Spirit R/E Strange Occurrence!

[TIA]

Flying my Spirit 2M this weekend, I was about 25 ft. from the ground making a gradual left sweeping turn into the wind when all of a sudden a huge gust blew my plane into a hard-right downfall.

I wasn’t able to complete my left turn and before I was able to straighten her out the wind seemed to pick up the left tip and throw it over the right tip where it shot straight down into the ground! :eek:
I couldn’t believe the lack of control I had as this happened in just a matter of a second or two! Is this a common occurrence with rudder elevator only sailplanes?

I had the CG set forward by about 8-10mm’s from stock (75mm). Maybe the “Too Forward” CG gave me lack of control? :confused:

Anyone ever had this happen to them?

The fuse is a total loss but the wing is in perfect condition!

So if anyone has a Spirit or similar fuse they would like to sell inexpensively, I would greatly appreciate it so I could get back in the air again.


:)

[Culver10]

Does the Spirit you have use rubber bands for wing attachment? It sounds like the wing might have shifted during the gust due to weak or lack of rubber bands??

[dephela]

Possible you ran into a strong thermal, these can even upset a well trimmed and flown 3M plane.

[Sparky Paul]

Any model can be upset seriously by a gust, regardless of the control configuration.
Here's one of my Ninjas doing exactly the same thing.. it has ailerons..
Models are smaller than the gust size, so it's easy for one part to be in smooth air, and another in air going in a quite different different direction and speed.

[jrgospod]

Did you build the Spirit 2M or was it the ARF. If you build another fuse look for the mods (Improving the Great Planes Spirit) that are on the Charles River site. They suggest adding 50% area to the V-stab/rudder. They also suggest that you sheet the wing tips to give better air foil and prevent tip stalls.

http://www.charlesriverrc.org/articles/kitmods/dickwilliamson_gpspiritmods.htm



John

[TIA]

Does the Spirit you have use rubber bands for wing attachment? It sounds like the wing might have shifted during the gust due to weak or lack of rubber bands??


Yeah it does have rubberbands but with two up, two crossed, then two straight up again, it should be pretty strong I would think? Maybe I should check that better next time who knows?

John, Thanks for the link. I'll read up on it although I haven't found a fuse yet... :rolleyes:

I've seen lots of good info come from the Chrles River R/C link.

[wingsnapper]

Sounds like you ran into a thermal.

[Thermalin]

I have a spirit and use the same rubber band setup you do with no issues... If the wing doesn't shift on hi-start launch then your fine..

you mention a huge gust...and gradual sweeping left turn into the wind... I'm assuming this means not a big bank but more flatter correct. Also what was your airspeed...I know mine can be sluggish if it's to low like most planes. I have a feeling the airspeed was low and when the wind hit pushing you over... there was not enough airflow moving over the rudder for correction.

As for the thermal.... was the wind blowing that day at all.. or did this come out of out the blue. When the air rises.. air moves in to fill the space.. so I believe you may have just gotten there after the thermal left and got hit by the breeze moving toward it coupled with the low airspeed (<-conjecture on my part) and you were doomed.

just my .02 (well more like .05 and all opinion only)
Mike

[aeajr]

I have a spirit and use the same rubber band setup you do with no issues... If the wing doesn't shift on hi-start launch then your fine..

you mention a huge gust...and gradual sweeping left turn into the wind... I'm assuming this means not a big bank but more flatter correct. Also what was your airspeed...I know mine can be sluggish if it's to low like most planes. I have a feeling the airspeed was low and when the wind hit pushing you over... there was not enough airflow moving over the rudder for correction.

As for the thermal.... was the wind blowing that day at all.. or did this come out of out the blue. When the air rises.. air moves in to fill the space.. so I believe you may have just gotten there after the thermal left and got hit by the breeze moving toward it coupled with the low airspeed (<-conjecture on my part) and you were doomed.

just my .02 (well more like .05 and all opinion only)
Mike

I have a Spirit 2M. I think Mike has this about right. Slow speed, strong gust, not enough energy to penetrate. Down you go! R/E, Ailerons, doesn't matter. If your speed is low enough and the gust is strong enough, you are going to lose control.

[TIA]

Well guys I have some bad/good news to report. Bad; I found the reason I had the problem the other day that crashed my plane/good because I'll make sure my other planes do not crash because of this.

I took the receiver out of the broken plane and put it in my new high performance electric plane. I noticed all kinds of glitches today, as in it was all over the sky! (amazing how problems are amplified by speed!!!) :eek:

I was lucky to have brought it down safely and then I had a few of my club buddies help me diagnose the problem. After an hour or two of testing for reoccurrence or duplication, we found the antenna wire had broken within the insulation. This explains my inability to complete my left turn and my lack of control the day of the crash. It also explains why it ground checked okay but then crashed like there was something really wrong. (wire not making connection)

Whew! Saved $500 worth of equipment from a crash & burning today!

Glad it was on a 100 dollar R/E plane & not a $1,000 competition RES plane!

I don’t know how this could have been avoided or avoided in the future as I don’t think everyone shakes their antenna out before they fly each time? Must have just been one of those flukey things……
:rolleyes:

[Peytr]

I was about 25 ft. from the ground making a gradual left sweeping turn into the wind

When using a poly -or any RE plane- it's a risky thing doing turns at low altitude. Try to be nose into wind below say 20 meters. When a high dihedral plane is hit by a gust the rolling effect will be worse than a less dihedral plane is hit. Above that these low dihedral planes will have better roll control by ailerons. Of course you can allways be turned over by vigorous thermals, but risks are minimised when your final approach is longer.

Having said that: I've been turned over more than once by gusts and/or thermals, mostly with RE planes. Keeping a bit of nose down and nose into the prevailing wind is the best thing to do in hot afternoon air.

Your RX glitching might be not so much the cause, but in fact the result of your 'crash'. Xtals can be very sensitive to shock and still function but give you many glitches. I'd try a new crystal and do comparative tests with the old one (with the same Rx) to see what happens.

[aeajr]

I don’t know how this could have been avoided or avoided in the future as I don’t think everyone shakes their antenna out before they fly each time? Must have just been one of those flukey things……
:rolleyes:

Thanks for sharing this. Would never have thought of that. Will keep it in mind for the future.

[northwest]

RE airplanes are simpler but you really have to have an idea how to fly them, especially if you dont have a prop to help with airflow. A sailplane can be so light that the stall speed is so low and there isnt enough slipstream over the rudder for a propper turn. You can see the rudder flailing but the plane doesnt respond, especially reversing a turn or correcting a wing-drop with a poly. So the most dangerous then is the turn from downwind to bring it round on final. Low alt. and speed is a bad recipe here and you may loose control and drop out. You must either fly downwind with plenty of speed or just know when you are too low to make a turn. The best is a long stabilized final. When flying a poly I tend to watch the fuselage a lot and lower the nose before making turns or corrections, just to make sure to put enough air on the rudder.

[Thermalin]

i'm still confused.. (what a shocker!) the flight was fine (you don't mention any twitching ,etc in the glider flight until you had the low altitude problem) until landing when it got turned over... I'm sitll not convinced the antenna issue was the cause of the crash.. but rather found as a result of the crash. Either way.. speed is your friend when low with a larger wingspan !

Mike

[TIA]

Mike,

I think you might be correct. I thought the receiver was the issue, but I changed the receiver and crashed again this weekend. This time the plane is rebuildable.
I’m starting to think it might be a bad crystal in the rx or tx.

I’ll change the crystal & see if that fixes the problem. What is really strange is, with the antenna all the way down on the radio, if I walk 20 feet away, the plane starts glitching like crazy. Shouldn’t I be able to walk out like 50 or 60 feet away and still maintain clean glitch-free control of the plane?

I was able to walk 50 feet away before I flew the plane, but after I crashed, I checked it again and this time gave me glitches around 15-20 feet. I’m really getting sick of these hit and miss problems. Being unable to duplicate them is frustrating as well and leads me to want to scrap my radio system and just buy a brand new one; not that I want to spend the money right now.
:(

[TIA]

Also, something that I was just thinking about, could a dirty servo connection or dirty servo potentiometer cause a problem with the radio airwave connection between the tx & rx.

Maybe I should try a Dean’s base loaded antenna for the rx? I originally thought it was my rubber duck antenna on the transmitter but nope, I changed back to the stock telescoping antenna and still same problem. I have the rx antenna trailing all the way out of the plane. What would cause glitches at 15 feet away but then everything works fine at 10 ft. away?

Thanks for all your help.

:o