Trainer crash - What went wrong?

Started by vishalrao, June 12, 2013, 06:44:37 PM

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vishalrao

What could have possibly gone wrong with the crash of this trainer?


arun.sreelakam

That's sad... :(
I think a bit of more ailerons.. or the servos might have strucked and hold to a position..
What about the damages..?>:(

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vishalrao

Thanks Arun. The plane nose dived into water below and wing was cut. Fuse is intact..

sanjayrai55

Let's see. It was flying smoothly, then a sudden nose dive  ??? ???

Probably a failure of a control surface (e.g. elevator hinge) or it's linkage.

Pilot error? Mosquito sat on his nose (been known to happen)

girishsarwal

I hope you did not lose range or binding mid air
gs

K K Iyer

Vishal,
You won't mind a candid analysis I hope.
Before the crash
5 secs, left bank starts
4 secs, left bank is 45 degrees
3 secs, left bank is 80 degrees
2 secs, left bank is 110 degrees
1 sec, left bank REDUCED to 80 degrees.
Conclusion:
Pilot held left bank for too long (3 secs)
Tried to correct by right aileron at about -1.5 sec.
Too late. Full down elevator might have saved it.
My condolences.
Request comments of senior pilots on this analysis so that i can learn from it.
I've had 3 crashes in the last 1 year due to old age of pilot (60), old age of plane (30), fading light, fading eyesight, disorientation

vishalrao

Quote from: sanjayrai55 on June 12, 2013, 07:08:26 PM
Probably a failure of a control surface (e.g. elevator hinge) or it's linkage.

Thank you Sanjay. The hinges and linkages were intact. And no mosquitoes on nose :)

Quote from: girishsarwal on June 12, 2013, 08:54:06 PM
I hope you did not lose range or binding mid air

Thank you Girish. The plane was not more than 500 feet and the TX was Sanwa 6G. So I guess that's very remote possibility. And all the receiver wires were intact too at the time of recovery.

Quote from: K K Iyer on June 12, 2013, 10:15:31 PM
Vishal,
You won't mind a candid analysis I hope.

Not at all Iyer sir :) Your inputs are most welcome.

Quote from: K K Iyer on June 12, 2013, 10:15:31 PM
Tried to correct by right aileron at about -1.5 sec.
Too late. Full down elevator might have saved it.

I think before right aileron, elevator was given which caused a slight inside loop. I feel that giving elevator when the plane has already banked more than 60 degrees, coupled with slow speed will further aggravate the situation.

I hope you are joking when you said you were flying a 30 year old plane :)

Soliciting comments from senior pilots.


asupan

sorry for the loss.

I think the aileron has got stuck. Was there aileron servos or one. If two then one could have got stuck.

nitro trainers gives very time to recover. Hope you switched off power.

Regards

Asutosh

praveen

which is the Rx battery you used! voltage and mah?
Servos?
To increase thrust you need more  money! But to reduce weight you  need nothing!

vishalrao

@Asutosh Just one servo for the ailerons Asutosh.

@praveen 2400 mah NiMH cells (4) for the receiver. Hitec standard servos for rudder and elevator. And Gotec standard servos for aileron and throttle.

praveen

well it seems you didn't had any problem with Rx battery! until n unless it was charged fully!
once i faced this problem with 50cc gasser ! it was very cold (1 to 2 degree), model started acting weird ,was locking on to one side ! like banked and no response upto 2 to 3 sec! any how landed safely ! after that i came to know battery voltage had dropped dramatically ! was using 2200mah in parallel 4400mah and 5 cell! reason :forgot to change battery after 4 flights!
To increase thrust you need more  money! But to reduce weight you  need nothing!

vishalrao

No Praveen. I had charged the battery fully previous day and it was the second flight only after 15 minutes first flight.

sanjayrai55

Did you check the voltage of the Rx pack post-crash?

vishalrao

I didn't check the voltage but I did charge it and the units that went through was not more than 1000.

rcpilotacro

#14
Vishal

where did you secure the bat, behind the fuel tank in the empty space ?. did you secure it wrapped in a foam, and batt and extension secured properly, could it have been that that the rx lost batt power fully,in the left turn due vibration/ dislodging and falling off
Gusty's Hangar and Introduction.

A Good pilot will practice until he gets it right,
A Great pilot will practice until he can't get it wrong.

vishalrao

Augustine sir, the receiver battery was held in place with velcro (below wing, not in fuel compartment) and it was in place (with wires intact) after recovery.

rajaram

RAJARAM SHENOY G

vishalrao


sanjayrai55

Loved the water coming out of the holes as it was drained  ;D {:)}

I think you should make an RC boat  :giggle: :giggle:

K K Iyer

Twin exhausts!
Awesome rescue from shark bite on right wing tip.
Pl add details of location and circumstances.

VC

Growing old is mandatory, growing up is optional!

arun.sreelakam

Vc sir its all iz well... all iz well...
:p


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Nithinraj Kotian

@ sanjay sir : when crash took place, we started running towards the river and started asking help from the local people who were having the boats but no one was ready to rescue our plane  :banghead: :banghead: later some workers came near us and that time vishal sir requested them. :salute:
Life is Simple Don't Make it Complicated

shobhit17

http://krepelka.com/fsweb/lessons/private/privatelessons02.htm
Mind if you guys read this article.... To me it appears that nothing went wrong... Its just that the pilot was not aware of what to do when in a steep turn.  When we do a LEVEL steep turn the lift of the wing reduces due to a reduced plan form projected to the lifting force and the aircraft enters a descent.  Hence to maintain the lifting force required some amount of UP elevator is required.... when this is done the strn becomes tighter and the "G" forces increases.... Mind you I am talking of a level steep turn.... or else you will be in a descent and this descent may turn into a spiral which keeps getting tightened and ends up in a crash.  Any pilot when doing a steep turn needs to pull the elevators up... therefore in a level steep turn the up elevator is necessary and because of this the "WING LOADING" increases resulting into increased "G" forces.  As a thumb rule in a 60 deg turn the "G" required is 2"G" i.e. two times the gravitional force as felt by the pilot.... if the wing is not strong enough it will show a bend i.e the tips will flex up and in an extreme case they will fold up and break. To fly safe.... avoid turns with more bank than 30 dec... in case doing a steep turn be ready to apply UP elevator...

Happy and safe flying
Well I been into aeromodelling since I was in School....  and then been in the air for over 30 years.  Now looking to be back into aeromodelling full time...