Cruise Performance
As we all know the book performance and the real world performance are not necessarily the same thing. Fair enough, but that’s not what I want to talk about.
I would like to know if anyone else has experienced the same differences between fixed props and constant speed’s that I have. Or if it might just be a case of those individual aircrafts that I happen to fly?
I have the impression that real cruise performance differ about 5-15% from the POH figures, (in most but the very newest aircrafts).
However, it appears that if we are talking about constant speed props we loose a quite large percent of the TAS, while fuel flow figures are quite correct. In fixed pitch, I generally notice a smaller reduction of cruise speed, but with a greater difference in fuel consumption. Once again, I do not fly enough numbers of different aircrafts to establish whether this is a general difference or not.
I have my theory for this, but let me first ask you if anyone else has experienced the same thing.