Airdata accuracy

PilotKris

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CDR Kenneth G Kopp, US NAVY
Helicopter Maritime Strike - 70
Repairman, Builder, CFI, Graduate of US NAVY TEST PILOT SCHOOL Class 120, Test Pilot, Weapons Tactics Instructor/Evaluator, and Future Commanding Officer,  BS in Control Systems Engineering, MS in Aeronautical Engineering.   Logged over 4500 hours in 77 different military and civilian aircraft - Go ahead and tell me again how I'm not smart enough..... J.A.

I never said, or even implied that you aren't smart enough, I said that you aren't "capable" as you have to be CERTIFIED to perform that paticular operation...

PERIOD! END OF DEBATE...AGAIN!
 

PilotKris

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  Its a damn free country! Then again I'm not affraid to take responsibility for the changes I make...I guess you are. Knitting sweaters is a really safe hobby - you might try that - watch out for those needles though I hear they might poke you in the eye.

CDR Kenneth G Kopp, US NAVY

Ken, What was it you said about someone lacking tack?...

It's a same that will all your experience that you resort to personal attacks rather than logic to make a point.

That was really uncalled for and in very poor taste. You have significantly lowered my my impression of Naval Aviators...

PilotKris
 

Ken_Kopp

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I love this guy! "END OF DEBATE" again....

You mince words - when you state someone isn't "capable" your are not saying the same thing as "not authorized".

I know the regs very very well and have discussed this issue and many others with the Washington FSDO as I was being handed my repairmen certificate after a rather lengthy review of those regs.

Clearly you are lost in your own arguement so lets rebase ourselves shall we:

1. The issue is that some of us ( not a "CONCENSUS") believe it would be nice to have a method for applying a correction to Ps which exits in all airplanes. Ps is an error. A correction would fix this error making ALL altitude reporting more accrurate and therefore safer - if of course it is done ah em..correctly.

2. Kris believes making these corrections is somehow a bad idea and a violation of the FARs. He also believes that homebuilders are not "capable" of determining or applying these corrections. What if I put my EFIS in an ultralight? What then? Hmmmm

3. I believe Kris is wrong and that I as the builder and repairman of my EXPERIMENTAL airplane am authorized and just as importantly "CAPABLE" of making those corrections in anyway I see fit -be it mechanically or digitally and that all I have to do is pass ALL the required inspections performed by an authorized technician when and if they apply (bi-annually or when I conduct maintenance on the system). If I add a static dam or resevoir or change the software corrections I should have the system re-inspected but I am allowed to make the changes!

4. Kris still believes I'm wrong.

5. Kris believes the debate is over (again)

6. Kris no longer likes Naval Aviators


If Dynon provided a Ps correction it, like everything else in Experimental aviation, would be the responsibility of the owner, operator, builder, to ensure any changes to the systems are done to an airworthy standard - most of the time certifyable by the repairman . My suggestion would be to determine your Ps correction curve through whatever means you have available (GPS, timed course) and if it is significant enough to warrant a correction then experiment with it until you are happy. If you break your Pitot/static system integrity or change values in software then you need to have it inspected - duh.

Brantel - No thanks required I love my job, very exciting and always a challenge. Working with young sailors and pilots is amazing. But thanks for saying so....
 

Ken_Kopp

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Oh I just cant let it go now...I'm on a mission:

You might want to re-read FAR PART 91.411. The PITOT/STATIC system check is only for IFR flight either biannaully or when maintenance is performed as stated in part A and guess what...Part B allows the manufacterer to conduct the check. Guess what thats - me.

FAR Part § 91.411: Altimeter system and altitude reporting equipment tests and inspections -- FAA FARS, 14 CFR
http://www.flightsimaviation.com/data/FARS/part_91-411.html

The transponder check is required VFR or IFR and is done Biannually and any time you mess around with the transponder and guess what Part 3 says...the manufacterer can do this check too provided the manufacturer installed the transponder...Yep..me again.

FAR Part § 91.413: ATC transponder tests and inspections -- FAA FARS, 14 CFR
http://www.flightsimaviation.com/data/FARS/part_91-413.html
 

josok

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Dec 25, 2006
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On a longer trip, through 7 countries, hello, this is Europe, i was asked twice to report my altitude. The transponder happely squacked several flight levels different from altitude, becuase of extreme QNH´s Weaker souls might have started adjusting the encoder if that was possible. Better and easier to have it calibrated and fixed. There remains more then enough to tweak on an airplane, if you find yourself in the fingering mood.

Jos
 

Mel

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May 10, 2005
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3. I believe Kris is wrong and that I as the builder and repairman of my EXPERIMENTAL airplane am authorized and just as importantly "CAPABLE" of making those corrections in anyway I see fit
The repairman certificate for an Experimental Amateur-Built aircraft has nothing to do with maintenance. Anyone can maintain an E-AB aircraft. The repairman certificate ONLY allows the holder to perform and sign off the condition inspection required annually.
 

PilotKris

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Ken, Ken, Ken....

You certainly don't lack self-esteem do you...?

While you may be many things, you aren't an aircraft manufacturer (in the eyes of the FAA).

You who have built experimental aircraft are not "Manufactures", you are "BUILDERS".

Manufacture
refers to those who have earned a FAA Manufacturing (or Production) Certificate (not a Repairman’s Certificate).

When are you going to give it a rest?...

YOU CAN'T DO YOUR OWN P/S or TRANSPONDER CHECK!

PERIOD... (still) END OF DEBATE!
 

PilotKris

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Well Ken?

I thought you said you were on a "mission"?

It's been two days. Certainly someone with all your "qualifications" could come up with an answer by now...

PilotKris
 

PilotKris

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Since Ken doesn't seam capable of answering I will.

Yes, a builder of an experimental aircraft can modify the pitot/static and transponder any way he/she feels fits. That would include adjustments either mechanical or electronic to the altimeter or encoder.

However...

The aircraft could not be flown IFR and the transponder can not be operated unless they have passed the Bi-Annual check mandated by the FAA. Additional checks are required after any maintenance or modification of the system. This would include any "adjustments" to the altimeter or encoder (either mechanical or electronic).

Since the technician checking the system is using equipment that has been certified accurate, it is best that any adjustment be made at that time. The builder making his/her own adjustment is just a shot in the dark unless he/she is using test equipment and procedures are at least as accurate as the equipment that will be used to check the adjustments.

Ken Kopp’s suggestion that someone could use a GPS or timed course to adjust the altimeter/encoder (Ps) is fundamentally flawed as that is not the method that will be ultimately be used to certify the system. It would just be sheer luck if it worked. But hey, even a broken clock is right 2 times a day.

While the FAA's mandated method of testing is not perfect as it can not detect errors from things such as static source position errors, it is the game plan that we are required to follow.

Builders of experimental aircraft should be aware that these errors exist and methods to minimize them. But an electronic fix for them is just not in the cards as there currently no way for the accuracy of those corrections to be verified and more importantly certified.

PilotKris
 

vlittle

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May 7, 2006
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As discussed in other threads, an error in TAS can make the Dynon wind arrow useless for small magnitude winds.

In my A/C with a 4% low TAS indication, it means that I'm always flying with a headwind indication in calm air.

So, my opininion is that we in fact do need a TAS calibration table so that the wind arrow feature can work. Fiddling with static port dams and such is not a good idea, in my opinion, because they make the indicated altitude vary with airspeed, which is worrying.

I think that it would be possible for Dynon to build a correction table, starting at (for example) 50 knots to 250 knots with several calibration points (and altitudes) and linear or spline interpolation. IMHO, calibration can be semi-automated in flight using EDC headings and GPS ground speed inputs. With the Dynon autopilot, you could just push a button and have a nap!

Vern Little RV-9A
 

PilotKris

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IMHO, calibration can be semi-automated in flight using EDC headings and GPS ground speed inputs.  With the Dynon autopilot, you could just push a button and have a nap!

Vern Little RV-9A

WAY too many variables to have automatic GPS based CAS. (this was discussed in other threads a while back).

However, if your IAS is off by that much, your problem is most likely mechanical (Static Source Position Error or pitot placement). Don't cover up the symtoms, cure the disease.

PilotKris
 

PilotKris

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I had an RST MB in my BD-4 for years until I discovered (by chance) that the Garmin GMA-340 I bought and installed had one built in.

LOL... I just noticed what you said (in another thread).
LOL…That's so funny

Ken Kopp, Gods Gift to Naval Aviation (self proclaimed) didn't know how install an audio panel? That's it! I'm giving up working on avionics. If he can't do it, how can the rest of us mere mortals ever expect to be able to do it? ;-)

In all seriousness, thank you Ken for making my point.
Homebuilders do make (sometimes stupid) mistakes... yes, even you.

As long as you fly in the same sky as me, I remain adamant about having someone else certify your altitude encoder's accuracy.

PilotKris
 
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