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Pitot static system..

J

JoeB

Active Member
Taking a poll on who used the safe air static system. Vs stock vans.... Results on either
Joe
 
For the static port portion of it, I end up changing what I had as flush-to- the- skin port to the Van?s method to get the accuracy. For the plumbing portion, I replaced all my fittings with Parker Hannifin type since I had a good degree of leak and these make the seal virtually guaranteed. When my pitot/static test failed, I consider the push type connector similar as safe air, but my tester advised against it and said they seal much better under pressure as oppose to vacuum.

Here is a link to US Plastic that I got my fittings.
http://www.usplastic.com/catalog/item.aspx?itemid=31110
 
I used stock Van's rivet with center removed. Dynon pitot. My airspeeds are correct within a knot or two, so I'm happy.

As a curious side note, static systems are tested on the ground under vacuum; but in flight they are usually slightly pressurized (cabin lower pressure than outside static pressure). Pressurized aircraft excluded, of course.
 
Bob, they are only pressurised IF there is a static line leak. Your pitot static test guy will test for this.

MOST IMPORTANTLY you need to do a flight and set up in smooth air, with a constant airspeed, calculated TAS, and compare that to a GPS BOX test to get your actual TAS. At around 160 knots TAS, I would say a good result is less than 2 knots, 4 or more needs more work.

Static error not only affects how fast or slow you think you are going, but it affects your altimeter and encoder/transponder output.

My first test revealed -9 knots and from memory this calculated to a 138' error:eek:
 
Yes, when I said my airspeeds were very close to correct, that was after converting to TAS and flying around at various headings and noting gps ground speeds and doing the math to eliminate the wind factors.

True, a bad static will throw off the altitude, too. But, just as you observed, the indicated airspeed is usually the most sensitive (only 140 feet but 9 knots!)

Finally, I stand by my statement that in flight in a typical -10, the static line is slightly pressurized with respect to the cabin pressure. Experiment: open the alternate static valve to the cabin. You'll usually see the altimeter and airspeed indicator go higher, due to the cabin pressure being lower than the static line (and outside) pressure.

But maybe the test guy does pressurize the line during the test. He'd have to, to test it at sea level, since we're sitting 400 feet up.
 
Testing of Pitot and static systems:

Static System: 1000 ft above airport elevation, 100 ft/min leak rate max

Pitot System: 150 kts, 10kt/min leak rate (if no other limits are given this is the standard per 43.13)

Vaccum on the static lines and pressure on the Pitot.

Pitot system test not required unless it's a pressurized aircraft or by request.
 
Finally, I stand by my statement that in flight in a typical -10, the static line is slightly pressurized with respect to the cabin pressure. Experiment: open the alternate static valve to the cabin. You'll usually see the altimeter and airspeed indicator go higher, due to the cabin pressure being lower than the static line (and outside) pressure.
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Sorry Bob, I mmisunderstood what you were meaning.....so you think the cabin pressure is lower, quite possibly so. :)

So do you guys who are flying VFR only aircraft not have to conduct a static test leak test and altimetry test up to 20,000' every two years? We do. To FAR part 43.
 
RV10inOz said:
Sorry So do you guys who are flying VFR only aircraft not have to conduct a static test leak test and altimetry test up to 20,000' every two years? We do. To FAR part 43.
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In the USA for VFR only, a transponder check is the only thing required per CFR 43 Appendix F every 24 months.

For IFR then the complete check per CFR 43 Appendix E (altimeter, encoder, static system) must be done plus the transponder check above every 24 months.
 
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Safe air

Safeair for me, including the static ports, and all the way from ports and pitot to instruments. Solid, no leaks first time. Love it.
 
douglassmt said:
Safeair for me, including the static ports, and all the way from ports and pitot to instruments. Solid, no leaks first time. Love it.
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That's good to hear. Not flying yet but have fitted the SafeAir ports and piping. Dynon heated pitot, all connected to the Dynon Skyview ADAHRS
 
And.....Andair!

Oh, and you didnt ask, but since they're also from the mother country, I love the Andair pump, filter, and especially the fuel valve. :)
 
I have found leaks in the quick disconnect style fittings like safeair. It's usually caused by "gouges" in the end of the tube from repeated installation and removal (caused by the locking fingers). So when doing the final installation trim off about 1/2" to get rid of the defect. I also use a little bit DC-4 grease on them when assembling.
 
Walt said:
For IFR then the complete check per CFR 43 Appendix E (altimeter, encoder, static system) must be done plus the transponder check above every 24 months.
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This is correct based on my understanding of Reg and what I had meant by it. Just had my transponder/static system checked as mine was up for retest this month. No issues where found :)
 
I think this discussion is slightly academic. True, for VFR flight no checks are needed as long as you don't have a transponder. But for much of the US this is impractical. Especially in an RV-10, you'd be limited to below 10000' without a mode C transponder, no Class C, 30 miles away from class B, etc.. And if you have a mode C then they check for "data correspondence", eg it's sending out the right altitude. And since (most?) of us get the mode C altitude from an EFIS, you end up doing a static check on it anyway, even if indirectly.

In the US part 91 requires these checks for IFR operations.

I looked into the possibility of buying the required test equipment to do the tests myself (as the manufacturer), and perhaps sharing the costs with others. Turns out the FAA requires frequent (I think every 6 months) and expensive test lab re-calibration of the equipment, so you need to get a lot of use out of it to amortize that cost. Our local 'pro' has 2 test sets, at any given time one of them is in for re-calibration. This is his full time job, btw.
 
I used the SafeAir system - found some leaks during the IFR check. That suggestion of using grease is probably a good idea.

John
 
SafeAir system with 460 hours to date. I have been through two IFR pitot static cert tests with no leaks. I seem to remember SafeAir recommending a very good tubing cutter to insure a smooth cut. Important for avoiding leaks, IIRC.
 
Vans

Used Vans stock system, with some replacement parts off A/S, I forget which type. Worked perfect, no leaks (other than the built in one on the pitot tube I forgot about for a couple days :rolleyes: )

Dwight
 
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