Guys

I have been actively considering either the Skymaster F18 / F15 as my next project to be powered by a Wren Supersport. To that end I contacted Ali Machinchy the UK Skymaster agent. The F18 is widely advertised as being suitable for 14lb turbines upwards so I felt the Supersport at 18lbs thrust would have plenty of power particularily as it is a very light turbine in manual start form and would not require a big fuel load.

Ali has advised me that this is not enough power for the F18 especially if operated from grass and I have decided to opt for the F15 in its simplest form i.e. with tailerons.

Perhaps Skymasters should amend their advertising to refelect this opinion of one of the most experienced fliers in the business or, alternatively, confirm the suitability of the 14lb turbine.

John

I'll second Ali's suggestion - 14 lbs of blow is not enough for the F-18. It would fly (though likely not off grass) but it would NOT be fun.

It's a pretty big and heavy plane with plenty of drag and a P120 is just about right, on mine I rarely use full throttle except for takeoff (pull back to 1/2 after cleaning up) and on some vertical manuevers. With missiles and tanks mounted it will need all 28 lbs. in certain regimes.

I just looked at the Skymaster website, it says 20-35 lbs. thrust for the F-18A/C..... big difference from 14 lbs! I suspect 20 lbs. would fly it OK, especially if you keep it light.

Barry

PS - Attached wrong pic...anyone know how to delete an attachment??? My F-18 is the pic on the right (obviously!)

18 lbs will fly the CRAP out of the Eagle, But i seriously DONT think it will fly the F-18. You need 24lbs+. Thats a big airplane. I was also Told this buy a skymaster REP at superman. He was the one that was doing most of the flying. Russ

Hi Barry,

This is Mike, the one with your Cyclone. I have a Skymaster F-15, still new in the box. I am an autostart RAM1000 that I plan to put in there. Is it going to be too much thrust? Some told me that RAM1000 is equivalent to P-120, is it?

Mike

Mike, I have a sm F-15 with a P-120 that's been turned up to 125K....making about 29 lbs of thrust. It seems perfect...especially if you are going to use tanks and/or missiles. You should be good with the 1000.

The airframe should handle the thrust....just check all of the factory glue joints and make the linkages slop-free and you'll be set.

John,

As you know, the Super Sport gets its 18 lbs. by producing a very high exhaust velocity...in excess of 800 m.p.h. according to the manual. I wonder how a bifurcated tailpipe is effected by this high velocity flow. I think of the P-120 as pushing a lot of mass at a slow speed and the Super Sport squirting a super fast stream. Any input from you thermo-dynamic and/or fluid dynamic guys out there?

The nice thing about the Super Sport for the Eagle is that you have enough fuel on board to fly all day!!

John

Cactusflyer

I was having similiar thoughts about the efflux velocity of the Supersport. I think I will have a word with Wren on that matter. As it's only a sport scale model I may just run a Wren single pipe between the twin tailpipes on the model if the bifurcated pipe is going to be a serious thrust reducer.

I see that Skymaster are now recommending a minimum of 20lbs for the F18 on their website although the magazine ads are still at 14lbs.

Thanks for the input guys.

John

John,

Skymaster recommends that you use a 17-28lb thrust turbine for the flap and aileron version for F-15. We also recommend a 12 to 28lb. the elevon version. The 14 lb. thrust can fly the elevon version of F-15 However, the performance will not be as high and we definitely don’t recommend such a small size engine on a grass runway. People may question if it is possible to fly such a big plane with just a 12lb. engine. In fact, if you check the Skymaster website, you can see that we’ve tested a plane with a WRAM 54 (12 lbs.). This shows that it is possible

We recommend a 14-35lb. thrust for the F-18C or E. However, a 14lb. engine is only recommended in the elevon version, no rudders and keep very light (this version is special order only, not legal for AMA in the U.S.). For the regular flap and aileron version, as other people recommend, 28 lbs. or higher is recommended. We don’t believe a 14 lb. engine can fly the standard F-18 though. I hope this answers your question.

The new batch of F-15B, F-18C and F-18E are near completed production. They are lighter and stronger! We will receive these new planes very soon.

Eric

Thanks for that informative reply. I will be going with the elevon version of the F15 and trying to keep it as light as possible. What is the delivery situation to the UK on the latest F15's?

John

Eric

The SuperHornet on the 2 posts back on the left side is that the stock factory paint job???

Because it looks fantastic when will they ship?

Ian

Hi Mike, looks like you got an answer... I also think the 1000 would be fine. You can always throttle back or RPM limit if need be.

Ian, thanks for the edit.

barry

Hi Barry and Bob,

Thanks for the info. That's right I can also throttle back. Mine is a cammo version, so don't want to fly too fast and too high. I will try to put some missiles and tanks to improve the visibility.

Mike

John,

I'm not sure about Ali's next shipment schedule for his container. I just left the factory last week, and it looks like there is still some more production to be finished. You might try and contact Ali (0208) 500 8884 or 8887 (UK) for the ETA. I'm sure it shouldn't be much longer. If you'd like yours right away, you can contact him to have air cargo shipped to you at a very small fee.

Ian,

Yes the picture you see is the black tail F-18E. That is one of the factory standard paint schemes with full rivet details. I will bring this plane to the Best in The West next week. Will you be attending the show as well? I didn't see you in Florida Jet this time, so maybe I'll see you in Cali.

Hi Eric,

Do you have the F-15B, like the one I see on the photo you posted in stock? How about the latest hawk with rivets and all the details? Any in stock.

Thanks,

Mike

While we are on the subject of the F-18 i was thinking of getting the Y/A twin but got put off by the size of turbine needed for it (35Ib+). Also the fact that is initialy set up for D/F. where as the skymaster ARF is near the size of the Y/A twin & Built for Turbines & only really needs a P120 to power it. I think the cost would be alot less to. Dont get me wrong i love the Y/A Twin but dont really have the time to build it to the scale i'd like or the extra expense for conversion kits etc....

Mike,

Sorry, but I've been tied up preparing for the Best in the West. I haven't had a chance til now to answer your question. The F-15B's production has been completed in the factory. The container is on its way here. We expect it to arrive at the end of this month or early next month, and should be ready for purchase. The F-15B comes with a white base primer color, Edward gel coat (red/white), or bicentennial gel coat (red/blue/white)color scheme. Although the new production has more details and is lighter than the previous version, but the rivets won't be seen on the F-15, and will only be available on the F-18E. We will see the publics reaction and see if we want to add this feature on to the rest of our product line.

AAC,

I believe both Yellow's F-18 twin and Skymaster's F-18Cor E are both good planes. It just depends on your personal preference. The Yellow is bigger and a nice kit, but you'll need take time to build it. The Skymaster is slightly smaller, but it is an ARF. I don't think there is anything to really compare since the 2 planes are different in size and need to be put together differently.