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10/23 Raptor Video

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BBerson

Light Plane Philosopher
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Dec 16, 2007
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14,307
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Port Townsend WA
What percentage of flights use pressurization? Is pressurization the essential feature of the airplane for you?
 

dcarr

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Oct 29, 2011
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120
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-
Something interesting happens when you start looking at pressurized GA aircraft. Arguably certified pressurized aircraft are actually less expensive than experimental ones (especially if comparing like for like).

Look at the Piper Malibu/Mirage, Cessna 340, Cessna P210, Cessna 421B--nice examples of these aircraft can be purchased between $200-$350K. These airplanes have real cabins, deice systems, air conditioning, weather radar, and mostly two engines. There's no way you could build an experimental with all those capabilities for that little. (Go look at completed RV-10 prices as a reference).

Perhaps you could build a pressurized experimental without these things to save cost, but I'd argue that pressurized airplanes actually need all of these systems and they need to be reliable. To get the most out of pressurization, you need to go high and you're likely to be going a fair distance. This means you're likely to encounter storms, ice, and widespread low IFR.

I'm not diving into operational costs like hangar, insurance, maintenance, and fuel, but it's not clear these numbers grossly favor experimentals either. Hangar will be similar for either, insurance more for experimentals (if available at all), fuel maybe a little better experimental (but see Piper Malibu), maintenance a win for experimental.

David
 
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speedracer

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Joined
Feb 4, 2020
Messages
49
My P210 has aux tip tanks for 120 gallons total fuel. That provides ~8+ hours plus and a ~1000+ nautical mile range. Have I ever flown a 1000 miles non-stop? No.

However what I do do is often fly to remote locations (like Baja MX or John Creek) that have no fuel then return with plenty of reserves. Or land at airports with sky high fuel prices then fly home to fill at my favorite FBO for better $$. And wherever I go I always plan a minimum of 30 gallons (2.5 hours) reserve so the safety factor is huge. Some jets only have 2.5 hours range when they take off!

These capability makes flying fun and relaxed. I'm never stressed about for example, arriving at a remote MX strip being fuel critical. There are hours and hours still in the tank to make an alternate. Or get annoyed with $7/gallon avgas. I can tanker fuel . Or get tense when ATC put you in a hold with 20 in the queue before you can shoot your approach.

So range has perks. Even if one doesn't fly across the country on every trip, I would always pick the longer range capability.
I flew my 290 powered Long EZ from Hood River, Oregon to OSH (1,610 statute miles) starting with 52 gallons of gas nonstop in 7.5 hours (with a tailwind). I landed with seven gallons of fuel. My friend Dave Lind built a back seat aux. tank for his Long EZ and flew to Hawaii..... and back to CA. Also, he landed in all 50 states.
 

berridos

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Joined
Oct 10, 2009
Messages
1,084
Location
madrid
Seems the new setup had nill effect. His solution has been to increase max cooling temp from 255 to 265 lol
I am jealous, he seems to have achieved vortex eddies at the root of the canard lol
 

lelievre12

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Joined
Jul 15, 2020
Messages
90
I am looking inside PM's water to air intercooler and the core looks simply like an air to air core? This would mean the ratio of water to air contact is 50/50 which is not exactly ideal. It means that 50% of the air passage is blocked by the water passages so the back pressure across the core is higher. These cores are designed to have air on both sides and seem a compromise for other duty. I expect that since PM's unit is designed for pressurized turbo air the compromise was made due to the expected air density from the turbo. However in this application there is no increase.


The proper way to do it is with a water to air core such as below. You can see the ratios are different. More air, less water.

 
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berridos

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Oct 10, 2009
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1,084
Location
madrid
With the space available in the nose there was absolutly no need to tweak current wisdom and choose the wiered option he used, omitting a nice plenum and using a propper inlet protruding tube and outlet ramp. Maybe he has become a slave of aestetics.
Could be that his final goal is succeeding in marketing and make a fashionable bird incapable of flying.
 

rv6ejguy

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Joined
Jun 26, 2012
Messages
3,992
Location
Calgary, Alberta, Canada
Plus a ten inch deep HX would never be selected (by any knowledgable person) for a radiator to aid cooling at 120 knots. It will have massive pressure drop and therefore low airflow plus no useful thermal gradient after about the first 4 inches of core depth.
 

bmcj

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Joined
Apr 10, 2007
Messages
13,595
Location
Fresno, California
Looks like he made it all the way around the airport.
I’m not so sure about that. The track image makes it look like he landed in the opposite direction of his takeoff. Barring a major wind shift, that might suggest a forced early landing or some other problem.

2F66C95B-B0C0-4273-BE6E-9620B819611C.jpeg
 
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