Lost radio contact - Spectrum DXe + Spektrum AR410

[Sussex Pete]

Yesterday (14 Feb 2020) radio failure showed just how well trimmed my SAS Wildthing was on failsafe settings when it flew away from Wilmington Long Man bowl (East Sussex) in 37mph winds about 10 minutes into an otherwise nice slope soaring session.

After searching the back of the hill for an hour a walker told me she'd seen someone local carrying it away from near Folkington Wood about half a mile downwind. Sadly I must confess I was waiting for my CAA number before doing a proper return address label. A big mistake: Sod's Law (aka Murphy's Law at the worst possible time!) applies as it always has.

I have put the word out locally (door-to-door!) and on local social media but if anyone hears anything let me know please - I will reward its return. Perhaps my BMFA registration number GBR197508, will turn up in a Google search. My mobile is 07952 910184.

I don't know the cause of the loss on contact yet. The elevons clearly went to neutral and the onboard Voltsaver battery alarm did not sound so I believe the battery was ok. I don't know if the receiver (Spektrum AR410) logged any losses as I don't have it. I am setting up a test of my Spektrum DXe transmitter, which itself was a warranty replacement for an earlier purchase whose RF board failed (without loss of a plane). Just glad it wasn't my Middle Phase in the air at the time - it would not bounce like a Wildthing.

 

Edited By Sussex Pete on 15/02/2020 12:25:01

Edited By Sussex Pete on 15/02/2020 12:26:18

[Stephen Smith 14]

Can't believe people still persist with Spektrum with dozens if not hundreds of reports of rf board failure along with failure of other parts. Hopefully no one was injured and no damage done where it came down.

[Denis Watkins]

What are the two whiskers sticking out underneath Pete ?

And, I always leave a Tiny bit of rudder out of trim for just such a situation

Edited By Denis Watkins on 16/02/2020 00:30:04

[Cuban8]

Posted by Stephen Smith 14 on 15/02/2020 22:16:59:

Can't believe people still persist with Spektrum with dozens if not hundreds of reports of rf board failure along with failure of other parts. Hopefully no one was injured and no damage done where it came down.

Spektrum user for ten years DX7 & DX8 hundreds and hundreds of flights without a problem. Never so much as a glitch or any reason to give me concern.

[JOHN MOSLEY 2]

Used Spektrum since early the DX7 in helicopters fixed wind etc, same old story's as when I started flying. on 27mhz.

Flat batteries poor installation (putting in carbon fuselage without external antenna's) Its like decorating 90% preparation leads to successful finishing.

Never had a problem but spent a lot of time on reading and installing correctly.

[Denis Watkins]

Posted by JOHN MOSLEY 2 on 16/02/2020 08:21:07:

Used Spektrum since early the DX7 in helicopters fixed wind etc, same old story's as when I started flying. on 27mhz.

Flat batteries poor installation (putting in carbon fuselage without external antenna's) Its like decorating 90% preparation leads to successful finishing.

Never had a problem but spent a lot of time on reading and installing correctly.

Exactly John

[CARPERFECT]

I know the horse has bolted but, always set fail safe to Zero throttle(yes i know it does not have one ) and off set the rudder, That way it can not get too far away if there is a problem. Or does Spektrum not have fail safe on all channels ?. Only ever used Futaba and they have it on all channels

[trebor]

I had a Dx6 v1 with a single antenna. I got fed up with Hold Last Command, switched brands to get a better choice of failsafes at a good price.

Edited By trebor on 16/02/2020 09:00:16

[Andy Stephenson]

Four experienced members of my club had unexplained crashes with Spektrum gear and as a result all changed to Futaba. with no further incidents. It's not like they suddenly knew any more about batteries or installation after the change. So I will leave it up to the reader to make up their mind about the reliability of said gear.

A.

Edited By Andy Stephenson on 16/02/2020 11:05:42

[Steve Nash 1]

I really hope you get your model back, Pete. Hopefully the reg. number inside will work to your advantage and help it's return.
I had three losses of control with a Spektrum dx9, all with different models and setups which resulted in the total loss of one model. I ended up getting rid of it and going back to Futaba 14SG with no problems since. I still have one of the old Spektrum dx7 transmitters that were built by JR and that TX is faultless. I use it on the bind'n'fly models that are readily available.
One difference between Futaba and Spektrum that I have noticed is that With Futaba, if I sit my model in front of me and turn off the TX and then turn it back on, the radio link is re-established almost instantly, whereas if I do the same with Spektrum, the link can take 3 to 4 seconds to come back, which, if the model had been flying, is the difference between being able to save the model or reaching for the bin bags.

Edited By Steve Nash 1 on 16/02/2020 11:30:16

[trebor]

Pete, how did you go about making a nice job of your registration number sticker ?

[Former Member]

[This posting has been removed]

[Paul Marsh]

I've had some radio issues in the past, but these were:

1. Fun fly Cambrian 109 25 size. Crashed after lost control. Culprit, failed aileron servo;
   Radio: Spektrum (Servo Futaba S3003)
2. Model fly away at a flyin last year. Suspecting switch as lost control, came back and lost again
   Radio: Spektrum DSM2 AR7000 rx no 1
3. Petrol model crashed, after going into failsafe, batteries (2) ok.
   Radio: Spektrum DSM2 AR7000rx no 2
4. Acro wot crashed after glitch - lost control
   Radio: Futaba FASST
5. Tactic: None
6. Futaba SFHSS: None
7. Hitec: None
8. Planet: None
9. Other cheap radios (FMS/Go-RC/etc: None.

[Former Member]

[This posting has been removed]

[Dickw]

Posted by Steve J on 16/02/2020 11:52:19:

Posted by Sussex Pete on 15/02/2020 12:23:24:

Perhaps my BMFA registration number GBR197508

I don't see the merit in putting a BMFA number on a model especially as you have prefixed it with GBR and not BMFA. I put a mobile phone number on my gliders.

If you fly in some international competitions you have to put your FAI Licence number on the model. In the UK, your FAI Licence number is your BMFA number preceded by GBR.

I have it like that on several of my models for that reason, but have no idea if that is the case in this instance.

Dick

[Steve Nash 1]

That is a pretty worthless test as it is giving you the time for the transmitter to boot and for the receiver to do its full DSM2 signal acquisition routine. Cycling the power on the receiver would give you the receiver's signal reacquisition time.

I understand what you are saying, but I have done it with turning the receiver off and back on with the same results.
As I said earlier, I still use my old JR built dx7 and that has never had any problems.
Saying that, I also know of other flyers who have had no issues at all with newer radio's, so it seems the problem is random.

I only knew it was my TX due to the fact that I had three identical signal loss problems with three different aircraft each with different genuine receivers and different battery packs on three different days, so there wasn't any link to each fault except the TX.

 

Edited By Steve Nash 1 on 16/02/2020 12:57:01

[Former Member]

[This posting has been removed]

[Sussex Pete]

To answer a few questions from earlier posts (thanks for the interest and recommendations!),

- I am happy to say nobody got hurt!

- The whiskers are connected to the on-off switch (recommended in the Wildthing instructions). BTW, the onboard battery was recently charged, and I've been running my Tx for 12 hours testing and not drained the Tx battery yet.

- I did indeed put GBR197508 on it, in 25mm high letters, to be competition-compliant. Same on all my planes!  (Doesn't everyone want to go fly at the Nationals?

- If I wasn't waiting for my CAA registration this month, the plane would have had the same, full, contact details all my other planes have (except they are on labels under dope, not removable as the CAA suggests!). Sod's Law...

- The plane was trimmed to circle on failsafe. And it did. Beautifully. And climbing in very strong slope lift! Perhaps I should have reset the failsafe with a load of up-elevator too to stall it in like a D/T.

Anyway, testing at home with several receivers (both Spektrum and Orange) points at the Spektrum DXe transmitter at fault. It's still generating radio frequency but the range is down to less than 50 metres. It is very clear the Spektrum Rx's deal with drop-outs, and with reconnection, better than Orange, but neither can overcome a 50m-range Tx!

I did take the back off to see if there was anything obvious or overheating (I have a good IR thermometer but nothing was hot). The 2mm co-axial connector between the R/F board and the external antenna seemed loose, so I tweaked the female connector on the cable with a pin. No difference (but boy is that a tiny connector!)

So, decision time: this is the second and, I now think, last Spektrum Tx I will own. The first (and the only reason I have Spektrum at all) was a DX5 that came with a (amazingly cheap at £140) RTF Supercub when I got back into the sport in 2016. That failed in a few months - same symptoms but luckily no lost aircraft and Hobbyzone replaced it under warranty in September 2016 with the DXe that has just failed. Before that, my last radio was a Futaba 6ch 27MHz set bought new for £400(!) about 1970, preceded by MacGregor single-channel in the '60s. I never had any radio problems with any of those (not even interference) even on my home-built 6ch Rx (with Real Transistors!).

So, given that I've just lost (or, hopefully, only mislaid!) £150 worth of kit, radio and servos, I don't think "cheap" is going to be on my list of attributes for a new set. Next decision: Futaba, or Multiplex?

Edited By Sussex Pete on 16/02/2020 13:55:55

Edited By Sussex Pete on 16/02/2020 13:57:09

[Sussex Pete]

Posted by trebor on 16/02/2020 11:47:35:

Pete, how did you go about making a nice job of your registration number sticker ?

Thank you for the compliment! I used: MS Word to put the letters together. Ink-jet print on waterslide transfer paper (from Amazon). About 6 coats thin of spray matt artists varnish to seal. Slide transfer onto the wing and dab down with paper towel. Cover with clear Fablon (from Hobbycraft). Done! Only use the Fablon on plastic covering - usually I just dope over the top on tissue or nylon. I tried gloss varnish but it doesn't take dope so well.

[Sussex Pete]

Posted by CARPERFECT on 16/02/2020 08:42:45:

I know the horse has bolted but, always set fail safe to Zero throttle(yes i know it does not have one ) and off set the rudder, That way it can not get too far away if there is a problem. Or does Spektrum not have fail safe on all channels ?. Only ever used Futaba and they have it on all channels

The later Spektrum receivers (eg the AR410 in the lost plane) do have failsafe on all channels though they default to "hold position" unless you follow a slightly different binding procedure. I know it failsafed in this instance as I was in a hard banking turn when it lost contact and leveled itself out.

[MattyB]

Posted by CARPERFECT on 16/02/2020 08:42:45:

I know the horse has bolted but, always set fail safe to Zero throttle(yes i know it does not have one ) and off set the rudder, That way it can not get too far away if there is a problem. Or does Spektrum not have fail safe on all channels ?. Only ever used Futaba and they have it on all channels

Wildthings only have elevons, no rudder, so that won’t help. You will hear lots of debate about failsafe in slope models, but in reality there is no hard and fast rule for such a dynamic environment. On most aerobatic slopers I tend to go for full up and a bit of right or left, the thinking being it should arrive back to earth in the same county with the minimum amount of energy. It doesn’t guarantee no damage, but if you want to avoid bumps don’t fly S.L.O.P.E (smashed, lost or pulverised, eventually)!

[Andy Stephenson]

Posted by Sussex Pete on 16/02/2020 13:54:30:...

- The whiskers are connected to the on-off switch (recommended in the Wildthing instructions). ...

Does this mean you actually connected the whisker antennas to the on-off switch???

I'm intrigued to say the least.

A.

[Don Fry]

As in a bit of fishing line. Nylon. Pull pull, on off.

[Sussex Pete]

Posted by Andy Stephenson on 16/02/2020 18:05:05:

Posted by Sussex Pete on 16/02/2020 13:54:30:...

- The whiskers are connected to the on-off switch (recommended in the Wildthing instructions). ...

Does this mean you actually connected the whisker antennas to the on-off switch???

I'm intrigued to say the least.

A.

Don's right, just a piece of fishing line tied to the on-off switch in the middle of the fuselage. I had a Spektrum AR410 rx installed which does not have external antennae.  And hot-glue is great for quick assembly!

Edited By Sussex Pete on 17/02/2020 11:26:57

Edited By Sussex Pete on 17/02/2020 11:29:08

[Andy Stephenson]

I have come across this mechanism before but I couldn't make it out from the photo.

Perhaps having a receiver with external antennae would have prevented the fly-away.