What I posted on another thread in answer to a question from Taildragger....who shares a little unplanned gliding time with me many moons ago.
No there is no doubt the waterskiing Harvards are real...many witnesses and the pilots too well known for it to be faked. My only point is they must have practiced quite extensively, both solo and together, before submitting to the photo flight....information on a SA website suggests the actual pass down the lake that is the subject of the photos was one of 5 that day....lots of people there watching...all very well planned....apparently.
On a thread on Private Flying forum there is a picture of two Jodels waterskiing in formation and another of two cubs waterskiing in formation...this particular 'art form' is a lot more widely practiced than I thought.
While not essentially difficult to achieve it is a passtime fraught with potential embarassment.
It is all based around the basic aquaplaning formula...9X square root of the tyre pressure. Clearly there is also some benefit from really big low pressure tyres like the Tundra tyres you see on some back woods cubs etc...the lower the tyre pressure the lower the aquaplaning speed and thus the larger the margin between the 'high speed taxi' and digging in and flipping over. 9 or 10 PSI in Tundra tyres gives an aquaplaning speed of about 25kts....faster than that and you're happily waterskiing.
If you don't have the brakes on you risk wheel spin up which probably wont, you hope, effect the aquaplaning formula (if you are travelling really fast) but will spray a lot of water all over the place.
If you hit something solid in the water you risk being tripped and flip over...remember when we hit that cable on our forced landing in Moresby. It hit about half way up the tyre and we nearly went over, but we ripped it out of the ground a split second later....even so our nose down attitude would have guaranteed the prop/nose impacted the water had we been waterskiing instead of 50+' above the road.
If you are not very carefull rotating to leave the water you may dip the tailwheel in the water or at least put the rear of the aircraft (horizontal stab) in the plume possibly slowing down enough that you almost stop aquaplaning and drag rises...quickly flipping you over.
The actual act of putting the aircraft on the water is the easy part...once you get over the pucker factor. The list of things that can go wrong after that gets a little scary....more so in a light/relatively underpowered aircraft like a cub than heavier/faster/more powerfull aircraft like a C185/Harvard....I would think.
While the statute of limitations has certainly long run out I really don't want to encourage youngsters...suffice it to say my limited experience in the subject was FAR from prying eyes and done in my own C185, flying by myself and done out of youthfull high spirits...not showing off...having seen someone else do it in another C185 some time before. Plus I was a full time bush pilot in those days and very 'comfortable' in the aircraft. The passage of time has made me more aware of the pitfalls of being 'young, dumb and full of come'.
Don't get me wrong...I enjoy the thread subject piccies as much, if not more than, most people...but I feel a little lucky to have got away with it so many years ago.
What is interesting is so many magazine articles and websites have piccies/ film of people doing it in the USA and you never here of the FAA taking peoples licences off them...using the river to extend takeoff and landing distances available...all good stuff but if you talk to pilots who do that they will be the first to highlight the pitfalls...and more than one has lost, or knows someone who has lost, an aircraft doing it. They are uninsurable while doing it and carry the entire financial risk themselves.
Having said all that it seems to me that it is no more silly than any other 'extreme sport'. As long as it's your aeroplane and you take full responsibility for it while endangering no-one else it's probably quite an acceptable passtime....who knows...if I ever have the spare money to own, and be prepared to wreck, a 150HP cub and some big tyres I might just take it up as a sport
