If you attend any competitive (any discipline) event that requires the absolute most out of any given engine you will find the Mas is in the minority compared to APC. Beleve it or not there are very real reasons for that and performance is only just one.

Now lets just talk about composite props a moment. All props experiance a negative pitching moment from aerodynamic forces (a tendency for the blade to flatten with rpm), propellors are very dynamic devices. The standard Mas is a very flexable design considerably more so than APC, now this is nice if your training simply because if you dig it into the runway all the time it won,t break quite as easy however this flexing plays havoc with performance. With a Mas as you increase RPM you can see a considerable forward flex and flattening of the blade. What is happening here is the pitch is considerably less than what it is marked. The Mas is far worse than the APC in this regard The Mas scimitar is somewhat better though.

The effect of this is a Mas and an APC both 11-7 are not even close in pitch when running. Now to really add to the confusion, I have checked many of both types among others new on the trusty Prather pitch gauge and the Mas is frequently not even close to the stated pitch. All mass produced props are subject to this error even wood type but the Mas is more so compared to APC.

Fred Burghdorf (spelling) 'Mr. APC' makes over 300 varietys of props and most you will never see in LHS with many special purpose sizes. Fred is a very active Pylon racer in 422 (thats the awesome ones) all over the country and thinks nothing of coming up with oddball diameter, pitchs, hub design, patterns and thickness ratios for all sorts of competitive venues beyond pylon.

Fastsky it sounds as though 3d stuff is your thing, great but may I suggest a 11-7 is not an ideal size for that use on a modern .40/.46 perhaps the APC 12.25X3.75 would be better or in the case for that use with a modern sixty the APC 13X4w. The ideal setup for funfly and 3d is not going to be for high speed flight. If that is what you want for your .40/.46 try among others APC D-1 8.8X 8.0,8.5 or even 9.0 narrow That D-1 means special hub design to withstand the 17,000 rpm range yo u will now be turning. Once agine with that set up if its a clean airplane you will be going far faster than you ever had before but you won,t be hovering.


Props are like ladies, try them all before you make your selection.


John