Efis one flying update.

[glenmthompson]

Nice pic ,Mark, ..... I seem to remember greg mentioning needing 30 deg. or so for throw, IMHO, 55 deg. is quite bit and if there is ANY play/slop/hysterisis in your rod ends, and you have the same failure I saw , well, ....I hope you have your parachute on that flight. If you look at your push rod, it seems to only take 1/2 an inch or so of for/aft movement at 55 deg. to make that servo arm go over center and point/jam below the 9/3 o'clock position, causing a fatal malfunction. Pushing the rod will have a greater chance of a malfunction, than pulling...Imagine if you will, that servo arm moving/jamming in the fwd and down position. The arm will jam against the bellcrank bracket/floor in an almost full down elevator position.... or, if you will, the mounting bracket for the servo could bend/torque a little, and you will have the same result.
Jim says he wants stops at the servo arms, say at the 60 deg travel limit or so. I whole heartedly agree!!!!!! This could have been a once/100 year event I witnessed, by like yuz guz said, there are 2 each 737's that had their 100 year event happen some what recently.

PS, I am extremely honored to have been the first one to give Jim the first ride in his pride and joy, modern, awsome, light, eye catching, best value for the dollar airplane!!!!!! Pretty much makes up for not having a life since last february while I helped him finish the 10. Keep it up boys and girls, this is the 6'th plane I have built/helped finish, and it ALWAYS seems like there is no light at the end of the tunnel BUT, remember all tunnels have an end and these planes, despite an occasional glitch, are always well worth it. Keep going and join the "I built an airplane club". You will NOT regret it. Right Brent and Jim?

Glen

[brenthg]

Originally Posted by glenmthompson

PS, I am extremely honored to have been the first one to give Jim the first ride in his pride and joy, modern, awsome, light, eye catching, best value for the dollar airplane!!!!!! Pretty much makes up for not having a life since last february while I helped him finish the 10. Keep it up boys and girls, this is the 6'th plane I have built/helped finish, and it ALWAYS seems like there is no light at the end of the tunnel BUT, remember all tunnels have an end and these planes, despite an occasional glitch, are always well worth it. Keep going and join the "I built an airplane club". You will NOT regret it. Right Brent and Jim?
Glen

Really enjoyed the flight Glen....this was the pay-off for all the hard work we put into this project. Dad was either overwhelmed sitting in the back seet with the excitement, or he couldn't get a word in edgewise with Glen and I jabbering back and forth about EFIS stuff and piloting the plane we helped make fly. As my 3 year old grandson keeps saying " Good Job Paw Paw....awepane fwey in da sky"

[N395V]

Has Blue Mountain shown up yet?

If so what did they have to say?

Milt

[brenthg]

Originally Posted by N395V

Has Blue Mountain shown up yet?

If so what did they have to say?

Milt

They will be here this Wed, Nov 30th

[ship]

Originally Posted by brenthg

Hello Ship,

Threaded tube isn't exactly what we used for the 3.5' linkage, it is solid hex alum bar stock. We are certainly concerned about the flex in this linkage, but to eliminate the "over center", we are adding stops on either side of the servo control arm to make things safe. We're interested in what BMA can add to this when they look at our installation, too.

just curious why you chose a solid rod vs. a larger diameter thin-wall tube since rod is far more flexible under compression than tube at this length.

Originally Posted by brenthg

For now the linkage and servos are not connected and we intend to add a dedicated toggle switch as another safety precaution to the separate breaker already dedicated to the autopilot controller. This will allow us to power up the Master Switch and avoid sending any surges or low voltage spikes to the controller after the main buss is powered up.

The additional lockout is worthwhile precaution, but just another element to add to checklists, etc. Hope it all works out for you.

[ship]

Originally Posted by brenthg

They will be here this Wed, Nov 30th

This event STILL gives me the creeps.

I would be very interested in the following:

1) seeing if they can repeat the conditions/event
2) somehow measuring/calculating the force generated by the servos during this "surge" event.

Based on Glen's description, the servos acted more like solenoids than servos (as happened in 737 crashes) .....very dangerous.

+90% of flight hours are in cruise or pattern.

if this event happens on departure/approach/pattern, the RV10 is probably unrecoverable beyond 90* bank angle, i.e. less than a few seconds. TOAST

if this event happens at cruise speed (above Vma) we're talking possible bent/broken spar with consequent results. TOAST

Originally Posted by glenthompson

What happened was, the servos went nuts for whatever reason ( Brent spoke to larry and he cannot see how this happened, Bob and possibly Greg are coming here next week to cure our gremlins hopefully

"he cannot see how this happened" This is a frightening statement by the mere fact that it DID happen. Voltage spikes are a fact of life in small airplanes. As painful as it might be, if BMA cannot repeat the event, you may need to consider an alternative system or fly with the a/p disconnected. Hopefully they'll find a fix for you.

[rv9aviator]

Did the autopilot come with servo mounting brackets and hardware or were they built by the end user? I've heard they don't come with brackets. Just curious.

Jim Wright RV-9A 90919 wings Arkansas

[brenthg]

Originally Posted by rv9aviator

Did the autopilot come with servo mounting brackets and hardware or were they built by the end user? I've heard they don't come with brackets. Just curious.

Jim Wright RV-9A 90919 wings Arkansas

Servo mounting is left up to the builder. We are going to add stops in both directions to eliminate this ever happening again.

[mark manda]

How about a nylon shear bolt and then have straps or tube where the rod won't hinder movement?

[rv9aviator]

I think having the servo brackets furnished and engineered is a big plus when buying an autopilot. Also, I believe some sort of shear pin should be mandatory. There are two many ways a novice builder could build in a design flaw that might proove fatal, but that's just me ranting. Good friends especially RV friends are hard to come by.

Jim Wright RV-9A wings 90919