IFR Check

[kandjw]

I have been flying my RV6 since 1999 and after my second vacuum pump failure last week I am thinking of replacing the vacuum gyro instruments with a D10A. I fly IFR occasionally and each two years have the attimeter and static system checks done by one of two local instrument shops. Will those checks be any different with the Dynon? I expect they will just power up the system and watch the altimeter reading on the Dynon as they run it through the altitudes, checking for leaks, etc. Is that correct? Have you had reports of shops not being willing to certify the instrument for IFR? I ask because the in my last check the shop owner questioned the suitability of my altimeter for IFR because it was not on a list he had. After some discussion he signed it off - but that is what prompts this question.

Thanks,
Keith W. Moline IL

 

[dynonsupport]

Yes, you can test it in the normal way.

We definitely have customers that are our there with our systems who have had them pitot/static checked, but as you said, sometimes individual shops will give you some resistance if they're used to only working with steam gauges. There isn't anything that we know of that prevents you from using our products in your IFR panel though, and I don't think there are any regulations that specify TSO'd or STC'd airspeed indicators and altimeters.

 

[Ken_Kopp]

you are correct that no regulation stipulates a specific instrument must be TSO'd but the altimeter does need to meet the standards of the applicable TSO. This is in the regs - Part 43. Some shops will interpret this to mean that the instrument must be TSO'd since they may not be able to (or willing) to verify it meets the standards.

 

[TRCsmith]

Also under part 43 it states that "43.1 (b) this part does not apply to any aircraft for which the FAA has issued an experimental certificate"....



tom

 

[TRCsmith]

Sorry.. That is if we are talking about Experimentals.......




Tom

 

[Mike_F.]

Actually, he meant 91.217 (not 43). So, the question is, does Dynon's products meet TSO-C10b and TSO-C88 specifications?? If not, then the operator of the aircraft would be in violation of 91.217 unless you had other equipment onboard that did meet the TSOs.

91.217 DATA CORRESPONDANCE BETWEEN AUTOMATICALLY REPORTED PRESSURE ALTITUDE DATA AND PILOT'S ALTITUDE REFERENCE.

No person may operate any automatic pressure altitude reporting equipment associated with a radar beacon transponder--

(a) When deactivation of that equipment is directed by ATC;

(b) Unless, as installed, that equipment was tested and calibrated to transmit altitude data corresponding within 125 feet (on a 95 percent probability basis) of the indicated or calibrated datum of the altimeter normally used to maintain flight altitude, with that altimeter referenced to 29.92 inches of mercury for altitudes from sea level to the maximum operating altitude of the aircraft; or

(c) Unless the altimeters and digitizers in that equipment meet the standards of TSO-C10b and TSO-C88, respectively.

 

[dynonsupport]

We have not tested or checked against the TSO standards, BUT.....

We satisfy clause (b) (we're within 0 feet 100% of the time when set to 29.92, because the devices are one and the same).

Note that the language specifies that only (b) or (c) need be met.

 

[Mike_F.]

Interesting interpretation but I don't think it's (a) AND ((b) OR (c)).  I interpret it to say that if you fail to satisfy (a) or (b) or (c), you "...cannot operate any automatic pressure altitude reporting equipment associated with a radar beacon transponder."  The semicolon after each subparagraph makes me think that each subparagraph stands alone, perhaps I am wrong.

Do you by chance have anything from the FAA supporting your interpretation? If not, I may initiate a request for clarification since this subject comes up frequently.

Mike F.

 

[meljordan]

Mike,

It is pretty clear if you just read (b) it ends "aircraft; or" . The semicolon comes after the "aircraft" but before the "or". To me it is very clear that you must meet (a) and either (b) or (c). (b) is for combined altimiter/encoders and (c) is for separate altimeters and digitizing encoders. If they had intended that you had to meet both (b) and (c) they would use the word "and", not "or".

To meet (b) you need to have the system tested in your aircraft ("as installed"), but this is part of the normal 2 year transponder check or as part of an IFR check.

If you choose to contact the FAA on this, please only do so in regards to your own aircraft. Remember the recent "clarification" that the FAA came up with regarding the use of TSO'd GPS units and DME fixes. Also, my experience with the FAA is that for any given number of FAA inspectors queried, you will get an equal number of different interpretations of any given regulation. I for one do not need any additional clarification. As the manufacturer of my aircraft I have read the regulations and am quite confident that the equipment I have installed meets all standards required by the FAA. Additionally, my Avionics shop had no problem doing an IFR cert. on my equipment (two Dynon EFIS units with no mechanical gauges) and in fact said that they were more accurate over the altitude and airspeed range than any mechanical system he had ever tested. So if you choose to bring this up with the FAA, please do so only on your own behalf and in regards of your own aircraft.

Thanks,
Mel Jordan

 

[Mike_F.]

Mel,

If you look through Part 91, you will find several instances where items are listed in a similar fashion. For example:

91.17   Alcohol or drugs.
   
   (a) No person may act or attempt to act as a crewmember of a civil aircraft—

          (1) Within 8 hours after the consumption of any alcoholic beverage;
          (2) While under the influence of alcohol;
          (3) While using any drug that affects the person's faculties in any way contrary to safety;or
          (4) While having an alcohol concentration blah blah .....

 
It is clear that they meant (1) or (2) or (3) or (4) or any combination, thereof.   All four items carry equal weight.

The reason avionics shops are not concerned about 91.217 is because it applies to the operator of the aircraft (you and me), not maintenance personnel.  Avionics shops perform 91.411 and 91.413 inspections, which do not mention anything about TSO requirements. In addition, those biannual inspections do not mean that the equipment meets any TSO specification.  

Not trying to rock the boat, just trying to understand the regulations. As an avionics shop technician, RV-7 builder and future purchaser of Dynon gear (nice stuff!), I was only searching for the truth.

 

[triple7driver]

Okay Mike,

Let me say this about that....in 14,000 hrs of combined military and civilian
flying never once, I repeat never once after making an approach in less than VFR conditions has there ever and I do mean EVER been anyone from the FAA anywhere in sight to see what kind of equipment that I had on board. Is that legal... I don't care, that's right I really and sincerely don't care. I do what I have got to do to get back to planet earth. I find the dynon with the battery back-up to be far better than anything that the powers that be have approved back in 1947 for then IFR flight. Would I file IFR as equipped ...NO. However if in the course of a VFR flight that started to go bad would I worry about it.....absolutely and positvely NOT. What are your questions ?

Cheers,
RP

 

[Mike_F.]

OK Randy.

Thats all real interesting but the discussion is about the interpretation of and compliance with 91.217, not what you can do in an emergency after getting yourself into a jam. The quality and reliability of the equipment was not in question, either.

I do have a question for you, though.  You said:

"Would I file IFR as equipped ...NO."

Why not?

Mike

 

[meljordan]

Mike F.

You may want to reference this EAA document;

http://members.eaa.org/home/homebuilders/faq/Equipping%20a%20Homebuilt%20for%20IFR%20operations.html?

The EAA has addressed this point in regards to the applicability of TSOs to experimental aircraft.

Also, be assured that I fully understand that a biannual check by an avionics shop does not bestow a TSO on a piece of equipment, I was only pointing out that I have test data and logbook endorsements that supports that my Dynon equipment performs at or above the standards required for equipment to be used in IFR operations.


Regards,
Mel Jordan

 

[Mike_F.]

Mel,

Sounds like the EAA agrees with my interpretation. According to the EAA, the altitude reporting equipment must "meet" 91.217c. Dynon said they have not tested their equipment to TSO standards and, therefore, cannot say it "meets" the TSO. If Dynon would belly up to the bar and say their equipment meets the TSO, the problem would be solved.

From the EAA:

The requirements for altitude reporting equipment associated with the transponder are called out in 91.217(c), which states that, the altimeters and digitizers must meet the standards of TSO-C10b and TSO-C88, respectively. TSO-C10b applies to the sensitive altimeter itself, and TSO-C88 applies to the automatic altitude reporting equipment. Again the equipment is required to meet the standards of the applicable TSO’s, but not necessarily be produced under a TSO authorization. But as with the transponder, the easiest way for a builder to meet this requirement is to install equipment manufactured under a TSO authorization.