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Way back when I wrote an introduction to UTM/MGRS. That should get you going. If not, ask questions in that thread and I'll do my best to answer them. I have it subscribed, and even if me leaving the army since then means I get less practice I think traces of it are still lodged in this old head of mine. :) It should probably be pointed out that while MGRS is based on UTM, they are not at all the same. The bug with JTAC dropping leading zeroes was fixed a long time ago, first with a simple LUA patch and then from ED IIRC. Cheers, /Fred

Fair call. Tracks are indeed invaluable!

It is not: Inertia Related to the CoG Unbelievable You have static friction and dynamic (rolling) friction. The static friction that you have to overcome to start rolling is significantly higher than the dynamic friction you have to overcome to keep rolling. It can take a good burst of power to start an aircraft rolling, but after that many aircraft roll and even accelerate on idle power, especially when light. In some aircraft, taxiing with an engine or two not started is an option sometimes used to save brake wear when light. With all engines on idle, you'll have to ride the brakes to keep the taxi speed down. This is something you want to avoid to save brake wear, especially if you have carbon brakes which wear by number of applications rather than by how hard they are used. The thrust line of the engines is above the wheels, which is why you get a nose down moment which compresses the nose gear oleo (and obviously, though to a lesser degree, extends the main gear oleos). Cheers, /Fred

Nah, in the F-15 you get out easy. Just fly that AoA indexer and be happy. :)

Assign a button to electrical cage.

Glide ratio depends only on L/D ratio. Mass is not a factor (unless you dive deep into the marginal effects), nor does it depend significantly on temperature. Wind will of course affect the achieved distance over the ground, so if that's how you arrive at a glide ratio it does need to be compensated for. Jets are surprisingly slippery. Not 33:1 slippery, mind you, but they often glide better than you would think (with quite a few noteworthy exceptions :) ). Here, I'm with the rest thinking residual thrust from the idling engine. Cheers, /Fred

While that does not seem right, bombs do tend to decelerate somewhat as they fall into increasingly dense layers of the atmosphere. Wasn't the F10 speed indication the horizontal component of TAS, or some such peculiarity, at one time? I seem to recall that from the "P-51D speed dive thread". Doesn't appear to be the case anymore anyway. :) Cheers, /Fred

Ah, missed that bit. No, you don't. The F-15C -1 FM says to use normal on-speed AoA, but that AoA variations are more critical with a crosswind. In other aircraft, you may add to the approach speed for headwinds and gusts, but not for crosswinds per se. For adding to the approach speed (Vref) due to wind, there's a Great Wind Additive Debate within aviation that has been going on for 40 years now, but the majority vote (which I consider fair advice) seems to be for adding half of the headwind and all of the gust factor to your approach speed, up to a sanity threshold. That's also the side the major manufacturers seem to be taking. If the wind is 12012G20KT and you are landing runway 12 (wind out of 120 degrees, 12 knots gusting to 20 knots, 120 degrees runway heading), the headwind is 12 knots and the gust factor is the difference betweeen the steady wind and the gusts, or 20-12=8 knots. You add 12/2+8 knots or 14 knots to your normal approach speed. Had the wind been out of 210 degrees - direct crosswind - you only add the gust factor or 8 knots. The headwind additive is to be prepared for the fact that the wind will drop off as you descend on short final, and the gust factor is so you won't end up slow if a gust catches you. The sanity factor advised for the big iron is 20 knots, so that's the maximum you ever add. The trick is then to let the additives trickle off as you are on short final (another hot debate issue, stabilized approach vs approach speed changes). If you leave them on the ASI, you're going to float and land very long indeed. But let it bleed off too soon, and you're setting yourself up to get in trouble as the headwind drops off on the final few hundred feet of the descent - especially if you're hit by an unfortunate gust of wind at the same time. What you can (and often should) do if the crosswind is approaching what you and your aircraft are comfortable with is to reduce the flap setting. This will mean a higher approach speed, but use the book number for that flap setting and the wind additive. The spam can community (Cessnas, Cherokees and the like) tend to go with half the gust factor as the additives become proportinally larger with the slower approach speeds. Then again, they tend to stay on the ground a lot sooner as the winds pick up. Bonus info: Not all crosswinds are the same. The saying goes: 'Learn to love left crosswind'. In the northern hemisphere, the wind tends to turn to the right in the gusts, so a left crosswind will have gusts which are more head-on, while right crosswind will become more crosswind in the gusts. I am fairly sure that's outside of what DCS models though. :) Cheers, /Fred

In the real world, the FM states to "Hold the crab through touchdown". Not uncommon among fighters. Delta wings and swept wings aren't ideally suited for slipping, and there's always the issue of clearance for underwing stores. The landing gears are built to take it. Expect to be adjusting your crab continuously as you approach. It's really a non-issue, and something you won't even pay much attention to after a while. Just look where you are going and keep the aircraft travelling down the extended centerline. I suspect you are focusing too much on where the nose is, and lose track of what you should be looking at - your track towards the runway.

You asked a question which is answered by physics/flight dynamics. You were given the tools to find the answer to your question, and you call it a fiasco? Do we have a language barrier issue here regarding the word 'fiasco'?

Bearing range altitude aspect - a call for situational awareness.

Level turn, I applied SI units. Turn rate ω=(deg/s)/180*π rad/s (1) True air speed (in m/s) V=ω*r m/s => r=V/ω m(2) Horizontal (centripetal) acceleration a=V^2/r m/s^2 Insert (2) a=V^2/r=V^2*ω/V=Vω m/s^2 Insert (1) a=V*(deg/s)/180*π m/s^2 g_centripetal=V*(deg/s)/180*π/g=V*(deg/s)/180*π/9.82 G load nz=sqrt(g_centripetal^2+1^2)=sqrt(a^2+g) = sqrt((V*(deg/s)/180*π/9.82)^2+1) G load nz= square root((V*(deg/s)/180*3.14/9.82)^2+1) For zero turn rate nz=sqrt(0^2+1)=1 Assume 90 m/s, around 170 KTAS and 18 deg/s. nz=sqrt((90*18/180*3.14/9.82)^2+1)=3 g The bank angle can be calculated from the centripetal acceleration from ba=atan(a/g)=atan(g_centripetal/1) (Now play a good game of hunt the error - it's getting to 2200 here :) ) (And that is essentially the doghouse plot guidelines expressed algebraically)

No need for charts. Just calculate the radius at the required (true) airspeed and then the centripetal acceleration. Finally, good old Pythagoras to find nz (i e the G loading). You didn't post an airspeed, which is a required parameter.

You can, and are supposed to, trim the RPM governor. Yes, it will maintain RPM automagically, but the RPM it shoots for can be nudged up and down. It's in the checklist to make sure you're getting the full RPM. Lower RPM means less power at a given torque setting. Not really to do with temp control at all. And apart from making sure you have all the nominal power available before overtorqueing, it doesn't help with landings.

Going to make a quick educated guess here, but if the pitch-up is a correct representation of the aircraft I'd guess at two main factors: The elevator in the downwash. Yes, the elevator is out of the main downwash, but there's still downwash. It's just not as intense as if the stab was in the main flow off the wing. Wing planform. The flaps increase the lift over the inboard section of the wing, which is also the foremost section. The lift increases forward of the center of pressure, moving it forward and creating a pitch-up moment. Could have done with a cup of coffee, so don't shoot me if I bot it all gackwards. :)

"Use about half flaps for any appreciable crosswind." Gusty landings: "Use about half flaps." Basic airmanship: Use all control surfaces available to achieve the required and desired results.

Dan, old chum, is that you?! I had no idea! Don't worry, I have you covered. Here you go. The explanation with an expansion chamber at the end of a total-loss system isn't a simplification or a broad description. It is incorrect, will not work (at least not efficiently) and will confuse those trying to understand the subject. That's why it needed to be corrected. Help those trying to understand the subject by just saying "oooops, that's right, sorry about that" rather than this, which only adds confusion. A kettle is a different cup of tea. :D That was a good example, and is actually rather similar in principle to some systems which are in use. See below. http://www.enginehistory.org/Reno/Reno2011/Reno2011Pub.shtml If I was to guess as to the actual design of the MiG's radar cooling, I'd expect nozzles spraying alcohol mixture directly onto the cooling baffles of the radar. BTW, I single-handedly designed and flew both the space shuttle and the Spruce Goose, if claiming credentials on the internet is the way to establish credibility in technical matters. ;) Personally, I think I'll stick with going on the content of people's posts rather than their stated background.

And jcomm is tranferring his licenses. I'm very grateful for the Dora and the Bf109. I wasn't going to buy either, but now I'm busy learning the Dora and will put in the hours on the 109 when it is released. I'll try to pass the kindness forward within the community as best I can! For a start, consider this a public invitation to hit me with questions regarding aviation, aerodynamics, flight simulation and what have you. Aero engineer, glider/spam can pilot, special mission crew, nav specialist, sim engineer - shoot. I'll do my best to answer! Cheers, /Fred

I just wish to second this, now that I have the Dora (thanks to jcomm :thumbup:). As an aero engineer and RL taildragger pilot - nope, this (and the excuse given) does not make sense. Cheers, /Fred

But you do need the evaporation to occur where the radar is dumping its heat. To allow it to evaporate after passing through the system would be to waste it. In the simplest form, you just spray or drip the liquid on the cooling baffles of the system.

Air cooling won't cut it for a radar. You'd have to have a nose and a half full of baffles. Especially true for ram air cooling at altitude, where the air is significantly less dense. I assume the alcohol to be used for evaporative cooling - true of false?

Happy to oblige! As for your question, post 33.

One of the differences between an amateur and a professional is that the latter knows he or she will at times be wrong, and is prepared to admit it once thoroughly (and, usually, repeatedly) convinced of the fact. I promise I will do the same in the unlikely event that it ever happens. ;) Rep inbound! Edit: Er, no. It says I can't. You'll have to get by on the warm, fuzzy feeling of the intention!

You might also want to read this post by yours truly from the other day. It provides a bit more on when, how and why. In the real manual (AAF 51-127-5, Aug 15 1945), it states to "make the following checks", and then "put the fuel booster pump switch at ON". Never really considered the wording - that's just the way they're usually/often written I'd say. I see how it can be read your way as well though, so yes - I guess it is indeed slightly ambiguous. Another suggested read is the fuel system section of the above real manual as well. On pg. 21 you have a bit more on why and how. Cheers, /Fred

If you read carefully, it doesn't say to turn it ON, it says to CHECK that it is ON (or EMERGENCY, if available). That's a world of difference. ;) Nowhere does the manual tell you to turn it off in flight. It stays on. Cheers, /Fred