Cessna 170B IFR

[danielfindling]

I am a 500+ hour private pilot and recently purchased a 1955 Cessna 170B. I am also studying for my instrument rating and would like to do so in my plane. I have no intentions of flying regular IFR, rather, I would like to be able to takeoff to improving conditions or get down safely from up top to a local airport and be safe.

My plane is currently equipped with a Narco MK12D with a VOR (non-glidescope) and a Apollo Garmin Sl60 GPS. The Sl60 is no longer supported and the database is too old to be practical.

I first thought of replacing the SL60 with a used Garmin GNS 430W however, the cost with the indicator and installation was exceeding $15,000.00 which causes me conflict considering my mission and airplane. I am looking for a more budget friendly alternative and here are my thoughts (to which I am requesting input). . .

1. Replace the Narco MK12D with a unit that has a glideslope (cost $1200.00 + installation);
2. Replace the SL60 with a Garmin GNC 300XL with an indicator (Not sure if the 300XL supports a glideslope?)
3. Other.

While I appreciate comments like - get a GNT 650 or 430XL. . . I already understand the cost/benefit. I just don't want to incur the expense in this airplane which is essentially a VFR platform and I intend on flying in VFR conditions. However, in my 500 hours of flying, I have been in situations in which I wish I had a safer "out". I also understand that, I will not be able to do a LPV or other GPS approaches and VOR/LOC are rapidly being replaced by GPS approaches (as an aside, my home airport has a GPS approach only - therefore, I intend on landing at another airport and getting a ride if circumstances arise)

Once again, my mission profile is "in case of emergency or just to be safe. . ." IFR. After all, I am flying a Cessna 170B and not a RV-6 or Bonanza . . .

Finally, I have just regurgitated about everything I know in my struggles researching this topic. I am ready to take the IFR written and grateful for any advice on moving forward with this upgrade to my plane including cost/benefit.

Thanks in advance.

Daniel

[Marc Zeitlin]

... I have no intentions of flying regular IFR, rather, I would like to be able to takeoff to improving conditions or get down safely from up top to a local airport and be safe.
... Once again, my mission profile is "in case of emergency or just to be safe. . ." IFR.I fly a COZY MKIV and am instrument rated. I MAYBE fly 5 actual (not simulated) approaches/year, if that, and it's not possible to justify spending $7K - $15K on a piece of navigational equipment that then needs $750/yr. in database updates just to be legal for GPS approaches.

So what I did when I wanted to equip my plane for LEGAL IFR flight was to install a Narco NAV-122. They're going for $1200 - $1500 on EBAY. These allow for VOR/LOC/ILS approaches legally, and while yeah, they're slowly going away, there are still a lot of them around. I got my instrument ticket in the COZY and took the practical in it as well.

As a backup, I have WingX on my iPad. It has ALL approaches, including RNAV/GPS approaches in it, and in an emergency, if I needed to get on the ground, I'd have no hesitation whatsoever in using it to complete the RNAV approach. Legal? Nope. On the ground and not dead? Yup. It's also a great backup for the VOR/LOC/ILS approaches from a situational awareness standpoint.

So purely from the standpoint of a cost/benefit, something like the Narco NAV-122 or the VAL avionics (if you want something less than 40 years old) INS-429 fit the bill.

My $0.02.

[Mike Switzer]

I agree with Marc, get something older that allows VOR/LOC/ILS. A few years ago finding someone to work on Narco was a bit sketchy, I haven't flown in a few years but you should check that out on whatever brand you buy. If you can get it cheap enough, I would recommend also getting DME, it greatly reduces workload. That is all the equipment that the 172 I did my instrument training in had (well, it also had ADF but those aren't real useful anymore) & I would not hesitate to fly "normal" IFR with that equipment. Personally I found "Hard" IFR to be a bit of a workload in that plane, but then it didn't have an autopilot. I once flew from Decatur IL to Lincoln NE, the plane I was in had a 430 & just for grins I set up the dual VOR receivers for both ends. I had VOR & DME data from one end of the trip or the other the whole way, with some overlap in the middle so I knew exactly where I was just as good as using the GPS.

[Marc Zeitlin]

... something like the Narco NAV-122 ...bad form to quote one's self, but there's one on EBAY now in working condition for $750, buy it now. Many others as well.

[martymayes]

Daniel, get a nav with a gs reciever. Then get a GPS for "situation awareness" If you wan to pony up a little more, get a GPS that can substitute for DME in many cases.

[Mike Switzer]

Daniel, get a nav with a gs reciever. Then get a GPS for "situation awareness" If you wan to pony up a little more, get a GPS that can substitute for DME in many cases.

This would work also, as long as the GPS is smart enough to give the same distance as the DME would. One reason I like DME is that it makes many approaches much easier, because if you are timing the approach it is fairly easy to make a mistake.

[martymayes]

Daniel, get a nav with a gs reciever. Then get a GPS for "situation awareness" If you wan to pony up a little more, get a GPS that can substitute for DME in many cases.





EDIT: To be more specific: Trade the Narco MK12D for a MK12D that has a GS receiver and install a Narco ID-825 VOR/LOC/Glideslope Indicator. You'll have to install a GS antenna. Should be able to do all that for ~$2k - $2.5k.

[FlyingRon]

What are you using for a vacuum source. The 170B I flew only had venturis. While these are passable once you get going, I'd not want to launch into IFR with my gyros potentially not stable.

The first thing I'd do is trash the Mark12D. The thing is an unsupported piece of garbage. I can't say less kind things about NARCO and the 12D+ pair we had in our club 180. Even when NARCO was in business they were boat anchors.

I have a friend who does have a similar vintage 172 with a 430W and mode C and does passable "light IFR" paired with an Android/AVARE combo.

I'd ditch both the SL60 and the Narcoleptic radio and get something like a 430W or a more modern radio.

[Mike M]

For pt 91 flight one need not have vacuum driven gyros. One may use a glass panel. So if one is contemplating replacing an entire venturi + gyros system, one might price out glass instead.

As I understand it, one must have a "certificated" gps with current database to substitute for a dme. Because it says so in a different section of the CFR, although not in 91.205. Someone else will provide a reference if I'm wrong.

Pt 91.205 d 2 doesn't specifically require a panel mounted TSO receiver for navigation. Just equipment suitable for the route to be flown. If TSO was required, the rule would say "approved equipment suitable for the route to be flown." Sportys has a couple of VOR/ILS/LOC receivers listed for less than $500 which require no installation paperwork or cost .. and they're backup transceivers, too.

Let the nitpicking begin :)

[martymayes]

A TSO is required when the reg says item must meet TSO 12345, as appropriate. Otherwise, not required.

It’s not legal to fly IFR with portable nav gear.

Years ago I flew freight in a 402 that had no DME. Nice to have but certainly not necessary.

[Mike M]

A TSO is required when the reg says item must meet TSO 12345, as appropriate. Otherwise, not required.

It’s not legal to fly IFR with portable nav gear.

Thanks for affirmation on when a TSO is required, Marty. As to portables?

Question One. Is an installed, TSOd VOR/ILS/LOC navigation receiver required by regulation for IFR operation?


Not this regulation:


§91.205(a) General...no person may operate … unless that aircraft contains the instruments and equipment specified ... and those instruments and items of equipment are in operable condition.
(d) Instrument flight rules. For IFR flight, the following instruments and equipment are required:
(2)Two-way radio communication and navigation equipment suitable for the route to be flown.


And not this regulation:

§91.171 VORequipment check for IFR operations.


(a)(2) Has been operationally checked within the preceding 30 days, and was found to be within the limits of the permissible indicated bearing error...


The Instrument Flying Handbook covers traditional navigation systems beginning on page 9-3. I can’t find a requirement for installed TSOd VOR/ILS/LOC equipment. The Aeronautical Information Manual covers VOR in Paragraph 1-1-3, ILS/LOC in 1-1-9, but I can’t find a requirement for installed TSOd VOR/ILS/LOC equipment there either.


So a VOR/ILS/LOC used for IFR must receive the transmissions needed for the route of flight from takeoff to landing and must have a current ops check. Nothing about being installed or TSOd. If anybody knows an FAA manual, handbook, or regulation that requires an installed TSOd navigation receiver for VOR/ILS/LOC please post that reference?


Question Two, is an installed TSOd GPS receiver required by regulation for IFR operation?


FAA-H-8083-15B Instrument Flying Handbook:
Page9-26: GPS equipment ... under IFR must meet ... Technical Standard Order (TSO) C-129 ...; meet the airworthiness installation requirements; be “approved”for that type of IFR operation; and be operated in accordance with the applicable POH/AFM or flight manual supplement. An updatable GPS database … is required when operating under IFR. Equipment approved in accordance with TSO C-115a... and hand-held GPS systems do not meet the requirements ... and are not authorized for IFR ... or as a principal instrument flight reference.


Aeronautical Information Manual:
Para1−2−3.2. b. ... When installed in accordance with appropriate airworthiness installation requirements... 1. An RNAV system with TSO−C129/ −C145/−C146 equipment, installed in accordance with AC 20−138...or AC 20−130A...and authorized for instrument flight rules (IFR) en route and terminal operations...


So an IFR GPS is required to be TSOd, installed, and approved. But. Manuals and Handbooks aren’t regulations. So does anybody know what regulations drive these requirements?

I'm confident somebody knows the regulation reference , but it's not me.

[FlyingRon]

91.205 ***IS*** the regulatory justification. The FAA states via AC's and the TSO documents what they consider an airworthy installation of a "suitable" navigation equipment is.

They've always held that any sort of area navigation for IFR (from the old rho-theta RNAV to LORAN to GPS) has to be so approved.

As for the gyros, yes you could put a glass panel in a 170 or electric gyros or an electric or engine driven vacuum pump, but you need some sort of "gyroscopic" horizon and direcdtion indicator. You're talking real money to go "glass panel" in a 170, even if it were possible. There's just not a lot of room there (you don't even typically get a traditional six pack layout). Something like the Garmin G5 may indeed suffice. I was just pointing out that I'd not spend a lot of money on IFR avionics if I didn't ALSO have a realiable horizon/direction indicator and venturis are fine once you're enroute but if you're serious about IFR, I'd be leery.

[Louis]

Getting the instrument ticket is always a good idea. Getting on top, if need be, is MUCH safer than low level scud running.

Can those old King KLN-89B's still be upgraded? One of those could probably be gotten dirt cheap, but don't know if they are still legal for IFR. Other than that, you could still get an approach anywhere with a VOR or localizer approach with the equipment you currently have. A handheld GPS would be a great asset for situational awareness and helping you stay on track on an airway or a VOR approach. If you can't find an IFR legal GPS in you're budget I'd tend to recommend just staying with what you currently have and using the money you save for gas to stay as IFR PROFICIENT as you possibly can.

[martymayes]

Question One. Is an installed, TSOd VOR/ILS/LOC navigation receiver required by regulation for IFR operation?

Yes, it must be installed but there is no TSO requirement. The non-TSO'd King KX-170A used to be one of the gold standards for navcom gear.


Question Two, is an installed TSOd GPS receiver required by regulation for IFR operation?


Yes to both. Just to be clear, I think the regs says a GPS has to meet the performance requirements of a TSO, not that is has to be specifically manufactured under a TSO authorization.


Regarding installation, this is cut & paste from FAA Oder 8900.1 Flight Standards Information Management System (FSIMS).

1. Section 91.205(d)(2) requires air navigation equipment to be appropriate to the ground facilities used. The current NAS is based on Very high frequency Omnidirectional Range (VOR) and VOR/distance measuring equipment (DME) ground facilities. Therefore, this regulation requires that VOR and/or VOR/DME equipment or an Area Navigation (RNAV) system that meets the en route criteria be installed in the aircraft and operable if it is to be used for IFR flight in the U.S. NAS. [emphasis added]

This is kinda of a neat reference because a lot of this material originated in the Federal Aviation Act of 1958 and rather than a hard fast rule in a rule book, it specifies the background, concept and intent (or what you might call the pre-preamble) of what is now 91.205(d)(2). The FAA obviously feels the intent of the rule is that IFR navigation gear has to be permanently installed in the aircraft to be legal.

[martymayes]

Getting the instrument ticket is always a good idea. Getting on top, if need be, is MUCH safer than low level scud running.

Can those old King KLN-89B's still be upgraded? One of those could probably be gotten dirt cheap, but don't know if they are still legal for IFR. Other than that, you could still get an approach anywhere with a VOR or localizer approach with the equipment you currently have. A handheld GPS would be a great asset for situational awareness and helping you stay on track on an airway or a VOR approach. If you can't find an IFR legal GPS in you're budget I'd tend to recommend just staying with what you currently have and using the money you save for gas to stay as IFR PROFICIENT as you possibly can.

I agree with all that, one can fly IFR with some very basic radio navcom gear. Add a non IFR GPS for "situational awareness" (like to situate you on the airway or help you locate your position, lol) Just need to have the discipline to say no when tempted to launch in hard IFR.

[FlyingRon]

Yeah, but if you're not going to use an IFR GPS, you likely would get better SA from a handheld device be it one of the aviation handhelds or a tablet running your favorite of Foreflight, WingX, Garmin Pilot, Avare...

[Mike M]

“Asfor the gyros, yes you could put a glass panel in a 170 or electricgyros or an electric or engine driven vacuum pump, but you need somesort of "gyroscopic" horizon and direction indicator.”
An FAA policy statement that attempts to amplify and rationalize the regs regarding glass panels etc:

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgPolicy.nsf/0/6a24902ae5f1aeac86257ec1005b2fbc/$FILE/PS-ACE-23-08.pdf


"In dual installations, a secondary G5 can revert to display attitude information in the unlikely event of a failure in the primary attitude indicator position."

http://www.nexairavionics.com/g5-as-a-dghsi-for-certificated-aircraft/

[FlyingRon]

You misunderstand. The reason I put the "gyroscopic" in quotes was that while it might not be a gyroscope, it needs to perform that function.

[Mike M]

You misunderstand. The reason I put the "gyroscopic" in quotes was that while it might not be a gyroscope, it needs to perform that function.

Well I certainly wasn't clear in my response, was I?

Trying again, one need not keep the vacuum system nor install electric gyros to have "gyroscopic" equipment. The FAA and EAA and industry have come up with ways to go glass, even all glass, without gyroscopes - and still have backup. In certificated aircraft. There are some wonderful choices available and not just ones over $ten grand.

The funny part of this is we're on a thread about a Cessna 170B, a CAR 3 certificated aircraft built in '55. When new it could have been operated Pt91 IFR without attitude or directional gyros. Backup? When you start on needle/ball/airspeed what the heck would "backup" be? How far we have come!

[FlyingRon]

But since 1956 it was required to have an attitude indicator and directional gyro to fly IFR and that requirement (albeit with allowances for changes in technology) remains to this day.

[Bill Greenwood]

e Daniel , no matter what the regs will let you get away with, flying real ifr that is in imc when you cannot see out of the plane to either the ground or the horizon is serious situation. If you disagree, get a CFI or good pilot friend and go up in a fully eqiuiped plane, preferably on a grey day or at night, put on a hood and then cover the att indicator and see how long you can fly safely. And can you do it with turns, climbs, descents and better yet some turbulence. And remember youll also have to navigate in real imc, that is turn radio channels or vors or gps or whatever, not the same as sitting at a console. And you have a basic plane probably without and autopilot and you are a new student at this. Be careful.

[Marc Zeitlin]

...The FAA and EAA and industry have come up with ways to go glass, even all glass, without gyroscopes - and still have backup...Minor nit - the glass cockpit EFIS's that have ADHRS systems DO have gyroscopes, just like your iPhone does - they're just electronic, not mechanical spinny things. They're rate gyros, for the most part, so require a lot of stabilization, but they ARE gyroscopic.

And most EFIS's have gyroscopic pitch and bank, as well as a directional gyro AND a gyro based rate of turn indicator, all built into the ADHRS. So you get everything in one package.

[FlyingRon]

Actually, iphone (and many of the electronic flight units) have accelerometers. They are not "gyroscopic" in the least. They perform the same function but without using gyroscopic principals.

[Marc Zeitlin]

Actually, iphone (and many of the electronic flight units) have accelerometers.That is very true.


They are not "gyroscopic" in the least.That is very true as well.


They perform the same function but without using gyroscopic principals.Well, you should inform Apple of this. Their spec pages at:

https://www.apple.com/iphone-6s/specs/
https://www.apple.com/iphone-7/specs/
https://www.apple.com/iphone-8/specs/
https://www.apple.com/iphone-x/specs/

show 3 axis gyros as well as accelerometers. I don't know which iPhone was the first to have gyros, but it was a number of years ago. My iPhone 6 certainly has gyros as well.

Accelerometers CANNOT perform the same function as gyroscopes, which is why people use gyroscopes. Your slip/skid indicator is an directional accelerometer - the ball points in the direction of airplane vertical axis acceleration. Even if it had a number on it to indicate the "G" loading in the direction of the acceleration, it would tell you nothing about the orientation of your aircraft in space. You could be upside down in the top of a loop pulling one G at a constant speed and your three accelerometers would believe that everything was exactly the same as if you were in straight and level flight at 1 G. This would obviously not be useful for orientation information - only a gyroscope can provide that. A 1.5 G spiral dive would be another situation where accelerometers would be useless for orientation information.

As I said before, the gyros in the ADHRS and iphones (and some android phones) are solid state electronic devices, probably with small vibrating cantilever beams (at least that's what I designed in one of the first ones in 1981) - see:

https://en.wikipedia.org/wiki/Vibrating_structure_gyroscope

under "piezo electric gyroscope". By measuring and integrating the measurements of the vibration of the beams, one can get orientation information that one cannot get from an accelerometer.