Hello,
I have recently made a performance comparison of the following MEP aircraft:
Type of aircraft: Baron PA34 C310 Climb SL: 1650 1400 1550 Climb 6000 ft: 1100 1400 1200 Climb 10000 ft: 750 1300 800 Climb 14000 ft: 400 1100 500 Climb 18000 ft: ~ 100 700 150 Ceiling: 19500 25000 20000
Does a Non Turbo Twin in Europe make sense at all if you intend to fly IFR in Europe (Alps!), Africa between March and November?
400 feet climb in FL140 might not be enough to fly above the weather or to climb through ice quickly.
Even take-offs from airports with high density altitude could be difficult…
How would you see the dispatch rate between Seneca (Turbo) and the other two?
I am looking forward to your opinions!
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The Baron and 310 have plenty excess power MULTI (not SE) to reach FL150 or 160.
The big advantage of the Seneca 2 or 3 is the STC to bring it under 2 tons and avoid airways nav charges. And while arguably more complex due to turbocharging, most engineers will know the type better, and therefore maintenance should be cheaper.
The Baron and 310 have plenty excess power MULTI (not SE) to reach FL150 or 160.
Do you think 400 ft/min is enough to climb through IFR (light/mod icing) and is FL160 enough to reach “on top” conditions?
Remember those climb rates are at MAUM, typically a normally aspirated twin will not have a built in oxygen system so you are unlikely to be more than two or three up using a portable oxygen kit. ie well below gross.
If you want to go on top reliably go turbine. FL280 is reasonably on top in Europe all year round, with the odd CB to avoid.
Do you think 400 ft/min is enough to climb through IFR (light/mod icing) and is FL160 enough to reach “on top” conditions?
400fpm is certainly ok.
FL160 is barely enough for European IFR if you want to reliably avoid ice by flying VMC on top. It will work quite often but it won’t be enough for the majority of Alps crossings if there is cloud about. I am not sure if wx is becoming more convective (many previous threads on weather) but I’ve seen a lot of ISA+17 conditions and that really knocks the aircraft ceiling.
Peter wrote:
00fpm is certainly ok.FL160 is barely enough for European IFR if you want to reliably avoid ice by flying VMC on top. It will work quite often but it won’t be enough for the majority of Alps crossings if there is cloud about.
in what percentage of cases would the turbo (MEP) help?
And in comparison: how would SET increase the dispatch rate across the Alps with regard to NA or turbo MEP?
These questions about “despatch rate” depend on what the reason for the flight is. I recommend reading some threads.
If you just want to do a flight on totally random dates, then a turbo helps a lot. But private pilots mostly don’t do that. They don’t go to places where the wx is crap 
Against that you have the extra expense / downtime of a turbo. Most owners get cracked cylinders and the engine might make just 1k hrs before a top overhaul.
A TBM will outclass any piston for despatch rate, except maybe the “heavy” ones like a 421 which are probably similar (radar, etc) and can fly up to the RVSM ceiling. But a TBM will cost a lot more to buy.
I used to know a 421C owner who documented a 98% despatch rate UK to Italy, across 50 flights. He no longer flies but used to fly to visit clients. Admittedly his flights were between ILS equipped airports and that makes another huge difference. You have enroute wx issues and you separately have terminal wx issues.
Please consider an Aerostar in this comparison. Will easily get to FL250, offer great pressurized comfort and is FIKI. And can be had for competitive prices. Bang for buck , they’re hard to beat.
I have an NA Twin Comanche and whilst dispatch rate has been 100% over 3 years I do wish I could fly above rather than under weather. I have the advantage that my flying is around the Mediterranean with generally static high pressure and few frontal systems
For European business travel an SET. SEP and MEP are fine for short sectors with reasonable weather, or for flexible personal travel.
Using turbo charged pistons in anger ie above FL250 is well outside their comfort zone. As @Peter points out the maintenance and engine reliability suffer.
An SET will punch up to FL280 and be very happy there.
