It's coming! Skymaster F-18 1/6 on 2016
04-29-2017, 08:15 AM
#251
Join Date: May 2006
Location: Lacombe,
AB, CANADA
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Thx Anton for completing this test, looking forward to the thrust angles used! Considering you completed a reverse Cuban 8 on a single engine restores my trust in the rear engine mount design.
04-29-2017, 10:39 AM
#252
Yes mine was a thrust line issue. With rear mounted engines it needs to be 100 percent dead on. My maiden flight flameout was with about 5 degrees stock angle.... It was very scary on one motor. On the crash I only had about 1 degrees angle out because the 5 degrees scared the crap out of me. Anton told me about 3.5 degrees is the good spot.
04-29-2017, 01:49 PM
#254
How hard is it to make the angle built into the mount, why leave it to possible guess work and cause folks to lose 15k plus jets?
this picture makes for a simple solution, have line perpendicular to the jet then ad 5 deg to the line
this picture makes for a simple solution, have line perpendicular to the jet then ad 5 deg to the line
Last edited by FenderBean; 04-29-2017 at 01:54 PM.
04-29-2017, 04:12 PM
#255
Thread Starter
here are some pictures can show you how to measure the 3.5 degree for turbine( from point of CG to center of nozzle) .,
Last edited by pilot tw; 04-29-2017 at 04:27 PM.
04-30-2017, 08:09 AM
#258
I saw the demonstration. You must not understand drag if you don't understand what the tanks have to do with it. You also must not understand what speed has to do with it, and Vmc. The approach was high and fast to touchdown. I've been following the thread so yes I understand the engine angles.
We also don't know how much fuel was on board. Full tanks or half tanks ? Weight makes a huge difference.
We also don't know how much fuel was on board. Full tanks or half tanks ? Weight makes a huge difference.
I had a friend take off with a large twin F-15 and he didn't even realize one engine quit when he was taxing out for takeoff, just that the takeoff was longer than expected and it had less power. With the correct angles on the turbine the F-18 is capable of the same thing. It did need some trim, but nothing like a Cessna 310 or something! I've never flown a twin turbine with an engine flame out, but the Vmc would seem to be very close on one engine as it is with two if set up properly, that is my point.
04-30-2017, 07:32 PM
#260
Join Date: Dec 2003
Location: Oudtshoorn, SOUTH AFRICA
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WOW - I have to agree with GUNRADD - the Skymaster F18C in this picture from Barry is the best looking and most realistic RC Model F18c that i have ever seen...... the agressor colours sure looks great..(maybe a tad more weathering will do)...great design Anton and Likai!
04-30-2017, 08:37 PM
#261
05-01-2017, 04:45 AM
#262
There is no indication that this was any kind of thorough test. Besides wasn't it with a different version of the model with different LEX etc (F vs D)?
CG position, all up weight, amount of fuel, aren't specified. The E/F are much larger aircraft if they are supposed to be 1/6 scale. Wing area including the LEX would be totally different. So either the E/F are 1/7 or 1/8 scale, or the C/Ds are larger than 1/6th??
Seems apples to oranges here.
CG position, all up weight, amount of fuel, aren't specified. The E/F are much larger aircraft if they are supposed to be 1/6 scale. Wing area including the LEX would be totally different. So either the E/F are 1/7 or 1/8 scale, or the C/Ds are larger than 1/6th??
Seems apples to oranges here.
Last edited by Chris Smith; 05-01-2017 at 04:57 AM.
05-01-2017, 08:21 AM
#265
WOW - I have to agree with GUNRADD - the Skymaster F18C in this picture from Barry is the best looking and most realistic RC Model F18c that i have ever seen...... the agressor colours sure looks great..(maybe a tad more weathering will do)...great design Anton and Likai!
Thomas
05-01-2017, 03:13 PM
#266
This all sounds like you are talking about prop twin engine plane with the engines way out on the wings, much of that is completely irrelevant in this situation.
I had a friend take off with a large twin F-15 and he didn't even realize one engine quit when he was taxing out for takeoff, just that the takeoff was longer than expected and it had less power. With the correct angles on the turbine the F-18 is capable of the same thing. It did need some trim, but nothing like a Cessna 310 or something! I've never flown a twin turbine with an engine flame out, but the Vmc would seem to be very close on one engine as it is with two if set up properly, that is my point.
I had a friend take off with a large twin F-15 and he didn't even realize one engine quit when he was taxing out for takeoff, just that the takeoff was longer than expected and it had less power. With the correct angles on the turbine the F-18 is capable of the same thing. It did need some trim, but nothing like a Cessna 310 or something! I've never flown a twin turbine with an engine flame out, but the Vmc would seem to be very close on one engine as it is with two if set up properly, that is my point.
Shout out to Chris S! Thanks for seeing some of what I see! I can see how Anton and his pilot would think this showed the consumer that it is a safe and easy jet to fly on one. This is my interpretation of the video. This is not to pick on Anton or the pilot. The pilot did a great job keeping the jet under control, and other then the single engine reverse Cuban 8, operated the jet at the speeds and altitude above ground to ensure success and not loss of the jet. We don't want that to show the test. The jet does have a very slow stall speed from another video, and excellent G test on this video. And, if you mount the engines in the tail, I truly don't think you can do anything else. All times are approximate.Flight One:
- .04 seconds- shows toe in at the starters
- Didn't see take off
- 1:32 - Break in the film...gas engine in back ground shows it was a continuous flight.
- 2:00 - Another break in the filming
- 2:06 - 1 Eng. - 60% power 1 Eng. - idle. The jet was still at good speed, but slowing, and for this type of approach, would have been at 50% anyway for gear and flaps down.
- 2:20 - Gear down on a HIGH Downwind
- 2:34 - Both engines are at idle, so no asymmetrical thrust and glided the jet to a landing, due to no further increase in power.
- The whole time the one engine was at 60% and the other was at idle was only .28 seconds on a HIGH downwind.
Flight Two:
- 3:16 - Starts
- 3:52 - Starts a full power twin engine Reverse Double Roll Cuban with both engines reduced on the backside as normal. But, coming out of the maneuver at speed!
- 6:10 - Call for 1 Eng. - idle thrust
- 6:13 - 1 Eng. - Full Power; 1 Eng - Idle Thrust. Still at high speed coming out of the Reverse Cuban. Completes direction change in right turn
- 6:35 - Enters Reverse Cuban. Still at speed, and not slowing much with the power reduction. So, no issues, due to the high speed and the slow flight characteristics of the jet.
- 7:07 - Gear Down and reduced power
- 7:39 - Both Engines Idle Thrust - no asymmetrical thrust.
- 7:41- Diving for runway. Fast enough in the flair to have a nice balloon with no issues.
- The whole time of 1 Eng Full Thrust, 1 Eng Idle Thrust = 86 seconds! During this whole period on both flights, the jet was never in danger of loss of control or Vmc. And never demonstrated what Gunradd was dealt. Hot day in Florida, full tanks of fuel, full drag of fuel tanks and weapons, engine failure close to rotation, high stress situation at an event. Poor runway control in an emergency situation. Flight line knew he was in trouble at take off, and should have cleared the runway. A go around low and slow.
Dionysusbaccusus! Wow! Google is wonderful tool. Any twin engine jet or plane can have Asymmetrical Thrust, whether the engines are mounted inside the fuselage or on the exterior of the fuselage, as long as both aren't on the centerline. IF two engines are both running at the same power settings, there is NO Vmc. So! Not irrelevant! Every time Gunradd's F-18 flipped onto it's back, the jet hit Vmc. Your Buddies F15 must have a great gyro with narrow gear and one engine out!
Last edited by RCFlyerDan; 05-01-2017 at 04:36 PM.
05-01-2017, 09:57 PM
#269
My 1/5.75 F18C is finished but I can't do the first test flight because of the RPM pickup interferences between the engines. I'm waiting for a mu-metal screen ordered few days ago. I'll keep you informed.
Arnaud
[ATTACH]2212821[/IMG]
Last edited by Looping31; 05-01-2017 at 10:15 PM.
05-02-2017, 12:56 AM
#271
The engines are parallel in the mid mounted version and very close from each other. The thrust pipes are divergent, they are aiming approximately 2ft in front of the CG.
My 1/5.75 F18C is finished but I can't do the first test flight because of the RPM pickup interferences between the engines. I'm waiting for a mu-metal screen ordered few days ago. I'll keep you informed.
Arnaud
[ATTACH]2212821[/IMG]
My 1/5.75 F18C is finished but I can't do the first test flight because of the RPM pickup interferences between the engines. I'm waiting for a mu-metal screen ordered few days ago. I'll keep you informed.
Arnaud
[ATTACH]2212821[/IMG]
05-02-2017, 03:47 AM
#272
If you bought a $15K new vehicle, boat, small car, etc, you would expect it to be perfect. We should expect no less from the airplane manufactures. After all, we can insure other vehicles for complete lost, and of course we all know we can't on these. How would you like to be Kris with 3 flight and $15K + gone due to a manufacturing issues.
Last edited by RCFlyerDan; 05-02-2017 at 04:07 AM.
05-02-2017, 04:37 AM
#273
That is fine for future sales, but only Anton knows how many sold airframes out there with crooked engine mounts in the tail. It is to help those guys. That is why. And, I think it is also about telling manufactures that the end users are tired of being R&D Department.
If you bought a $15K new vehicle, boat, small car, etc, you would expect it to be perfect. We should expect no less from the airplane manufactures. After all, we can insure other vehicles for complete lost, and of course we all know we can't on these. How would you like to be Kris with 3 flight and $15K + gone due to a manufacturing issues.
If you bought a $15K new vehicle, boat, small car, etc, you would expect it to be perfect. We should expect no less from the airplane manufactures. After all, we can insure other vehicles for complete lost, and of course we all know we can't on these. How would you like to be Kris with 3 flight and $15K + gone due to a manufacturing issues.
05-02-2017, 05:12 AM
#275
Lets please let this thread get back on track