Minimum equipment for legal IFR?

[newt]

Interestingly, the language regarding the clock is even more specific that a digital representation is permissible.

The old (superseded) Australian CAO 20.18 specifications for required equipment for various classes of flight were less prescriptive than that: They required a "timepiece."

Which led to a memorable argument I had with someone at CASA after the Garmin G5 was introduced, about whether it was IFR legal.

CASA's position at the time was that any Experimental aircraft flying IFR could only be equipped with TSO instrumentation. Cheap knock-offs from Aircraft Spruce earned frowns, they really didn't want to consider approvals for anything that didn't have an FAA PMA number and a TSO compliance statement on it.

So Garmin brought out the G5. No TSO at all. Solid state gyros, color LCD screen. Exactly the kind of thing that sent CASA into a kermit-arms frenzy. Oh no no no, you can't use that for IFR, it isn't TSO.

So I asked them which IFR instruments didn't require a TSO. And they said, "they all need them."

So I pointed to the clause about the "timepiece" in CAO 20.18 and asked them if my wristwatch needed a TSO.

That led to a lot of incoherent harrumph noises, and a conclusion that all the IFR instrumentation in CAO 20.18 except the timepiece needed a TSO, even though the only parts of CAO 20.18 which mentioned TSOs were the parts applicable to transponders and GNSS navigators.

Anyway, it all finished abruptly as soon as Garmin/EAA brought out the STCs for the G5s, which meant IFR capable Cessna 172's could use them in accordance with their type certificate. It changed the argument from, "Why is this impossible?" to, "You've already approved it for the type certified aircraft by accepting the STC under your FAA equivalence rules, so why the heck can't the same instrument go in an RV?"

There was no reason for them to be obstructive, they just were. It's like the fable about the frog and the scorpion, "It's my nature."

- mark

 

[Desert Rat]

The old (superseded) Australian CAO 20.18 specifications for required equipment for various classes of flight were less prescriptive than that: They required a "timepiece."

Which led to a memorable argument I had with someone at CASA after the Garmin G5 was introduced, about whether it was IFR legal.

CASA's position at the time was that any Experimental aircraft flying IFR could only be equipped with TSO instrumentation. Cheap knock-offs from Aircraft Spruce earned frowns, they really didn't want to consider approvals for anything that didn't have an FAA PMA number and a TSO compliance statement on it.

So Garmin brought out the G5. No TSO at all. Solid state gyros, color LCD screen. Exactly the kind of thing that sent CASA into a kermit-arms frenzy. Oh no no no, you can't use that for IFR, it isn't TSO.

So I asked them which IFR instruments didn't require a TSO. And they said, "they all need them."

So I pointed to the clause about the "timepiece" in CAO 20.18 and asked them if my wristwatch needed a TSO.

That led to a lot of incoherent harrumph noises, and a conclusion that all the IFR instrumentation in CAO 20.18 except the timepiece needed a TSO, even though the only parts of CAO 20.18 which mentioned TSOs were the parts applicable to transponders and GNSS navigators.

Anyway, it all finished abruptly as soon as Garmin/EAA brought out the STCs for the G5s, which meant IFR capable Cessna 172's could use them in accordance with their type certificate. It changed the argument from, "Why is this impossible?" to, "You've already approved it for the type certified aircraft by accepting the STC under your FAA equivalence rules, so why the heck can't the same instrument go in an RV?"

There was no reason for them to be obstructive, they just were. It's like the fable about the frog and the scorpion, "It's my nature."

- mark

I think those of us who've been around for a while would agree that what makes a situation like that frustrating is that some of these rules are so arbitrary as to seem like they were made up on the spot.

Your "Timepiece" wording allows a wristwatch. In the Good 'ol USA, the "Clock with sweep second hand etc." Has to be panel mounted. undoubtedly because when that reg was written back when dinosaurs roamed the earth they threw in the word "Clock" for no good reason other than it was a common word for something that measures teh passage of time. I'd imagine at some point later when the question came up, somebody else said nope- the reg has said clock for the last 500 years and clocks go on a wall, so thats the way it's gotta be."

Also, circling back to your TSO comment. are the davtron panel mount chronometers TSO'd? I've never looked but I suspect not.

 

[mburch]

On most displays isn't the PFD clock on pretty much all the time? I know it is on the stuff I currently fly.

Yes, and on the G3X Touch system shown above, you can put a nice big Timer button at the top of the screen (I have mine set up this way), and/or trigger the timer with an external pushbutton switch.

 

[BobTurner]

Just to throw gas on the fire: quite a few years ago I saw an FAA letter of interpretation that said a ‘clock’ did not have to actually show the time - a simple up/down timer that showed hrs/min/sec was sufficient. It was never clear to me how you did position reporting in non-radar environment (anyone remember those rules?) with a ‘clock’ that didn’t show the time!

 

[henrysamson]

Oh, that's part 125 operations, nvm

That's true and at some point the requirement for pitot heat for an IFR aircraft was added to part 23 which applies to the construction of certified aircraft. So it doesn't apply to EAB or ELSA.

 

[airguy]

On most displays isn't the PFD clock on pretty much all the time? I know it is on the stuff I currently fly.

Yes, but it doesn't have a seconds display, typically. Using a clock/timer for purposing of timing a standard-rate turn requires the ability to measure time to the nearest second, not minute.

 

[Desert Rat]

Yes, but it doesn't have a seconds display, typically. Using a clock/timer for purposing of timing a standard-rate turn requires the ability to measure time to the nearest second, not minute.

Having been a CFII for a little over 30 years at this point I understand how timed turns work

I can't speak to other brands, but I don't recall ever seeing a Garmin PFD where the clock didn't show seconds. In fact, if you zoom in on they panel picture in Webbs post higher up in this thread you can see he's got both a clock showing seconds and a timer function on the bar at the bottom of the PFD

 

[airguy]

Having been a CFII for a little over 30 years at this point I understand how timed turns work

I can't speak to other brands, but I don't recall ever seeing a Garmin PFD where the clock didn't show seconds. In fact, if you zoom in on they panel picture in Webbs post higher up in this thread you can see he's got both a clock showing seconds and a timer function on the bar at the bottom of the PFD

Fair enough. I know Dynon's clock does display seconds (and it's always on), I don't know how ubiquitous that is.

 

[Desert Rat]

So anyway- OP, I think this thread has gotten off track with all the talk about clocks and whatnot and I did my part to derail it. Sorry about that.

Back to your original question; somebody mentioned FAR91.205 which is a good place to start. At a basic level, you need the required Day & Night VFR equipment (lights and whatnot), an artificial horizon, some kind of direction gyro, a turn coordinator and a slip/skid indicator, and here's the kicker...comms and navigation equipment appropriate to the route being flown.

Yeah, the radios need to have TSO, the required checks have to be signed off, etc.etc.etc., but at it's core, this means that if you have a good old basic steam gauge 6 pack and a single nav/com with the nav portion displaying on a single VOR Course Deviation Indicator, you are "IFR Legal".to file and fly an IFR flight that would have you take off, intercept a victor airways, then shoot a VOR approach at the other end. It doesn't get much more basic than that and the workload is high while the functionality is low.

Nobody is going to want to fly an airplane in IMC equipped like that in the real world. It's IFR legal, but it' so limited in teh routes it can fly and teh airports it can go into that it's kinda pointless.

For a minimum level of low budget IFR that will get you some practical functionality, but is not an anywhere anytime sort of airplane, I think most folks would agree that certified GPS/Comm plus whatever level of duplication and redundancy you can cram in is a good way to go. For me, single pilot, I'd like a way to monitor a second comm frequency, and a way to shoot an approach if the GPS craps out. That could be a second GPS, an ILS/VOR receiver, you get the idea.

In all cases, in addition to my own proficiency my go/no go decision will take into account the equipment on the airplane and how "hard" the IMC is. Shooting an approach down to minimums with only one GPS receiver and no backup? No thank you. 5,000' ceiling where I know I'm going to break out way above MSA at my destination? Thats a different story.

I wouldn't even consider going in actual hard IMC without some sort of attitude backup instrument even if it isn't required.

Sorry if that didn't directly answer your question, but as with a lot of things in life, the answer seems to be "it depends"

note- All my comments are an attempt to answer you question as related to day to day IFR operations. If your going to want to take a checkride in said winged chariot, it needs to be equipped so that you can do the required checkride tasks.

 

[Dugaru]

It was never clear to me how you did position reporting in non-radar environment (anyone remember those rules?) with a ‘clock’ that didn’t show the time!

I was asked to do position reports once, near Philadelphia, when their radar urped. And yes I did need to remind myself how to do it by reading a ratty old AIM in the back seat. As I was blowing the dust off my E6B it finally dawned on me that the 430’s flight plan page was basically designed for this purpose…

 

[gmcjetpilot]

FAR's 91.205.
Sub par (d)(2) talks Com and Nav
Three things:

1) What Nav? VOR/LOC/GS/DME/MB/ADF/GPS:
You can fly with just a VOR if that is sufficient for intended flight. Many like me have GPS only. You need a TSO'ed GPS w/ current data-base (updates not cheap and ongoing cost). Up to you. If you are an Inst pilot you know GPS RNAV is now common at small airports and VOR/LOC/ILS less (phased out). Some Victor airways are now (T), GPS only. If you go all terrestrial NAV DME is highly recommended w/ no (legal) IFR GPS. You can always use a VFR GPS or GPS w/ out of date database as Ref for backup.

2) Vacuum 6-Pack or Glass? Combo of both? There is no required redundancy for EAB aircraft with glass cockpits (dual electrical sys, dual AHRS, dual display, backup Elec/Vac Inst.). For Part 23 aircraft the TSO for GA glass does specify redundancy. FAA AC discribes required redundancies. Use as guide, but its optional. Up to you. Obviously there shoukd be common sense. IMC with no AI, or AS, ALT, VSI or TC is bad.

3). Up to you and wallet. What"s your budget? Are you Inst rated pilot? Plan on flying hard IFR to mins often? Plan on autopilot. If you rarely fly IFR or not rated save the money and weight.

Bottom Bottom line at Min typically an IFR TSO'ed GPS w/ current database (and all 91.205 equip) is price of entry. Autopilotis nice singke pilot. Since most glass has Autopilot function built in ( adding $2000 for servos, brackets, wiring) that's a no brain'er. Just the GPS is about $7K, just for GPS and $170 per update or almost $700/yr subscription. That does not include flight instruments and COM, which adds approx. $15-$25,000. You can get a COM or GPS with built-in VOR/LOC/GS. You need a NAV head to display CDI/GS. VAL electronics makes an all in one unit. Many ways to go.

If you have IFR approved TSO'ed GPS DME is not needed. If you do terrestrial NAV only DME is needed in my opinion because many IAP's need it, due to LOM's (NDB/MB) being decommissioned. Only way to ID FAF or step downs is DME (or approved GPS) on many approaches . Crossing radials are sometimes used. However a 2nd VOR would be handy. Otherwise you will need to switch back and forth between Aprch NAV and cross radial? I've done it in past but not ideal.

If you are an all weather go anywhere anytime pilot you need it all and two of everything. If you are just an occasional IFR to get on-top, let down through undercast, depart IFR when too low for VFR, high mins approaches... etc., GPS only may work OR VOR/LOC/GS/DME only may work great. If you are hard core both GPS and terrestrialNAV, but DME not needed with TSO'ed GPS (and current NAV database). If you fly over 24,000 feet you need DME. Not sure too many RV's are in Flight Levels (I've come close at 17,000).

 

[Dugaru]

For me, single pilot, I'd like a way to monitor a second comm frequency, and a way to shoot an approach if the GPS craps out. That could be a second GPS, an ILS/VOR receiver, you get the idea.

Agreed, and for my flying a non-certified GPS source seems totally adequate. Flying an approach with an iPad and a G5 running on battery backup is pretty easy, and that backup gear has the advantage of working even with zero aircraft power — which is a conceivable scenario. I also have ILS/VOR and although that needs aircraft power, it has the obvious and major advantage of working if the GPS system itself fails. I guess one could try to shoot an approach using a handheld radio with nav capability, but that seems like real thrill-seeking. I’d want it velcroed to the panel right in front of my face, at least!

I wouldn't even consider going in actual hard IMC without some sort of attitude backup instrument even if it isn't required.

Agree SO much.

In the Before Times, in my Long Long Ago 1979 Warrior days, installing a backup attitude indicator would have been a pretty major deal. Like most low rent IFR pilots I flew around in clouds with one (vac powered!) AI. The “backup,” which was probably more than most Warriors had, was a Precise Flight standby vac system (with some real quirks, but with the absolutely crucial feature of a low vac warning light). Plan C was putting a post-it note over the failed AI (we actually carried post-its for that purpose) and using needle/ball/airspeed. Yuck! Gives me the willies just thinking about it. With all the G5s etc. available today, flying around like that in IMC would be pretty silly.

I’m starting to sound like the guys who reminisced about the four course radio range and griped about those newfangled VORs!

 

[BobTurner]

Okay, I’ve never flown a four course radio range! But I have done my fair share of partial panel approaches, and honestly, they aren’t that bad, especially in a plane as stable as a Warrior or 182. I’ve also done non-precision p/p VOR approaches (vfr, under the hood) using just an old Sportys hand held nav-com, where the vor readout was just a digital bearing to or from. The trick is to fly it like an NDB approach: do as best you can to get lined up, fly it halfway in, look at the radial, make one course correction, fly it the rest of the way to the (timed) MAP.

 

[BobTurner]

FAR's 91.205.
Sub par (d)(2) talks Com and Nav
Three things:

1) What Nav? VOR/LOC/GS/DME/MB/ADF/GPS:
You can fly with just a VOR if that is sufficient for intended flight. Many like me have GPS only. You need a TSO'ed GPS w/ current data-base (updates not cheap and ongoing cost). Up to you. If you are an Inst pilot you know GPS RNAV is now common at small airports and VOR/LOC/ILS less (phased out). Some Victor airways are now (T), GPS only. If you go all terrestrial NAV DME is highly recommended w/ no (legal) IFR GPS. You can always use a VFR GPS or GPS w/ out of date database as Ref for backup.

2) Vacuum 6-Pack or Glass? Combo of both? There is no required redundancy for EAB aircraft with glass cockpits (dual electrical sys, dual AHRS, dual display, backup Elec/Vac Inst.). For Part 23 aircraft the TSO for GA glass does specify redundancy. FAA AC discribes required redundancies. Use as guide, but its optional. Up to you. Obviously there shoukd be common sense. IMC with no AI, or AS, ALT, VSI or TC is bad.

3). Up to you and wallet. What"s your budget? Are you Inst rated pilot? Plan on flying hard IFR to mins often? Plan on autopilot. If you rarely fly IFR or not rated save the money and weight.

Bottom Bottom line at Min typically an IFR TSO'ed GPS w/ current database (and all 91.205 equip) is price of entry. Autopilotis nice singke pilot. Since most glass has Autopilot function built in ( adding $2000 for servos, brackets, wiring) that's a no brain'er. Just the GPS is about $7K, just for GPS and $170 per update or almost $700/yr subscription. That does not include flight instruments and COM, which adds approx. $15-$25,000. You can get a COM or GPS with built-in VOR/LOC/GS. You need a NAV head to display CDI/GS. VAL electronics makes an all in one unit. Many ways to go.

If you have IFR approved TSO'ed GPS DME is not needed. If you do terrestrial NAV only DME is needed in my opinion because many IAP's need it, due to LOM's (NDB/MB) being decommissioned. Only way to ID FAF or step downs is DME (or approved GPS) on many approaches . Crossing radials are sometimes used. However a 2nd VOR would be handy. Otherwise you will need to switch back and forth between Aprch NAV and cross radial? I've done it in past but not ideal.

If you are an all weather go anywhere anytime pilot you need it all and two of everything. If you are just an occasional IFR to get on-top, let down through undercast, depart IFR when too low for VFR, high mins approaches... etc., GPS only may work OR VOR/LOC/GS/DME only may work great. If you are hard core both GPS and terrestrialNAV, but DME not needed with TSO'ed GPS (and current NAV database). If you fly over 24,000 feet you need DME. Not sure too many RV's are in Flight Levels (I've come close at 17,000).

Small correction: I think most gps database subscriptions run more like $300/yr.
Comment: another plug for the SL30, which unfortunately is no longer in production. For that ‘no gps, ILS with VOR cross fix for the FAF’, the SL30 can monitor the standby VOR while providing the active cdi data. e.g., on my GRT Hx HSI display, I see the localizer as the main CDI, while an RMI needle shows the vor cross fix. One nav, easy ILS.

 

[Rrhsch]

Hi All,

I'm looking for some advice on what's the minimum equipment I'd need to add to my VFR RV-7 to be IFR legal? Asking because I equipped my RV-7 for VFR only and now I'm scoping out the possibility of an upgrade. I currently have a Dynon Skyview system with one HDX display, a single ADAHRS and a Dynon (non IFR certified) GPS. I believe I need at a minimum second/backup attitude indicator, a second ADAHRS and a IFR-legal GPS. Is there anything else I'm not thinking of? And a related question, IFR GPS units seem to range in price from very reasonable to well over $20K. What would the high end units give me that the cheaper ones would not?

Again, I'm just in the initial stages of scoping the possibilities of an up grade. I'd still have to go get the IFR rating if I chose to go that way. Just trying at this point to understand the possibilities.

thanks
-Ivan

Ivan, The $20k GPS will give you GPS, ILS, LOC, VOR, full Vertical navigation and a large moving map display. A large display can give you a geo referenced chart so you can use your HDX as is without splitting the display for reading approach information. $12K units have smaller screens and still give you VOR, LOC, ILS, and GPS with full Vertical navigation, but charts are displayed on your PFD or IPad. Most $5K units that I know of are GPS only and do not include step down altitudes in the vertical navigation.

If you do not have a transponder capable of ADS-B out you will also need to have an upgrade. The above GPSs will send the required position data to the transponder for ADS-B out for ATC.

If your plane is equipped for day/night operation, with legal ADS-B out, the cheapest certified IFR GPS will work. You will need the required database updates and required static and transponder checks so your plane can fly legal IFR fights to airports with matching requirements for approaches.

If you plan on getting your IFR ticket in your plane, the IFR ACS as interpreted by most DPEs require two different NAV sources for two of the required non-precision approaches. GPS alone doesn’t make it unless you have a separate unit that has the VOR and LOC with it. There are a few DPEs that interpret the ACS differently, but good luck finding one. Check with the DPEs in your area before doing the minimal.

There is a higher risk if you don’t plan for back-ups for your systems and equipment. There is a possibility of getting ice in your pitot/static system. There are some pilots that won’t fly IFR in an RV because it only has one engine and limited de-icing. You need to determine your risk based on the mission for your intended flights.

You can PM me if you wish to discuss.

 

[gmcjetpilot]

Ivan, The $20k GPS will give you GPS, ILS, LOC, VOR, full Vertical navigation and a large moving map display. A large display can give you a geo referenced chart so you can use your HDX as is without splitting the display for reading approach information. $12K units have smaller screens and still give you VOR, LOC, ILS, and GPS with full Vertical navigation, but charts are displayed on your PFD or IPad. Most $5K units that I know of are GPS only and do not include step down altitudes in the vertical navigation.

If you do not have a transponder capable of ADS-B out you will also need to have an upgrade. The above GPSs will send the required position data to the transponder for ADS-B out for ATC.

If your plane is equipped for day/night operation, with legal ADS-B out, the cheapest certified IFR GPS will work. You will need the required database updates and required static and transponder checks so your plane can fly legal IFR fights to airports with matching requirements for approaches.

If you plan on getting your IFR ticket in your plane, the IFR ACS as interpreted by most DPEs require two different NAV sources for two of the required non-precision approaches. GPS alone doesn’t make it unless you have a separate unit that has the VOR and LOC with it. There are a few DPEs that interpret the ACS differently, but good luck finding one. Check with the DPEs in your area before doing the minimal.

There is a higher risk if you don’t plan for back-ups for your systems and equipment. There is a possibility of getting ice in your pitot/static system. There are some pilots that won’t fly IFR in an RV because it only has one engine and limited de-icing. You need to determine your risk based on the mission for your intended flights.

You can PM me if you wish to discuss.

You missed the point. Yes you can get a full IFR panel.

Yes Geo sync approach plates are a thing. I have it free on my iPad, just not legal as primary NAV. Topic is not the state of art most wiz bang magic avionics available, but MIN equipment.

Of course yiou need ADS-B out to operate in IFR system, for all practical purposes.

Yes a Garmin GTN750 Xi does it all for example. Base price $18K. By the time you add all the boxes needed to make it do everything it's north of $30K. Dealing with Garmin and their Certified Garmin units for amateur planes and builders is difficult to impossible. They will want approved distributor and shop to install. Add $$$$$ for labor. G3X, G5 for experimental and GPS175 no problem DIY. Those are their "over counter" products.

A used GSN 430W Garmin Nav (GPS, VOR ILS) that came out in 1998 might be tempting at $10K used, but long out of production and support is being phased out. Also the 430 is a certified unit. Garmin does not deal with homebuilders and want an A&P.

If you could only have one NAV for IFR and be most useful, a TSO'ed GPS w/ current database is obvious choice in 2024. The rest is in FAR's for instruments and NAV required. Flying IDR w/o IFR approved FPS navigation is limiting. Yiu can get away with out having ILS capabilities.

For me my IFR Nav is Garmin GPS175 backed up with (for Ref Only) GRT EFIS GPS and database and iPad (internal GPS) EFB map (including Geo Sync approach plates). One mode S transponder ADS-B out and one COM (with standby Freq monitor) rounds out my IFR Lite panel. Sure VOR LOC GS DME would be nice. However not needed for what my mission is.

 

[Dugaru]

A used GSN 430W Garmin Nav (GPS, VOR ILS) that came out in 1998 might be tempting at $10K used

Good Lord who is paying $10K used for a 430W? More like $4K.

 

[turbo]

There is one piece of equipment not listed in 91.205 that I consider to be a necessity for flying IMC.....AUTOPILOT.

DITTO!

 

[rocketman1988]

DITTO!

Not going to disagree with having an autopilot. It is a definite benefit when flying IMC. It should, however, never be an excuse to lose hand flying proficiency.

 

[gmcjetpilot]

Good Lord who is paying $10K used for a 430W? More like $4K.

That was my shock, but my recollection looking a year ago about $9K Looking at eBay current prices average $6K, High $8K low $4K. Does it have antenna, tray, connectors. Cosmetics, working? No need to argue, but a few points on the 430W, great unit, introduced 25 yrs ago, out of production 13 yrs ago. Garmin announced it was phasing out support and parts would progressively become unavailable. Some parts are already not available from Garmin. Also to use a GNS420W fully, you need a G5 or some external display. G5 base price does not include installation kit, battery, so expect over $2K for experimental and + $3K certified G5. If you buy a used GNS430W (assume $6K with tray, connector, antenna) and G5 ($2K) will put dent in $10K. Add cost and weight for COM, VOR/LOC/GS antennas and cables. That is why I am going with just GPS175.... Granted I can use my GRT Horizon EFIS to display Garmin's NAV data (with an ARINC 429 adapter), for the 430W or GPS175. So apples and apples a GNS 430W used and GPS175 about same price, may be a little less for the GPS175. However the GPS175 is GPS only. I really don't want or feel I need to add a second COM and VOR/LOC/GS of the GNS430W. A second COM is nice but you can add a remote COM (controlled for through EFIS) for $2K. My iCOM has standby Freq monitoring. MIN IFR going with one COM. (Yes I have handheld but if it gets that bad and I am in terminal area CELL PHONE might work better.)

When I say IFR I mean light IFR... Departing airport with low VFR, to climb on top, or en-route undercast, IMC let down to high MINS approach. I have no desire to fly night IFR over terrain with potential convective or icing conditions with low ceiling and visible at MINS, in single engine single pilot sky scooter. I want enough to legally get into the system even if VFR conditions. If going into say LA area, far better to be on IFR flight plane arrival than hunt peck around the airspace VFR. Even if the weather goes to MINS a GPS175 and LPV approach will get me down low mins, even as low as a CAT 1 ILS, 200 and 1/2, although 300 and 3/4 are common the low MIN LPV are not rare. In some cases LPV is better than ILS due to signal interference of an ILS when near mins, including aircraft on taxiway.

If a 430W fell into my lap I might cut a hole in my panel for it, but the new "over the counter" direct to user GPS175 with touch icon driven screen (albeit smaller) is for me. Their combo units GNX 375 (GPS+TXPD'R) and GNC 355 with (GPS + COM) are nice, and kit plane freindly. Call them.

GPS 175 is new, OK for end user to buy, install and get Garmin support.