Certify a straight tail 172 for IFR?

[poadeleted20]

Really? For flying IFR? What? I wouldn't have spent the money if I didn't see the extraordinary value flying Av's Comanche.

In a $100K light twin which will be flown in heavy IFR, it probably makes sense. In a $30K 1950's 172 which will probably be flown only lightly under IFR, I think the expenditure of that extra amount on an advanced avionic display bears considerable deliberation. For example, unlike that light twin, that $12K differential is the price of most of an engine overhaul, compared to maybe 20% of the cost of overhauling the engines on a 310.

 

[poadeleted20]

You guys are advocating that this guy spend $50k on a $25k airplane!

Henning might be; I'm certainly not. Only reason I'd even consider the Aspen is, if a vacuum pump isn't feasible, the OP will probably have to spend $5K on an electric gyro setup anyway, so in addition to the $12K or so for the 650, another $7K doesn't seem so excessive. But $23K for a G500 installation? I think that's beyond reasonability, even if I won't say it's not worth considering.

 

[Henning]

You guys are advocating that this guy spend $50k on a $25k airplane!



Oh...don't forget the auto pilot!

It's not a $25k plane with a glass deck, it's the operational equivalent of a G-1000 172, they go for over $125k with high time and a run out engine.

The guy said he is buying it, I figure since he's putting the 650 and asking about IFR cert, he plans to keep and fly the plane, so resale value isn't particularly relevant as he will get his money's worth out of the equipment by flying it, using, and enjoying it.

So, let's consider him getting better than venturi vacuum. What will it cost to change to an engine that accepts a pump? More than an Aspen I bet. Even switching to an electric AI and DG is still going to end up $4k, and you end up with brand new 75 year old technology.

If he's already putting in the 650, the Aspen would be the highest value way to achieve his goal of making a working IFR plane out of it. I chose to go with the G-500 due to the bigger screen area and easier legibility.

 

[Tom-D]

Henning might be; I'm certainly not.

But Ron ,,, Every body on the blue page knows you must have new paint, windows, interior, and a zero timed engine before you up grade

 

[German guy]

Wow, this discussion has taken an interesting turn....

We want to the plane solely for recreational purposes, therefore neither speed nor serious IFR capabilities are important factors. We are looking for a vintage aircraft which appeals to us, but which still offers some utility for personal travel. If we would need a hard-IFR travel machine, we would look for something else... :wink2:

We neither want to fly it in icing condition nor in for longer periods in IMC. The goal is to have an aircraft which allows us, for the peace of mind, to fly IFR in MVFR conditions and with which we can climb / decent through thinner cloud layers with a basis at a minimum of 1,000 ft. AGL.

Also, while my wife is already instrument rated, I want to use it to work on my instrument rating.

And - while we are willing to throw some money into the aircraft, we would prefer if the costs for the avionics upgrade would not exceed the value of the aircraft...

 

[JoseCuervo]

But Ron ,,, Every body on the blue page knows you must have new paint, windows, interior, and a zero timed engine before you up grade

When AI first joined POA I mentioned a budget that I wanted to spend on a plane.

I was told if that was my budget, then I couldn't afford a plane that cost my budget, because of all the other nonsense that might pop up.

 

[jesse]

Wow, this discussion has taken an interesting turn....

We want to the plane solely for recreational purposes, therefore neither speed nor serious IFR capabilities are important factors. We are looking for a vintage aircraft which appeals to us, but which still offers some utility for personal travel. If we would need a hard-IFR travel machine, we would look for something else... :wink2:

We neither want to fly in icing nor in for longer periods in IM conditions. The goal is to have an aircraft which allows us, for the peace of mind, to fly IFR in MVFR conditions and with which we can climb / decent through thinner cloud layers with a basis at a minimum of 1,000 ft. AGL.

Also, while my wife is already instrument rated, I want to use it to work on my instrument rating.

And - while we are willing to throw some money into the aircraft, we would prefer if the costs for the avionics upgrade would not exceed the value of the aircraft...

Understand all those goals but the operational reality of instrument flight is that quite often you'll enter a layer that you don't expect to be in for long and the flight terminates with an ILS close to minimums. Once the clouds start coming down, they often times continue to do so.

I also understand the desire not to dump a bunch of money into a low value airplane (I have the same problem with the Flybaby) the problem though is $100k airplane or $10k airplane avionics cost basically the same and you need a certain level of equipment to do things.

I wouldn't' make the habit out of using it for instrument conditions at all without the equipment I would feel is required. You're free to do whatever you'd like though

The other part to consider, is that if you use it once in a rare occasion to go through some thin layer that probably means you're not staying current to actually utilize your instrument rating regardless of the equipment.

I don't have the stats - but if I had to guess - I'd figure less than 10% of the people who get instrument ratings and aren't professional pilots remain competent to fly on instruments three years after their checkride. I see it time and time again. Someone wants an instrument rating, they barely have the right equipment for it, they pass their checkride and they never use the certificate and a few years later they've forgotten everything. Then they show up wanting an IPC and are disappointed when they realize it's going to take a good ten hours of training to get them up to speed.

I had a guy come to me a few weeks ago looking to get an instrument rating so that he can use it "once in awhile if he needs to". He had a Cherokee 140 with no markers, no GPS, no ADF, no DME no glideslope, a single VOR, and a single COM radio. I told him we can't do it unless he upgrades his equipment and gave him a list of what we could get done to do it at the minimum budget and a list of things to buy to do it right.

He was frustrated to learn that he had to put a bunch of money into his airplane that's "not worth much" to be able to have an instrument rating to use "once and awhile when the weather gets bad". He decided to do the minimum set of equipment.

The problem with his plan is that flying instruments with his minimum set of equipment is going to be a giant pain in the ass which means he's not actually going to use his instrument rating when he is done and won't have any instrument skills a few years after his checkride.

I'm not saying you fit into the above profile but it's quite common. Do you even know how well your venturi gyros work? I suspect you'll discover once you get to flying it under the hood during training that they don't work very well at all.

If it were mine - and I'm not rich by any means - and I wanted to use it for *ANY* sort of instrument flying I would put an IFR GPS in and at minimum an electric AI and electric DG (keep the venturi driven AI). If I had some extra money in my pocket I'd skip the above and drop an IFR GPS in and an Aspen.

Just please keep in mind there really is no such thing as only using your instrument rating on the rare occasion that you need to go through a thin layer. Often times that thin layer will become a thick layer. And if you're not using your IR often you won't retain the skill to do it anyhow.

I advise all my students to file IFR *EVERYWHERE* they go over 25 miles for at least the first year after they finish their rating. That will "burn in" their new instrument skills. Those that do show up and actually can pass an IPC after six months.

Those that don't, and just planned on using it months later if they needed to go through a thin layer, are by no means competent to go through any layer after about a year after their checkride pass.

Just some thoughts from an instrument instructor that has flown most levels of "equipment"..and has given a lot of training in poorly equipped airplanes. I've flown plenty of older 172s with venturi gyros and I've yet to see one that works well enough that I'd enter any layer with it. Perhaps if you rebuilt those gyros it'd be better but if you're going to put money into it you might as well do it right.

You're making a REALLY good decision putting a GTN650 in. That will make flying IFR a pretty simple thing to do which means you'll do it more often. I'd suggest you put the extra money into decent gyros as well. But..your money your plane

 

[Henning]

Wow, this discussion has taken an interesting turn....

We want to the plane solely for recreational purposes, therefore neither speed nor serious IFR capabilities are important factors. We are looking for a vintage aircraft which appeals to us, but which still offers some utility for personal travel. If we would need a hard-IFR travel machine, we would look for something else... :wink2:

We neither want to fly in icing nor in for longer periods in IM conditions. The goal is to have an aircraft which allows us, for the peace of mind, to fly IFR in MVFR conditions and with which we can climb / decent through thinner cloud layers with a basis at a minimum of 1,000 ft. AGL.

Also, while my wife is already instrument rated, I want to use it to work on my instrument rating.

And - while we are willing to throw some money into the aircraft, we would prefer if the costs for the avionics upgrade would not exceed the value of the aircraft...

With Venturi gyros and a 650, you have a fine VFR plane with the limited ability to get you through a layer safely if you get caught on top. As long as that is all the capability you want, that's fine. There is no way in hell in this day and age though that I would launch on an IFR flight into IMC with that set up.

If you want real IFR capability, either do an upgrade to the vacuum system (probably requiring a change in engines) or the gyros, and I can't imagine spending $4-5k and having old style gyros.

My personal opinion is that as little as I fly IFR, I want as much advantage as possible. I bought the 310 to travel in, and that means I may need to go IFR, so Imequipped it accordingly. There is nothing that is remotely similar in the ability to provide me situational awareness at a glance that can compete with SVT.

 

[peerlesscowboy]

Understand all those goals but the operational reality of instrument flight is that quite often you'll enter a layer that you don't expect to be in for long and the flight terminates with an ILS close to minimums. Once the clouds start coming down, they often times continue to do so.

I also understand the desire not to dump a bunch of money into a low value airplane (I have the same problem with the Flybaby) the problem though is $100k airplane or $10k airplane avionics cost basically the same and you need a certain level of equipment to do things.

I wouldn't' make the habit out of using it for instrument conditions at all without the equipment I would feel is required. You're free to do whatever you'd like though

The other part to consider, is that if you use it once in a rare occasion to go through some thin layer that probably means you're not staying current to actually utilize your instrument rating regardless of the equipment.

I don't have the stats - but if I had to guess - I'd figure less than 10% of the people who get instrument ratings and aren't professional pilots remain competent to fly on instruments three years after their checkride. I see it time and time again. Someone wants an instrument rating, they barely have the right equipment for it, they pass their checkride and they never use the certificate and a few years later they've forgotten everything. Then they show up wanting an IPC and are disappointed when they realize it's going to take a good ten hours of training to get them up to speed.

I had a guy come to me a few weeks ago looking to get an instrument rating so that he can use it "once in awhile if he needs to". He had a Cherokee 140 with no markers, no GPS, no ADF, no DME no glideslope, a single VOR, and a single COM radio. I told him we can't do it unless he upgrades his equipment and gave him a list of what we could get done to do it at the minimum budget and a list of things to buy to do it right.

He was frustrated to learn that he had to put a bunch of money into his airplane that's "not worth much" to be able to have an instrument rating to use "once and awhile when the weather gets bad". He decided to do the minimum set of equipment.

The problem with his plan is that flying instruments with his minimum set of equipment is going to be a giant pain in the ass which means he's not actually going to use his instrument rating when he is done and won't have any instrument skills a few years after his checkride.

I'm not saying you fit into the above profile but it's quite common. Do you even know how well your venturi gyros work? I suspect you'll discover once you get to flying it under the hood during training that they don't work very well at all.

If it were mine - and I'm not rich by any means - and I wanted to use it for *ANY* sort of instrument flying I would put an IFR GPS in and at minimum an electric AI and electric DG (keep the venturi driven AI). If I had some extra money in my pocket I'd skip the above and drop an IFR GPS in and an Aspen.

Just please keep in mind there really is no such thing as only using your instrument rating on the rare occasion that you need to go through a thin layer. Often times that thin layer will become a thick layer. And if you're not using your IR often you won't retain the skill to do it anyhow.

I advise all my students to file IFR *EVERYWHERE* they go over 25 miles for at least the first year after they finish their rating. That will "burn in" their new instrument skills. Those that do show up and actually can pass an IPC after six months.

Those that don't, and just planned on using it months later if they needed to go through a thin layer, are by no means competent to go through any layer after about a year after their checkride pass.

Just some thoughts from an instrument instructor that has flown most levels of "equipment"..and has given a lot of training in poorly equipped airplanes. I've flown plenty of older 172s with venturi gyros and I've yet to see one that works well enough that I'd enter any layer with it. Perhaps if you rebuilt those gyros it'd be better but if you're going to put money into it you might as well do it right.

You're making a REALLY good decision putting a GTN650 in. That will make flying IFR a pretty simple thing to do which means you'll do it more often. I'd suggest you put the extra money into decent gyros as well. But..your money your plane

I'm sure that wasn't what the OP wanted to hear but it's the truth.

 

[Henning]

And - while we are willing to throw some money into the aircraft, we would prefer if the costs for the avionics upgrade would not exceed the value of the aircraft...

How do you determine the value of the aircraft?

 

[German guy]

Jesse, Henning,

I hear you. As also mentioned by somebody above, it heard that it is difficult to add a vacuum pump because this modification is not (any more) covered by a STC. My understanding is that it would be possible to install a later version of the engine with a vacuum pump, what however appears to be cost prohibitive. To convert the engine also seems to be an possible.

So, either some kind of electronic AI and DG or to simply buy a later 172 are the most viable options. We are leaning toward the latter...

 

[Hank S]

How do you determine the value of the aircraft?

Since they are in the final stages of purchasing, I think they know their value for the plane.

 

[Henning]

Since they are in the final stages of purchasing, I think they know their value for the plane.

That doesn't answer my question. What criteria are in use?

 

[Henning]

Jesse, Henning,

I hear you. As also mentioned by somebody above, it heard that it is difficult to add a vacuum pump because this modification is not (any more) covered by a STC. My understanding is that it would be possible to install a later version of the engine with a vacuum pump, what however appears to be cost prohibitive. To convert the engine also seems to be an possible.

So, either some kind of electronic AI and DG or to simply buy a later 172 are the most viable options. We are leaning toward the latter...

Buying a later model with a less antiquated system would be the cheaper option for getting in a plane with proper IFR capability.

 

[weirdjim]

:wink2:
Standards require you protect for lightning strikes if the plane will be in IMC and require no such requirement it it's VMC only.

Could you get struck by lightning in VMC? Probably. But they consider it a low enough risk that you don't need any engineering data to say nothing bad will happen if it does get struck.

So what are the criteria for 'protection" a 6" wide strip of copper tape every 12"? A #55 wire every foot? Nobody seems to be able to come up with the "magic number" for "protection"

I go back to the certification FAR. If nobody knows what "protection" is or how to define it, then the FAR requiring it is worthless.

Jim

 

[Henning]

So what are the criteria for 'protection" a 6" wide strip of copper tape every 12"? A #55 wire every foot? Nobody seems to be able to come up with the "magic number" for "protection"

I go back to the certification FAR. If nobody knows what "protection" is or how to define it, then the FAR requiring it is worthless.

Jim

Well, Diamond seemed to figure it out for the DA-40.

 

[JHW]

OP, your 172 will serve you just fine without any of this stuff. It was just finr for flying IFR in the 1950's with the instruments it has, and the same is true today. Don't let anyone convince you that big screen televisions in the panel are needed for IFR.

 

[Henning]

OP, your 172 will serve you just fine without any of this stuff. It was just finr for flying IFR in the 1950's with the instruments it has, and the same is true today. Don't let anyone convince you that big screen televisions in the panel are needed for IFR.

After having the venturiis ice up in the clouds I won't be flying any extended periods of IMC with them again. There's a reason the were given up 60 years ago. Pop up and down through a layer, sure.

 

[MBDiagMan]

I would think that you would want to install a vacuum pump. My 140 has a custom panel with six pack and center stack, but it has a vacuum pump which seems to make all the difference in the reliability and consistency that you need.

Other than the pump, there is no reason whatsoever, not to make an IFR plane out of it. If it can be done with it's older and smaller cousin, it can be done with an early 172.

 

[peerlesscowboy]

OP, your 172 will serve you just fine without any of this stuff. It was just finr for flying IFR in the 1950's with the instruments it has, and the same is true today. Don't let anyone convince you that big screen televisions in the panel are needed for IFR.

"big screen televisions" aren't necessary but a reliable vacuum source to power the gyros is. Personally I wouldn't fly IFR without an engine driven vacuum pump to drive the AI & DG plus an electric T&B for redundancy.
…plus I might add…..a heated pitot tube.

 

[Fearless Tower]

"big screen televisions" aren't necessary but a reliable vacuum source to power the gyros is. Personally I wouldn't fly IFR without an engine driven vacuum pump to drive the AI & DG plus an electric T&B for redundancy.

…plus I might add…..a heated pitot tube.

Please educate me on what is not 'reliable' about a venturi vacuum system?

 

[German guy]

When my wife and I spoke about this topic, we decided to follow the recommendations, to drop the idea to get a good looking straight tail 172 and to get a newer 172 with a vacuum pump instead.
That was yesterday.

After some more digging into this topic, particularly in the Cessna 170 forum, where quite a few people happily fly IFR with a venturi vacuum, I am however not so sure anymore. Word is that venturi systems are, other than mechanical pumps which seem to be prone to failure, pretty much bullet proof. Icing would be the only concern, these were however not the conditions a 170/172 should be operated in anyway. It is also said that the icing of a venturi cannot be compared to the icing of a carburetor, as no gasoline is being evaporated. The only real advantage of vaccum pumps would be that the vacuum driven instruments are fully functional before take off, so that one could take off into low IFR conditions, what would however again not be something one wants to do in a 170 / 172. To go from a venturi system to a vacuum pump would therefore mean to give up a very reliable system, with well defined limitations (no take off into low IFR, no flights into icing conditions) for a system which is pretty likely to fail, what could happen anytime and which offers very little, if any, benefits over a venturi system under real-world-recreational-travel-IFR conditions.

Frankly, I am confused.
On one hand, we would rather make concession regarding the plane we actually want, in order to be safe(r). On the other hand, the arguments of the venturi advocates sound very reasonable and I don’t want to invest into a system which is less reliable and which advantages are actually almost irrelevant for us!?

 

[Fearless Tower]

Here is the question I think you should ask: how much IFR do you really want to be doing in this airplane?

I kept my 170 IFR certified. I flew it in actual. It was great for flying through the SoCal marine layer and making occasional cross-country trips.

Never had any issues with the Venturi vacuum system that those who have never used one seem to think exist (aside from fixing a few leaks when I did my first pitot static test). It is an extremely reliable system (there are no moving parts to break).

A Venturi system does have its limitations. Ice is obviously a problem, but you shouldn't be taking an ancient 170 or 172 anywhere near ice. Respect that and it isn't an issue. You also aren't able to fully check that your gyro instruments are fully functional until you get in the air ( this to me is the biggest drawback). In my book that limits low IFR departures. I used to use the departure airport's circling minimums as my departure mins. If I had noticed a problem in the initial climb, I would keep it out if the clouds and return to the runway. Respect that and again, it is a non-issue.

Detective Harry Callaghan said it best...."man's got to know his limitations"....I would add that you need to know AND keep it with those limitations. I never flew my 170 IFR like I fly my Baron IFR.

Aside from that, the only issue I ever experienced flying in IMC in my 170 had nothing to do with the Venturi system. It was the shotgun panel arrangement. Having the instruments haphazardly spread across the entire panel really does increase your mental workload when flying in
IMC.

I will also add that I always had a Garmin Aera GPS and iPad with Foreflight on the yoke whenever I flew the airplane IFR.

If a vintage 172 is what you have your heart set on, find the best looking one you can and enjoy it.

 

[James331]

When my wife and I spoke about this topic, we decided to follow the recommendations, to drop the idea to get a good looking straight tail 172 and to get a newer 172 with a vacuum pump instead.
That was yesterday.

After some more digging into this topic, particularly in the Cessna 170 forum, where quite a few people happily fly IFR with a venturi vacuum, I am however not so sure anymore. Word is that venturi systems are, other than mechanical pumps which seem to be prone to failure, pretty much bullet proof. Icing would be the only concern, these were however not the conditions a 170/172 should be operated in anyway. It is also said that the icing of a venturi cannot be compared to the icing of a carburetor, as no gasoline is being evaporated. The only real advantage of vaccum pumps would be that the vacuum driven instruments are fully functional before take off, so that one could take off into low IFR conditions, what would however again not be something one wants to do in a 170 / 172. To go from a venturi system to a vacuum pump would therefore mean to give up a very reliable system, with well defined limitations (no take off into low IFR, no flights into icing conditions) for a system which is pretty likely to fail, what could happen anytime and which offers very little, if any, benefits over a venturi system under real-world-recreational-travel-IFR conditions.

Frankly, I am confused.
On one hand, we would rather make concession regarding the plane we actually want, in order to be safe(r). On the other hand, the arguments of the venturi advocates sound very reasonable and I don’t want to invest into a system which is less reliable and which advantages are actually almost irrelevant for us!?

How much IFR flying do these folks on that 170 board do? How much IMC time?

Frankly if you're doing REAL IFR work in actual you're going to be much much more likely to ice up your Venturi than have a vac pump failure.

There is a reason all the working piston IFR planes don't have venturis, there is a reason the pilatus I fly for work doesn't have a Venturi.

Yeah they are dirt simple and more or less work, but for actual IMC they are not a good choice, that's comming from someone who flys IFR for a living.

So far I've had two full engine failures in my career, one full vac failure, that's in over 4,000 flight hours.

Also another good option, save some money and get a GNS430W and take some of that savings, through in a couple more bucks and get a aspen or something, you'd have a really nice IFR panel at that point.

 

[Fearless Tower]

Frankly if you're doing REAL IFR work in actual you're going to be much much more likely to ice up your Venturi than have a vac pump failure.

Which is why I asked the question about what his real goal is. So far from what he has posted, I don't think his primary goal of ownership is REAL IFR.

 

[Fearless Tower]

I'm wondering when we are going to get into the twin vs single debate....

We might as well start now and push him to start looking at Aerostars....of maybe a KA.

 

[Fearless Tower]

Okay, Duke....there I said it. He would look cool in a Duke.

 

[James331]

Which is why I asked the question about what his real goal is. So far from what he has posted, I don't think his primary goal of ownership is REAL IFR.

If it's just IFR for a IFR rating, it doesn't even need to be legal IFR.

 

[F01LA]

How do you determine the value of the aircraft?

Well, how did you determine the value of your aircraft when you listed it for sale? How did your potential buyers determine its value? Did you make a sale? Who was right?

You may be close to right about the operational capabilities of this aircraft vs. a G1000 172, but that doesn't make their value equal. How much would a $25k 172 with $50k of avionics really be worth?

OK, enough questions.

 

[German guy]

[...] how much IFR do you really want to be doing in this airplane?

[...]

It is an extremely reliable system (there are no moving parts to break)

[...]

Ice is obviously a problem, but you shouldn't be taking an ancient 170 or 172 anywhere near ice. Respect that and it isn't an issue. You also aren't able to fully check that your gyro instruments are fully functional until you get in the air ( this to me is the biggest drawback). In my book that limits low IFR departures. I used to use the departure airport's circling minimums as my departure mins.

[...]

Aside from that, the only issue I ever experienced flying in IMC in my 170 had nothing to do with the Venturi system. It was the shotgun panel arrangement. Having the instruments haphazardly spread across the entire panel really does increase your mental workload when flying in
IMC.

I will also add that I always had a Garmin Aera GPS and iPad with Foreflight on the yoke whenever I flew the airplane IFR.

[...]

This is pretty much the condensate of what I read in other forums and what sounds reasonable to me. Before I started this thread, I thought the shotgun panel and the low installation of the GPS would be the biggest drawbacks.

Again, the mission is to fly comfortably in MVFR conditions, to climb / decent through a not too thick cloud layer at temperatures well above freezing and to get my IR in it (my wife is already instrument rated). Extended flights in IMC are not on the agenda and probably never will.

To add an electric AI sounds like a good idea to me, also in combination with a vacuum pump.

We already fly most of the time with a tablet on the yoke.

 

[weirdjim]

When my wife and I spoke about this topic, we decided to follow the recommendations, to drop the idea to get a good looking straight tail 172 and to get a newer 172 with a vacuum pump instead.
That was yesterday.

You might want to touch base with EAA to find out their current definition of "classic" year. When you take the airplane to Oshkosh, that big chunk of classic parking next to the bus line is worth it's weight in unicorn dung.

Plus the mug. Plus the plaque for the wall.

Jim

 

[James331]

This is pretty much the condensate of what I read in other forums and what sounds reasonable to me. Before I started this thread, I thought the shotgun panel and the low installation of the GPS would be the biggest drawbacks.

Again, the mission is to fly comfortably in MVFR conditions, to climb / decent through a not too thick cloud layer at temperatures well above freezing and to get my IR in it (my wife is already instrument rated). Extended flights in IMC are not on the agenda and probably never will.

To add an electric AI sounds like a good idea to me, also in combination with a vacuum pump.

We already fly most of the time with a tablet on the yoke.

How much TT time do you and your wife have?
How much IMC time does she have?

Launching into marginal conditions or just punching through a layer, you're giving the weather gods a lot of predictability credit lol.

To think you're going to launch into MVFR, pull IFR clearances to punch layers and not ending up fly a good chunk of IMC on occasion is VERY naive.

 

[jesse]

To think you're going to launch into MVFR, pull IFR clearances to punch layers and not ending up fly a good chunk of IMC on occasion is VERY naive.

James and I might not agree with everything, but I agree with the above, although I'd probably replace naive with a little friendlier word

 

[poadeleted20]

It's not a $25k plane with a glass deck, it's the operational equivalent of a G-1000 172, they go for over $125k with high time and a run out engine.

You really think someone could get $125K for a 1950-something Cessna 172 with a run-out engine and a G500/GTN650 panel? Sure, if this is a plane the OP will keep for the next 20 years, maybe investment in avionics of half again the plane's purchase price makes sense, but I'm just not seeing the real value of the G500 over an Aspen being worth $12K unless the OP is doing a lot of heavy IFR flying, and maybe not even then

 

[jesse]

You really think someone could get $125K for a 1950-something Cessna 172 with a run-out engine and a G500/GTN650 panel? Sure, if this is a plane the OP will keep for the next 20 years, maybe investment in avionics of half again the plane's purchase price makes sense, but I'm just not seeing the real value of the G500 over an Aspen being worth $12K unless the OP is doing a lot of heavy IFR flying, and maybe not even then

No way I would drop a G500 in over an Aspen for any sort of flying. Well, maybe I would, but I would need a hell of a lot of extra money sitting in a bank that I didn't know what to do with. Not a problem I'll have anytime soon.

 

[poadeleted20]

But Ron ,,, Every body on the blue page knows you must have new paint, windows, interior, and a zero timed engine before you up grade

Well, I must admit I'm doing that to my Tiger, but I'm doing it on the Johnny Cash "One Piece at a Time" program, and like his plan to get a Cadillac "that's long and black", my schedule is also on track for about a 30-year completion date, by which time (like painting the Golden Gate Bridge), it will be time to start over again (God willing I should only live and keep my medical so long).

 

[jesse]

Well, I must admit I'm doing that to my Tiger, but I'm doing it on the Johnny Cash "One Piece at a Time" program, and like his plan to get a Cadillac "that's long and black", my schedule is also on track for about a 30-year completion date, by which time (like painting the Golden Gate Bridge), it will be time to start over again (God willing I should only live and keep my medical so long).

Sneaking parts out of your client's airplanes in your lunch box?

You're going to really need to grease the wheels at the FSDO since it'll take the whole staff to type up the 60 lbs of paperwork.

 

[poadeleted20]

Wow, this discussion has taken an interesting turn....

We want to the plane solely for recreational purposes, therefore neither speed nor serious IFR capabilities are important factors. We are looking for a vintage aircraft which appeals to us, but which still offers some utility for personal travel. If we would need a hard-IFR travel machine, we would look for something else... :wink2:

We neither want to fly it in icing condition nor in for longer periods in IMC. The goal is to have an aircraft which allows us, for the peace of mind, to fly IFR in MVFR conditions and with which we can climb / decent through thinner cloud layers with a basis at a minimum of 1,000 ft. AGL.

Also, while my wife is already instrument rated, I want to use it to work on my instrument rating.

And - while we are willing to throw some money into the aircraft, we would prefer if the costs for the avionics upgrade would not exceed the value of the aircraft...

Then I'll go with my original advice -- if you can mount a vacuum pump, do that and use it to power your existing AI/HI, while installing an electric TC/T&B (or keeping a venturi powered vacuum T&B if that's what's there already). If you can't mount that vacuum pump, keep the venturi AI as your second gyro (see AC 91-75, and you might have to mount a simple inclinometer if your don't already have a ball somewhere in the plane) and install electric AI/HI instruments. Even the most expensive option there will only run you on the order of $5-6K.

If you really want to splurge, you can sink $12K into an Aspen while keeping the venturi vacuum AI as your backup (along with your existing airspeed and altimeter instruments). But that's as far as I'd go for what you want, and maybe a bit farther.

 

[poadeleted20]

So what are the criteria for 'protection" a 6" wide strip of copper tape every 12"? A #55 wire every foot? Nobody seems to be able to come up with the "magic number" for "protection"

I go back to the certification FAR. If nobody knows what "protection" is or how to define it, then the FAR requiring it is worthless.

The regulations aren't meant to go to that level of detail. They merely state standards. The AC's give you means of meeting those standards, although you're certainly free to propose alternative methods as long as you meet the standards. And without doing the digging, I'm pretty darn sure the FAA has an AC telling you how to determine if a method you want to use meets the regulatory standard for lightning and static discharge protection.

 

[bnt83]

So what are the criteria for 'protection" a 6" wide strip of copper tape every 12"? A #55 wire every foot? Nobody seems to be able to come up with the "magic number" for "protection"

I go back to the certification FAR. If nobody knows what "protection" is or how to define it, then the FAR requiring it is worthless.

Jim

Really isn't as difficult to understand as everyone is making this out to be. They use basically a hybrid fabric that have wire filaments in the weave. Cessna calls them an als ply (woven graphite with aluminum) which is the outermost ply in the composite skins. They give you their part number in the SRMs but there are others I've seen in non-OEM engineered FAA approved repairs. I've never seen these sold at commercial fiberglass/composite suppliers so I'm not sure where we get them if not from the OEM.

Beech (think Premier) is pretty much the same.

There is about a 5 page table of electrical bonding values given for each type of structure. If we repair a couple damaged plys on the composite rudder of a citation 750 the last step of the repair requires an electrical bonding check of the als ply with the surrounding undisturbed skin.

There are also thin wire meshes that are used on wingtips etc, layed up similar to a veil in a fiberglass layup. Static wicks are usually mounted over top of these bare meshes to ensure good conductivity.

Radomes are a special in that repairs can affect transmissivity of the radar antenna below. Pretty much all of these I'm familiar with use a strip of metal embedded in a Teflon-like plastic that is basically double sided taped onto the radome. The aft most end of these strips are terminated at a metal fastener (screw) that bonds them to a metal bulkhead that is then screwed to the airplane. http://lightningdiversion.com/home/diversion-strips/

Even with all this protection a lightening strike can still easily damage a composite surface.

I'm sure with good Google foo anyone can bring up all kinds of NASA and FAA guidance on lightening protection of aerospace vehicles. I'm also sure it is dry long reading.