as you may have seen in my other question im currently compleating a university aerospace design project. this project involved attching a total head probe to an aircraft and route the appropriate pipes and electrical cables towards the apropriate areas.
the one part im confused with the the choice of pipe to be used, my lecturer said that any old pvc pipe will do (must be flexable BTW) but im thinking as it will be in a preasurised cabin it will be crushed under the differance in preasure.
what is used in the real world? where can be sourced etc
any ideas?
2006-12-29 00:50:01 · 9 answers · asked by Anonymous in Cars & Transportation ➔ Aircraft
Sorry for it not being too clear in that description but part of it does have to be flexible as it will need to be fitted from the outside of the aircraft
2006-12-29 01:07:27 · update #1
aluminum tubing, usually.
2006-12-29 00:57:49 · answer #1 · answered by delujuis 5 · 0⤊ 0⤋
For a project like this you could use just about anything as long as all the connections are air-tight. Just go to your local hardware store and pick up some flexible water lines typically white or clear and use this for the static side. Then to your local automotive store and ask for some rubber hoses. This hoses will be made of pvc and usually have a 120-150 psi rating and use this for your pressure side and you could also use this on the static side.
Due to personnel safety, you guys are not pressurizing the cabin more than a few psi. I don't even know why you will pressurize the cabin at all since there is no reason to do so to test a pitot static system.
It all depends on the equipment you will be using. Check the altimeter and find out if it has a 20K to 30K altitude scale. Which is probably what you are using and if so the internal bellows will be damage before you collapse a line. This is the altimeter used on non pressurized acfts and you could actually use worm clamps or tywraps to secure your hoses. But if you are using a 50K to 55K altimeter, then you better start practicing you metal tubing bending and flearing techniques.
The lines and hoses mentioned above are very similar to those used in the real world. The only difference that the stuff you buy locally is not FAA-PMA approved. But all you are doing is a school project. So I highly doubt the airworthiness of the probe, altimeter and airspeed indicator you are using.
The only electrical wires you should have are the wires for the heating element on the static probe and that is easy.
2007-01-01 03:20:08 · answer #2 · answered by jetech001 1 · 0⤊ 0⤋
Maybe this can help. As a mechanic, I have seen several ways on different aircraft. Mainly flexible nylon tubing, and aluminum tubing. Right now I work on CRJ-200s, they use aluminum with diameters of 3/16" and 1/4". The smaller for the drain line. With that, rigid lines need at least one bend, even if its a straight shot, to allow for flex, expansion/ contraction.
Smaller aircraft and helicopters use flexible lines. Maybe not all of them do, but the ones i've seen. Worked on helicopters for 7 years, this model used nylon with flared fittings.
As far as one type collapsing in a pressurized aircraft, I would have to look into that. Can't say for sure either way.
Flexible is easier to install/ remove as a mechanic. Rigid lines can be to, but our pitot probes are not easy to get to.
Mainly, it is not allowed to leak pressure ( outside of FAA limits ), or your instrumentation will not be accurate.
Try looking up Aeroquip on the net, large manufacturer of fittings and hose, don't know about rigid tubing though. Anyone who sells ALCOA aircraft metal may sell the tubing too.
2006-12-29 01:16:08 · answer #3 · answered by JET_DOC 2 · 0⤊ 0⤋
Use reinforced PVC piping, should be fine. I assume its a Pitot Head probe you are installing? Note there are a number of things to consider in addition to the piping, like "how are you mounting it", "do you know the resonant frequency of the probe/mount"? and "what is the resonant frequency of the aircraft"?
2006-12-29 01:15:30 · answer #4 · answered by Anonymous · 0⤊ 0⤋
%pipe is utilized in water purposes and regularly occurring enjoyed ones water tension is around 60 psid. what's the strain distinction your airplane will see? regularly airplanes have an 8000 ft cabin altitude at their optimal qualified ceiling. finding on their ceiling, you may assume 5-8 psid. whether you have been engaged on an airplane that maintained sea point cabin all a thank you to outer area, the strain differential would be below 15 psi. you will desire to be wonderful with the %.
2016-12-15 10:32:28 · answer #5 · answered by ? 4 · 0⤊ 0⤋
PVC or nylon that will hold 150 psi will not collapse under pressurizaton in an aircraft.
2006-12-29 16:26:19 · answer #6 · answered by eferrell01 7 · 1⤊ 0⤋
Aluminum tubing.
2006-12-29 01:02:50 · answer #7 · answered by strech 7 · 1⤊ 0⤋
Just don't bang your head into the pitot, don't ask how I'd know how painful this is.......
2006-12-29 09:18:00 · answer #8 · answered by Anonymous · 0⤊ 1⤋
yes
2006-12-29 00:57:05 · answer #9 · answered by Anonymous · 0⤊ 0⤋