It’s been over a year since we had a prop strike for the second time and I have had a permit to test the new improved ground clearance three blades composite prop for about a month.
Last weekend presented itself as the first long awaited chance to fly so I was excited to see how she performed and taxied across the grass to fill the tanks for MTOW.
During the run-up checks a misfire developed so I had to abandon the flight and return to the hangar to investigate but the now much heavier aeroplane became uncontrollable on the soft ground and I ended up off the mown taxi way and in the long grass. I was bloody lucky not to have suffered yet another prop strike and certainly would have had we stuck with the two blade prop.
I am a strange blend of feeling both grateful and irritated at the same time!
The airfield staff, BTW, had no interest in helping me extricate the aircraft and I was left to my own devices….
Stickandrudderman wrote:
The airfield staff, BTW, had no interest in helping me extricate the aircraft and I was left to my own devices….
Incredible! Some people have a very irritating understanding of their job. Where did this happen?
EGTB
It looks like swamp :(
It looks like 93.75% of UK grass 
The staff attitude is also not wholly unfamiliar…
A good outcome though. My TB20’s prop would be several inches underground in this situation, and a second £20k…
This is one advantage 3-blades have over 2-blades. The increased ground clearance is often only about 1 inch, but that 1 inch may indeed do the trick. But the smaller diameter and is not always there. Many years ago, a local flight school had a 2-blade Bonanza equipped with a 3-blade, and it was found to have exactly the same diameter as the old 2-blade, so no increased ground clearance and actually slightly more propeller noise.
I opposed going 3-blade a few years ago, when our syndicate 2-blade Piper Dakota had a prop strike and needed a new prop. I feared reduced cruise speed (theoretically you get that from adding more blades), saw no need for improving the already satisfactory take-off and climb performance, and saw no reason to add 8 kgs of empty weight about 2 metres in front of CoG. In the end we had the 3-blade, which because of better aerodynamics (scimitar profile) did not impair cruising speed, did improve vibration a little bit maybe, never made me think any more of loading than before, and improved ground clearance by one inch. It might also slightly have improved the ability to do steep approaches and reduce float during landing round-out, but that also means it will not glide quite as well in case engine failure, I guess. The noise footprint should be slightly smaller but we have no measurements and the low-RPM Dakota is not very noise in any case. Everyone says it looks better (some say “sexier” although I find it awkward using that word about a Dakota) and that it definitely will make a resale easier. Overhaul will even be slightly less expensive with the 3-blade because of longer intervals (that was what tipped the scale for me in the end).
But for an aerodynamics purist, the 2-blade will be the right choice for speed, at least for low-Mach-number piston aeroplanes. Just look at early big-bore Mooneys and Malibus.
@Stickandrudderman would you be comfortable sharing with us size of the front wheel in your aircraft?
The image you posted is kind of striking
It does have a small 6” wheel but I believe it would have to be significantly larger to have provided a different outcome. Tricycle undercarriage with 70 litres of fuel just behind the fire wall is a bit of a problem on sodden ground.
That’s why I generally avoid grass; there are just few known grass airfields where I land and even that is very rare.
Peter wrote:
It looks like 93.75% of UK grassThe staff attitude is also not wholly unfamiliar…
And you wonder why European pilots don’t want to fly to the UK ?
