Hatman335

Salty has already written a great intro text on the basics of the secondary power system, I'll copy it, and he's also drawn a great illustration as well. "The Jet Fuel Starter is jet engine in it of itself. We used stored potential energy in the form of hydraulic fluid and pressurized nitrogen. This gets the JFS started. The JFS has its own electric and fuel requirements completely separate. Once the JFS is started the lubricating oil turns into control oil. This control oil, when prompted by finger lift on the front of each throttle, will put 350psi of oil into the “iso decoupler” we call them “stub shafts”. These extend out and into the “Pawl Carrier” on the AMAD. The pawl carrier is the catchers mitt. Once engaged it begins to rotate and spin the AMAD which has 2 pumpnulls 1 generator and the Power Take Off (PTO) shaft. The PTO connects the AMAD to the engines gear box. This is where your rotation is coming from. Once over 20% you are cleared to go over the hump with the throttle, but I wait untill atleast 24% N2 RPM. The motor will accelerate with the JFS until it reaches 50%-54% which is when the JFS will disengage/shut down depending on if the other motor is already cranked"

Thanks, that's indeed pretty poor phrasing on my part, I'll fix that. Have you found any other issues or inaccuracies that I should fix as well?

Sorry, what part is this referring to in particular? I may have misphrased something.

INS PVU. I've learned most of this from Klarsnow and Notso on the Discord and the workbooks. I'm not an SME. The AGR series and the AGD-4 designations go into a lot of detail with this.

.90IMN/525 KCAS or .95IMN/575 KCAS depending on where it's loaded. Modelling overspeed would be very tricky because it would have a higher chance of some kind of failure related to the seeker but nothing guarantees it wouldn't be working just fine.

I fail to see any tactical reason to fly at low speeds. The lower your speed is the less energy the bomb will have, you will spend more time in the target area, you'll have less energy to manuever or to defend yourself. Passing over the target is generally a terrible idea, you'd do a check turn 60 degrees away and lase it that way.

PVUs most certainly help with drift. Assuming you're running MN, it will get velocities from the INS and from a known starting position it integrates the velocities over time to calculate position changes and since it has a known starting position, adding those changes together will result in the system knowing your present position. If the velocities are inaccurate the system will essentially think that you're moving across the ground at a different rate than you actually are. Since this is provided by the INS using accelerometers the actual value can be slightly off and even slight errors can have huge impacts. (I'll give an example later) The radar in turn directly measures this based on the rate of change of the ground returns and this is significantly more accurate. It then calculates delta values (the difference between the velocities it measured vs the velocities supplied by the INS) and adds these corrections to the MN for 5 minutes. After 5 minutes these values may no longer be valid so the system does not use them anymore. An MN PVU can give you sub knot accurate velocities. If all you're doing is just updating your position but keep the velocities inaccurate it will drift again anyway and if that happens the aircraft's understanding of the relative position of the target can also drift away rendering the designation inaccurate and hurting bombing accuracy as well. SAR mapping also relies on knowing exact velocities since if there's a velocity error the Doppler shift is calculated incorrectly and the result will be a significantly degraded map. Therefore, having accurate velocities without EGI is crucially important. INS PVU is another ballgame, that is typically done once per flight and it's purpose is to calibrate the INS to what its drift values are and its a bit more convoluted when performed properly than an MN PVU. This can lead to lowered drift over the course of the flight and it can also clear up the SAR image and this latter part is true even with EGI. Obviously if the mission has GPS available, drift will not be a concern and position updates are not required. To sum it up, assuming all gets added properly and working as it should, do your INS PVU once per flight during your way to the target area or on the way to the tanker or whatever, use MN PPKS and do a PVU for every map and update and try to keep the time between the last PVU and the weapon release within 5 minutes if possible for the greatest accuracy. If running EGI doing an INS PVU once per flight should still help with the SAR image to some degree. As an illustration, one knot of velocity error in the system is 1.7 feet of drift each second. So if you mapped the target at 10 nm and flew the attack run at 500 KTAS, by the time you get there the target would have drifted 120 feet. This gets further complicated if you add in squint angle error to the equation, but just to avoid making this message even longer, let's just agree to have the WSOman do those PVUs. Or just run EGI and let the geepus magically carry you to victory.

According to Grinelli's statements, the F-105 is 'not available'. Therefore either something prevents this particular jet from being made (which is very unlikely) or someone has it licensed or at the very least has serious plans to deliver it. (Very likely)

The target area where I did the designation tests was the Eastern section of Batumi airfield and the area has a constant 33 feet of elevation. Even the initial designation is off, I tried to do it just once, targeting the Western part of the ramp and the HUD indicator was significantly short of the actual point designated on the patch map. 4. had an elevation of 33 feet.

I will make a video or track, but let's ensure that my methodology is sound. I set up a very short airspawn, in a mission dated 1991, with 70 minutes of flight time set on the drift slider. I selected MN PPKS. I did my MN PVU, then I did my initial map. Steerpoint 2 was a big bunker on a smaller land feature, it was very easy to find, I updated my system using that. Then I mapped the target area and designated 4. There were no PB#17 errors, I double checked. Freezed the map and as I got closer, I did several redesignations, they were all noticeably short of the designated area and slightly offset right. The time between the designation tests and the MN PVU did not exceed 5 minutes. All points were added through the mission editor and that automatically loads the correct elevation, but I also double checked it manually. The update was as good as I could do it, the PVU was still valid, the elevations were all correct. What could be the issue? I repeated the same test using EGI and I only mapped and then repeated the designations, without the PVU or the update. As expected, the issue was significantly lesser pronounced but it was still noticeable.

The target cursor functions works for me as intended, but I also experienced the same mismatch between the target location on the HUD versus on the AG radar map, even right at the moment of designation.

That depends on how they implement the rest of the system. If we get ACQ cursor function and TMTT (ie, the real mover logic) then sure, hitting movers will require very little marksmanship.

To further provide some context, in more modern suites the aircraft has actual mover logic through a new cursor function called ACQ cursor function, this allows you to point track a mover and create a target pod moving target track or TMTT. This is an actual air to ground trackfile with a known direction and speed. This can be used to automatically calculate a lead impact point for a weapon, a point where it would ballistically hit the mover assuming the current direction and speed stays constant. Another feature that helps with this is called lead laser guidance, this automatically shifts the laser slightly in front of the mover to help the bomb compensate for lag, sag and energy loss. Now, in Suite 4 with LANTIRN they had none of this, the LIP calculator was called the WSO, so they had to designate in front of the mover and lead with the laser all manually using rules of thumb estimates based on travel speed. CDES was not used by most people, it really just has the potential to create a lot of issues while its benefits are very questionable in the first place. Point track was also seldom used, it really is just better to track stuff manually with LANTIRN. Using CDES and point track at the same time is just asking for trouble. Manually follow and lead the movers and area track stationary targets, be extremely careful when using CDES (mainly going to be useful with Mavs but that's another topic) and try to approach this without the bad habits that DCS ingrains into people's heads.