"Micromaster"-- Centerline twin using small industrial engines

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by Vigilant1, Nov 13, 2018.

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  1. Oct 11, 2019 #821

    Vigilant1

    Vigilant1

    Vigilant1

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    Right, but what you or I think doesn't seem to matter much.
    Regarding a single-seat twin: The important thing is what the DAR writes into the operating limitations when the airworthiness certificate is issued. From what the EAA has seen with Cri-Cris (another single-seat twin), it could go either way. I didn't get a reply back from Kitplanes magazine (I noticed that the "ask the DAR" column is not in the latest edition--maybe Mel isn't writing for them anymore). I probably need to follow this up with the FAA or a DAR (hopefully a really young one who might still be in service if I ever finish building a twin aircraft!)
    Regarding two-seats: I agree with you--there's no special treatment for E-AB multi engine aircraft if you are flying passengers: If you fly with a passenger, you'll need an MEL rating. IIRC, it is permissible to use the E-AB for your own instruction (if you can find an instructor willing to do that). At the end of the multiengine instruction in your own MicroMaster, you'd certainly be better trained to fly it than if you'd gotten the training in an old Aztec.
    There's no way a 2-engine Micromaster with 30 HP engines and two people aboard would be able to climb with one engine out. It's probably very feasible to design a triple with engines this size (or even smaller) and two seats that could climb with one engine out (we did some thinking about this before). Now, a BeetleMaster (with two seats and two 75HP VW engines) looks like it could climb safely on just one, and be a very good performer with both engines running and (approx 1600 to 1700 lbs MTOW)
     
  2. Oct 11, 2019 #822

    Dan Thomas

    Dan Thomas

    Dan Thomas

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    Yup, around 25% for combustion, and the rest for cooling. The flame in the combustors has to be kept away from the metal, so there are many points of entry for the air to form a cushion between the flame and metal. The turbine rotor blades and guide vanes are usually drilled for air passages, to cool them and provide a layer of air between them and the hot gases.

    Besides all that, the engine nacelle has to be kept cool, and on airplanes like the P3 (I worked on Lockheed Electras for a time) the long exhaust duct is in a housing atop the wing and has cooling air flowing through it. All that is from the prop.
     
  3. Oct 30, 2019 #823

    Sockmonkey

    Sockmonkey

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    Plus that unburnt air still undergoes heating and expansion, contributing to thrust.
     

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