It should stall slower than the 58P it was derived from, it gains about 3 ft of wing on either side(no nacelles).

Last year I hitched a ride with Steve in this beautiful plane, from La Paz back to Phoenix. What an amazing ride! It was a bit strange to be at 21,000' with absolutely zero vibration. I cant remember our speeds, but I do remember how comfortable the ride was.
If you want to haul as much as a C90 King Air, for about the same speed, but half the cost, this is your bird!

Why the tip tanks as the 58P as 200 gal in the wings.
Whats the HP on that engine? It probably compare to a Pratt -20.

I don't fully understand the reason they clip the wings to Bonanza length and then add Bonanza tip tanks. Maybe Steve can explain it. I think leaving the P Baron wet tip and the longer wing would be better for climb and high altitude performance. This decision to clip might have something to do with the nacelles getting excised and the resultant increase in lift from this removal.

I think the Walter D is 750HP. I'd love to be educated on the fuel controller on Walters and how you deal with a failure vs a PT-6.

The tip fuel is an option on the Pbaron. standard fuel is 166 useable. I suspect this airframe did not have the optional tip fuel.

From what I was told, yes. Since the original wing gained 3’ of lifting surface they clipped the tips for extra fuel and to maintain essentially the original surface. I’m not sure if the original had 166 or 200 gal.

Stall speed dirty is about 65kias. I have never taken it to a full stall at high power, too much propwash over the big Barron tail. With the strakes it is very stable at low speeds. My ref speed is about 90, and will go down to 80-85 for a short strip. I have been in and out of 2000’ strips with ease, reverse makes it too easy.

The fuel controller has an isolation function. If the factory FCU fails, there is a bypass switch that turns the condition lever into a manual fuel metering rod. It essentially turns it into a giant carburetor to keep the engine spinning and get you on the ground.

The 601d is rated at 750hp, and it will maintain 100% torque to about 8000’. We cleaned up the intake quite a bit, so it almost always hits itt and n1 limits about the same time. Starting is stupid simple with the VR system. Turn fuel on, push the button and everything else is monitored. Of course your hand is still on the lever and abort switch, but I have never used it!

Cool plane- I can see the utility.

Ok, I'll admit it; when I saw "Harpoon" for sale, my first thought was a Lockheed PV-2 Harpoon... which is way cooler than this Harpoon BTW; unpressurized, no A/C, no autopilot... but a huge cabin to roam around in and two badass P&W R-2800s! Fuel burn? Don't ask!

I have a soft spot for these contraptions. You would be looking at clapped out Jetprops and Silver Eagles at that price point. It is quirky to own a “one of a kind” but whoever buys this thing will be burning Jet-A on a fuel program...sky is the limit with experimental avionics..and there will be plenty of donor Pbarons in the fleet to cannibalize for parts...it is the perfect hedge against the death of 100LL and the big piston twin.

Perfect plane for my mission and wants.

I have a hard time with this engine putting out 750 hp and only getting 210 kts speeds. Or was that IAS ot TAS?

Replace these wings with stock 58P wings with 200 gal will get you more speed and better climb and stability up high.

That's the great thing, find a set of 58P wings and bolt em on and see if it works! The 51% was achieved very creatively. Among other things, there are windows in the floor in front of the 3rd row!

There is only 1 other 58P conversion and we have about the same speeds. I know this one is going to be slightly slower with full de-ice boots. https://flightaware.com/live/flight/N615TS

Quentin Cook(THE Walter Engine whisperer) has one of the 55's and reported about the same 220ktas.

When you figure a Baron has Turbo 700hp that maintains power at altitude where the turbine in naturally aspirated it doesn't seem that far off. But it's doing it on the same GPH(maybe less?), that costs 40% less per gallon(on average) and can carry 1000lbs more.

The owner of 615 sourced a lot of his conversion pieces from us. Last I spoke with him, he was really enjoying that airplane.

Definitely a pretty cool plane, but I’m not seeing the King Air comparison. Cabin class, potty, two engines, redundant systems, much faster (240-265 kts or higher depending on the model), walk-through aisle, drop-masks for pax and rapid-donning for pilots, and certified...etc. etc. It’s a whole different animal.
As others have said, this aircraft is more in line with things like the Meridian, Jet Prop etc....but slower, apparently much slower. I have a friend with a Bonanza converted to to a Pratt up front; and for whatever reason, it appears to be quite a bit faster than this Harpoon...don’t know why that would be.

A straight C90:
Range
Normal Range: 840 nm
Max Range: 900 nm
Service Ceiling: 30000 ft
Distances
Takeoff Distance: 2557 ft
Balanced Field Length: 5200 ft
Landing Distance: 3417 ft
Performance
Rate of Climb: 1955 fpm
Climb Rate One Engine Inop: 539 fpm
Max Speed: 223 kts
Normal Cruise: 217 kts
Economy Cruise: 217 kts
I was comparing speed and payload, not volume. Obviously the King Air is bigger, but its not faster,and will not carry as much, and it is far more expensive to operate.