sudden dive

[erhard52]

If the failsafe is set to HOLD all positions then it is not possible for the servo itself to move on its own if there is a loss of radio control.  That would leave either a problem on the transmitter side - pot glitch, encoder glitch, module pin failure (especially for Futaba transmitters - EVO's are not known to have any issues with the module pins), or a servo/power/mechanical issues on the aircraft.  Did you look at the LED on the Nano when this happened?  The LED will blink if there was a loss of power.  We have seen cases where fast power glitches can cause servos to move to one end, especially analog servos, but the servo signal returning immediately corrects this.  The power glitch can occur with just a single servo when the connector makes poor contact.  Remember, servo connectors are only good for about 25 insertions/removals before you are suppose to throw them away and use new connectors.

Let us know about the LED on the Nano.

thanks so much for the reply. sadly yesterday it went into a dive again and did not recover. entire front part crashed but could be repaired. but no fun really. 
i forgot to check if the receiver was blinking , indicating a power outage. i tried to use the XDP to check the failsafe settings in the nano receiver but cannot install on w11 PC so far.

what i do now is switching to spectrum system - just needed to order a receiver - i will fly with that setup and if it dives again it is not XPS.

i use my multiplex evo 12 transmitter with a XPS 2.5GHz RF module which i thought usually works but then again it gives my these sudden dives .
to check the failsafe i turn the transmitter off and all servo stay where they are - 
i did a range test with reduced power and all servo stay where they are 

i just cannot reproduce erratic servo behavior. also i tested the system with the same battery after the crash and never could introduce a power loss even with running motor.

i simply have a problem to explain this behavior with aerodynamics but it is little bit gusty  in the hills but i have seen the dive in quiet conditions too.

this time i use a vtail glider - when it had crashed the elevator was all in neutral condition.

when i fly again i will try to produce a stall higher up and a controlled dive to see how long it takes to recover

the failsafe takes about 2 sec to recover which is the default setting as for as i am reading

other question:
do people still fly with XPS or they all moved on?

last question
way back i bought a spectrum DSM2 module for the hitec transmitter, i wonder if i could use this also for the EVO 12 - does it only need the PPM signal line to be connected to the RF module.

or maybe it is time to move to a new system - i must say the EVO 12 is a very flexible nice transmitter and i hate to give it up

and where is all the XPS community chatting these days or are you and me the only one left?

thanks
erhard