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And that is exactly the issue - I won't waste my spare time teaching those who will not.

Art, you need to look elsewhere to find the confusion. I don't think you need to search far, to be honest. Standing, moving, jumping up and down while doing the moves to Nellie the Elephant - the prop governor doesn't care but keeps doing its thing the same way regardless. Airspeed changes the pitch/torque/RPM relationship, but the governor only looks at the RPM and increases or decreases pitch accordingly, not even knowing the current pitch. When idling, there is not enough power to bring the RPM up to the governed range, even with the prop at the fine pitch stop. The governor senses the low RPM condition and attempts to move the propeller towards lower pitch. To reiterate, it has no knowledge of the current pitch setting - all it knows is that low RPM => pump oil towards lower pitch. If there was no fine pitch stop, it would keep driving the propeller to even finer pitch, through flat pitch and into the reverse range - as I described earlier. The prop only comes off the fine pitch stop as you add power. More power (torque) increases the RPM. When it exceeds the set RPM, the governor will start acting the other way, bringing the propeller towards more coarse pitch until it can suck up the increased torque at the set RPM. If you believe the prop will be at the fine pitch stop for take-off, you need to do some serious reading. Ask yourself: Is the governor regulating the propeller RPM when you are at take-off power? How does it regulate the RPM? If you are at 40", will it maintain the set RPM? If you increase to full take off power, will it still maintain that RPM? How will it do that, if the prop is still on the fine pitch stop? The aero loads and counterweights only come into play if the prop governor fails. If you intend for that quote to "save" people from reading which is by broad consensus one of the best articles to read if you want to understand CSPs, you must think it is in some way relevant to the discussion. That's what could do with some explaining. But never mind, I think I'm done here...

They are solutions to different problems, so one is not dropped in favour of another. However, I'm willing to bet that no one who owns a Mustang will start the Merlin if is cold enough to require oil dilution these days. It's not good for a rare engine. Besides, multi-grade oil would be a better way to deal with the issue...

If you are trying to make a point, I'm not seeing it. Please elaborate.

Ah, my apologies. Didn't catch your first post. You have a mechanically driven engine driven pump and then you have electrical boost pumps in each fuel tank. The engine driven pump is running whenever the engine is running and will suck enough fuel to run the engine, except for possibly at high power settings and/or high altitudes. That's in the FM. The electrical boost pumps in the tanks are controlled by the boost pump switch, which I assume is equivalent to the fuel pressure switch we're talking about here in the B model. When on, the pump in the tank runs when the tank is selected. Kermit turns the electrical pump on for priming and starting. In the D model Mustang, it's supposed to be on at all times during flight so the same should apply - no time to dig into the manuals right now. This is unlike certain other more common types, e g the Pa-28, where you use the pump for takeoff, landing and switching tanks but otherwise turn it off. He then turns it off for the taxi and runup, to make sure that the engine driven pump is OK. If you don't and you have a faulty engine driven pump, you will only find out when the boost pump goes out and your engine dies from fuel starvation. Finally it goes back on prior to takeoff. Cheers, /Fred

http://www.aoe.vt.edu/ http://books.google.se/books/about/P_51_Mustang_Pilot_s_Flight_Manual.html?id=SfwqCTY9I6MC&redir_esc=y http://www.avweb.com/news/pelican/Pelicans-Perch-16-Those-Marvelous-Props182082-1.html

The fine pitch stop decides the minimum pitch the prop can go to - or, to put it another way, it is the lowest pitch available. It's not something you can disable on the Mustang. Can't get that to make any sense. If there wasn't a mechanical stop there, the governor would keep driving the prop into the reverse range until the prop hub disassembled itself or the engine stalled - whichever comes first. It would still start governing RPM properly as power was applied, provided the above didn't happen. If not for the landing gear, the aircraft would actually flop onto its belly...

...while saying it's the fuel pump.

Gun sight switch on the right wall panel?

The failure modes aren't as straightforward as in the OP. Detonation, molten pistons, blown gaskets, gearbox failures... In a turboshaft, as on the Huey, you don't have all that but you do have a gearbox which will wear out or even break down.

When idling, the prop is on the fine pitch stop. When you bring the power up, the prop starts regulating the rpm by going to a coarser pitch.

The pre-oiling is a common mod on warbirds flying today, to save wear and tear on engines where replacement parts are getting scarce and expensive. You essentially have an extra oil pump making sure there's oil in the places where it counts before you start cranking. Otherwise, you have metal on metal. Starts are hard on engines. That's why you see gearheads flinching whenever some genius with a ballcap on sideways guns a cold engine up to the rev limiter when starting to show off how cool they are. Letting the tail up is a good idea in real life, but the way "our" Mustang works make it less suited for this than the real life counterpart. This is due to the fact that recent advancements in desktop consumer flight simulation technology can capture phenomena which hitherto were undiscovered, due to the limited fidelity of real aircraft and the unimaginative approaches taken in traditional aerodynamic research. It has been covered in length elsewhere in these fora, so I won't delve deeper into this here.

My apologies. I'll shut up now. :D :pilotfly:

It would seem our resident crosswind expert has withdrawn from the thread and does not wish to quantify the "higher wind speeds" used. 25 knots is the crosswind component the handbook states is manageable, with the suggestion to find another runway if there's more xwind. That'd probably be a demonstrated xwind component today, meaning that an experienced pilot who is on top of his game may well get away with a few knots more, but even skilled pilots could get in trouble below said speed on a bad day. That's 12.86 m/s, so already at 10 m/s you're getting close to what the aircraft can handle. Chances are the "higher wind speeds" were simply in excess of what the aircraft can handle and thus the loss of directional control experienced was as it should be. Edit: At 14 m/s (27 knots) it's quite manageable, but there's not much room for error. Sounds about right to me. Cheers, /Fred

In the real world, Batumi RWY13 it is 126°M (magnetic), 131°T (true). In DCS, for the aforementioned reason... it's whatever. According to the charts provided with DCS World 120°M and 126°T, so the variation is off by a degree as well. The WMM of 2010, which should be good up to 2015, is included with the installation but either the coords are off enough to affect the variation, they're not applying the predictive terms or the calcs are just plain off. The latter is unlikely, as the math and method are provided with the model. Cheers, /Fred

Bart, you may want to read the replies in the other thread where you posted the same text before taking the discussion further here...

How much higher? 12.86 m/s? 13? 15?

Differential braking and castering nose (or tail) wheel isn't all that uncommon. The lever activation is also old hat. I think there may just be a thread... or ten... on the subject already. ;) You have your rudder bar reversed. Press on the right side to go right. Rather common, I think it's the steering bar from a bike which throws people off.

A jet engine at idle provides a significant amount of residual thrust. That's why you want to employ reversers if you have them, even if you only idle the engines. You want to kill that residual thrust or it will hurt your runway performance. Depending on the design, how much of the exhaust you reverse with the chute (yes, it will reverse part of the exhaust), the intake vs exhaust velocity, the effective velocity of the turned flow vs the velocity of the peripheral flow which is not caught by the chute... you may, or may not, be able to achieve negative net thrust. Replace the buckets with a theoretical perfect chute with the same performance in the same location and it will still be possible. Now, if you gradually convert that theoretical chute to a real chute, replacing the metal with mesh and moving it backwards, the efficiency will gradually reduce. At one point, you will no longer be able to achieve negative net thrust. But where that point lies is far from obvious. If you did the same exercise on a MiG-21, would that point be before you had degraded the bucket-analogue chute to the actual chute or not?

The planform is pretty much irrelevant in this respect though. However, a big, flattish fuselage with loads of side area will contribute more to a boat turn than a slender oval or round fuselage. High speed will also reduce the resulting turn rate. I'd expect to see a significantly lower turn rate for an F-86 than for an A-10... but not no turn rate.

The rudder allows the pilot to control the beta (slip) angle of the aircraft. You can either remove unwanted slip, such as adverse yaw due to aileron use or yaw due to asymmetrical stores, or add slip e g to perform a side slip to steepen the angle of descent when coming in to land*. This, the rudder of the BST F-86 does splendidly. When you fly with a beta (slip) angle, the forces acting on the aircraft are no longer symmetrical. First off, you get a lateral component of the thrust of the engine. Secondly, you set the fuselage up at an angle to the free stream which tends to induce a further lateral force in the same direction. The combined lateral force sets up an acceleration towards the 'leeward' side. An acceleration results in a curved path, in this case with a wings level side slip a flat turn. This does not seem to happen in the F-86. In other words, the rudder is effective and performs its primary function quite allright. However, the effects of a side slip on thrust components and aerodynamic forces on the fuselage seem to be largely missing. It's not exactly disasterous, as you'll never see this when flying by the book, but I'd say something was left out of the FM. It'd be interesting to see if the increased drag due to a side slip is there. Easy enough to test. Cheers, /Fred *) Less common when flying swept wings, but that's for another thread.

People often underestimate the size of aircraft in general, and the size of hung stores in particular. What looks small slung under the wing of an aircraft at distance is rather large when you get up close - but for obvious reasons, most people rarely get to walk up to tactical jets. Googling for some numbers results in an F-4 370 gal drop tank at over six meters. That's a sizeable canoe right there - and those aren't all that big, as far as drop tanks go. Edit: Do you recognize a feature? Cheers, /Fred

Finding out if the problem is a general one, affecting all installations, or if it is a local issue is rather central. If the former - wait for a fix. If the latter - continue troubleshooting. Considering this, Isegrim's post was very helpful, and I certainly would not want to see similar posts discouraged in the future by negative feedback. Cheers, /Fred

'cos this thread... THIS thread has charts. And goes to eleven.

No, fog and clouds form no significant obstacle to the signal.