Congrats, Patrick! I hope she treats you well!

Can you tell us a little more? What model, what year, what engines, panel?

Thx Adam.
1974 690A
Mid time Dash 5 engines
Full glass with dual G600 and a GTN750/650 stack
Very nice paint and interior
It seems a very well maintained and cared for bird, all ADs and SBs have been complied with
Fingers crossed on the prebuy
The test flight was what sold me, it was a blast to fly, especially back to back with the Baron, which I enjoy but the performance isn't in the same league. If this goes through I will be selling the Baron.

Wow, fantastic!

At sea level,where we live the -5 is just as good as the -10 when single engine. Lots of excess performance.

Can't wait to see it!

Thx Adam.
1974 690A
Mid time Dash 5 engines
Full glass with dual G600 and a GTN750/650 stack
Very nice paint and interior
It seems a very well maintained and cared for bird, all ADs and SBs have been complied with
Fingers crossed on the prebuy
The test flight was what sold me, it was a blast to fly, especially back to back with the Baron, which I enjoy but the performance isn't in the same league. If this goes through I will be selling the Baron.

I had my eye on that one! Congrats!!

On the 690A, the engines are flat rated to 718 HP/side. The -5 engine is an "840 HP" engine, meaning you have about 122 HP of derated power left. If the conditions are sea level and cool, the -10 makes no difference in runway performance. It doesn't take too much elevation or temperature to reach the point the engine will be temp limited on the ground. At that point, the -10 engine makes an ever increasing difference in takeoff and climb performance (both 1 and 2 engine). The -10 engine is over 1000 HP but also derated to 718 HP, so you have much more margin.

The real benefits of the -10 engine are better takeoff and climb in high, hot, heavy conditions, faster climb to altitude, higher altitude operation (reduced fuel use), faster cruise speeds, and greatly reduced maintenance costs (much longer HSI/OH intervals, much cheaper HSI due to the parts just lasting longer). It is much cheaper per hour, per mile to own a -10 engine, but they cost more up front.

Mike C.

The panel is awesome! It's crazy you can get that much technology for the money.

Coming from a unpressurized recip to a glassed up TP will really be fun.

Let me know if I can help with anything. There are several nice ones on the market which should help your negotiating.

Good luck with pre buy.

Because there are so many that have done the -10 upgrade, I actually don't think that's true. There are a lot of -5 parts and engines out there. More than any other TPE331, probably.

On the 690A, the engines are flat rated to 718 HP/side. The -5 engine is an "840 HP" engine, meaning you have about 122 HP of derated power left. If the conditions are sea level and cool, the -10 makes no difference in runway performance. It doesn't take too much elevation or temperature to reach the point the engine will be temp limited on the ground. At that point, the -10 engine makes an ever increasing difference in takeoff and climb performance (both 1 and 2 engine). The -10 engine is over 1000 HP but also derated to 718 HP, so you have much more margin.

The real benefits of the -10 engine are better takeoff and climb in high, hot, heavy conditions, faster climb to altitude, higher altitude operation (reduced fuel use), faster cruise speeds, and greatly reduced maintenance costs (much longer HSI/OH intervals, much cheaper HSI due to the parts just lasting longer). It is much cheaper per hour, per mile to own a -10 engine, but they cost more up front.

Mike C.

The fuel savings alone make the -10 cheaper than a -5.

The 2500 HSI and 5000 OH make it much cheaper. There's a lot of labor in those, not just parts.

The -5 will eat its ITT harness at every HSI, and you have to buy new parts for that since all the used ones are dead, too. The -10 EGT probes last much longer and can be replaced without tearing the engine apart down to the turbine wheels.

Mike C.

Yes, but you get that back to a large degree on sale.

Some costs are tied to value, though, such as taxes and insurance. But the savings in operating the -10 probably pay for that.


That is true for most older airplanes.


If you come up to OH, then the -10 conversion is relatively cheaper when thought of as an adder on what it would cost to overhaul the -5. You get an all new hot section.

But I agree, hard to justify when you could buy an already converted airframe instead, which is what I did.

Mike C.

Biggest surprise for me in this process was the insurance, it came in at around half what I was initialing budgeting and half the mentor pilot time as well (although I will probably do more than the minimum on that front). Kudos to Tom Hauge and his team.

My insurance also went down compared to the Aerostar. Bizarre.

Care to elaborate?

The -10 engine gets its power from two things, higher temperatures and more efficient turbine section extracting mechanical power from the hot gas. Both things increase the efficiency of the engine overall.

Because the -10 engine can allow the plane to fly higher and faster, it increases the efficiency of the airframe as well.

Those two factors make the -10 more efficient per mile than the -5.

Further, since you fly faster with the -10, you get an even larger benefit from the engine TBO since it took fewer engine hours to fly the miles.

Mike C.