zinhawk

I forsee the J being the next obvious step, but I would like to see the G, lots of local history with it.

Ignitor power is routed through the inverter regardless of power source. I'm weak on aircraft E/E, but If memory serves we could run the inverter off the main battery. I only say that because I don't recall needing a power cart for ignitor checks, but I've also done it with which is like listening for a blinker with someone firewalling a CAT 6 ft away. That aspect of no ground power and no APU and still getting inverter may or may not be a booboo. Edit: Verified for sure inverter runs on Main Battery in case there was any lingering doubt.

DCS is correct.

Hmm, I only dug into engine behavior a couple years ago and as far as I know they always started right up. If they did change it, it was changed to the more correct behavior, with the caveat that you are now inducing a hot start that doesn't seem modeled. Starting without ignitors would create a long tornadoing fuel cloud coming out the tailpipe. Flicking on ignitors would create a giant fireball. Which is funny for YouTube videos followed by shear panic, but the engines would start. The correct procedure after non ignition is motoring for 2 min, wait 5, and check the pipe for pooling and try again. We do this all the time on test cell to prime the fuel system before the first light off. You may be remembering procedures or they used to enforce the procedure with the start sequence. In any case, its correct operation as is besides the lack of explosion.

Thunderbirds of course. I would prefer the "dirty tail" for No. 4 rather than the black painted one later

Pave Penny was completely removed from the A-10 as part of the Charlie upgrade. You can make an argument for a full fidelity Alpha model and maybe a very tiny one for the original Charlie suite, but the Pave Penny has no place in the suite series represented by "Tank Killer II"

Unless they changed something recently, the override switch is not modeled, or modeled appropriately.

It's for stuffing things and not have it fly around the cockpit.

You misunderstand, politics includes military leadership and the entire industrial complex, not just the suits in congress. There was an important third word. Fifth Gen systems integration. I'm not talking stealth jets, just the pod, information sharing systems, and ECM being included in the design from the ground up. Think F-35 brains, in an actually good CAS platform. Sure lots of things can drop bombs, but not many can loiter and keep a high Mission Capable rate like the A-10 which is incredibly important to CAS. B-1 needs 3 jets to just launch 1 and the gun will still be important when the computers inevitably fail in a 21st century peer to peer fight. Main point is that the A-10 is not going to stay around forever as suggested in the OP. Certainly will not last my career. It needs rebuilt with lessons learned or replaced all together with something fully vested in CAS or the AF just needs to give it up and hand that mission over to the Army and Marines.

From a maintenance perspective it's a s*** or get off the pot kind of situation. Like any government system, supply is mired i politics and Uncle Jim's Backyard contracts more than usefulness. Most issues affecting MC are a result of cobbling 4.5 gen systems into an old platform. A clean sheet redesign is needed with gen 5 systems integration and much more advanced propulsion to increase the capabilities of an A-10 like platform and make maintenence easier than it is. If they can prototype the next gen A2A in a year they can do the same for a CAS centric bird like what gave birth to the A-10 in the 70s to begin with.

My mistake. The switch implies BOTH functions of the switch where I thought GRD was guard mode for that purpose. What a dumb layout. Thanks.

What position should the UHF Radio Frequency Mode Selector Switch be in to load a frequency? - PRESET (The instructions get this backwards. I don't know what is right, but this is how it works. It makes sense that to do Preset things, you should be in PRESET mode.) What position should the UHF Radio Frequency Mode Selector Switch be in to use a preset frequency? - PRESET After loading a frequency should the UHF Radio Preset Channel Selector Switch actually do anything? - Select the Preset Channel you wish to use/modify next. What position should the UHF Radio Function Selector Switch be in? - MAIN or BOTH to monitor Guard Is the UHF Radio Manual Frequency Dials (Indicator) supposed to change? - You have to use the STATUS button under the Preset Selector Switch and the programmed channel freq will show for a few seconds. If you cycle the Preset Selector switch after pushing STATUS you can see all the frequencies per channel in that allotted time.

Really big birds and ducks have been recorded that high, but the probability of hitting one up there is low compared to takeoff and landing where the majority of bird strikes happen. Before my maintainer days I was servicing a Q400 that speared a bee right in the ass with a pitot tube on final and they lost instruments. Stuff happens I guess.

I'm not a sensor expert but to my knowledge the A-10 is pretty good comparatively in IR, hence the tail configuration. The net benefit of halving/killing your available power (plus killing all systems) in combat conditions for the sole purpose of defeating IR is about as non-existent as air force warrant officers. Great you defeated the heater, now you are locked, now what?

I would most definitely not recommend ever do anything like that

Yeah I was misremembering everything completely.

Is there a shut off valve on the aircraft side? To my knowledge the handles only blow the extinguishing agent into the compressor inlet. There is no fuel shutoff function on the engine besides the throttle. Perhaps the reloaded extinguisher blew again? "Repair" should have fixed anything broken in any event. APU should keep loading until the starter craps out. Did you have a fuel leak associated with the hit? Did you fill up after repair?

Plus one. This is our heritage demonstration jet now.

The big thing is 3 way flap switch enabled on default for me. I run a combined TARGET profile to enable all the 3 way positions for the TMWH throttle to use in the various modules. Before I could slide the Warthog UP/MVR, MVR/DN function into default but this doesn't seem to work anymore. Haven't tried since 2.7 though. Regardless flaps should be presented as 3 seperate UP, MVR, DN positions as well as UP/MVR, DN/MVR, and the current simple flaps up down toggle to cover the spectrum of controls

Sorry was out a few days trying to merc bears. I don't see this being the case with high bypass or at least this engine if I am understanding correctly in that you are associating X pounds per hour with Y pounds of thrust. Newer/well built engines will run with much less PPH at max than worn engines but have essentially the same thrust because of tuning to the same fan speed. And there are different levels of worn depending on how good the builder was. We often want to slap pilots silly who align PPH for fuel burn calculations and then complain of asymmetric thrust. "Well, dummy, you throttled back your weaker engine!". Of course this point is moot for the purposes of DCS with 2 clones. Super heated yes but compared to chamber and turbine temps it is considered rather cool. I'm not 100% positive on compressor temps since we do not measure that but those numbers sound about right. Discharge pressure is in the 300s. I don't know the balance of power between the turbines but sure that makes sense. 1 set of IGV and the first few stages of the compressor are VSVs that are adjusted within fine limits closed and opened. These actuate from the fuel control based on a complex analog system of throttle input and mechanical feedback. A nitpick on vocabulary as it means totally different things. These are cans: https://engineering.purdue.edu/~propulsi/propulsion/jets/basics/burner.html This is annular: The compressor, HPT, gearbox and accessories run at the same RPM. For the gauge this is taken from one of the accessories. Fan Speed is read directly from the fan shaft. Yes. Real world thrust checks we throttle up to max and compare to GE values on an OAT chart. That is how I came up with the discrepancy and why it is important to thrust. Even went so far as to recreate local environments on real test (installed) days. The answer is always the same. Now that is not overly helpful to those who do not have access to cross check. How to go about the real nerdy engineering way like GE did in the 60s I don't know, but I'm real keen on learning how. Acceleration checks sounds good to my limited Physics 101 brain.

This is getting in the weeds of engine theory so I'm hoping to learn as well. What I can offer is my practical experience as I am a TF-34 builder and maintainer. Hopefully this answers some questions: 1. TF-34 is not a turbojet. Turbojets are single spool (1 compressor, 1 turbine). Pretty much just the core part of a bypass engine so yeah fuel flow means more direct relationship with single compressor speed and thrust. Low bypass turbofan (F100/400 series engines) are a close cousin running dual spool (2 compressors, 2 turbines) and while the low pressure section helps with efficiency and performance, the majority of the thrust still comes out of the core. I don't know enough about those metrics to compare, but I am curious to check that out. A high bypass turbofan (TF-34 and any heavy/civilian application) is the inverse function of the former. ~80% of your thrust equation is directly proportional to the volume of air coming off the Fan (low pressure compressor). A near linear relationship with fan speed and thrust makes sense. 2. Faster fan/compressor speed is more efficient due to heat. The blades of the rotors and stators expand to ideally capture all the airflow throughout with zero leakage and increasing discharge pressure. On the turbine side the seals around the rotors do the same thing to capture the outflow and drive the fan to faster speeds with less required fuel flow. Over time the seals wear out and we have to up the fuel flow to achieve the same fan speeds as before. We don't care about fuel flow (as long as it is in limits) or core speed (as long as it is in limits) or ITT (as long as it is in limits), we just focus on fan speed for thrust. The previous three things are a problem when fan speed isn't reached. 3. No the A-10 does not fly around at max the whole time. The DCS engine is 4% too low at max on the average. How that scales at the other settings I do not know for sure.

The T5. At full throttle the fuel control is like an analog Scotty, just giving her all shes got until the T5 limits the fuel flow output. T5 ops checks are pucker time. Lots go into making sure that box works perfectly every time. As far as I am aware they have plenty of data on a normal worn in engine and when you compare things like the calculated fan speed curve at OAT vs DCS it has the same slope so their tables are probably really solid for a worn in engine. Two engines on the same aircraft will have slightly different core and pick an ITT within the limit range and they will have it. But what will be nearly the same between the two and the whole fleet within 1% is the Fan because we set them that way. What appears to me is that they have a really good RPM data table for a typical mid life TF-34. It is just choked down way too low and not achieving fan speed limits. That is a fair statement. Without a digital readout of pounds of thrust it is hard to say. No one has come out and said it is producing x pounds of thrust though and discussion always revolves around ITT and RPMs as if we were discussing the real thing.

Especially frustrating since the real world fix is the equivalent of hitting backspace 3 times and typing in a new limit. Not a million dollar coding problem.

yes. That is my experience block when comparing apples to apples. We dont typically look at flight data unless a fault code is taken and 9 times out of 10 it is related to things other than core. There are reasonable inferences to be made looking at calculated fan speed charts for instance. colder, denser, more speed vise versa and mixed in between. Much of the test limits are designed to make sure stuff works at altitude.

The Fan (single stage low pressure compressor) is physically coupled via fan drive shaft to the Low Pressure Turbine. Sandwiched in between is the High Pressure Compressor (Core on the guage) physically coupled to the High Pressure Turbine through the Combustion Chamber. The link between low and high pressure systems is core exhaust. Interstage Turbine Temperature (ITT) is read between the High Pressure Turbine and Low Pressure Turbine. This is partly why you dont have modern EGT readings instead. This is station (flange) 5 in answer to T5 Amp is actually mounted on the forward portion of the engine but reads station 5 ITT data and limits it by (ding ding) fuel rate. There are zero limiters besides the T5. Less dumpy fuel, less High Pressure exhausties, slower fan. If ED put one on besides that, that is in correct. Generally though I think they are faithful to original piece as much as can be. Except........ Compare to reality that is horrible. We never got below 84 in the 100 degree Nellis weather, 85-86 are normal days. Considering we can't be less than 1-1.5% off target and DCS is on the average 4% less it is like smashing the defcon 1 button for an engine troop. But since I can't share the decades of engine data to change peoples minds it just is what it is. ITT by itself isn't bad, we see new engines trim to that. Core RPM by itself isn't way off, we see both lower and higher but usually scales with the T5 trim. Low T5 limit and lower core jives. But when you put all three together: low fan, lowish core, low ITT, it spells a T5 limit set too low circling back to what I said earlier. Of I were king for a day I would change the T5 limit coding (however that is done) to something more average like mid 820s-30s and I bet the DCS TF34 will hum pretty close to realsies. Sorry for hijacking a bit Nealius, but also I wouldn't be terrible concerned with core numbers by itself and thinking about the cold situation more it makes sense that you would run out of throttle range before you hit the T5 limit. Engines love cold dense air like me and a fat kid like milkshakes. I am still curious it figure out what the old timers say.