From: tunebonk@eleven.com   
      
   On 03/20/2019 11:57 AM, Bret Cahill wrote:   
   >>>>>>> 4.  Increased Safety.  If a fan blade snaps off it can't   
   >>>>>>> impale any passengers or critical structures.   
   >   
   >> 5. When the power fails in VTOL mode it won't autorotate, and it   
   >> won't glide.   
   >   
   > For a quick pre take off check the pilot first runs the engines at   
   > max locked in the launcher.  The plane is only released at a somewhat   
   > lower safer RPM still well above take off thrust.  Maximum power is   
   > only used for this test and is not necessary or desirable for the   
   > rest of a fuel efficient flight.   
   >   
   > The props on an Osprey would hit the runway if they aren't tilted   
   > back a little.  The fans are fixed here so, if you don't want 1 story   
   > high landing gear, it's the same situation as an Osprey that somehow   
   > got rotors stuck in horizontal flight.   
   >   
   > Fans always need to be strong enough to chop up birds, but, without   
   > landing gear, they need to disintegrate like tempered glass when they   
   > first contact the runway in emergency landings so large shards don't   
   > impale passengers in the aft cabin.   
      
   I read that Osprey blades disintegrate into broomstraws.   
      
   You lose far more than half the performance if you lose one of your two   
   engines. The second engine just brings you to the crash site, as they say.   
      
   You'll want at least collective pitch control on your 100 fan blades.   
   Probably cyclic control too. Lose a single blade, and you may lose   
   control of all the rest.   
      
   A helicopter rotor disk is mostly empty space, and your fan disks are   
   mostly solid. This isn't going to autorotate. Won't glide either unless   
   you can stop the fans and feather all those blades.   
      
   But I don't want to discourage you.   
      
   --- SoupGate-Win32 v1.05   
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