Additional ASI to rear cockpit

[goosepool]

I am thinking about fitting an adittional ASI to the rear cockpit of my RV4, to allow my rear to take a spell at the controls, whilst I check charts, eat buns, drink tea etc. There is a throttle lever fitted in the rear cockpit. He is, like me, an old Pitts pilot and is quite used to looking at the back of someones head; whilst flying and carrying out the usual sideslipping trick, to enable him to see forward when required.

In the front I already have a standard 3-1/8 Vans bought ASI gauge and a Dynon EFIS unit; also with ASI. As a pilot with 44 years experience I prefer to have two ASI's on my front panel; just in case the Dynon (electronics/fuses) fail. Both are fed by a Dynon pitot tube located in the usual place under the port wing and are "Tee'd" together behind the panel.

I suppose the real question is; can I go on adding airspeed gauges to my present static and dynamic systems ad infinitum, or is there a limit to the length of tubing that can be used and the total number of gauges fitted, without causing inacurate readings. If I add a Vans miniature (2-1/4) ASI in the rear cockpit; it will add approx a further 4' of static and dynamic tubing.

[Kevin Horton]

The more volume there is inside all the tubing and instruments, and the longer the length of tubing, the greater the lag there would be before any change in airspeed or altitude is displayed on the instruments. But, practically speaking, lag effects are only significant when you have very large rates of change of airspeed or altitude (lag in altitude indications is a factor in fighter aircraft doing high dive angle weapons deliveries, for example). There would be no significant additional lag to adding a full suite of flight instruments to the back seat of your aircraft. There will be absolutely zero change to the accuracy when in a static condition, assuming that you haven't introduced a leak in one of the new connections.

[loopfuzz]

Originally Posted by goosepool

I am thinking about fitting an adittional ASI to the rear cockpit of my RV4, to allow my rear to take a spell at the controls, whilst I check charts, eat buns, drink tea etc. There is a throttle lever fitted in the rear cockpit. He is, like me, an old Pitts pilot and is quite used to looking at the back of someones head; whilst flying and carrying out the usual sideslipping trick, to enable him to see forward when required.

In the front I already have a standard 3-1/8 Vans bought ASI gauge and a Dynon EFIS unit; also with ASI. As a pilot with 44 years experience I prefer to have two ASI's on my front panel; just in case the Dynon (electronics/fuses) fail. Both are fed by a Dynon pitot tube located in the usual place under the port wing and are "Tee'd" together behind the panel.

I've been wanting this same thing. And I have been working on a solution. Here is pic of a pre-built lcd circuit I bought and have been programming to take the serial out of the dynon and display in the back seat for the co-pilot.

Chris.

[larryj]

Great info. I too am looking to put something in the back of my Rocket. I have spent quite a few hours in the backseat of an -8 with a Garmin 295. While the older Garmin's have slower processors I was still able to fly from the "six-pack" page. I now have a 496 and easily fly from the "six-pack" page with its faster processor and resulting faster responding VSI and HSI. I'm hoping that when the time comes I may have more options for the Rocket.