Thread: IFR, IMC, etc., by DanJohnson

I'm hearing this stuff a lot too... My friend Dan Johnson at bydanjohnson.com has put up some good information:

A Raging Debate... IFR, IMC, VMC, and LSA
By Dan Johnson, August 28, 2010

In the last month, I've received many calls and emails from more than a dozen flight schools. Here, I will try to reduce the confusion — and some alarm — regarding IFR (flying by instrument reference) and LSA. *** ASTM's F37 committee is comprised of people with technical knowledge and they have done the nearly-impossible: start with a blank sheet of paper and create aircraft certification standards for the LSA sector... in just five years, and on the leanest of budgets. These volunteers from many countries created a series of standards, one of which is the Design and Performance Standard. Following a positive vote by committee members, all have been accepted by FAA.

*** For more than three years the same group has tried to create an IFR standard that has yet to find agreement. Until consensus may be found and to provide an interim defensive position for the committee and for manufacturers, F37 added a point to the revised but yet-to-be-accepted-by-FAA D&P Standard. The ASTM committee revised the standard to prohibit use of a SLSA for flight into IMC, that is, into clouds or no-visibility situations. This does not prevent flight in the IFR system -- filing and flying IFR into controlled airspace by qualified pilots with a current medical. And, importantly, it does not affect any LSA approved under earlier standards, that is, any LSA currently in flight school operation assuming that LSA is properly equipped with the correct instrumentation, lighting, and powerplant. Flight at night is not affected by this decision and remains acceptable in a suitably equipped LSA for a qualified pilot with medical.

*** In the future (after FAA accepts the newest D&P Standard version) a LSA builder will be able to equip a LSA with instruments specified in FAA regulations permitting qualified pilots to file and fly IFR but only into VMC (Visual Meteorological Conditions).

*** An interesting contrast: Numerous FAA personnel with whom I've recently spoken support the use of LSA for IFR training including into IMC (though not all FAAers nor ASTMers agree!). FAA regulations governing LSA do not prevent IMC ops. *** This is a complex topic that will continue to stimulate debate. The important fact to remember: No presently registered SLSA, nor any issued an airworthiness certificate before the new ASTM standard gains FAA acceptance, are prohibited from IMC flight if properly equipped and flown by a qualified pilot.

*** Additional info on the revised standard: IFR training in visual meteorological conditions (VMC) may be conducted by qualified pilots in a SLSA that meets the equipment requirements of part 91, sections 91.109, 91.205, and — for an airplane operated in controlled airspace under the IFR system — 91.411 and 91.413. However, if the aircraft is not approved for IFR operations under a type certificate, operations in instrument meteorological conditions (IMC) are prohibited by the proposed ASTM standard.

Is IFR legal in LSA...or NOT?
By James Lawrence, August 31, 2010

We've all seen the ads: "Full IFR-Equipped LSA!" *** A few top-line models offer such instrument packages, such as Flight Design CTLS, Evektor MAX, Tecnam's P2008. *** But is an LSA legal to fly IFR? *** Quick tell: Yes -- when flown by an appropriately rated pilot. *** We already know that a Sport Pilot license holder can only fly in day VFR up to 10,000 feet. This discussion is about the airplane. *** As pal Dan Johnson, who just took up this issue on his own blog, notes, ASTM's F37 committee has worked hard to create an IFR standard, but unsuccessfully so far. The committee did add a line to the latest Design and Performance (D&P) Standard (yet to be adopted) that prohibits S-LSA flight into Instrument meteorological conditions (IMC). *** This does not however prevent a rated IFR pilot with a current medical from flying a currently registered SLSA into IMC, and of course let's also assume the airplane is rigged with the appropriate Full Monty: IFR instrumentation, lighting and powerplant. *** That last item gives LSA watchers some pause, since most Rotax and Jabiru engine models, which power the vast majority of S-LSA, are not certified for IFR flight. Only an FAA-certified powerplant is legal. *** (Note: Rotax does indeed have certified versions such as the 912F and 912S, certified to Part 33 and used on Diamond aircraft, which are IFR legal.) *** The same criteria hold for night flight: it's legal, as long as the pilot is rated and the airplane is properly equipped such as with landing lights. *** Just to say it one more time: a Sport Pilot-only licensee cannot legally fly at night or into IMC. *** As Dan notes, once FAA accepts the latest D&P Standard, LSA makers will be able to outfit LSA with instruments as specified in FAA regs that will allow qualified pilots to file and fly IFR...but only into VMC (Visual Meteorological Conditions). *** Ironically, many (if not all) FAA folks, sez Dan, are supporters of allowing LSA for IFR training including into IMC, which is currently verboten. *** But to sum up, the bottom line remains: all currently registered S-LSA and those that are registered before the new D&P Standard is finally approved by FAA can legally operate in IMC flight — but only if they have the proper equipment and a suitably rated pilot at the controls. *** And here's yet another distinction: IFR training on LSA is also legal in the IFR airspace system — but only into VMC. Only an aircraft type-rated for IFR training in IMC can legally do so. *** Head buzzing yet? Mine is. *** This topic surfaces consistently on various pilot forums online. *** One poster recently suggested that potential IFR-equipped LSA buyers make sure they talk it all over thoroughly with the manufacturer/dealer first, to ensure everything stays kosher. *** Of course, since we pilots, especially when we post on the internet, are deliberative beasts who love to parse a topic until its magnetos fry, the idea has been put forth that pitot heat should be required on any hypothetical IFR LSA, and composite versions shout have a metal mesh impregnated into the airframe to handle lightning strikes, such as on a Columbia 350. Others, of course, disagree. *** And at this point, my brain cries "Enuf!" and defers this fine topic for another day, in the interests of preserving what little cognitive power I have left for my J3 flight later this afternoon (before dark, natch).

LSA, IFR, And IMC: An Update


For a while now, an ASTM committee that develops the standards for light sport aircraft to operate under instrument flight rules has struggled to reach consensus on a key point -- whether Special-LSAs should be allowed to fly in actual instrument meteorological conditions -- and although the committee members still disagree, they have decided to move forward and change the standards to prohibit the use of S-LSAs in IMC. That proposed change now must go through some further approvals and then be submitted to the FAA for an OK before it takes effect. That process could take until the end of this year or perhaps longer, Dan Johnson, chairman of the Light Aircraft Manufacturing Association, told AVweb on Wednesday. The change will not be retroactive, Johnson said. Any S-LSA that is flying today, or that is built before the new standard takes effect, is not prohibited from IMC flight if the aircraft is properly equipped and flown by a qualified pilot (although manufacturers may choose to prohibit IMC flight in their aircraft even when the ASTM standard allows it).

The IMC change is driven more by committee members' concerns about liability than about safety, Johnson said. FAA officials have not expressed any safety concerns about LSAs operating in instrument conditions, he said. "This is a complex topic that will continue to stimulate debate," Johnson wrote at his blog. The important fact to remember, he said, is that the change is not retroactive. Johnson further told AVweb that under the ASTM process, the standard could change again in the future, in as little as 30 days, if a new consensus is reached on the issue.

The only thing I'd like to add is that if you would like to be involved with ASTM decisions just join, read and debate the proposals, and vote. It's only $75 a year and you get all the light sport standards for free with your membership. LSA pilots and owners are underrepresented on the committees and should be heard.

IFR and LSA: Much Ado About... What?
By Dan Johnson, September 4, 2010


I was mighty busy last week, talking about my blog regarding IFR-IMC on LSA. Whew! Sometimes I had useful discussions. Some of what I got was hate mail; a few took the shoot-the-messenger approach. What's all the furor about, exactly? *** Among my many conversations, I spoke with Sebring Aviation's John Hurst. He has led the IFR subcommittee that is working to find consensus. John griped about weak support, even from those who said they'd help and then were curiously absent during meetings. The effort to create a standard that should restore IMC flying to Light-Sport Aircraft will continue.

*** Meanwhile, why all this heated talk? To my knowledge — and John knew no differently — only three LSA manufacturers actually pursued IFR-equipped aircraft: Tecnam, Evektor, and AMD. Perhaps others sold suitably equipped aircraft but these three promoted the capability. Two of the three use Rotax so they'd be required to offer the certified engine, for about $10,000 more. AMD uses the Continental, which has no restriction against use for IFR flying. *** So, are all those who express concern about the future loss of IMC privilege flying a properly equipped LSA? John Hurst and I doubt it. Neither of us believe many LSA have been sold that are properly outfitted for IFR flight. (John has one for sale right now.) Conversely, many "Day/Night VFR" LSA are marvelously equipped with high-tech systems like Dynon's SkyView (photo). These instruments can certainly guide flight through a 400-foot-thick cloud layer but they are not legal, certified IFR-flight devices. You can fly through clouds with them, yes. But you may not do so according to FAA regs.

So... do owners of these nicely appointed LSA merely believe they are IFR-qualified? *** We don't have all these answers yet. John and I agreed to try to determine how many true IFR LSA may have been delivered. Personally I'd be surprised if we're talking more than a few dozen out of nearly 2,000 SLSA sold in the USA. *** I repeat: if you already have an IFR-equipped LSA, you will not lose any IMC privilege.
AMD CH-601 formation photo courtesy AMD
The ASTM committee prohibition only applies to new LSA built under the latest standard revision. I don't expect that revision to be accepted by FAA until later this year. Therefore — and this is important — if you have an LSA now, or buy one before the new standard is accepted by FAA, the IMC prohibition does not apply to your aircraft.

FR "Certification" of Avionics
By Dan Johnson, September 10, 2010
Lately the subject of flying IFR (Instrument Flight Rules) has occupied my time and more than a few pixels on this website. The debate centered on flight into IMC (Instrument Meteorological Conditions... or situations with no or low visibility, or simplistically, flight into clouds).

Although I spend 100% of every day on the subject of Light-Sport Aircraft and other flying machines used for aerial recreation, I can also make mistakes explaining all the ins and outs of the six-year-old regulation abbreviated as SP/LSA. I corrected my last SPLOG post on this subject, but I enlisted Robert Hamilton of Dynon to help further. Robert had politely explained to me that I'd made an error. Rather than tackling this myself, I asked him to contribute. *** From Robert... "At Dynon we are often asked if our avionic products are 'Certified' for IFR flight. In fact, there is no such thing as 'IFR Certification' for amateur-built and LSA aircraft, and so answering the question requires an explanation. *** "The relevant regulation is FAR 91.205, which lists equipment that is required for various types and times of flight: VFR, VFR Night, and IFR. Included for IFR flight are such things as two-way communication and navigation equipment, gyroscopic rate-of-turn indicator, sensitive altimeter, artificial horizon, etc.
Here's what you don't want to see when you emerge from flying through clouds.
Most modern digital glass panel avionics meet these requirements for the analog gauges they replace. Interestingly, the definition of 'gyroscopic rate-of-turn' is based on functionality, and so includes solid-state MEMS (micro-electro-mechanical system) devices which are used in most digital, solid-state AHRS (Attitude Heading Reference Systems). There are many thousands of home-built aircraft legally flying IFR with 'non-certified' Dynon digital avionics. *** "Does this mean a Light Sport Aircraft with the same digital avionics is IFR legal? The answer to that question must come from the ASTM F37 LSA committee and the aircraft manufacturer. Assuming a LSA is equipped to meet the requirements of FAR 91.205, the avionics equipment is not a restriction. However, the overall aircraft operating limitations are specified by the manufacturer according to the standards written by ASTM committee members and subsequently accepted by FAA." *** Hopefully Robert answered the question, but as I've noted earlier, this is not likely the end to the vigorous IFR/IMC discussion.