Piper Aztec?

You have to feed two 540 engines. Ted is the guy to ask around here about specifics.
 
Yeah, they're practically giving twins away these days because of the expense in operating them.
 
And that left engine has 30 years on the overhaul. I bet it is ready for another one.
The right engine was overhauled in 2009, but only has 77 hours on it. This thing does not fly much.
I'm sure I can dig up the fuel & speed numbers, but does anyone know them off the top of their heads?
 
Kiddo's Driver said:
And that left engine has 30 years on the overhaul. I bet it is ready for another one.
The right engine was overhauled in 2009, but only has 77 hours on it. This thing does not fly much.
I'm sure I can dig up the fuel & speed numbers, but does anyone know them off the top of their heads?
Click to expand...

I did notice the hours and date on the engines as an issue. I would love to know the speeds and numbers!

Twin_Flyer said:
You mean other than the paint???:eek:
Click to expand...
Haha, yes the paint is... interesting.
 
Soldier64 said:
Day dreaming here. Just curious why this airplane is priced at $69,900? What is wrong with the Aztec? Anyone have the pros/cons over others in the class?

http://www.aso.com/listings/spec/Vi...l=True&pagingNo=1&searchId=23075074&dealerid=
Click to expand...

They don't call them an Az-Truck for nothing. I wrote a piece for the Piper Flyer magazine that i think will come out in the April edition.

For the C model and later you can expect 170 knots at about 25 gph. They will carry about anything you can fit in it and is probably the best all-weather light twin in its ability to soldier through the weather, provided the pilot is up to the task.

Like any 50 year old, complex aircraft, if the maintenance has been let go, it will take huge coin to catch up.
 
High time engines,high fuel burn,three times maintenance costs. Plenty of twins on the market. Traded my twin for the little two seater I have now.
 
It's a C model with no de-ice. Most potential Aztec buyers want de-ice (the Aztec is the best airplane I've ever flown in icing) and most also want an E or F model because they're newer. You see the same thing with 310s. Really, the price isn't too far off, but it is a bit high (most asking prices are). The paint is unique, the one old engine and one low time but barely flown engine do give pause, but don't necessarily mean that they're bad.

My Aztec experience is slower than Kristin's. Aztecs also have some of the worst engine cooling I've seen. I ran my D model LOP and got about 155 KTAS at 21 GPH combined. At 25 combined, I'd expect your CHTs to be somewhere well into the 400s, even with baffles in good shape. While Aztec engines are stout beasts that don't have much asked of them, I've still seen them throw cylinders.

As I type this, I've spent about 900 hours in an Aztec and about 900 hours in 310s. Like anything, they have their pros and cons. The 310 is a much faster plane - on the same fuel burn as the Aztec I'm about 25 KTAS faster in the 310, but keep in mind the 310 I fly has 520s and I've spent a lot of time optimizing it. It also has a smaller cabin and is worse in icing conditions (thinner, hotter wing) which is how it achieves this. The Aztec is very forgiving, it really handles like a big Cherokee. You can find 310s of similar vintage for similar prices, and probably also 55 Barons.

The Aztec I find to be a bit cheaper in terms of $/hr, but similar in terms of $/mile to the 310 (I figured $250/hr for the Aztec and $300/hr for the 310). However, I think that most of the difference has to do with the work that I did on the 310 that I didn't do on the Aztec (avionics upgrades, some drag reduction, engines, etc.).

Really, I think the 310 ends up being a better airplane if you don't need the space of the Aztec. I suppose the best summary of my opinion is that I had the option to keep the Aztec or the 310. I chose the 310, both because of the specific airframe (it was in much better shape overall) and also because of the speed and my feeling that it was a better overall bird.

Any of the twins represent a good value if you have a mission for them. You do have to be able to put some cash at them - I figure it's around $10k/yr before you start the engines. There are plenty of ways to help keep costs down, which mostly come down to LOP operations and owner-assisted maintenance. Of course, you can do these to get the costs down on any plane.
 
Ted,

Thank you for the write up. I do as much owner assisted maintenance as I can within regs. I have kept the cost of my airplane down fairly well. I do have a mission for the useful load and capability of a twin with the family. Not sure I could keep up with those costs. The cost of the twins in the market seem tempting.
 
If you compare something like a 310 to an Arrow, you're looking at roughly 2x the fuel for almost 50% more speed. Hangar cost probably won't be much different (unless you have a super small hangar). Insurance will probably be 2x, but that depends on hull value. For aviation, that's a pretty decent trade, but there's still more money required at the end of the day. A lot of your personal costs come down to what breaks on you which is a roll of the dice. I've historically had good luck with props, although bad luck with de-ice (and specifically prop de-ice). A lot of de-ice has to do with boot condition, though, as boots are the big money. When I replaced the three tail boots on the Aztec it was $10k. If you think about it, that added $10 to my hourly cost of the Aztec over the 1000 hours I owned it! I'd love to ditch de-ice, but can't for my mission.

I'm glad to answer any questions on owning these birds you have, feel free to PM me. Historically, I haven't done that much owner-assisted maintenance, although it has been increasing over the past year, so the numbers I've come up with reflect shop rates.
 
Soldier64 said:
Day dreaming here. Just curious why this airplane is priced at $69,900?
Click to expand...
because the seller is having a wet dream. After it sits a few more months maybe he'll slash that price to something that could encourage some offers. In the meantime if you have $70k to spend you can get a pretty good baron and go a whole lot faster with better reliability.
 
I agree with Ted. The Aztec is great in ice, with or without de-ice equipment (although don't consider this to be advocating flying around in icing conditions without the proper equipment). The asking price seems pretty average to me, although I wouldn't be surprised if it sat around a while before selling with that paint job on it.

I regularly fly a D model Aztec, and speed wise my experience has been similar to Ted's, 155 at 21-22 gph. Like Ted mentioned, the one I fly will get hot at higher power settings and I've never been able to find anything terribly out of order causing it so I've always just flown it at the lower power setting.

Maintenance wise, the Aztec is a complex machine. I would personally suggest buying the nicest example you can find, otherwise you could spend a small fortune in maintenance getting hydraulic system problems fixed, mechanical linkages adjusted, worn parts replaced, etc. But, they are a tough airplane and although there have been quite a few small repairs needed it has never left me stranded anywhere.

Overall, I like the plane. It is like a truck, and will haul everything I've tried sticking in it so far.
 
There are faster and better looking twins than the Aztec, but I don't think any will match it's ice carrying capability.
I used to fly them about 28 years ago for 135, so I've forgotten some of the details. We had a couple of D models and they had boots, hot props and a hot plate and tip tanks.
We had the Met-Co Aire tip tanks with an extra 24 gals on each side giving you 120 gallons total, that's a lot of range. I do remember burning 24-25 per hour, but not the speeds.
I did my ME training in them and found them to relatively easy to fly, if flown properly.
On some of the cargo trips we hauled explosives, that was interesting.
 
To what degree are these cost structures airframe related versus engine related? Reason I ask is it would be nice to be able to compare piston twins more "predictably"; i.e. engines are a more predictable quantity cost-wise for us single engine owners regardless of application, but the intricacies of these twin airframes seem to vary quite a bit, which seems more like uncharted territory and prone to "surprise costs" than singles.

I suppose another way to figure out if the engine is the driving piece, would be to compare to the 4-banger twins. If an Aztec is a 250/hr airplane and a 310 a 300/hr, is there scale-down relationship to the Twinkies/TravAir/Senecas and Seminole/Duchesses? If it was all engine, I would expect these costs to scale down, but if the airframe and systems are the driver, then I expect them all to be pretty high (sans the Seminole/Seneca I suppose). Of course I have no data point for the 4 banger twins, and haven't found much on POA discussing the hourly figures for these types, as they largely reside in the hands of training facilities and otherwise relegated by the twin crowd on here as not worth the ownership compared to high HP singles.
 
As a blast from the past...

In another lifetime I was hired to fly some pilots from S FL to the factory in Lock Haven in a Turbo Lance to pick up five brand new Aztecs and fly them New Tamiami airport in S FL, where some other pilots were going to deliver them to Bolivia.

We did so. Got a call about a week later asking if I could ferry one of them to Bolivia along with the other four.

Quite an adventure, that involved landing at a grass strip on the Amazon for fuel out of drums (Leticia, Colombia), getting quite worried that same night when a late start had the sun setting with us still over the Amazon and the Trinidad NDB not coming in like it was supposed to - this was all pre-GPS, of course. And the ONC charts we used warned that geographical points on the chart might be offset by up to 10 miles (!).

Well, it finally did come in after a nerve-wracking eternity, and ultimately the planes all got safely delivered to Santa Cruz, Bolivia.

Flights like that were among the highlights of a long flying career.

15009889755_fe21f04666_o.jpg


26058907671_c61749d3aa_o.jpg


Anyway, I had gotten my multi in an Apache, and the Aztecs felt similar - honest, solid twins. A lot more performance of course, and new was nice after the clapped-out Apache. Nothing too exciting, but they get the job done!
 
Last edited:
Soldier64 said:
Day dreaming here. Just curious why this airplane is priced at $69,900? What is wrong with the Aztec? Anyone have the pros/cons over others in the class?

http://www.aso.com/listings/spec/Vi...l=True&pagingNo=1&searchId=23075074&dealerid=
Click to expand...

I own a '79 'F' model Aztec. It's highly modified with a full canopy, ejection seat and weapon hard points as you can see in my avatar photo. :cool:

The price for this '67 is reflective of the radio stack and autopilot, and at the right price this plane might (might!) be attractive to someone planning to do serious IFR work:
- Twin WAAS capable IFR GPS is rare in an Aztec (although the 430Ws are getting long in the tooth)
- Updated autopilot; most Aztecs of this vintage with the OEM autopilots will have non-functioning, unrepairable units without altitude hold
- GPSS; the roll steering is rare in an Aztec

This one looks like it was somebody's project airplane circa 2009. The one engine was overhauled then, the paint was done that year and if I was a betting man I would say the interior and the radio stack will date from the same time frame. Someone poured a lot of money into this airframe and then either ran out of motivation or money or both not long after ('09 being the peak financial crisis year).
 
Last edited:
Pilawt said:
Fuel may be getting cheaper (for now, anyway). But those machines aren't getting any younger or less complex, nor maintenance any cheaper.
Click to expand...

Short of spending $200k+ (used) to $800k+ (new) on a red handle seems to me the same issues apply to the aging fleet of singles.
 
Kristin said:
They don't call them an Az-Truck for nothing. I wrote a piece for the Piper Flyer magazine that i think will come out in the April edition.

For the C model and later you can expect 170 knots at about 25 gph. They will carry about anything you can fit in it and is probably the best all-weather light twin in its ability to soldier through the weather, provided the pilot is up to the task.

Like any 50 year old, complex aircraft, if the maintenance has been let go, it will take huge coin to catch up.
Click to expand...

I don't get quite those numbers, but I have heard the earlier 'C, D & E' models are lighter & faster than my 'F'. I get a consistent 165 kts TAS @ 10,000 running 2350 RPM and ROP at 25 gph in cruise. All in fuel including taxi, climb, descent runs 28 gph +/- 0.5 depending on trip length. If I slow it down to 2250 RPM and lean it out I cruise at 150 kts at 22 gph, with an all in trip fuel of about 25 gph.

I second your warning about neglected maintenance.
 
Last edited:
Soldier64 said:
Ted,

Thank you for the write up. I do as much owner assisted maintenance as I can within regs. I have kept the cost of my airplane down fairly well. I do have a mission for the useful load and capability of a twin with the family. Not sure I could keep up with those costs. The cost of the twins in the market seem tempting.
Click to expand...

Here's a link to another thread discussing twin op costs:
http://www.pilotsofamerica.com/community/threads/light-twin-owning-and-operating-costs.89350/
 
hindsight2020 said:
To what degree are these cost structures airframe related versus engine related? Reason I ask is it would be nice to be able to compare piston twins more "predictably"; i.e. engines are a more predictable quantity cost-wise for us single engine owners regardless of application, but the intricacies of these twin airframes seem to vary quite a bit, which seems more like uncharted territory and prone to "surprise costs" than singles.

I suppose another way to figure out if the engine is the driving piece, would be to compare to the 4-banger twins. If an Aztec is a 250/hr airplane and a 310 a 300/hr, is there scale-down relationship to the Twinkies/TravAir/Senecas and Seminole/Duchesses? If it was all engine, I would expect these costs to scale down, but if the airframe and systems are the driver, then I expect them all to be pretty high (sans the Seminole/Seneca I suppose). Of course I have no data point for the 4 banger twins, and haven't found much on POA discussing the hourly figures for these types, as they largely reside in the hands of training facilities and otherwise relegated by the twin crowd on here as not worth the ownership compared to high HP singles.
Click to expand...

Generally, twins of similar capacity have engines of similar horsepower. In my experience, the Continentals and Lycomings have both been about the same in terms of $/hr MX. I've found the 310 to be a bit higher MX cost than the Aztec was. There are a few bad failure modes of each engine. Overall, I'd rather have Lycomings, but the planes that I like to fly came with Continentals.

If you look at a Twinkie/Travel Air/Seminole/Duchess, you've got basically indestructible engines. The Seneca with the TSIO-360s will drive costs up.
 
hindsight2020 said:
To what degree are these cost structures airframe related versus engine related? Reason I ask is it would be nice to be able to compare piston twins more "predictably"; i.e. engines are a more predictable quantity cost-wise for us single engine owners regardless of application, but the intricacies of these twin airframes seem to vary quite a bit, which seems more like uncharted territory and prone to "surprise costs" than singles.

I suppose another way to figure out if the engine is the driving piece, would be to compare to the 4-banger twins. If an Aztec is a 250/hr airplane and a 310 a 300/hr, is there scale-down relationship to the Twinkies/TravAir/Senecas and Seminole/Duchesses? If it was all engine, I would expect these costs to scale down, but if the airframe and systems are the driver, then I expect them all to be pretty high (sans the Seminole/Seneca I suppose). Of course I have no data point for the 4 banger twins, and haven't found much on POA discussing the hourly figures for these types, as they largely reside in the hands of training facilities and otherwise relegated by the twin crowd on here as not worth the ownership compared to high HP singles.
Click to expand...

The airframe complexity varies widely. The Aztec has more complex systems, including hydraulic gear and flaps, than many other twins. But there shouldn't be any surprises if one does their homework before you buy one and maintain it with reasonable attention; the same would apply to any complex single. I am actively involved with the maintenance wrenching as that gives me both knowledge of and confidence in the systems when I am flying.

I spend more on consumables than I used to on my singles - that's proven to be the dominant difference so far. Fuel, of course. Spark plugs, oil & filters, air filters, magneto servicing. In addition I tend to do "both sides" when I replace some parts - so far the ignition harnesses and the starters (one side failed, the other side got changed out soon after). Eventually I will have to service the electric fuel pumps, vacuum pumps and the dual hydraulic pumps but in these cases I will deliberately stagger each side (like I have for the magnetos) so the hours in service are not the same. All of these are "engine related" components imo. As for the airframe, so far nothing serious has broken, and I don't expect anything will; the Aztec has no "fragile" parts, it's built like a pick-up truck with wings, which has a lot of appeal for me. Wear parts on the gear and control surface hinges should be no different than maintaining them on a single. The radio stack upgrade I am contemplating (partly driven by ADS-B) would be essentially the same cost as a single.
 
Last edited:
Ted DuPuis said:
Generally, twins of similar capacity have engines of similar horsepower. In my experience, the Continentals and Lycomings have both been about the same in terms of $/hr MX. I've found the 310 to be a bit higher MX cost than the Aztec was. There are a few bad failure modes of each engine. Overall, I'd rather have Lycomings, but the planes that I like to fly came with Continentals.

If you look at a Twinkie/Travel Air/Seminole/Duchess, you've got basically indestructible engines. The Seneca with the TSIO-360s will drive costs up.
Click to expand...

The engines on the Seneca seem to have to work too hard in service on that airplane; they almost never make it to TBO without at least one "top overhaul". In my research I also noted that a good number of them were fitted with aftermarket intercoolers and the Merlin upper deck controllers - suggesting the OEM configuration needs "help". Yes, hamfisted operation of the turbocharged engines may be part of the longevity problem, but the stats just seemed too prevalent to attribute solely to that. The rather high incidence of nose gear collapses was enough to put me off that type (you almost never hear of a gear collapse in an Aztec)

You noted the Aztec engines run hot, and I won't disagree. But the Aztec is remarkably tightly cowled for an aircraft of that vintage, and I have found attention to the baffles and cowl flaps can make quite a difference. Because the cowl flap linkages have to be disconnected to remove the bottom cowl (I have modified mine with the Nomad STC to avoid that hassle now) it is not unusual for the cowl flaps to end up out of whack over time. When I bought my plane I had one that wouldn't fully open and another that wouldn't fully close. Regardless, I found numerous NA Aztecs with engines well beyond TBO - after all that venerable IO-540 is just an IO-360 X 1.5 :D
 
Ted DuPuis said:
My Aztec experience is slower than Kristin's. Aztecs also have some of the worst engine cooling I've seen. I ran my D model LOP and got about 155 KTAS at 21 GPH combined. At 25 combined, I'd expect your CHTs to be somewhere well into the 400s, even with baffles in good shape. While Aztec engines are stout beasts that don't have much asked of them, I've still seen them throw cylinders.
Click to expand...

I was mostly operating in the Great Lakes Area, and the northern end at that. OATS might account for some of the difference. E model and fresh G&N engines might account for a bit of it as well.
 
FastEddieB said:
As a blast from the past...

In another lifetime I was hired to fly some pilots from S FL to the factory in Lock Haven in a Turbo Lance to pick up five brand new Aztecs and fly them New Tamiami airport in S FL, where some other pilots were going to deliver them to Bolivia.

We did so. Got a call about a week later asking if I could ferry one of them to Bolivia along with the other four.

Quite an adventure, that involved landing at a grass strip on the Amazon for fuel out of drums (Leticia, Colombia), getting quite worried that same night when a late start had the sun setting with us still over the Amazon and the Trinidad NDB not coming in like it was supposed to - this was all pre-GPS, of course. And the ONC charts we used warned that geographical points on the chart might be offset by up to 10 miles (!).

Well, it finally did come in after a nerve-wracking eternity, and ultimately the planes all got safely delivered to Santa Cruz, Bolivia.

Flights like that were among the highlights of a long flying career.

15009889755_fe21f04666_o.jpg


26058907671_c61749d3aa_o.jpg


Anyway, I had gotten my multi in an Apache, and the Aztecs felt similar - honest, solid twins. A lot more performance of course, and new was nice after the clapped=out Apache. Nothing too exciting, but they get the job done!
Click to expand...

Cool story FastEddie, thanks for sharing.
 
GRG55 said:
The airframe complexity varies widely. The Aztec has more complex systems, including hydraulic gear and flaps, than many other twins. But there shouldn't be any surprises if one does their homework before you buy one and maintain it with reasonable attention; the same would apply to any complex single. I am actively involved with the maintenance wrenching as that gives me both knowledge of and confidence in the systems when I am flying.

I spend more on consumables than I used to on my singles - that's proven to be the dominant difference so far. Fuel, of course. Spark plugs, oil & filters, air filters, magneto servicing. In addition I tend to do "both sides" when I replace some parts - so far the ignition harnesses and the starters (one side failed, the other side got changed out soon after). Eventually I will have to service the electric fuel pumps, vacuum pumps and the dual hydraulic pumps but in these cases I will deliberately stagger each side (like I have for the magnetos) so the hours in service are not the same. All of these are "engine related" components imo. As for the airframe, so far nothing serious has broken, and I don't expect anything will; the Aztec has no "fragile" parts, it's built like a pick-up truck with wings, which has a lot of appeal for me. Wear parts on the gear and control surface hinges should be no different than maintaining them on a single. The radio stack upgrade I am contemplating (partly driven by ADS-B) would be essentially the same cost as a single.
Click to expand...

In my experience, the hydraulics of the Aztec were almost a $0 system. When I first bought it, we went through and replaced a lot of the landing gear hoses because things were moving slowly. However, after that there was absolutely nothing that I did to it in 900 hours. Had one ignition wire that was worn and needed replacement, changed one mechanical fuel pump, one or two magnetos...

The built like a truck is right. I called it my F-350 of the skies, and I used it as such.

Kristin said:
I was mostly operating in the Great Lakes Area, and the northern end at that. OATS might account for some of the difference. E model and fresh G&N engines might account for a bit of it as well.
Click to expand...

I found OATs made a big difference in the Aztec, so that was likely part of it. I operated the full range from 85F days in Denver to -20F in northern Quebec. My 155 number is an average.

I'm also sure your engines were in better shape. Both of mine were narrow deck cases that had been overhauled by the lowest bidder. The left engine got a lot better after its top overhaul, and the right had big chunks missing from the propeller (still within limits, per Hartzell). Actually, the right engine was my less troublesome engine despite having an extra 1,000 hours on it.
 
GRG55 said:
I don't get quite those numbers, but I have heard the earlier 'C, D & E' models are lighter & faster than my 'F'. I get a consistent 165 kts TAS @ 10,000 running 2350 RPM and ROP at 25 gph in cruise
Click to expand...
therein lies the problem. If you slow a baron down to 165kts it's going to be using <18gph
 
JHW said:
therein lies the problem. If you slow a baron down to 165kts it's going to be using <18gph
Click to expand...

Right, but you also will still have much less space. The tradeoff is the consideration.
 
Shepherd said:
I've flown the round tail Aztec. I loved it. It's a "heavy" airplane to fly. Solid as a rock.
Click to expand...
Y'mean the Apathy ... err, Apache? Got my MEL in this one -- though eleven years after this photo and it was pretty tired and faded. It really did fly like a big Cub with tons of room. I enjoyed it immensely.

N4374P_04b.jpg


Then when I flew a Turbo Aztec D I was surprised how much heavier it was in pitch. That tail really makes a difference.

One that I wanted to fly but never had the chance, is the "Apache 235". Just like the original pug-nose Aztec with the PA-27 tail but with de-rated O-540s -- nicknamed "Half-Az...tec". :p

pa-23-235.jpg
 
JHW said:
therein lies the problem. If you slow a baron down to 165kts it's going to be using <18gph
Click to expand...
Very true, but the Aztec has other charms. I don't like to mix Barons and ice, for example.
 
If you look at Trade A Plane, there are rather a lot of piston twins available in that price range, from Cessna, Piper, and Beech. It's plain old supply and demand, there aren't that many people who have the wherewithal to afford to operate a twin that want that old of an aircraft.
 
JHW said:
therein lies the problem. If you slow a baron down to 165kts it's going to be using <18gph
Click to expand...

I am stunned that an airplane as superior as a Baron requires any fuel at all. Must be something wrong with yours ;)

I have never considered owning and flying an airplane, any of them, "a problem". Regardless of what we fly we are a privileged group.
 
Last edited:
JHW said:
therein lies the problem. If you slow a baron down to 165kts it's going to be using <18gph
Click to expand...

Admittedly, the Baron I've flown is pretty ragged out and the Aztec I've flown is pretty nice, but I haven't seen that big of a difference in efficiency. The bigger reason I favor the Aztec personally, is because the Baron won't haul the load I typically carry without being overloaded and potentially aft of CG.

That said, if I could choose one to fly over the other, the Barons are a lot nicer to fly in my opinion.
 
These debates about various airplane types are always entertaining.

The reality is every airplane is an engineering exercise, and every engineering exercise is a compromise. Comparing one with another on the basis of one criteria (such as fuel consumption) is amusing, and not much else.

Looking at the proliferation of different models there isn't even a "perfect" Van's RV, apparently - and they are a lot closer to being alike airplanes than the range of basic singles, high performance singles or the selection of light twins.
 
Last edited:
I know in the scheme of cost-to-capability the Apache loses, but I think they never made a better looking twin than the round-tail Apache.
 
You must log in or register to reply here.
Back
Top