S-27 flip in Key West
 

Wild video!

Dayuuuum!!

Wow!!!

that air tank flying at ya' would be like getting socked by a sledge...

Always good to see them moving to get out ASAP.

Vid taken from Shore of the flip/rescue (Not my vid - credit goes to "Lake Expo" )

Wow! What did his leg hit to cause it to bleed so much and quickly?

i think the yellow bottle hit him

I watched it again and you are right. It was the bottle. Yikes! That had to hit hard and now everyone needs to look at how secure their air tanks are. I'm glad they are ok and got them out of the KW waters quickly with that much blood in the water.

Wow! Glad to see both guys moving quick and knowing what to do

Must of been a strong gust of wind to send both boats over together

Made it into the Yahoo news ticker reel...

https://ca.yahoo.com/news/two-racing...074925019.html

Looking back I remember to the mid 90's an air bottle came loose in a Top fuel Hydro 1/4 mile dragboat crash and beat the driver to his death. Granted that crash was at a much greater speed,but I think everyone here gets the drift …………………………...………...Robertjr

the dash, watch his legs go up, then the bottle comes up.. id be adding some padding on the edges of the dash.. hopefully it will never happen again.

when you cut the throttle, it's like braking in the back causing the stern to go down and bow up = flip. A cat you first trim down. At their defence those cats don't warn you :(

Yes they do! All capsule drivers and crew have a survival program to pass, the dunk tank!

In post 1 from Jupiter Sensation, you can see 2-17 start to blow over in the Stb canopy window of S-27... So to see both boats parallel + vertical, S-27 blew over in a heartbeat,

At least everyone is going home.

Yeah I saw that "oh sh!!ttttttt" moment too! Glad everyone is ok but this event tells me that I don't want to ever run those small cats at their limits especially in an open cockpit design. A full 5/6 seater blowing over at triple digit speeds wouldn't have a happy ending

I believe they said that the bottle was secure but the crash broke the mount right off the boat.

Wasn't the wind that caused them to go over at same time. It was a pretty calm day concerning the wind. I asked Rusty Williams (PBC) what the deal was and he said when the boats came together so close the air couldn't escape from the tunnels and that's what brought them over at the same time.

Not sure if I buy into that explanation. These guys race next to each other all the time and I t has never happened before. With that being said I have no answers either.

Just relaying what another driver in the race that is buddies with the guys involved said they felt the cause was. All is fine until they are right on top of each other and then liftoff. Was definitely not a gust a wind. I thought they may have both packed water from a roost in front of them as they had already passed me on the mole. I didn't know what else would have caused both to lift off at the same time. Crazy deal. Just glad all are OK including the Hammerhead guys.

https://ww.speedonthewater.com/in-th...-when-cats-fly

This article from Speed on the Water explains what caused the two boats to flip at the same time.

Thanks for the story link!

One of my friends racing in that class was trying to explain it to me and made no sense. That article helped me understand the situation better but I definitely don't have a brain for the sciences!

Really surprised to see 3 outboard cats flip in one weekend. Thought they would be safer at the speed they run. Glad everyone is alright. Sorry but I would only race a V hull. It's crazy how many lives where lost in past 5 years in cats flipping. But I also give these guys credit to have the balls to do it!

These aerodynamic proximity effects can be tricky to lock down without running CFD. Certainly any vortex lift would need to act in a manner that enhances lift on the adjacent boat by virtue of the proximity of a counter-rotating vortex. Generally that would mean increasing the negative pressure on the deck side as I cannot quickly work out how the vortex interaction would act on the high pressure tunnel side. Whist counter-rotating vortex interaction may have a small role to play I suspect the endplate effect will be the predominate source of any lift enhancement. If the cats are running with a bow up attitude then high pressure air is leaking out from under the sponsons. This leakage may be mitigated by the mirror image flow in relative proximity (i.e. the high velocity air escaping from Cat number 1 is blowing against Cat number 2 thereby reducing the leakage, increasing the pressure and increasing the lift).

Sorry for the over-analysis

ND1

Think of an airplane wing, it has high pressure underneath it and creates low pressure over it. I believe what the story was saying in english (at least my interpretation) is that it increased the low amount of pressure on the top of the boat. With the same high pressure under the boat, and LESS pressure on top of the boat, the boat goes up and the further the bow goes up, the more pressure under it and the less pressure over it.

In the story it seems Steve David is solely attributing the initial pitching moment to the vortex interaction but given 2/3+ of the lift (of a wing in ground effect) is derived from the lower (high pressure) side the math doesn’t add up. The endplate effect is a much larger contributor. That said – it was only a short quote and he is certainly correct in that once that initial rotation occurs it is all over. That’s where vortex lift and drag really take over. Great this conversation is happening. Hopefully some of the lesser experienced open cockpit cat operators are reading as well : )

ND1