Pitot Static Check needed

While on a recent trip I noticed that when I set the altimeter it read about 200' low! I just moved to the DFW area and need to know who at Hicks or NW Regional or another close airport can do VFR pitot-static checks?

Thanks,

John

Call Mike Ferrer

Hi John,

I just had my altimeter/ transponder certification done by Mike Ferrer. Mike will come to your location or you can go to his hanger at Stagecoach Hills Airpark (4TX2).

Mike is a good guy who understands Experimentals. He is building an RV-7. His prices are very reasonable and he was very patient in sorting out my goofy static system.

His phone number is (817) 422-2714. Also check out his Website.

Call Mike. I'm certain you will be happy you did.

John:

I also used Mike Ferrer just a couple of months ago and recommend him.

Chris

Mike also does Prop Balancing.

Thanks. I'll check his web site and call him.

Mike Ferrier

Call Mike, He is a good man and will help.

He goes to the Bahamas every so often, so if you have to wait for a return call, wish you were where he is, it is a good place.

what is a VFR pitot/static test?

Bubblehead said:

VFR pitot-static checks?

Click to expand...

John's post got me thinking, and now I need some education here. John'd altimeter is off, but where in the FARs is the requirement for a VFR pitot-static altimeter test?

I found 91.411 but it start out with "No person may operate an airplane, or helicopter, in controlled airspace under IFR unless--"

In fact, I looked in 91.205 and John isn't even required to have a "sensitive" (which I think means adjustable) altimeter under VFR

So my question is, do we have to get regular pitot/static tests for anything other than the transponder?

Please don't flame me - I certainly think John should get his altimter fixed! Just trying to understand the FARs a bit better..

IowaRV9Dreamer said:

...t where in the FARs is the requirement for a VFR pitot-static altimeter test? ... Just trying to understand the FARs a bit better..

Click to expand...

I can understand your confusion, because the more I tried to write what I thought was the correct answer, the more complicated it became. Someone like Mel is probably your best source for comment here.

If your VFR only, I don't think you need the pitot static checks required in 91.411.

If you look at FAR 91.413 sections a) and b) you need a transponder check every 24 months. And since an encoder works through the transponder, I assume it needs to be checked as well. Yet the encoder depends on static air -- so wouldn't you need the static system also to be checked?

So someone who really knows the FARs please chime in since a straight read of 91.411 and 91.413 could leave a wrong impression of what is and is not required.

Assuming you're using Mode C (altitude reporting) then (required or not) I would think a prudent person would want to have the encoder that works through the transponder checked for accuracy within the error limits established by FAA (I believe it's a 125 foot error). After all, you fly based on your altimeter but if your encoder is sending out a far different altitude to ATC it could cause a serious safety problem. For pilots like me who fly VFR but under the Mode C veil of Class B airspace, I want to be sure that I have an accurate match between altimeter and encoder.

As a side note, my most recent encoder check in July showed it to be off by about 200' and was adjusted to correct this. I use the Ameriking AK350 -- an inexpensive but popular unit with RVs. What the technician and I conjecture about the incorrect setting is that the previous inspector who adjusted the encoder wrongly probably had not let the unit warm up long enough before making adjustments. My AK350 unit showed a change in readouts of more than 800' during the warm up period (5 minutes) before stabilizing. Taxi would usually take care of the warmup, but on a test bench someone inexperienced might not know to do this and start making adjustments too quickly. These days I seldom talk to ATC so I didn't know I was flying around with a 200' error in my readouts.

Now it's right on the money. I call a tower every now and then to check.

Chris

My encoder was originally about 200' off also. Was flying under Class B, when ATC reported to another aircraft that there were two targets. One was 200' off the altitude I was, and the other didn't have a reporting transponder. I later asked ATC for an altitude check to verify.

I did have the encoder adjusted at the hangar & signed off. For altitude checks these days, I use my Zaon MRX traffic avoidance monitor. It has an altitude reporting function that sees what ATC picks up. You just set your altimeter to 29.92 & compare. Some of the more expensive transponders will do this too.

edit. And since I fly around Class B often, but under the veil; I do monitor ATC, and find that I'm transmitting the correct altitude, when they pass it on to others.

L.Adamson --- RV6A

Here is what I think

The 24 month transponder check is for everybody, but this is to make sure that it is transmitting correctly. I don't think it has anything to do with the encoder. Now if you fly IFR, you need the static check to make sure the transponder transmits the correct altitude. If you only fly VFR and have a certified, TSO'd encoder then I don't think you need the static check. The reason most of us need it is because we have non TSO'd encoders and the FARs say they must be checked every 24 months. That is what I gleaned out to the FARs. I'm not sure I'm right though. Fire away.

cguarino said:

The 24 month transponder check is for everybody, but this is to make sure that it is transmitting correctly. I don't think it has anything to do with the encoder. Now if you fly IFR, you need the static check to make sure the transponder transmits the correct altitude. If you only fly VFR and have a certified, TSO'd encoder then I don't think you need the static check. The reason most of us need it is because we have non TSO'd encoders and the FARs say they must be checked every 24 months. That is what I gleaned out to the FARs. I'm not sure I'm right though. Fire away.

Click to expand...

I can't cite chapter and verse Charlie, but I don't think that TSO'd versus non-TSO'd makes a difference, becasue for IFR flight, you have to have the Mode C check regardless of if you have a TSO'd unit or not - TSO is not cited (as a discriminator), as I recall.

I'll let a legal-eagle track down the specific requirements, but I think that if you are going to be operating where mode C is required (like under a Class B veil), then it has to be operating within the regs, and the only way to ensure that (in the FAA's mind) is to have the 24 month check.

Paul

Mike Ferrer did a great job

He met me at the hanger last night and the job took about 2 hours. My transponder was off about 200' from the altimeter but not is withing 25 feeet or so. That's well within the requirements.

His website has some info from the FARs about what is required for VFR and IFR. Trnasponder check for VFR and pitot static check for IFR. He checked my pitot-static system and found a big leak that is probably at the static ports. I pulled the rear cargo floor and will track the leak down. It may be no sealant was used when they were installed. He also noted that they are the flush kind, not the raised kind so I need to do some digging into the VAF archives to refresh my memory on that issue. I am hoping I don't have to change ports and can just find a way to seal it up on the inside.

My thanks to Mike for fast, professional service and an intersting evening. Here's the link again for his website http://www.ferrer-aviation.com/.

Here is some info

Paul, I wasn't talking about the IFR check. I was talking about VFR static checks. The IFR checks are absolutely required but according to the website below, it looks like a one time deal for a VFR guy. The transponder check is still required every 24 months though. That can be done on the bench and does not require checking the encoder. At least that is how I read it. I couldn't find the FAR reference I was looking for.

http://bryanwristonaviation.com/index.htm

Maybe I can answer the question...

Let me see if I can shed some light on the subject without getting too tangled up in the FARs.

In all cases, the transponder has to be checked initially and then every two years (91.413a). This involves testing the transponder to see if it complies with the requirements in FAR 43, Appendix F. No check of the static system, altimeter or encoder. Really just a check to make sure the transponder works properly and doesn't cause interference to the ATC system.

Now, the first time a transponder and altitude reporting system is installed, the altitude encoder has to be checked and calibrated against the primary altitude indicator (91.413b). The altimeter and encoder must be within 125' of each other at various altitudes when set to 29.92 Hg. This also checks the wiring and insures you won't be transmitting the incorrect altitude. The only time this needs to be checked again is if you make a wiring or equipment change that could affect the altitude reporting system accuracy. For VFR aircraft, this is usually a one-time thing. Might be 20 years before it's tested again. However, if ATC says you are at one altitude but your altimeter says something else, you should get it tested. Still no requirement to check the static system or altimeter accuracy.

The above applies to both VFR and IFR certifications. In addition to the above, IFR certification requires the altimeter, static and altitude reporting systems to be checked for accuracy and leakage (91.411a) every 24 months.

Hope this helps. I tried to keep it simple so I'll stop here...

Thank you Mike. That clarifies a lot.

Chris

stub out the lines for testing

Mike, et.al.,
Would you recommend stubbing out a connection in the lines (pitot and static) to make it easier to attach the test equipment or is it just as efficient to disconnect from an instrument?

Doug

Generally speaking you should make every effort to test as close to the port as possible... If you're checking for leaks, they may be "downstream" of the instrument.... so hooking up directly at instrument isn't the best test of the whole system.

Just got back from the Bahamas and getting caught up...

For the static syustem, you could insert a tee fitting with a line that runs out to an easily accessable area and then cap it off. I would then place tape over the static ports and use that capped off line to attach my test equipment. From my perspectiove as a tester, it would be nice, especially for those with a slider canopy. Tip-ups offer easier access and the stub is not really necessary.

No need to do that for the pitot as my equipment simply attaches to the pitot tube.