Toobuilder

Toobuilder

Well Known Member
As I?m adding the rear throttle in the -8, I'm wondering if it would make sense to add an autopilot disconnect back there as well. My thinking is if something should happen to me in flight with the A/P engaged, my back seater (likely my wife) would have one heck of a time fighting the autopilot. I don?t need full controls back there, but a throttle and full command of the flight controls is the bare minimum needed to get back on the ground. Any thoughts?
 
Dual everything

I am going to the expense of dual infinity sticks and both stick will have the same functions except no start switch for the back seat. I will only have throttle as well. My thoughts are like yours if I am back there I want all the controls, if someone else is back there I want them to have as much control over things in case I take a bird and or pass out.

Cheers
 
Same here. I have dual Infinity stick grips with PTT, Flaps, AP disconnect, Ident, Comm switch radios, Pitch & Roll trim. Also have throttle and rudder so have as much control in back as possible. Both for safety and to let my co-pilot have as much control as possible.
I also but a 'flap disable' switch on the panel to prevent an accidental flap lowering during cruise.
 
Just finished wiring autopilot disconnects (separate pitch and roll), PTT, and elevator trim for the back seat.
 
Stick Wiring

I started out thinking I wanted a simpler solution with an Infinity grip for the front but only PTT for the back seater...then changed my mind and added throttle and rudder pedals. Just ordered a second Infinity grip for the back so this is a timely thread in terms of planning the interconnect wiring.

I'm also interested in how you routed the stick wiring for the rear stick...both in the stick itself and then to the interconnect with the forward stick.Any pics of switch locations, terminal strip locations, wiring diagrams, etc. would be greatly appreciated!

Thanks,
Mike
 
Autopilot disconnect

I'm just wiring the two Tosten grips, which fit my hand very well. My wife will have access to disconnect, or more usefully the control wheel steering capability of the TruTrak Digiflight IIVSGV in our -8. We're using the trigger for PTT, small button below it for ident, right top button for freq swap and left top button for the autopilot. If any thing happens to me it should be helpful for her to put the airplane in any desired attitude and have the autopilot hold it. I'll make sure she knows how to do this and she could use the com swap to access guard (121.5). She'll have rear seat throttle and the rudder "buttons" which are at least somewhat useful. Electric trim should be easy and intuitive to use. It would still be very hard for the rear seater if I become incapacitated in front, but hopefully surviveable.
 
Transporter said:
Just ordered a second Infinity grip for the back so this is a timely thread in terms of planning the interconnect wiring.

I'm also interested in how you routed the stick wiring for the rear stick...both in the stick itself and then to the interconnect with the forward stick.Any pics of switch locations, terminal strip locations, wiring diagrams, etc. would be greatly appreciated!
Click to expand...

Can you install an Infinity or Tosten without hitting the front seat back?

Just curious....I wanted the rear stick easily removable (kids, nervous non-pilots, etc) so I never considered installing anything on the grip. The GIB's switches are on the left. Note the autopilot disconnects are located in a "bump-free zone". Same for the throttle pushrod. I got tired of backseaters bumping things in cruise and making my heart jump.



The trim relay block and terminal strip is up front, behind the panel.
 
Last edited:
Ironflight said:
Only if you want it - the airplane is flyable in a full out-of-trim condition at either end of travel. Not enjoyable, but flyable.
Click to expand...

If it was going to be only experienced pilots in back, I fully agree that fighting the trim long enough to get on the ground is not too difficult. In my case however, I'm thinking that a non-pilot (or limited experience) backseater will have enough on their hands while being "talked down" by ATC without having the airplane diving for the ground trying to maintain 170 kts in the pattern.

In my case, I think that all switches for the back seat should be placed so that it takes a deliberate act to move them though. Trim will normally be "hot", but the front seater can disable the rear switch if needed for some reason.
 
DanH said:
...I wanted the rear stick easily removable (kids, nervous non-pilots, etc) so I never considered installing anything on the grip. The GIB's switches are on the left. Note the autopilot disconnects are located in a "bump-free zone". Same for the throttle pushrod...
Click to expand...

My thoughts exactly...

...And I wish I'd seen your throttle control before I bought the Vans kit! As it was, I modified the Vans lever by shortening it a few inches and eliminating the bend to keep it out of the way. It's tucked in nice and tight against the sidewall now, but not as clean (and light) as yours.
 
...And another question...

Considering the "bare minimum" controls needed to land the airplane from the back seat in an emergency, how about mixture? If you're in cruise at 10,500 running 50 LOP (a common scenario for us out west), I'm thinking the engine will quit sometime before pattern altitude if the mixture is not moved. Thoughts?
 
If you're in cruise at 10,500 running 50 LOP ....I'm thinking the engine will quit sometime before pattern altitude if the mixture is not moved.
Click to expand...

There you go, complicating things again ;)

I got the throttle idea from Paul, and as I recall his original concept was dead simple, something like an arrow shaft to push or pull the power levers from the back seat as required.
 
Toobuilder said:
...And another question...

Considering the "bare minimum" controls needed to land the airplane from the back seat in an emergency, how about mixture? If you're in cruise at 10,500 running 50 LOP (a common scenario for us out west), I'm thinking the engine will quit sometime before pattern altitude if the mixture is not moved. Thoughts?
Click to expand...

Backseat passenger can use their foot to push engine controls forward in an emergency.

Skylor
 
skylor said:
Backseat passenger can use their foot to push engine controls forward in an emergency.

Skylor
Click to expand...

Absolutely - in fact, if the rear seat passenger stretches their legs out, make sure to guard the mixture or you'll discover later you've been cruising way rich.....:rolleyes:

With a "swizzle stick" for the rear seater to grab the throttle, you've got what a pilot/passenger needs to land. A non-pilot trying to fly for the first time doesn't need much to complicate their life in my opinion. Remember - there probably won't be a Controller to talk to who knows the configuration of your plane - it's not like a certified airplane with a well-known configuration. Imagine describing to someone how to operate someone else's RV - without ever having seen it.

My thoughts for back seat operation are to keep things insanely simple - and for the front seater to stay healthy and avoid birds.;)

Paul
 
A word from an experienced RV-8 GIB

After reading this discussion, I've concluded that Paul's swizzle stick really is the best answer (for us). Not only can I control the throttle, I can also reach the mixture and prop. I bet that I can disconnect (and engage) the AP, as well, although I haven't tried. Trim? I've flown an RV badly out-of-trim for over an hour before. I could probably also hit the flip-flop button on the radio, although I doubt that I could tune them. Of course, we'll ground-loop after landing with no rudders, but that will be the least of my worries in such a situation. (BTW, my legs can reach the throttle control but I wouldn't expect everyone's to be that long.)

As for someone with little or no pilot's experience landing an RV-8 from the back, I think they have virtually no chance. If you really want your non- (or low time) pilot/passenger to have a shot at landing the plane with an incapacitated PIC, build a side-by-side and build the panel as standard as possible. (Of course, then they get hit by the bird, as well.) I'm not seeing a real value in adding a lot of gizmos to the back for emergency uses. A PTT, swizzle stick, and rudders seem to me to cover the emergency applications.
 
Louise Hose said:
...As for someone with little or no pilot's experience landing an RV-8 from the back, I think they have virtually no chance...
Click to expand...

That's a bit harsh, especially if you're not expecting to reuse the airplane again. ;)

As for the comments about a standard configutation, I don't think it makes a whole lot of difference. Elevator trim performs the same function on an RV as it does a Cessna, so in that respect I'll bet a controller could talk someone down to the runway environment with a fair bit of success. 70 MPH is a fairly survivable speed in an airplane. The main concern (I think) is ending up with the airplane on its back.

Anyway, thanks for the discussion. Lots of good info and ideas.:)
 
You must log in or register to reply here.