz, and an equivalent arrangement on 2,4 gear, not that I possess any 2.4 equipment. This practice appears to work very well but of course does not guarantee no crashes, but movements of all controls are checked from about 40 yards distance. At my other club it would seem that most flyers will only range check when a model is new or has not flown for a while but certainly not on every trip to the flying field, although that could be a misjudgement on my part ?
Not good weather again , I have only been out once with the IC planes this year, so perhaps I will nip into the garage and do a bit more refurbishment of my 54 year old Junior 60 which I am re-covering with Oratex. Some of the balsa frame on the fuselage has become very brittle and gluing with Super Glue where the old Balsa Cement has failed has not been satisfactory.
|Percy Verance||21/05/2016 11:27:19|
8108 forum posts
Fair comment Mike. My radio manufacturer (Multiplex) recommends regular range testing in their info manual before committing to flight. They also recommend checking servo and control linkages on a pretty regular basis too. That said, I don't see that many flyers actually doing it....
It's the ones who sometimes bounce a model across the strip - occasionally with damage on landing - and simply repair on the field with cyano, and resume flying without a range check etc. They're the ones who worry me more than a little.....
Edited By Percy Verance on 21/05/2016 11:28:09
|Colin Leighfield||21/05/2016 17:26:37|
5975 forum posts
It's so easy to be distracted by a change of routine or something else. When you think that the brilliant designer of the Lancaster Roy Chadwick was killed in the crash on take-off of the prototype Tudor 2 because the ailerons were reversed you realise just how mistakes like this can occur even at the highest level. Where were the pre-flight checks on that day? The mistake I've made once is to forget to switch the transmitter from one model to the other and not noticing that the elevator was reversed. That was the end of my Twin Star!
|1220 forum posts|
Most of us have done something similar and if we haven't, we probably will.
A few weeks ago I thought on dismantling my Flair Stearman I noticed I'd not fitted the upper bolts to one half of the wings. I know what happened, I got distracted by clubmates talking to me and I didn't check that the 'bolt tin' was empty.... or not. Luckily no issues, but I won't be doing that again.
I try and instil into beginners that they must establish a routine and go through the same routine each time they fly, that way nothing will be missed. However, many seem to fail to grasp my approach...never mind.
|Steve Colman||22/05/2016 09:52:04|
743 forum posts
Some very interesting comments in response to my post gents. Thanks for the support.
Just to prove to myself that I've not yet completely lost the plot I managed a couple of quick flights yesterday morning without incident.
|Dave Hopkin||22/05/2016 10:06:01|
|3672 forum posts|
I think its fair to say "There but for the grace of god go us all"
|Chuck Plains||22/05/2016 10:28:03|
1096 forum posts
I think most of us are in that club Steve, so beat yourself up all you like and we'll recall our own pain right along with you.
Worst one I ever did was when I went windsurfing one time about 4 years back. I got all my gear ready, drove to Exmouth, found the free parking, carried it all across the main road, assembled everything on the beach, donned my wetsuit in the nearby toilets, bouyancy aid and all, grabbed the board and sail launched myself on the water, mooched around for a bit, fell off, got back on, looked at the sail and realized I had not put the uphaul rope on it!! That's the bit that you see windsurfers pulling on to lift the sail while they stand on the board.
The wind was light so I was using a large sail ( = heavy-ish sail ) . I found it impossible to get the sail up out of the water. I nearly managed it one time by facing it into the light breeze to get air under it, but failed anyway.
Luckily, or unluckily, the tide at Exmouth goes somewhat sideways due to the river outlet that goes right along the beach. I was able to eventually swim my gear back to shore an hour after launching, but then had to carry it all a quarter of a mile back where I started, exhausted!
The words face and palm are applied liberally by most of us at one time or another. That's life!
Edited By Chuck Plains on 22/05/2016 10:28:29
|Josip Vrandecic -Mes||22/05/2016 10:52:06|
2993 forum posts
Dear Steve, I'm sorry to hear that but no one is exempt from such events.....
Tomorrow is a new day with Spain's almost summer sun...
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