title_body: Datasheets for lift of a 27x12x2 inch propeller? I'm looking to find the amount of lift produced by a 27 inch diameter, 12 inch pitch, two-blade propeller spinning facing the ground. Are there any datasheets that show the amount of lift given at any rpm?
upvoted_answer: There are too many factors to be able to give you a precise plot. All the below have major impacts on propeller performance:
  
  
  Activity factor
  
  
  A blade with a thicker chord will generate more thrust, but have less efficiency
  
  Airfoil selection
  
  
  Prop airfoils change as a function of radius. Some airfoils are good (bad) at low Reynolds and/or low Mach, but are bad (good) at high Reynolds and/or high Mach
  
  Proximity to ground
  
  
  If you're close to the ground, pushing air at the ground, then you have a good efficiency bump from ground effect.
  
  
  
  However, https://www.apcprop.com/files/PER3_27x13E.dat is a good first step. The change in pitch from 12" to 13" is not going to dramatically change matters, and probably has less of an effect than flying in ground effect or airfoil changes.
  
  You can also compare to https://www.apcprop.com/files/PER3_26x13E.dat, which reduces diameter by an inch, while increasing pitch by an inch. You will likely find that a theoretical APC 27x12 will be in between the two in terms of performance.
  
  I hope this is helpful. Ultimately, once you get close enough to your desired theoretical performance there's no option but to try a few blades out for empirical results.