Airplane Altimeters in an 80?

[RavenTai]

no Air data computers and display drivers are way out of our price range, I was originally thinking more of the stand-by instruments, they are fairly self contained and somewhat resemble GA instruments

sounds like this might actually be more do-able than I thought,

 

[IBCRUSN]

I hadn't thought of the standby units. Here in KS more standby's do get O/H'd and finding a red tagged unit is very rare.

eBay is probably the best place to start if price is the main driver.

 

[scubasteve]

My encoding altimeter has a range from -2000' thru 85000', the back up is a 2" model nonencoding. I also have a 2' verticle speed indicator with a 3000'/minute scale. These are cool to watch going up and down steep grades. I've hooked up and ran an airspeed indicator (Knots and MPH) a few times. Dealing with the pitot line and getting it set up is a pain in the ass.

Use Exmilitary stuff when possible, better quality s***.

 

[ginericLC]

Ginericfj80- does the Beechcraft unit run off of 12V for lighting?

It has luminous dial. ie it glows in the dark

 

[John E Davies]

I used to work on aircraft as an A&P - I even had a couple of non-certified altimeters for a while. You can certainly mount one in your Cruiser, but they are huge compared to modern digital automotive units. I don't know where you would put it except in a custom console.

If you want one really cheap, go down to your local small FBO radio shop at the airport and talk to the manager. They usually have some used ones sitting on a shelf that are removed when they can't be calibrated precisely. The cores are sent off to an instrument shop for rebuilding. I'm not sure about today, but ten years ago they only had a core value of about $25, so if you offer a little more than that they should be happy to sell you one. An out-of-spec instrument is still plenty accurate for 4 wheeling.

These are delicate instruments. Because small planes vibrate, normally they are mounted in an instrument panel with rubber shock isolation mounts. They will work fine on a car or truck - just be careful when handling so you don't give them too many Gs.

As others have pointed out, unless you know the current barometric pressure ACCURATELY they are not so great. If you only want accuracy within a few hundred feet they are fine. Otherwise you had better have an aviation weather band handy. Pilots routinely adjust their altimeters to field barometric pressure prior to every landing, and this gives them accuracy within 20 feet, usually.

If you don't know the current air pressure, but you DO know your exact current elevation (using a topo map or USGS marker) then you can dial in the correct elevation and be confident you are set right. This actually would work pretty well. You could just go to the top of a hill or mountain of known elevation, set the altitude, and continue driving for the rest of the day knowing your setting was right on.

My recommendation? Use a gps and some good topo maps. That's what I do. The topos are free, if you use a freeware program like USAPhotoMaps. You need the gps anyway, to get unlost.

John Davies
Spokane WA

 

[RavenTai]

one aircraft navagation aid I do lust after is inertial reference, (dream on)

you can tell it where you are in the US and fly half way arround the world and it will record every movement along the way with no external input at all, can tell you withing a few hundred feet where you are when you get there, couple it with ocational GPS correction and it is super accurate,

if soume one could mass produce a automotive version it could provide improvements not only in navigation but in ABS, traction control, roll stability rct, anything that need to know the speed, position, heading and orientation of the vehicle

 

[CELICA XX]

Also, mid 1980's Toyota 4x4 wagon Tercels had an almost identicle gauge set, however a 4WD light indicator was in place instead of the altimeter.

I LOVE those cars...

 

[IBCRUSN]

IRU's are nice and as you mentioned it's a pipe dream. Something a couple of the Garmin units have is dead reackoning for when you lose satellite signal. It is sort of similar to the IRU in that it bases future movements off of the last known position. It appears to reasonably accurate however I don't have it in my current model. I don't know that I would try it out in the woods w/o some practice first.

 

[RavenTai]

Is it accelerometer based or does it just continue you on at the speed and heading when it lost signal?

I have a laptop based GPS and when it looses signal (tree covered lanes etc) it would just continue on the arrow in a straight line at that speed, it was not very accurate here as there are no straight roads, it would show me in a field on the map. Maybe on foot it would not be as bad as you are not moving as fast,

Maybe in 20 or 30 years technology will bring the price and size of laser ring gyros down and they will start showing up in luxury vehicles.

 

[SUMOTOY]

one aircraft navagation aid I do lust after is inertial reference, (dream on)
if soume one could mass produce a automotive version it could provide improvements not only in navigation but in ABS, traction control, roll stability rct, anything that need to know the speed, position, heading and orientation of the vehicle

They've been in cars for years already, btreplacedt. Inertial brake controllers, inertia ABS, traction control, stability control, seat belts, gtech performance meter, all these are inertia based controllers.

I bought my inertia based G-analyst some 20 years ago RT, and it has data logging capability to draw the race course and overlay peak lateral and accel/decel g's. The hardware and technology is already in just about every new vehicle with stability control. Making the jump to black box tracking is coming, but there really isn't a big demand for it, yet. I suspect the insurance companies will probably mandate it before we will ever see it as a aid or tool.

Scott Justusson

 

[RavenTai]

the stuff you are talking about is bassed on accelerometers, not near as sensetive or accurate as lager ring gyros

 

[Grench]

Redneck measurements

Lateral force meter?

A fish scale and a weight suspended from the mirror should do it. You could use a gimble with a test tube, spring and a washer stack if you want to get fancy.

 

[450 DUDE]

If any one is interested in used avionics or aircraft parts for that matter Faith aircraft in Sac. has all kind of crap, with ok pricing .
Dont touch the seat belts (nasty)

ken

 

[SUMOTOY]

the stuff you are talking about is bassed on accelerometers, not near as sensetive or accurate as lager ring gyros

I disagree. The active traction control and stability control accelerometers are very sensitive and very accurate, and can easily be used in accurate navigation. The gtech meter for 270 bucks put it in perspective. I've run hundreds of quarter mile times over the years, and that gtech is about the most accurate 1350ft tool I've ever used. Add the software, and it can become a navigation instrument. In fact, I suspect that we will see automotive systems integrated with GPS to get accuracy below 50 feet. Think about it, the accelerometer only has to be accurate until the next GPS triangulation.

The tool is there, and it's extremely sensitive and accurate. The software isn't. Gyros are more accurate for in situ 'orientation' but I've always been able to tell other ways when my trucks are upside down.

SJ

 

[gnx7]

This company should be contacted about an altimeter guage. They make aircraft, commercial, industrial, and vehicle guages.

http://www.westach.com/

I have run their 30/30 boost/vac guage and 0-1650* EGT guage before in my Buick GN (turbo V6) powered RX-7

 

[evrythngbdaz]

I like the ideas. I am going to pursue the altimiter idea for my 40. I will keep you posted on my results.

 

[airlaird]

Well...I use helicopter cockpit lighting "stems" in my LC...very cool effect
airlaird