According to https://defence-blog.com/irans-copy-us-made-fenix-air-air-missile-goes-production/ the fakour’s guidance system is 30% smaller then the AIM-54 allowing for an increased range of 15%.
You are guessing this. Nothing you’ve shown supports this idea and especially not if you’re finding the impulse to be well over 260 for a 60’s CTPB propellant.
Again, no. That cannot be the average thrust for the aforementioned reasons.
That source is incorrect.
And there is no chance that between the 2005 handbook to the 2023 that the motor changed in anyway? The 2005 book is much more specific which generally is telling of it being test data. This is a hard one, I’d probably attach everything and let the devs decide.
Both the 2005 and 2023 are acceptable source materials and I’d normally lean on the old “newer version is best” but we’re dealing with an old rocket motor so the more specific figure being in the older one gives it more weight in my opinion. But yeah best to provide all materials and let the devs decide.
Is there a reason why the Iranian F-14 in-game can only carry 4 phoenix instead of 6 ?
I know the US Tomcat rarely used the 6xAim54 loadout but was there a physical limitation with the iranian F-14A wing pylons? If not, why not allow it? I haven’t seen anyone discuss this.
No, its literally in the document.
It lists “Average thrust” for other motors and “Approximate thrust” for this one.
Can you cite the source you are using for M112’s propellant composition?
The “Improved Orion” motor is the civilian designation for “Military surplus M112 motor” as confirmed by many sources.
The motor has specs, you can’t simply make a different motor and market it under the same name …
And it’s not like NASA’s handbook is based on singular launches and “they used one motor in 2005 and it had lower thrust and longer burn time and they launched another one later and it had shorter burn time and higher thrust”
Those values are listed there for engineers and scientists looking to choose a rocket motor for their experiments … Those are typical values based on many samples that NASA has launched and are intended to be practically useful for its audience.
They are literally two revisions of the exact same handbook.
Just compare the tables of content.
Format and content are also largely the same.
2023 Handbook:
The 2005 Handbook:
It’s literally the same handbook
Which figure are you referring to?
Because both the 2005 revision and the 2023 revision provide equal amount of details / information.
Just the numbers have changed.
So I’m not sure what you are referring to by “specific figure”
It is likely calculated in some way. The motors are all surplus from military storage that is sold off just before they expire.
Yes, so it isn’t average. If it was average thrust, it would be the highest impulse CTPB propellant on planet earth and defy the laws of physics at the same time.
While I thought it was similar to the Mk58 of the AIM-7F I was mistaken as it was produced in the same facility as the SM-1’s Mk56.
The HAWK motor retained many manufacturing similarities to the MK56 motor.
https://spacenews.com/aerojet-to-remanufacture-dual-thrust-rocket-motors-supporting-the-standard-missile-program/
This document details a change in the type of chemicals used to bind the sustainer to the wall of the motor and the booster propellant during production that caused unreliable motors for a certain number of lot numbers.
https://apps.dtic.mil/sti/citations/ADA056401
The assumption that it uses the highest performance fuel type available on the market at the time is dubious, you’re right. In fact the aforementioned study suggests it still uses poly fuels predating CTPB but it might just be the composition of the sidewall binder.
The fact that it doesn’t use CTPB complete invalidates your argument based on typical Isp values for contemporary CTPB based fuels.
So, again, your own sources indicate that it is using a composition designed for very high specific impulse by sacrificing stability.
Hence why it’s so popular for space and sounding rocket applications where high specific impulse is desirable.
Actually this is pretty funny
The Mk58 of the AIM-7F uses AP/CTPB and was produced later than the M112 of the I-HAWK.
The I-HAWK’s M112 uses AP/Polyurethane
Interestingly, this is an inferior propellant type to CTPB but is what eventually led to the use of HTPB.
It would apply to “metal bonding agents containing polyurethanes”. Aerojet did not produce an HTPB propellant with similar ISP to their CTPB counterparts until the late 80s.
If you have any source to prove the typical Isp limit for AP/polyurethane propellants please cite.
Currently it can pull 10Gs of the rail, slowly increasing to about 13G near the sustainer shut off. I couldn’t test instantaneous pull with high speed though, only sustained.
*at sea level
What sources are you using?
This is information the developers are already well aware of, I’m not wasting my time reeling through various sources to show you aerojets average impulse from poly compounds in the 60s.
Not entirely. I have not looked at the manual but is this a 1 for 1 test. Meaning the same engine, grain configuration etc? We get stuff in the lab all the time for a number of reasons. Sometimes its a simple QC check to see if things are within tolerance from lot to lot. Sometimes its a degradation test, atmospheric test. We have a chamber for stabilizing the temp and humidity of test powders and propellants. Sometimes its a “new” design they want to test in our lab since the previous results will be under the same conditions so they have a solid comparison vs using multiple labs.
Is this a 1 for 1 test with the exact same composition, arrangement, and atmospherics? Was the test normalized to ICAO standards or ASM standards first? Was it a simple QC check? Why did NASA do the test?
Rocket thrust ratios are entirely altitude dependent. Was this converted for an air launch? I provided the formula to do this before if not.
1- This is a mass production commercial / military rocket.
2- NASA’s rockets user handbook as the name suggests would have typical and representative values intended to be useful to its intended audience (engineers and scientists who want to choose an appropriate motor for their application / experiment)
As far as the conditions go we only know it’s based on launch from ground.
But there is no reason to think that the launch conditions are different between two revisions of the exact same handbook, when there is no such indication.
Obviously not.
This is a reference handbook
I am surprised this isn’t already in game. Something I have also not seen accounted for in this conversation. The outgoing thrust does reduce drag on the missile. For artillery and other long range projectiles we did years of experimentation with burn butt projectiles. The biggest problem was getting production to apply the chemical exactly the same every time. By putting a small compound on the back end we could reduce drag in some tests as much as 30%. Same does apply for missiles and I don’t think its accounted for in game.
Also, and again, the formula to increase or decrease thrust based on altitude is relatively simple and would be easy to implement. Then you wouldn’t have to do janky things with the drag to play around with how it performs.