[Al Posts: 1008 Status: Offline WWW]

Yes, brake works, but the front drops quite a bit when brake is applied.

[Ian Brooks Posts: 3598 Status: Offline]

First question: Does the brake work?

[Nick Flint Posts: 5067 Status: Offline]

Only my thoughts Eric, (NOT Necessarily "facts")

[Eric Yeoman Posts: 779 Status: Offline]

Hi Nick,           Very informative. Thank you. cheers.

[Nick Flint Posts: 5067 Status: Offline]

I would suggest you tie the REAR of the craft to your car, and hover on a level surface, and control sideways front drift, with the same ballast (people or weights) and set throttle to similar level you experienced plough in. With YOU OUTSIDE CRAFT--The front curtain should be clear of the ground allowing excess lift to escape out from underneath front. Then push down hard on nose of craft. When the front curtain seals the losses, ie touches ground- as you know--the nose should go VERY hard because at THAT moment the centre of lift is immediately moved forward about TWO FEET AND there is an immediate pressure RISE in forward compartment..
For THIS to happen the divider skirt must be allowing sufficient lift air UNDERNEATH  to allow this to happen (whilst using correct rev band of course).
IF (for instance) your divider is too long (or being sealed off by long grass) then this front compartment is mainly THEN being supplied by the SMALL transfer holes (at the forward end of each front bag/tube) which would perhaps be insufficient to prevent plough in your case?.
Tail winds increase the chances because revs are sometimes THEN allowed to fall rather than moderate speed with brake (AND keep revs UP!) BUT it normally should present more as a "slow down" with a gradual resumption of flight. Such virtual STOPPING should not IMHO be occurring.
If all appears correct whilst static testing the above, Then your driving technique could be "in question"? If you are still wearing ear defenders- DONT as you don't really need them any more. You DO need to be aware of revs changes to help drive "correctly"
What revs does the craft plough in please?
When flying my OTTER I like to "mess about" on very low revs (stealth mode) to occasionally explore the outer limits of the crafts performance.
In short- to test the crafts lift/thrust under tail wind conditions- TRY full brake but with higher than needed power. Is brake on full effect?
Here IMHO- you would be able to test if sufficient air is escaping under the divider to supply the forward cushion
Clearly my opinion is only "OPINION" and of my OTTER, which does however use a "similar skirt"! Its also worth noting I run my skirt slightly differently from "standard advices" ie
1 Longer front curtain
2 Divider allowing sufficient lift air to STILL lift the curtain off the ground to prevent my front side bags to sink below water level.
SO when MY craft is travelling at cruise, the side view of bag skirt is level (with a hint of nose up at speed due to air ram) with just a hint of lift loss from out of the front curtain. It's THIS gap which closes off under plough in conditions which immediately makes the prow go SOLID.
3 As I say, I sometimes just mess about whilst cruising (ON WATER) and slowly decrease power until the lift pressure drops and  the divider curtain constricts the forward flow and the hover then goes "mushy"! I can fly at 2000 rpm under these unnatural (still over hump) flight conditions. ONLY on WATER tho!
All part of the fun Al.
as ever--- I.M.H.O.....
Let us know what you find. Nick

[Al Posts: 1008 Status: Offline WWW]

I've just took the Surveyor out and it ploughed in twice, so I turned around and came back ashore.


I was heading out on the loch with the wind behind me, according to XC, gusting to about 15mph.  There was a small amount of swell, but only a few inches and no white caps etc.


The first time it ploughed I was doing about 18mph, the plough was gentle, but it brought the craft almost to a stop.  I thought perhaps that I wasn't giving the craft enough revs, so gave it some throttle craft popped over the hump and up to 25 mph then it ploughed again, this time more violently bringing the craft to almost a complete stop.  At this point I turned back around into the wind and flew the half mile or so back to shore.


I tried to have a look at the partition skirt back at the car park, but of course as soon as I lifted the front curtain, it dropped its nose.  The partition skirt is there, so I'm thinking possible has a tear on the bottom half or it was stuck to the bottom of the hull.


I haven't got time to look at it today or even next 2 weeks, as back to work tomorrow until Thursday night, then off on holiday again for a week on Friday. 


Any suggestions as to cause welcome