Turbo vs. Non-Turbo

[kingaira90]

Turbo vs Non Turbo

A friend of mine is in the process of buying and aircraft (later model Aztec) for the company he works for which he will be flying. He of course wants the turbo model his employer says the maint/ dependability doesn't justify it. The airspeed and hot n high performance is a known quantity (of course us pilots want that!). Are the maint, cost, dependability downsides really there? The initial purchase price really isn't important, it is after the purchase that they are worried about. Anyone have opinions or facts (links to facts would be super useful) about the following.



-Additional maint cost for turbo vs. non.

-Real world dependability on turbo Aztecs specifically, compared to non-turbo.

-Any extra worries w/turbo besides over boosting, and turbine temp?

-Does a good engine monitoring system decrease the fatigue or stress on a turbo?



Thank you in advance-kingaira90

 

[TimsKeeper]

Only thing good about a turbo model airplane is selling it!

 

[Lead Sled]

A friend of mine is in the process of buying and aircraft (later model Aztec) for the company he works for which he will be flying.

Kingaira90...
The additional cost of turbocharging is not that big of a deal. Yes it costs more to maintain, but if you can use or need the benefits of turbocharging then the costs are managable.

The first question I'd ask is do they operate out of high density altitude airports where the turbo's single-engine performance would be nice to have? As far as the altitude performance of the turbo Aztec, sure it's better, but few people are willing to suck on a tube or have a cannula stuck up their nose for hours on end. It gets old fast and eventually most turbos are flown at non-supplimental oxygen altitudes most of the time.

What type of operation does your buddy work for? From the question, it almost sounds like he's got himself a part 91 babysitting job for an owner pilot. Good luck.

'Sled

 

[TrafficInSight]

A lot of what you'll get in the turbo vs. non turbo argument is opinion.

Mine happens to be unless you absolutely need it that a turbo is a waste.

 

[guido411]

Sorry, can't give any average numbers on turb vs. Non-turbo costs. But I totally believe that a pilot that flies the engine rather than the airplane can have very good luck with a turbo. An impatient, no warm-up or cool-down throttle-jerker is going to buy a couple cylinders every year.

That said, don't get the turbo unless you're at a high DA airport. IMHO

 

[kingaira90]

The first question I'd ask is do they operated out of high density altitude airports where the turbo's single-engine performance would be very important? As far as the altitude performance of the turbo Aztec, sure it's better, but few people are willing to suck on a tube or have a cannula stuck up their nose for hours on end. It gets old fast and eventually most turbos are flown at non-supplimental oxygen altitudes most of the time.

-Out of lexington Kentucky lex, (979ft) not exactly a high alt just rolling hills. Although the Appalachain mountains are immediatly to the east and must be crossed to get to the east coast or warm sunny spots. Bringing in the engine out at gross scenario. I would venture to guess that cannula or masks are out so alt limited to around 8000ft.


What type of operation does your buddy work for? From the question, it almost sounds like he's got himself a part 91 babysitting job for an owner pilot. Good luck.

-even better, no babysitting. Just a 1 aircraft single pilot flight dept.

 

[Lead Sled]

Out of lexington Kentucky lex, (979ft) not exactly a high alt just rolling hills. Although the Appalachain mountains are immediatly to the east and must be crossed to get to the east coast or warm sunny spots. Bringing in the engine out at gross scenario. I would venture to guess that cannula or masks are out so alt limited to around 8000ft...

-even better, no babysitting. Just a 1 aircraft single pilot flight dept.

Out in that part of the country, a turbo Aztec would be harder to justify than if they were based in one of the intermountain States. Personally, I'd be more concerned about finding an airplane with known-icing certification. I spent 8 years flying a Lear out of a small airport in Ohio. One of my buddies flew a non-deiced Baron B-55 to Lexington all of the time. During the winter, he was always having to deal icing issues of one type or another. I believe that you can find normally-aspirated KI Aztecs. From your question it sounded like someone in the company has at least some knowledge of what's going on. Your buddy needs to make a realistic evaluation of what type of airplane will meet their needs.

'Sled

 

[kingaira90]

I know he is looking for an aircraft with boots, and downlink weather for t-storm season and icing. The man that writes the checks has a few hours but no ratings. Although he is an aviation buff to some extent.

Thanks Lead Sled, -kingaira90

 

[flyinlow67]

The turbo vs. non-turbo debate has raged for ages. The simple answer is.....it depends. It depends on where you want to fly it, and how you are going to use it.
The Aztec is a good airplane, but if you really need the hot and high performance you mentioned, another aircraft might be better.

Another factor you need to consider, is the increased fuel burn of a turbo. In this day and age, that may just be the difference in buying or not buying.

 

[tarp]

1-Additional maint cost for turbo vs. non.

2-Real world dependability on turbo Aztecs specifically, compared to non-turbo.

3-Any extra worries w/turbo besides over boosting, and turbine temp?

4-Does a good engine monitoring system decrease the fatigue or stress on a turbo?

1 -Turbo will increase maint costs and fuel expense a bit. There are more moving parts and more tubing so there are extra things that can go wrong. (See #2) Running at 8000 - 10,000 and just using the boost will raise your fuel consumption without the benefit of high altitude.

2 - Quite good. The big block Lycoming (IO-540) takes turbocharging pretty well as compared to Continental equipment. The Aztec is only asking for 250HP while the Navajo Chieftain is asking for 350HP out of the same engine. My personal experience (which doesn't say anything for the rest of the world) is that the Lyc-540 and turbocharging do well. On the other hand, I've had turbo problems with the Turbo Charged Continental 360 on the Arrow and Seneca. I've had trouble with the 540 on the Cessna 340 but have had great success with the Continental 550 on the Baron/Bonanza stuff.

3 - Nope, except a deep respect for shock or super cooling the engine. I know, it's not popular to talk about shock cooling, but taking an engine running at 1450EGT's and then pulling the throttle back to less than 1000 EGT's is asking for a lot of stuff to start cooling rapidly. The old "inch a minute" rule (more or less) keeps me honest and seems to protect my turbo engines.

4 - Yes - watch all the "T's" as in temps - I like to see EGT's, CHT's and oil T's staying steady warming up - cruising level - and cooling slowly. EGT and fuel flow go hand-in-hand and there is a "sweet" spot for your engine - find it.

Smarter people than me have written books on the stuff.