back to basics

[JC]

A cautionary tale with regards to carrying out correct pre flight checks.

 

I swapped the RX in my Travel Air recently and flew the model last night for the fist time with the new RX. It was not a long flight.

 

On starting the engine it immediatley ran at full throttle. Strange I thought, pushed the stick to full throttle and it went to idle. The servo needed reversing. I should of realised then. Engine now running fine a quick wiggle of the sticks, all surfaces moving, lovely.

 

Across the patch she went, started to lift off on her own, a gentle pull on the elevator and in she went. Full throttle back into the deck. Off came the landing gear and the wings. Repairable and thank goodness I was on my own so no ribbing from the guys for being a complete prat.

 

I had checked that the surfaces moved but not that they moved in the correct direction. A basic check that I failed to carry out correctly. It could have ben a lot worse.

 

We have a saying in my job' never short cut drills' never a truer word said.

[IanN]

Yep, no matter how careful we all think we are, there's always room for error and its easy to lull ourselves into a false sense of security. I'm certainly far from perfect in that respect

 

There's no substitute for thorough routines. I have a half remembered quote from one of my favourite (full size) aero books struggling to force its way into my mind that sums this up well - I'll see if I can dig that out

 

 

[Tim Mackey]

Well said JC - I did almost the exact same thing a few months back, as explained on my "bad day at the office " thread ( lost 3 in one day )

Had been flying my Tiggy moth on my DX6i ( wifes tx actually ) and for whatever reason had recently swopped it over to my DX7, with a re-bind as necessary.

Also checked the controls were waggling as required, took off, - bang whollop straight in.

Reversed ailerons

[Ian Jones]

The moment of realisation is a sikening one isn't it. Someone asked me to "just trim it for me" once. So I asked if the aeroplane had been flown before and yes it had. Headed out to the strip, waggled everything etc and took off. One wing dropped a little on take-off and so a liitle squeeze in the opposite direction and smash. Yup reversed ailerons. I knew immediately and when I apologised to the owner, told him what happened and expressed surprise at how he had managed to fly it before he said, "Well it was okay last time on my mates transmitter so I don't know why it's like that on mine."

 

Poor communication in the first place followed by my presumption that what I had been asked to do was all I needed to do lead to a very avoidable crunch. I wa svery annoyed with myself. Oh well we live and learn.

 

Hope you soon have it fixed JC.

 

Ian

 

 

[Engine Doctor]

I know wev'e all done it ,but surely the reversed throttle would have wised you up to check all the other controls ? I made it a rule some years ago after a very embarrasing crash to check the correct orientation of controls prior to EVERY flight . I'm still amazed how easy it is to get caught out after some basic maintenance or repair , but the check usually finds it before it before the model gets airborne . hope the repair goes well .

 

E.D.

[David Gilder]

E.D.

 

I do exactly the same.. Check correct movement prior to each and every takeoff.

Even if i have just landed, refuelled and gone straight out for another flight..

Somthing can always have happened during taxiing so best to check before opening the throttle!!

We had an aerobatics comp at our club recently and it was something that our judge (IMAC Pilot) noted this practice and was clearly impressed with the thoroughness.

It really is a basic pre flight check and should be carried out prior to EVERY flight!!

 

A good reminder of what can happen if you dont follow the checklist!!!

 

Dave

 

[David Davis]

I built a small simple electric three-channel glider years ago. It took me ages to build because having started, I soon lost interest in the model. Having finally finished it I took it out to the local football pitch as the sun was setting one winter Sunday afternoon. Switch on, motor running, launch. she climbs away, drops the right wing, apply left rudder,right wing drops steeply. Yes you've guessed it, rudder moving in the wrong direction. Motor off and glide in for a very fast flat landing....straight into the bottom of the hedge. Leading edge of wing stoved in.

 

Then there was the time when I put down my Spektrum and picked up my old Futaba FM transmitter to fly my Precedent T240. This time I checked that all of the controls were working correctly, advanced the throttle and the old lady started to trundle along the runway, climbed out and about twenty yards away suddenly crashed into the ground from about thirty feet. I had forgotten to extend the aerial.

 

But wait it gets better.

 

Years ago I had a Unowot and permission to fly from a farmer's field near Welshpool. I'd flown it several times that particular day but decided on one last flight. I started the engine and launched the model. It looked lovely in a straight climb-out against a cobalt blue sky. It dropped its right wing. I applied left aileron, no response. I fed in more aileron, still no response. It crashed into the ground at full chat with me holding in full left rudder and aileron. I had forgotten to switch on the receiver!

 

Now everybody after me!

 

Switches, Meter, Aerial, Rates, Trim!!!

[Biggles' Elder Brother - Moderator]

We've all done it of course - but that doesn't make you feel any less of a prat when its your turn!

 

One thing I have decided on, and try very hard to stick by, is if anything seems strange at start up or pre flight checks - STOP! Investigate fully.

 

The model is "trying to tell you something". OK 9 times out of ten it will turn out to be something and nothing, but surprising often its an early hint that something major eith is wrong or is about to go wrong.

 

An example, I was starting an engine the other day and it was a bit reluctant. Now this engine is usually an "easy starter" - but not today. Eventually I get it to start - not a big effort but she spun over for a good 5 secs before starting - much longer than usual. When running it wasn't just right. OK but just that bit "off". Mainly the throttling was a just a bit hesitant. Now I could have just opened the needle a couple of clicks she'd have been OK, then shrugged my shoulders and said "Ah well, one of those things.

 

But I didn't. Instead, I stopped the engine and had a good look round. Quite quickly I found the fuel line was right on the point of splitting where it joins the tank - there was a definite crack, but it hadn't actually separated - yet! I guess it was able to just suck a little air at this point and that was the cause of the starting problem. Recut the line. refitted it and all was well. But if I hadn't listened to the "warning signals" I would have taken off and could have gone dead stick at any time.

 

Moral: always listen to your model!

 

BEB

[Airwilf]

Yep, been there too.

 

Put some new metal gear servos in my Stryker, failed to notice the airleron function had reversed somehow.

Elevator was ok, so flew, soon realized left turn wa right & right turn was left.

Oops.

A VERY wide circuit later, brought it in safely & re-configured the tx to give the correct movement.

Phew.