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.