S

sjhurlbut

Well Known Member
I'm fighting a battle here in Canada of whether I need a TSO'd altimeter or not for IFR flight.

I've had the "VFR only" restrictions removed over 2 years ago and have been flying IFR with a non-TSO'd altimeter all along.

Now it time to get my re-cert and the avionics shop insists I need to replace my altimeter (which works perfectly) for a $850 TSO'd version. This is despite the fact that a senior advisor from Transport Canada agrees with me that I DO NOT require a TSO'd altimeter (have the email to prove it). Since there is only 1 avionics shop in the Canadian maritimes I'm kind of stuck until the issue gets sorted out. So either I've been flying IFR illegally for 2 years or someone else has the info wrong.

So I'm looking for US documentation that specifically says TSO'd equipment is not required for IFR flight in amateur built aircraft. If I can find the US documents it will help track down the Canadian equivalent.

Thanks
Steve
7A Flying
 
Issues

1. Canadian rules are likely different than U.S. If the airplane is to be registered in Canada then U.S. rules won't help you much.
2. If you intend to fly to the U.S. then when crossing the border except with a prior, explicit waiver, you will need and operating Mode C transponder and that does have to be TSO'd.
3. I can't cite the rule in the FAR's but my altimeter IS certified for IFR flight and is NOT TSO'd. That said, it did have to have an IFR check to 20,000' by a technician legally entitled to perform it. That check included the reported pressure altitude sent to the transponder.
4. There is a mutual letter between FAA and Transport Canada. EAA has a copy on their website. If you intend to fly in the U.S. then carry a copy of the letter with your aircraft papers.

I hope this helps a little.
 
hevansrv7a said:
1. Canadian rules are likely different than U.S. If the airplane is to be registered in Canada then U.S. rules won't help you much.
2. If you intend to fly to the U.S. then when crossing the border except with a prior, explicit waiver, you will need and operating Mode C transponder and that does have to be TSO'd.
3. I can't cite the rule in the FAR's but my altimeter IS certified for IFR flight and is NOT TSO'd. That said, it did have to have an IFR check to 20,000' by a technician legally entitled to perform it. That check included the reported pressure altitude sent to the transponder.
4. There is a mutual letter between FAA and Transport Canada. EAA has a copy on their website. If you intend to fly in the U.S. then carry a copy of the letter with your aircraft papers.

I hope this helps a little.
Click to expand...


I'm aware of all these issues and have flown IFR and VFR in the states many times.

The reason I ask for the US documentation is that is WILL help me. Transport Canada uses FAA generated documents especially TSO documentation such as C10b, C74c, and C88b.

The altimeter checks (to 20,000 ft), transponder checks, and the pitot-static checks are the same in both countries.

Just need to find a firm statement on the TSO non-requirement.

Steve
7A Flying
 
The US FAR sys...

Sec. 91.411

Altimeter system and altitude reporting equipment tests and inspections.

(a) No person may operate an airplane, or helicopter, in controlled airspace under IFR unless--
(1) Within the preceding 24 calendar months, each static pressure system, each altimeter instrument, and each automatic pressure altitude reporting system has been tested and inspected and found to comply with appendix E of part 43 of this chapter;
(2) Except for the use of system drain and alternate static pressure valves, following any opening and closing of the static pressure system, that system has been tested and inspected and found to comply with paragraph (a), appendices E and F, of part 43 of this chapter; and
(3) Following installation or maintenance on the automatic pressure altitude reporting system of the ATC transponder where data correspondence error could be introduced, the integrated system has been tested, inspected, and found to comply with paragraph (c), appendix E, of part 43 of this chapter.
(b) The tests required by paragraph (a) of this section must be conducted by--
(1) The manufacturer of the airplane, or helicopter, on which the tests and inspections are to be performed;
(2) A certificated repair station properly equipped to perform those functions and holding--
(i) An instrument rating, Class I;
(ii) A limited instrument rating appropriate to the make and model of appliance to be tested;
(iii) A limited rating appropriate to the test to be performed;
(iv) An airframe rating appropriate to the airplane, or helicopter, to be tested; or
[(v) deleted]
(3) A certificated mechanic with an airframe rating (static pressure system tests and inspections only).
(c) Altimeter and altitude reporting equipment approved under Technical Standard Orders are considered to be tested and inspected as of the date of their manufacture.
(d) No person may operate an airplane, or helicopter, in controlled airspace under IFR at an altitude above the maximum altitude at which all altimeters and the automatic altitude reporting system of that airplane, or helicopter, have been tested.

---------------------

The actual requirement seems to be "tested"

(3)(c) seems to say that no testing is needed on new TSO equipment until the first two years....

But the rest of the FAR says that "if tested" by the appropriate folks in the previous 24 months.

The Part 43, Appendix E, which define the testing standard, is here...

http://rgl.faa.gov/REGULATORY_AND_G...6d8dd8e42faab642852566ab006bcd8b!OpenDocument

...sounds like any avionics shop should be able to test your non-TSO altimeter to these standards.

Anyone else read it differently?
 
The testing standards are exactly the same in Canada. But no where in the regs have I found a statement that says "non-TSO'd equipment is permitted for IFR flight as long the aircraft is non-certified, i.e. amatuer built".

All the testing, all the paperwork is the same in Canada for certified aircraft and amateur built, I just can't find that magical statement that permits me to use non TSO'd.

I know its allowed I just need that killer statement to present to the jury.

Steve
7A
 
What does it say...

sjhurlbut said:
The testing standards are exactly the same in Canada. But no where in the regs have I found a statement that says "non-TSO'd equipment is permitted for IFR flight as long the aircraft is non-certified, i.e. amatuer built".

All the testing, all the paperwork is the same in Canada for certified aircraft and amateur built, I just can't find that magical statement that permits me to use non TSO'd.

I know its allowed I just need that killer statement to present to the jury.

Steve
7A
Click to expand...

Did you find one that says "it must be TSO'd"?

If not, then I would say the IFR flight requirements would be applicable...:)

FAR 91.141 says what is needed for IFR flight, and even has an initial constuction statement.
 
The regs never state that something "non-TSOd may be used." It is the fact that it does not say that it MUST be TSOd. FARs are usually written in "negative" terms. Example: Regs don't say, "You can fly at night if properly equipped." They say, "You can't fly at night unless properly equipped."
 
Last edited:
Steve,

The equipment requirements in CAR 605.18 do not mention a TSO requirement for altimeters for IFR flight. The calibration checks are called up in CAR 605.86, (requirement for a maintenance schedule), and the details of the required maintenance schedule are in CAR Std 625 Appendices B and C. CAR Std 625 Appendix C says:

Altimeters and other Altimetry devices installed in aircraft operating under Instrument Flight Rules, or under visual flight rules in Class B and C Airspace or Class C and D Airspace that is designated as ?Transponder Airspace? shall be calibrated at intervals not exceeding 24 months, to the parameters and tolerances outlined in Appendix B of Standard 571, or to equivalent standards acceptable to the Minister.
Click to expand...

I had a somewhat similar discussion with Woodlawn Instruments in Ottawa. I took my non-TSO'd altimeter there for a check before first flight, as I want to be able to fly VFR in Transponder Airspace during the test phase. At first, they didn't want to touch it. Then I told them that I didn't need them to certify it - all I needed was a test report that documented the results of their bench tests - I didn't need them to put their official stamp on the test report if they didn't want to. Then, I compared the results of their bench tests to the official pass-fail criteria in Appendix B of Standard 571, and once I was satisfied that the altimeter had passed, I attached a copy of the test report in the logbook, and made a logbook entry something like "I certify that the altimeter has been calibrated to the parametres and tolerances outlined in CAR Std 571 Appendix B". I also made a logbook entry documenting the static system leak check I did after I reinstalled the altimeter and altitude encoder.

You are the one who has the responsibility to determine whether the altimeter complies with the requirements or not. The avionics shop is simply providing you test data to help you make that determination.
 
I don'y want to add confusion, but the IFR Ops Rule CAR 605.18 (a) and (b) refer to CAR 605.16 (1) where sub-paragraph (b) says : "a sensitive altimeter adjustable for barometric pressure".

Many moons ago when I was involved with TCCA on an encoding altimeter issue, I did receive from HQ a ruling where "sensitive altimeter" mean't an altimeter complying to TSO c10b or equivalent.

As far as I can read it, CAR 605 makes no refrence to the nature of your Flight Authority. Therefore, my understanding is that unless exempted under 5.9 (2) of the Aeronautics Act an Experimental a/c needs to comply with CAR 605.16 and CAR 605.18 though it may not have to have parts or their installation certified other than iaw the provisions of CAR 571 and other referenced regulations.

No matter the above, anyone will agree that it is proper airmanship to have the systems that provide the required IFR separation with other a/c, poeple or property in compliance and maintained iaw the relevant regulations and standards (note that the regulator doesn't care about the way you choose to go, but you can't choose for the others !).
 
They have you over a barrel

The guy who sold me my 9A ran into the same problem. They refused to do the cert on a non TSO altimeter so he had to buy one. He was in a time jam because we were closing the sale so he couldn't shop around.

Its BS, but the IFR cert forces you to do what they say if you want it from them.

I'm going to look around for a shop that doesn't require that for the next one

By the way, the EAA seems very clear that NOTSO equipment is required for experimentals whether VFR or IFR
 
JetA4GA said:
I don'y want to add confusion, but the IFR Ops Rule CAR 605.18 (a) and (b) refer to CAR 605.16 (1) where sub-paragraph (b) says : "a sensitive altimeter adjustable for barometric pressure".

Many moons ago when I was involved with TCCA on an encoding altimeter issue, I did receive from HQ a ruling where "sensitive altimeter" mean't an altimeter complying to TSO c10b or equivalent.
Click to expand...
Interesting. I had always understood a sensitive altimeter to be one that had a needle with one revolution per thousand feet, as compared to the one in the J-3 Cub I learned to fly on, that had a single needle, with one revolution per 10,000 ft.

Several years ago when I was deciding which flight instruments and avionics to purchase, I dug into the regs, and then queried the guy in TC who is responsible for the regs dealing with amateur-built aircraft. He confirmed my understanding that while altitude encoders, transponders and IFR GPS units must have TSOs, ASIs, altimeters, etc do not require them, even for IFR flight. As long as my non-TSO'd altimeter will pass the tests I will use it. Based on the initial test results, it has lots of margin to the test requirements.
 
I just reported what I officially received from HQ many moons ago (that memo is probably still in my old binders at NAI); I did not mean I fully agree with it; Obviously it changed in the last 20 years.

From a practical standpoint and a flight test point of view I think day-VFR flights are not a concren; As for IFR flights the hazards should normally be assessed and risks mitigated against the specifics of any intended IFR flights (i.e. IFR in VMC vs IMC CAT I ILS to minimums). The a/c are experimental and by definition do not require to be or have approved systems (i.e. TSO or equivalent). Based on the capabilities and qualifications of each individual, enough evidence/data/comparables should be obtained for any system to ensure that it will perform its intended function as envisaged by the relevant Ops rule and sound airmanship in the context of a given flight.
 
US is similar

Kevin Horton said:
Interesting. I had always understood a sensitive altimeter to be one that had a needle with one revolution per thousand feet, as compared to the one in the J-3 Cub I learned to fly on, that had a single needle, with one revolution per 10,000 ft.

Several years ago when I was deciding which flight instruments and avionics to purchase, I dug into the regs, and then queried the guy in TC who is responsible for the regs dealing with amateur-built aircraft. He confirmed my understanding that while altitude encoders, transponders and IFR GPS units must have TSOs, ASIs, altimeters, etc do not require them, even for IFR flight. As long as my non-TSO'd altimeter will pass the tests I will use it. Based on the initial test results, it has lots of margin to the test requirements.
Click to expand...

This is similar to the US...

FAR 91.215 is quite specific about meeting the requirements of a TSO for transponder systems....

ATC TRANSPONDER AND ALTITUDE REPORTING EQUIPMENT AND USE.
(a) All airspace: U.S.-registered civil aircraft. For operations not conducted under part 121 or 135 of this chapter, ATC transponder equipment installed must meet the performance and environmental requirements of any class of TSO-C74b (Mode A) or any class of TSO-C74c (Mode A with altitude reporting capability) as appropriate, or the appropriate class of TSO-C112 (Mode S).

This FAR also seems to be an exception to "Mel's rule" (negative terms) about saying what you can't do...:)
 
Kevin Horton said:
Interesting. I had always understood a sensitive altimeter to be one that had a needle with one revolution per thousand feet, as compared to the one in the J-3 Cub I learned to fly on, that had a single needle, with one revolution per 10,000 ft.

Several years ago when I was deciding which flight instruments and avionics to purchase, I dug into the regs, and then queried the guy in TC who is responsible for the regs dealing with amateur-built aircraft. He confirmed my understanding that while altitude encoders, transponders and IFR GPS units must have TSOs, ASIs, altimeters, etc do not require them, even for IFR flight. As long as my non-TSO'd altimeter will pass the tests I will use it. Based on the initial test results, it has lots of margin to the test requirements.
Click to expand...

And that is what I understood as well and have had my "VFR only" restriction removed for over 2 years now. However the only avionics shop in the Maritimes refuses to perform the cal on my altimeter.

Steve
 
Kevin Horton said:
He confirmed my understanding that while altitude encoders, transponders and IFR GPS units must have TSOs, ASIs, altimeters, etc do not require them, even for IFR flight. As long as my non-TSO'd altimeter will pass the tests I will use it. Based on the initial test results, it has lots of margin to the test requirements.
Click to expand...


One thought: The altitude encoder needs a TSO but if of the blind encoder type, for ATC purposes it forms a system only when associated with the a/c altimeter (Re. data correspondance check); If non-TSOd the altimeter then becomes the weak certification link of the chain; To me it sounds like a case where the regulator missed it when it is coupled to a blind encoder (TCAS was also probably not envisaged back then) !


Note also this excerpt from TSO c10b:

? 514.20 Aircraft altimeter, pressure actuated, sensitive type - TSO-Cl0b--(a) Applicability--(1) Minimum performance standards. Minimum performance standards are hereby established for aircraft altimeters which specifically are required to be approved for use on civil aircraft of the United States. New models of altimeters manufactured for such use on or after September 1, 1959, shall meet the standards set forth in SAE Aeronautical Standard AS 392C,1/ ?Altimeters, Pressure Actuated Sensitive Type,? revision date February 1, 1959, 2/ with the exceptions listed in subparagraph (2) of this paragraph. Altimeters approved under prior issuances of this section may continue to be manufactured under the earlier provisions.
 
I thought a "sensitive altimeter" was just one that is adjustable for atmospheric pressure. I don't think non-sensitive altimeters exist anymore.

Steve
7A
 
Canadian definition, eh

sjhurlbut said:
I thought a "sensitive altimeter" was just one that is adjustable for atmospheric pressure. I don't think non-sensitive altimeters exist anymore.

Steve
7A
Click to expand...

The Canadian definition is a bit more involved....:)

Definitions
For the purpose of this PL, the following definition of a ?sensitive altimeter? (Sensitive Type,Pressure Actuated Altimeter) has been taken from NPA 2003-007:
?A sensitive aneroid barometer, constructed so as to respond to pressure changes with a high degree of sensitivity that is graduated and calibrated and used chiefly in aircraft for finding distance above sea level, terrain, or some other reference point by a comparison of air pressures.?

Specific North of the Border requirements are spelt out in this document for VFR and IFR markings (50 ft markings vs. 20 ft markings) -

http://www.tc.gc.ca/CivilAviation/certification/guidance/551/pdf/551-001.pdf

Interestingly enough, having an adjustable pressure window is not mentioned - but certainly would be needed to get 20 ft increments and calibration...:)
 
The 50 feet markings are somewhat inconsistant for IFR use since the airspace system for approaches is designed around 20 feet increments.

I remember having discussed that with my counterpart at the FAA around 1990; They said that a small a/c OEM got them approved in the 70's as part of the a/c TC but that they would not allow it anymore.

As for the NPA 2003-007 you are referring to, it looks like that once CAR 551.110 is promulgated, TSO c10b will become mandatory where sensitive altimeters are required; However, the 50 feet markings is still there for IFR to CAT I !
 
How does this relate to an EFIS

Pardon my lack of technical insight on this subject but are there any differences in the way an EFIS would detect altitude vs a mechanical altimiter? My set up has the AFS unit feeding a dynon encoder (just a serial to parallel converter) then to the transponder. Do EFIS units have to be checked/calibrated for altitude just like the mechanical units? I do also have a mechanical back-up + GPS altitude so I will hopefully be able to see if one of the 3 disagrees. I know this has nothing to do with certification or transponder broadcasting of alt but it is good redundancy :)
 
andrew phillips said:
Pardon my lack of technical insight on this subject but are there any differences in the way an EFIS would detect altitude vs a mechanical altimiter? My set up has the AFS unit feeding a dynon encoder (just a serial to parallel converter) then to the transponder. Do EFIS units have to be checked/calibrated for altitude just like the mechanical units? I do also have a mechanical back-up + GPS altitude so I will hopefully be able to see if one of the 3 disagrees. I know this has nothing to do with certification or transponder broadcasting of alt but it is good redundancy :)
Click to expand...
You will have two problems with this setup:

  1. You do not have a TSO'd altitude encoder (the TSO requirement comes from CAR 551.103). Thus you cannot legally operate your transponder, which means you cannot fly in transponder airspace, and there is a lot of that around Ottawa.
  2. You may have some problems finding a shop that will consent to do the altimeter calibration on the AFS EFIS. Although Woodlawn Instruments eventually agreed to do the altimeter calibration tests on my non-TSO'd round dial altimeter, they refused to do the same on my Dynon EFIS, as they claimed they had no ability to make any needed adjustments on it. I didn't do a "Press to Test" by saying "why not do the test and maybe it won't need any adjustments". You might try First Air - they are reputed to be a bit more customer-service oriented. For example, they will apparently do work very quickly, while Woodlawn takes forever. I'm going to try First Air next time.
 
gvgoff99 said:
http://members.eaa.org/home/homebuilders/faq/Equipping a Homebuilt for IFR operations.html

If you are a member of the EAA then the above link is the most authoritative response to the TSO question that you will find. I think that there is a Canadian EAA and, most likely, they will have info on the topic too. The combo of both hopefully will crush the avionics shop's desire to sell you an altimeter!

Hope this helps!
Click to expand...

SWEET! Now thats what I'm looking for.

Steve
7A Flying
 
A little late jumping onto this thread, but another uninformed question... suppose you do buy an altimeter that is "TSO'd". Does this mean you get a certificate to that effect and you don't need to do any special testing (like what Kevin went through for his)?
 
prkaye said:
A little late jumping onto this thread, but another uninformed question... suppose you do buy an altimeter that is "TSO'd". Does this mean you get a certificate to that effect and you don't need to do any special testing (like what Kevin went through for his)?
Click to expand...


You'll still have to get it tested every 24 months to validate it's accuracy.
 
You'll still have to get it tested every 24 months to validate it's accuracy.
Click to expand...

Wow, what a pain! I guess this means pulling the altimeter, encoder and xpnder out of the panel, disconnecting them, taking them to the shop for validation, and then reinstalling them!?!?
 
prkaye said:
Wow, what a pain! I guess this means pulling the altimeter, encoder and xpnder out of the panel, disconnecting them, taking them to the shop for validation, and then reinstalling them!?!?
Click to expand...
No, they need to be tested in the plane. They will also verify any static system and/or pitot system leaks.

Where I'm based, we are under the Class Bravo shelf and well within the Mode-C veil. Because of this, the FAA required a transponder check prior to the first flight. Actually, they wanted it done prior to their inspection.

I think the bill was around $350 for the guy to come to the airport and do the check.
 
The components must be tested IN the plane, as you're testing not only the indifidual components, but the entire pitot and static systems (as a complete system). A typical IFR check takes anywhere from 2-4 hrs, and usually runs in the $300-350 range (depending on the shop and where in the country it's being done) as well as how much "fidlling" the tech has to do in order to get the check completed. Yes, Bill is right, many times the tech will come to you, however there can be additional fees for that sometimes.

Cheers,
Stein
 
You must log in or register to reply here.