Comparison by Spurts

New and old developments in aviation technology.
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energo

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Unread post17 Mar 2020, 23:57

sprstdlyscottsmn wrote:"Okay, .67 to 1.83 happens pretty smoothly, 1.83 to 2.02 takes almost as long, doubles the fuel, and more than doubles the distance"


Probably old news and not very relevant, but one RNoAF F-16A pilot once told me that pushing Mach 1.6 was like "hitting a wall". It wen't slowly from there. Mostly due to the inlet, I was led to believe. Most RNoAF pilots I've talked to have barely had it much past Mach 1.9 in FCSs. As one said, to the effect of: "I couldn't bother trying Mach 2. Not enough fuel!" This was way before the -220E, so it might not be accurate today.
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sprstdlyscottsmn

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Unread post18 Mar 2020, 00:03

energo wrote:
sprstdlyscottsmn wrote:"Okay, .67 to 1.83 happens pretty smoothly, 1.83 to 2.02 takes almost as long, doubles the fuel, and more than doubles the distance"


Probably old news and not very relevant, but one RNoAF F-16A pilot once told me that pushing Mach 1.6 was like "hitting a wall". It wen't slowly from there. Mostly due to the inlet, I was led to believe. Most RNoAF pilots I've talked to have barely had it much past Mach 1.9 in FCSs. As one said, to the effect of: "I couldn't bother trying Mach 2. Not enough fuel!" This was way before the -220E, so it might not be accurate today.

I'm analyzing the -129
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energo

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Unread post18 Mar 2020, 00:21

sprstdlyscottsmn wrote:I'm analyzing the -129


Absolutely, keep up the good work! :mrgreen:
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rheonomic

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Unread post18 Mar 2020, 02:00

sprstdlyscottsmn wrote:Working on the thrust model for the F-16.

It's probably a shitty model but NASA TP-1538 (PDF) has a static engine model as a function of PLA, Mach, and altitude for an "F-16 like" aircraft. There's also an aero model that might be ok to ~M0.6 or so. There's a MATLAB version of the reduced model the Stevens & Lewis textbook has available here for non-commercial use.
"You could do that, but it would be wrong."
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Unread post07 Apr 2020, 12:07

New AIM-120C model in DCS, closer to real life?
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sprstdlyscottsmn

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Unread post07 Apr 2020, 15:32

There are a few takeaways from that video.

Aspect: These were head on shots.

Launch conditions: 1.6M from 50,000+ft... hmm, isn't there some Wunderjet that cruises at those kinds of conditions where it was stated it would roughly double launch ranges? Now it is highlighted why. The missiles were able to stay faster for longer in rarified atmosphere.

Target dynamics: The targets were all at high altitude so the missile never had to slow down in thicker air. The targets did not have much time to maneuver either so they did not have the opportunity to generate lateral separation.

Crunching numbers on the three shots

50nm shot, 64s time of flight, actual flight range 40.4nm (target covered the rest)
55nm shot, 74s time of flight, actual flight range 43.9nm
60nm shot, 75s time of flight, actual flight range 45.6nm
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sprstdlyscottsmn

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Unread post08 Apr 2020, 16:20

Update: No update right now. During the midst of all this craziness I am also changing jobs and moving cross country.
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lamoey

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Unread post08 Apr 2020, 17:23

sprstdlyscottsmn wrote:Update: No update right now. During the midst of all this craziness I am also changing jobs and moving cross country.


I'm please to hear that you have a job, under the current climate.
Former Flight Control Technican - We keep'em flying
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eloise

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Unread post09 Apr 2020, 02:42

sprstdlyscottsmn wrote:Update: No update right now. During the midst of all this craziness I am also changing jobs and moving cross country.

It is scary, I hope US find out the cure soon

sprstdlyscottsmn wrote:There are a few takeaways from that video.

Aspect: These were head on shots.

Launch conditions: 1.6M from 50,000+ft... hmm, isn't there some Wunderjet that cruises at those kinds of conditions where it was stated it would roughly double launch ranges? Now it is highlighted why. The missiles were able to stay faster for longer in rarified atmosphere.

Target dynamics: The targets were all at high altitude so the missile never had to slow down in thicker air. The targets did not have much time to maneuver either so they did not have the opportunity to generate lateral separation.

Crunching numbers on the three shots

50nm shot, 64s time of flight, actual flight range 40.4nm (target covered the rest)
55nm shot, 74s time of flight, actual flight range 43.9nm
60nm shot, 75s time of flight, actual flight range 45.6nm

Thank you
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sprstdlyscottsmn

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Unread post18 May 2020, 16:59

Okay, so now I do have an update! I have "finalized" my F-16V model. Now on to mission work.
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sprstdlyscottsmn

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Unread post19 May 2020, 02:35

I swear, 100 hours to make the model, and in 5 hours after that I have have the analysis work done.
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eloise

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Unread post19 May 2020, 02:44

sprstdlyscottsmn wrote:I swear, 100 hours to make the model, and in 5 hours after that I have have the analysis work done.

I knew your model take very long to make but holy **** 100 hours, I'm deeply impressed.
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