Douglas X-3 Stiletto FSX Native

[fliger747]

That's looking very nice Milton!

I was peripherally involved in the Milviz T-38 a number of years ago. Not being and Airforce (gentleman?) I never even got near one. But very interesting to fly, probably a little like a civilized version of the X3 with a better view and bigger engines.

My opinion flying with Navy pilots was that they had a better trainer. There was a great book that I read carefully transitioning to jets called "Fly The Wing". Anyway flying the T-38 if you can find a good one would be a little illuminating.

I totally agree that a major aspect of FS aircraft is historical preservation of a world that is totally analogue.

Cheers: T

 

[Milton Shupe]

Interesting points Tom; thanks

A few wire-frame shots and a solid.

 

[fliger747]

Yes, the perfect idea in the 50's of what a supersonic plane should look like!

: )

 

[Cazzie]

Love it Milton

I did the very old Lindberg scale model a few years ago. I did the NACA markings for the aircraft. Here's a review link. be sure and include a Paint Kit, nudge, nudge, wink, wink.

https://modelingmadness.com/review/korean/cazx3.htm

 

[henrystreet]

That's looking very nice Milton!

I was peripherally involved in the Milviz T-38 a number of years ago. Not being and Airforce (gentleman?) I never even got near one. But very interesting to fly, probably a little like a civilized version of the X3 with a better view and bigger engines.

My opinion flying with Navy pilots was that they had a better trainer. There was a great book that I read carefully transitioning to jets called "Fly The Wing". Anyway flying the T-38 if you can find a good one would be a little illuminating.

I totally agree that a major aspect of FS aircraft is historical preservation of a world that is totally analogue.

Cheers: T

Thanks for the heads up about "Fly the Wing"...just ordered a copy.

 

[Milton Shupe]

I did the very old Lindberg scale model a few years ago. I did the NACA markings for the aircraft. Here's a review link. be sure and include a Paint Kit, nudge, nudge, wink, wink.

https://modelingmadness.com/review/korean/cazx3.htm

Thanks Cazzie. That's a good looking model too.

Will be modeling for a while yet; haven't thought about paint or a kit but I'm sure that will come.

Trying to get the gear doors cut in and looking correct. First try went well but I overlooked the rounded corners underneath the main gear lower forward door corners, so must go for a second shot at it.

 

[warchild]

I suppose I made a bit of progress last night. I'm till finding documentation and sifting through it like theres no tomorrow.. I installed the fuel tanks, but i havent found anything yet that tells me how much each one holds. i decided to make a pretend amount for the moment while i continue hunting. Tonight i'll be working on the flaps. they played a very prominent role in the testing, especially the leading edge flaps. I've got numbers for the LE flaps for maximum extension and minimum extension, but theres not a lot that says anything bout the TE flaps angles. I'll keep looking. its got to be out there, even if i have to take a compass to a screenshot and estimate from that. Max engine output has been corrected to 4850 pounds with afterburners, but i'm not so sure i'm getting the 3570 pounds when the afterburners arent being used. I'll be firing up afsd tonight and checking that. I think the biggest question i have is: "What was Douglas's liminal for safety?" With the change of a single number i can make this plane as stable as a rock on solid ground, or as unstable as a mass murderer.. where in that spectrum did this plane actually operate? Video's from the period dont provide a lot of clues as most data was classified and even the plane itself was carted around inside a big box on the back of a semi truck.. Somehow ive got to get inside their heads.. Still a long way to go. Still trying to remember things. It's frustrating when things you knew so well, all dribble away like steam. Worst comes to worst, i'll relearn what i need, but how do you relearn understanding?? How do you take an airfile, and see not a table of numbers, but interacting systems all working together and effecting each other in sometimes very subtle ways?? Quite an adventure..

 

[Milton Shupe]

Pam,

I have the fuel and flaps info.

Center1 = 8.000, 0.000, 0.000, 455.000, 0.000
Center2 = -18.000, 0.000, 0.000, 453.000, 36.000


LE Flaps 0-10-20-30

TE Flaps 0-15-25-50

It's all in the manual I sent.

[flaps.0] //Trailing Edge Flaps
type = 1 // 1 - trail, 2 - lead
span-outboard = 0.8 // 0.0 .. 1.0
extending-time = 5 // seconds
flaps-position.0 = 0 // degrees
flaps-position.1 = 0 // degrees
flaps-position.2 = 15 // degrees
flaps-position.3 = 25 // degrees
flaps-position.4 = 50 // degrees

damaging-speed = 500 // KIAS
blowout-speed = 550 // KIAS
lift_scalar = 1.0
drag_scalar = 1.0
pitch_scalar= 0.2
system_type = 1 //Hydraulic

[flaps.1] //Inboard Leading Edge Flaps
type = 2 // 1 - trail, 2 - lead
span-outboard = 0.8 // 0.0 .. 1.0
extending-time = 3 // seconds
flaps-position.0 = 0 //
flaps-position.1 = 10 //
flaps-position.2 = 10
flaps-position.3 = 30
flaps-position.4 = 30
damaging-speed = 550 // KIAS
blowout-speed = 600 // KIAS
lift_scalar = 1.0
drag_scalar = 0.0
pitch_scalar= 0.02
system_type = 1 //Hydraulic

I can send you my basic flyable FDE that has all that and more.

Just wrapping up gear doors for the mains now.

 

[Mach3DS]

Interesting points Tom; thanks

A few wire-frame shots and a solid.

Wow Milton this looks spectacular! I'm very interested in this project. The exotic jet bug has bitten again!

 

[fliger747]

I'm surprised that an official flight manual was produced! I more expected a loose leaf binder full of scribbled notes. Wondering what the effect of the LE and Trailing flaps were at higher Mach numbers. They can be disturbing indeed, All the Boeing products I have flown prohibit uate of any flap devices or slats above FL 200. The Alaska MD 83 that lawn darted into the Ocean N of LA was upset by the flight crew exacerbating a CG/trim problem by experimenting with LE slat extension at altitude. The recovery that was pulled broke the T Tail trim jackscrew (which had been jammed) and control of the stab was totally lost. A particular airline which shall remain nameless did the same thing with slats at altitude crossing the Pacific, damaging the plane in the recovery, injuring some pax and crew and effected an emergency landing at I believe Shemya.

So... Another corner that the experimental aircraft exploring the frontiers that would get boxed into!

 

[warchild]

I'm surprised that an official flight manual was produced! I more expected a loose leaf binder full of scribbled notes. Wondering what the effect of the LE and Trailing flaps were at higher Mach numbers. They can be disturbing indeed, All the Boeing products I have flown prohibit uate of any flap devices or slats above FL 200. The Alaska MD 83 that lawn darted into the Ocean N of LA was upset by the flight crew exacerbating a CG/trim problem by experimenting with LE slat extension at altitude. The recovery that was pulled broke the T Tail trim jackscrew (which had been jammed) and control of the stab was totally lost. A particular airline which shall remain nameless did the same thing with slats at altitude crossing the Pacific, damaging the plane in the recovery, injuring some pax and crew and effected an emergency landing at I believe Shemya.

So... Another corner that the experimental aircraft exploring the frontiers that would get boxed into!

I've got that data.. all the results for all speeds and from 7* to 30*.. lets trade ..

 

[warchild]

Pam,

I have the fuel and flaps info.

Center1 = 8.000, 0.000, 0.000, 455.000, 0.000
Center2 = -18.000, 0.000, 0.000, 453.000, 36.000


LE Flaps 0-10-20-30

TE Flaps 0-15-25-50

It's all in the manual I sent.

[flaps.0] //Trailing Edge Flaps
type = 1 // 1 - trail, 2 - lead
span-outboard = 0.8 // 0.0 .. 1.0
extending-time = 5 // seconds
flaps-position.0 = 0 // degrees
flaps-position.1 = 0 // degrees
flaps-position.2 = 15 // degrees
flaps-position.3 = 25 // degrees
flaps-position.4 = 50 // degrees

damaging-speed = 500 // KIAS
blowout-speed = 550 // KIAS
lift_scalar = 1.0
drag_scalar = 1.0
pitch_scalar= 0.2
system_type = 1 //Hydraulic

[flaps.1] //Inboard Leading Edge Flaps
type = 2 // 1 - trail, 2 - lead
span-outboard = 0.8 // 0.0 .. 1.0
extending-time = 3 // seconds
flaps-position.0 = 0 //
flaps-position.1 = 10 //
flaps-position.2 = 10
flaps-position.3 = 30
flaps-position.4 = 30
damaging-speed = 550 // KIAS
blowout-speed = 600 // KIAS
lift_scalar = 1.0
drag_scalar = 0.0
pitch_scalar= 0.02
system_type = 1 //Hydraulic

I can send you my basic flyable FDE that has all that and more.

Just wrapping up gear doors for the mains now.

I would love to check that out.. Thanks Tom ..

 

[warchild]

Tom.. try this link.. it has all the leading flap data..

https://digital.library.unt.edu/ark:/67531/metadc64336/m2/1/high_res_d/19930090188.pdf

 

[Milton Shupe]

I'm surprised that an official flight manual was produced! I more expected a loose leaf binder full of scribbled notes. Wondering what the effect of the LE and Trailing flaps were at higher Mach numbers. They can be disturbing indeed, All the Boeing products I have flown prohibit uate of any flap devices or slats above FL 200. The Alaska MD 83 that lawn darted into the Ocean N of LA was upset by the flight crew exacerbating a CG/trim problem by experimenting with LE slat extension at altitude. The recovery that was pulled broke the T Tail trim jackscrew (which had been jammed) and control of the stab was totally lost. A particular airline which shall remain nameless did the same thing with slats at altitude crossing the Pacific, damaging the plane in the recovery, injuring some pax and crew and effected an emergency landing at I believe Shemya.

So... Another corner that the experimental aircraft exploring the frontiers that would get boxed into!

Tom,

If you will look closely at the chart I posted above, you will see that LE flaps at 10 degrees were required for cruise speeds at high attitude.

 

[Milton Shupe]

During modeling breaks, I have started working to add the effects and test a basic flight model.

Also showing effect of using 10 degree LE flaps at high altitude cruise versus not.

 

[fliger747]

I expect that these LE flaps are merely an adjustable "cuff" to add some camber rather than the rather large Kruger Flaps or slats that move well away from a more rounded LE such as we had. I can see that the X-3 as underpowered as it was was just hanging in there at altitude!

Almost everything they tried in this era was an exploration of the unknown!

 

[Milton Shupe]

I expect that these LE flaps are merely an adjustable "cuff" to add some camber rather than the rather large Kruger Flaps or slats that move well away from a more rounded LE such as we had. I can see that the X-3 as underpowered as it was was just hanging in there at altitude!

Almost everything they tried in this era was an exploration of the unknown!

Here are some close ups Tom, and how I have them modeled at 30 degrees, and at zero.

 

[Mach3DS]

I imagine that as speed increased the LE slats would retract nicely as the center of pressure moved aft naturally rolling about the lateral axis and pitching the nose down?

 

[warchild]

well, keep in mind that the CG was just in front of the LE of the wing, and above and behind the wing, you had 453 gallons of fuel. That was balance by the fuel that was directly in front of the CG. So the main purpose of the LE flaps was to control the point on the wing where the supersonic flows ( top and bottom ) break away from the wing. Since normally, the lower supersonic flow breaks away from the wing at a later point than the top of the wing, i'm not quite certain of how that effects the attitude of the aircraft..
If i might take a guess here, I'd say it was most likely the experiments done with this plane that led to the developments of the LE Slats and other LE devices you mentioned..

 

[Milton Shupe]

I do not know what the cruise speed was as I have not seen that mentioned.

See the chart attached for flaps use guidance.

Per the test pilots' reports, flaps must be used to 350 kias.
I take off with 3 notches per the chart below, retract one notch at 250-ish, and the last notch (LE = 10) at 350.
Cruise - add back one notch for LE flaps at 10 degrees for lift and pitch adjustment.
BTW, I have AfterBurners kick in at 80% throttle, so cruise at 78 or less, one notch of flaps. This gives around 550 ktas at FL300.

I set up my base flight model that way and it works well.

The LE flaps increase lift but do not add much drag the way I have them set up; they are set for lift and slight nose down pitch.
The trailing edge provides drag, lift, and pitch moments.

I have not added speed brake as it is not modeled yet. Not needed unless you are coming in hot. Provides drag and no pitch moment per the docs.

There is an equal amount of fuel in two tanks spread equidistant fore and aft CoG.
The forward tank feeds the port engine; the aft tank feeds the starboard engine.

Pam, we need to change the fuel tank designations to Left Main and Right Main so they will feed each engine equally to maintain balance.

LeftMain = 8.000, 0.000, 0.000, 455.000, 0.000
RightMain = -18.000, 0.000, 0.000, 453.000, 36.000