nairb121

For what it's worth, the F-5N NATOPS includes this line regarding the AN/ALR-87, pages VIII-26-4 - VIII-26-5. I assume this is the devs' source for these keys not being functional. null

The F-5 has been used by many countries in various upgraded configurations. Most of the stuff you listed has been on one variant or another... not necessarily all at once though, and generally not as early as the 90s. Ours is about as good as it would've been in the 90s, though some users had in-flight refueling and an expanded A-G capability (I know some 90s upgrades had Maverick capability). Most of the "big" stuff, with upgraded radars, INS/GPS, and limited BVR would've been in the 2000s-2010s. Our F-5 isn't a 60s F-5A, it's a early 80s F-5E-3 - so it would not have actually been all that dated by the 90s, given the expected capabilities for its role as a cheap, reliable light fighter. I've never seen anything on it carrying AIM-7 though, nor Maverick as early as pre-revolutionary Iran - do you have a photo you can share?

This is the Steam page for the full fidelity F-5E: https://store.steampowered.com/app/411894/DCS_F5E_Tiger_II/

Cool, thanks. Is there a good reference for the various avionics packages in the export models? There seems to have been a lot of variation, I'd be interested in learning more. Yeah you're right, it does seem to be a mix of those versions. It's not quite an N either though is it, since those have INS, and I think a second UHF radio? Unless there's an earlier version of the N that I'm missing. Yeah, the flyable version was what I was referring to, I just somehow didn't see in in OP's second screenshot and didn't remember if I'd specifically noticed it before.

Looking more closely at the comparison, while most of the changes appear to just be improved details, there are a couple things that caught my eye: 1. I can't believe I never noticed before that the countermeasure dispenser (AN/ALE-40(V)) is completely missing from the DCS F-5E external model 2. Most of the antenna locations are consistent between the before/after pictures, and match the locations shown in the F-5EF-1 or F-5E/N NATOPS (below) - but I don't know what the large dorsal antenna shown in the "new" model is for. It's not shown in any of my reference material, but many export F-5Es were equipped with it - probably an additional radio?

Our F-5E is effectively a Swiss F-5 already, I believe the E-3 with the RWR is pretty much unique to Switzerland – the "standard" E-3 as described in the USAF manuals doesn't have one. I would certainly like to have an updated 3D model though!

The F-5E modeled in DCS uses the ALR-87 I believe, which has very little public documentation. I agree that it should be very similar in capabilities to other similar RWRs, but it's difficult to prove.

I was able to find data on roll response for an F-5A, which should be similar enough aerodynamically for direct comparison, in the public release document at https://apps.dtic.mil/sti/tr/pdf/AD0738625.pdf . However, this is mostly concerned with roll initiation rather than damping, though there were a few references to the F-5A having strong roll damping. Were you testing this with a clean aircraft, or carrying wingtip/pylon stores? Particularly with how light the F-5 is, and how thin its wings are, its roll inertia is extremely sensitive to outboard stores - per the document linked, the roll mode time constant can increase by over 4 times from a clean aircraft to fully loaded. It's possible that the DCS F-5E is overly sensitive to wingtip missiles - I think this has also been discussed elsewhere. It should still be capable of Mach 0.8 or higher with most loads, but with a heavy/high drag load the AOA required to get airborne can make it difficult to accelerate to cruise speed in MIL - if you use afterburner to accelerate to 400 or so can you maintain it in MIL? Also, if you took off from a cold start make sure you're retracting the airbrake. This will depend on CG location - if you're carrying centerline stores the F-5 can't hold its nose up with much weight on the wheels, but with a more moderate CG, you should be able to aerobrake with a good flare and a gentle touchdown - as long as the nose doesn't come down you should be able to hold it up for a little while.

Checking back on this - is there any other information needed on this? With the FC2024 version of the F-5 using the same flight model, this is now an issue with two modules.

He means that, unless it has that capability to protect itself, it would be correct to rapidly lose all the hydraulic fluid. I personally have not been able to find evidence either way, my documents don't have much detail on the hydraulic systems. I would guess though, that there wouldn't be a cutoff system like that. If damage is severe enough to cause leaks in both hydraulic systems - then odds are that much more is damaged and the airframe is lost anyway.

There are 2 systems, the flight control and utility hydraulic systems. Both redundantly serve all flight control surfaces, while the utility system also controls wheel brakes, gear, speedbrakes, stability augmentation, and the gun doors.

It's kind of a weird situation... theoretically the fuselage and wing stubs can still provide some lift, and you still have elevators for pitch and the rudder for roll. There are no fuel tanks in the wings to leak fuel when damaged, so the engines should still run. As long as the damage is symmetrical, maintaining stable flight theoretically should be possible. The main problem (and I haven't thought to check this in game) would be loss of hydraulic pressure - I'd think losing the wings should drain the hydraulic systems (since there are lines to the ailerons), I don't think they have any sort of cutoff valve in case of damage like that.

The F-5E-3 would not be able to use Mavericks without significant upgrades, it wouldn't be able to interface with the missile and doesn't have an appropriate display. It also has no means of laser designation - I believe some F-5Fs were equipped with laser designators in the rear cockpit, but the E doesn't have anything like that.

I haven't seen anything to indicate that the AIM-9L was ever carried by the F-5E — the -1 and -34 manuals only reference B, E, J, N, and P.

My understanding is that the correct behavior of the Search mode is as something of a declutter option, to show or remove search radars (i.e. early warning, AWACS, etc.), rather than toggling between these and threat radars. Threat radars (either surface or aerial) should always be visible.

This section of the -1 manual (page 6-13) states that the effect of asymmetrical wingtip stores is negligible:

I located an additional source for further clarification on maximum AOA for the F-5E: https://apps.dtic.mil/sti/tr/pdf/ADA029071.pdf Page 5-10 has this chart showing the AOA limits as a function of CG for tail deflections limited to 17° (as in the production F-5E) and 20°. CG with full fuel and no ammunition is approximately 12.5% MAC, full fuel and ammo loaded is about 11%. Correction - I had read these values from the incorrect charts - for the clean E-3, guns empty CG is about 17.5%, and with guns loaded it's about 12%. This gives a AOA of up to about 30°, which closely matches the references above.

Yes, that is correct. I'm not disputing the stall AOA (in units) - the manual is very clear on that. The sources I've posted seem to indicate that the F-5 should be able to pull more beyond stall than we can currently, depending on CG position. The manual supports that the F-5 should have some degree of post-stall AOA capability (page 6-4): It's difficult to properly correlate units and degrees, since no source seems to use both, each using either one or the other. The only factor I've seen relating them is the stall AOA, which is stated in the Taylor/Skow report to be 23 degrees, and in the -1 manual to be 27-28 units - however, in DCS 27-28 units corresponds more closely to 20° AOA. See below, from my track attached in my original post. null Is it possible that the relation between true AOA (in degrees) and indicated AOA (in units) is slightly off in DCS, with the stall and maximum AOA being based on the incorrect indicated AOA and therefore falling short of the true values?

Yes, the numbers referenced in my post are true AOA in degrees, as reported by the status bar. The NASA and Taylor/Skow documents are both also measuring true AOA.

There's no independent bar selection, but it does switch from 1-bar to 2-bar depending on scope range selected. Azimuth will always be the full 90 degrees. Your main controls are the elevation knob, the range selector, the TDC, and the ACQ switch.

There's a mic switch on the throttle which should be used for this.

Isn't the reticle collimated, projected to infinity? Unless there's an issue with how that's simulated, seat position should have no effect on the reticle's alignment.

The F-5E in DCS, when clean, has an angle of attack at full aft stick of approximately 21° when gun ammunition is loaded, and approximately 25° when the guns are empty. Based on the public sources I've found, these are too low; capability should be approximately 30° (presumably with guns empty). The paper here https://arc.aiaa.org/doi/10.2514/3.45660 concerns the departure characteristics of the F-5E and the means by which an impending departure could be detected and the pilot warned. This section (found at the top of the second page) states that pitch acceleration follows stick position up to about 30 degrees, at which point further pitch up is prevented by the aircraft's aerodynamic stability. Fig. 7 also supports this - it shows time history of various flight parameters during an extended full-aft stick stall. The angle of attack can be seen as approximately 30 degrees for the majority of the time, further increasing to 40 degrees at the onset of post-stall gyration. (It should also be noted that the DCS F-5E shows little tendency toward PSG in this regime) An additional source for the F-5E's AOA capabilities is this NASA report regarding the development of the "shark nose" used in the F-5E and F-5F. https://ntrs.nasa.gov/api/citations/19790001876/downloads/19790001876.pdf . This report mostly concerns the F-5F, but also includes some F-5E data. Figure 6 shows flight data for 1g power-off stalls for the F-5E - the charts are more difficult to read, but they do show similar AOA tendencies of 30 degrees at full aft stick, and up to 40 degrees upon departure. I've attached a track in DCS attempting to replicate these tests by performing an extended wings-level 1g stall with guns unloaded. Upon full application of aft stick, the AOA remains between 25-26°, never approaching 30. F-5 1g stall test.trk Edit: I didn't realize the first document linked was incomplete; a full version is attached. F-5E_Depature_Warning_System2.pdf

I found a few relevant sections in the F-5E-34 manual (accessible at https://www.digitalcombatsimulator.com/en/files/1946809/) : From page 1-89, in the section relating to the Snakeye: From pages 1-119 and -120, in the section on the FMU-54/B tail fuze used in the Snakeye: And page 1-134, showing arming wire/lanyard installation for the Mk-82 Snakeye: There only seems to be one swivel and link, rather than two as used on typical GP bombs. If I'm understanding the diagrams and descriptions correctly, the swivel and link (if the station is armed) pulls the fin release wire, causing the fins to open. The tail fuze, if present, is linked to this wire and is also pulled. The nose arming wire is linked to the fins, and pulled out by their opening action. This is supported by the first excerpt, "As the retarding fins open, the noze fuze arming wire is withdrawn from the nose fuze". However, it seems like it would be possible to have an additional swivel and link connected to the nose fuze arming wire, which would be connected to the nose fuze arming solenoid. The manual makes no mention of this for the Snakeye, though it's similar to the arrangement used on GP bombs. It would have the effect mentioned though - if this was pulled, but not the swivel and link connected to the fin release wire, this would arm the nose fuze but not release the fins or arm the tail fuze. Maybe this is the setup used on the other Snakeye-equipped modules?

A g-load that high can't be sustained for long, but the pilot should still last at least 2-3 seconds (and that's all this maneuver was). There's an IRL case of an F-15(C I think) pulling 13-14g in an emergency dive recovery. IIRC they were able to RTB safely, but the plane's structure was permanently bent, so it was written off.