jlmaviation

My Feedback: (54)

The Pilot Dolphin threads have died down. It's been a couple of years with guys flying this jet. I am considering one. I would like to get everyone's feedback and experience with this jet after owning and flying it for a couple of years.

Dave Wilshere

If you buy one increase the tailplane span 4" overall (cut the old 1/2" tip off, leave the elevator as it is and add a 2 1/2" fixed extension each side.
The U/C mounts are fixed to the balsa top skin, so grass use or a heavy landing can flex and crack the top skin. Lay glass cloth in the U channel between the mounts and make sure you bond all the joints properly.
With a sports wing, its then a reasonable flying aeroplane.

Dave

gilslo

Why increase you the tailplane span? Only on training Dolphin or also on sport Dolphin? Can you give some explanations what you call U/C mounts (pics if it's possible). Thank you.

Dave Wilshere

The Dolphin series is short coupled (probably for balance) and lacks stability in pitch, particularly when it's flying in drag mode. The flaps are in the tail area, so once the air is being churned up the pitch control (elevator) becomes vague. Increasing the tail span helps partly by increasing area and partly by pushing some of the stable tail clear of the flaps.
I'll try and do some pictures do the wing to explain.

Dave

gilslo

Thank you for this first part of answer. I am very interested by pics.

Helijet

Requires careful set up as Dave remarked.
I was able to get mine to fly extremely well with an igyro so no butchering was needed.
Many modelers have reported little company support. Electric retracts from Pilot are definitely NOT recommended.
It had potential when first introduced but Pilot dropped the ball on it. There are more successful and better supported airframes out there.

Good Luck
Dean W.

paultzr

Hi I bought a second hand pilot jet without doing a thorough research it had a gyro fitted and after two outings and two return journeys home with repairs required I can see this plane is very sensitive in pitch when on final approach. Dave has been very kind in helping me and I will be extending the tail-plane as suggested by Dave. I've also had under carriage mount problems and I can see why the previous owner had stuck a sticker on the top of the wing to hide the ripple in the balsa sheet above the U/C mount. I have strengthened one side and I'm about to do the same to the other side, when the U/C mount failed it damaged the flap and wing tip. I have posted two photos of the wing damage and after the results of the repair.

Si_B

Paul,

Good looking repair. Did you find a Long Marston pot hole as well?

Simon

Dave Wilshere

No I did :-) Big one on the other side of the intersection!

paultzr

Thanks Simon,
Dave was on the sticks it was a difficult landing with a gusting cross wind which blew it of course just at the wrong moment catching the pot hole.

Si_B

Paul,

Didn't realise Dave was on the sticks, but a shame anyway. I wandered slightly off the centreline in that cross wind and caught some of the rough stuff on my last flight. Didn't realise I'd damaged my retract plate until I was packing away. The strip at Long Marston does seem to be deteriorating quickly, don't remember it being so rough a couple of years ago.

I see yours has the sport wing. Could I ask where you started with your c of g.

Hopefully catch up at one of the future meetings. You are only down the road from me I think? (I'm in East Grinstead).

Cheers,
Simon

paultzr

Hi Simon
Yes you are correct Horsham, Long Marston was my first outing with a turbine it was a busy afternoon didn't get a chance to see who was there. What were you flying? Ashamed to say I haven't checked the C of G as I was assured it was correct as it had been set up by previous owner. I will check it before I next fly and let you know.
Regards
Paul

paultzr

Hi Simon
Yes you are correct Horsham, Long Marston was my first outing with a turbine it was a busy afternoon didn't get a chance to see who was there. What were you flying? Ashamed to say I haven't checked the C of G as I was assured it was correct as it had been set up by previous owner. I will check it before I next fly and let you know.
Regards
Paul

ash 26

Hi
I have done 12 flights on mine and have not come across any of the problems I was told to use a gyro but to date can not see any reason why I should use one I have moved my c/g 20 mm forward and it is spot on for me

regards

Andy

Si_B

Andy,

Is that 20mm back from the factory cg marked on the root of the sport wing?

Simon

ash 26

Hi Simon
I started at 15 and am now at 20 mm forward from the factory mark and it works very well for me I am also using 60% expo on the elevator

Andy

Si_B

Andy,

I guess that means you cg is behind the wing tube? If so I could start at the wing tube and still be in a safe area. I think the factory position is only just in front of the tube so it would make it very easy to balance.

Simon

ash 26

Hi Simon
sorry I meant to say forward start at 15mm and see how you like it

Andy

Si_B

Andy,

Sorry mate, completely misread your post which clearly states FORWARD of the factory cg. Thanks for spotting my mistake. Does your model need much elevator input when inverted, or is it pretty neutral at the cg.

Everything is starting to go back into mine quicker than I thought so will be measuring cg in the next week or so.

Simon

Dave Wilshere

Moving the balance is an Elastoplast fix. It just loads up the tailplane more. Make the tail bigger and it's a much nicer aeroplane.

paultzr

Simon & Andy
I checked my C of G with fuel left over from last flight of 8 minutes it balances 10mm forward of the manufactures recommendations.
Paul

Si_B

Paul,

Cheers mate. Will go with that once I get a chance to set it up on the table and crunch the numbers. Mounted stuff towards the front so hoping it will not be far off.

Once I've checked the CG it will be time for a maiden.

If you get 10mins, could you measure control movements and flap settings for your model. Did it need much elevator mix when the flaps were used? All useful stuff to make my first flight a but easier.

I've got a igyro in mine to play with, but don't intend using it to start with. It is set up on a switch with some low gain values set. Can't get my head around fiddling with a slider or rotary switch when I'm flying, so I will slowly up the gains till I find a sweet spot. I can always turn it off if anything bad happens.


Simon

ash 26

Hi Dave
I have more then 20 flights on mine now and can honestly say that I have not experienced any problem only thing I have remarked is a bit of fishtailing at high speed but can not convince myself to start using a gyro
hope you are keeping well

regards

Andy

Dave Wilshere

Making it nose heavy will remove the pitch sensitivity, but messes up the general flight characteristics.
I did it on the small one during testing and it was then OK to fly...but a bigger tail just makes it a better aeroplane-as Paul will see when he flies his again.
We have a kit in stock I am going to increase the tail span on before selling.
You can see from the test flight video Essential RC did on Paul's Dolphin, it flies fine in smoother conditions.

Dave

ash 26

Now I have 30 flights on my Dolphin all of grass today on a very spongie grass runway the u/c got really tested and was not up to the task material proved to be to soft and suspension not up to the task I will change the legs to to Jet 1 A had them in my ELAN for 300 plus flights and are still perfect I will also do the mod on the stab as per Dave W as on a real calm day I did find that elevator response got very poor on flare out exactly what Dave was on about .