Futaba 9CHP tx Signal Lost!

[aeronautical]

i used a 9chp with a 29mhz module to fly my friend's school project aircraft. Today was the first time using the 9chp which belongs to the school as well. previously i was using my own tx/rx for the aircraft and it worked

did the usual ground checks for orientation and response, all was ok. antenna was extended fully.

so upon hand launch, it was going straight and true in a climb attitude. then, when i wanted to throttle back, there was NO RESPONSE! it was still at full throttle. it started drifting right and did not respond to my aileron or elevator input. gradually, it rolled right and nose dived at full throttle into the grass. thank goodness it missed the concrete by 30 cm and the damage was repairable. there was no jittery behaviour so a signal clash is unlikely.

has anyone seen something like this before? this occurred at jurongwest

when we got to the a/c, i tested the whole setup again. now all the servos were working. strange huh?

i'll be changing the tx module and rx for the next flight

[aeronautical]

any other warnings before tmrw's 2nd test flight? :p

[chiadennis]

I know it a stupid question to asked, did you unwrap your RX antenna?
I know a lot of people so use to fly 2.4 that when they switch back to FM, they left the antenna wrap.

[foxkilo]

Brown-out? Are you using a ESC with built-in BEC and is the BEC supplying enough current to power all the servos and receivers?

Could also be the contacts between the module and TX have become loose? I know that for some modules, the plastic mounting tabs break off after prolonged use, so there is nothing securing the module to the TX except friction. In this case, can wrap some electrical tape around the side of the module to get a tighter fit.

[aeronautical]

I know it a stupid question to asked, did you unwrap your RX antenna?
I know a lot of people so use to fly 2.4 that when they switch back to FM, they left the antenna wrap.

yup i've been using fm all the way. rx annt was extended to the tail

[aeronautical]

i suspect the esc was the fault as you mentioned. with 4 servos and an old esc that was found in the lab which only tells me the max draw is 30 amp for the motor. it did not mention what brand or the bec capacity. so what they did was to change to another 40 amp esc from another plane.

works alright now. thanks!

Brown-out? Are you using a ESC with built-in BEC and is the BEC supplying enough current to power all the servos and receivers?

Could also be the contacts between the module and TX have become loose? I know that for some modules, the plastic mounting tabs break off after prolonged use, so there is nothing securing the module to the TX except friction. In this case, can wrap some electrical tape around the side of the module to get a tighter fit.

[aeronautical]

thanks for the replies chiadennis and foxkilo. see if this makes sense: problem might have been esc failing to supply current to the rx due to overload and the state in which all the chns were in were frozen as they were. ie, max throttle and neutral servo positions. only when the plane came down and the motor jammed to a halt, then power to the rx was returned because there was no more load? possible?