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  1. Same thing. Compressibility is the cone of pressure that surrounds an aircraft. The higher the speed the tighter the cone. Eventually the cone is almost slick with the airframe, and the control surfaces become useless. This is why a major breakthrough in supersonic aircraft was the introduction of the horizontal stabilizer instead of the elevator. The stabilizer remains functional at much higher speeds. So as you can imagine, as the p47 approached 600 or so miles per hour in a dive, the resulting compressibility renders the elevators useless. Meaning the pilot can no longer recover from the dive. At least that's how Chuck Yeager explained it. Sent from my SM-G973U using Tapatalk
  2. Fun fact, Alexander Kartveli, the designer of the p47, was from Tbilisi Georgia. Way to come full circle ED. Sent from my SM-G973U using Tapatalk
  3. Most of the time the rear fuselage tank wasn't filled up. There's a special note in the manual where it says don't fill it up except under special order by the squadron commander. The reason being that the P51 already has incredible legs as is, and the extra 40 gallons and resulting instability isn't worth it unless you need every spare gallon. If you do fill up the fuselage tank, select that first, then once it's empty switch to another tank. If you're running drop tanks, use either the fuselage tank (if it's full) or one of the wing tanks for takeoff, then at 2000 feet switch to your drop tank. As far as knowing when your drop tanks are empty, the only real way is to look up the fuel burn per hour for your cruising speed, then calculate in minutes how long the fuel tank will last before being depleted. Alternatively, the p51 retains enough fuel pressure to keep the engine running for a few seconds(albeit roughly) when the tank runs out, so if your quick, once it sputters you can switch it over real quick and restore normal operation. It helps to have a general idea of when to start thinking about switching it over though. That's where fuel burn per hour comes in. As for booster pump, don't quote me but I'm pretty sure you leave it on when running drop tanks, then turn it off after switching to your wing tanks. Sent from my SM-G973U using Tapatalk
  4. There are two. Three if you count the pressure pump. One engine driven fuel pump, and an electric fuel booster pump. Sent from my SM-G973U using Tapatalk
  5. Okay I found it. The mixture control was retrofitted to be the carberator idle cutoff switch in later model spits. Essentially the fuel cock controls fuel from the tank to the fuel lines, and the cutoff switch controls fuel from the lines to the carberator. The problem with having the valve open when the booster pump is active, has to do with the design of the carberator. Fuel and air are mixed inside the supercharger. This was a design choice to eliminate the need for a carberator heater, but it also meant that if the fuel cutoff was forward when the pump was operating, excess fuel would flood into the supercharger, creating a serious fire risk. EDIT: To clear up further confusion, the fuel booster pump is an electric pump designed to deliver fuel to the engine during the startup procedure before the engine driven fuel pump takes over. This is completely different than the fuel pressure pump, which pressurizes the fuel system and should be used at altitudes above 20,000 ft. Essentially the short of it is that there are two ways to start the spit. Booster pump, or manual using the wobble pump and cutoff switch. You can't do both at the same time. In any case, if you want to use the booster pump: pull the switch aft to idle cutoff, run the pump for 30 seconds then switch it off, hit the booster coil and starter buttons, and once she sputters move the cutoff switch forward to run. Remember to release the starter once the engine catches, but hold the booster coil until the engine is running smoothly. Hopefully that clears up some stuff.
  6. From what I've read, the fuel cutoff was actually the mixture control system in earlier models. Setting it aft was essentially Auto lean/idle cutoff, and setting it forward was auto rich. Later spits ditched the system for a completely automated mixture control system along with a pressure carberator which kept fuel flow during high g and negative g maneuvers. I think the confusion is as to why the switch was kept in place in the mk IX, and what purpose it served. In DCS it essentially serves as a second fuel flow cock,and I can't find anything talking about what it did in the real mk IX. Sent from my SM-G973U using Tapatalk
  7. The stop valve must be aft as long as the fuel pump is active. Basically the fuel cutoff being forward floods the supercharger with gas, possibly causing a fire. Not sure if it's modelled that way though. I pulled that from the actual pilots notes. Sent from my SM-G973U using Tapatalk
  8. I was so close to buying but I just can't justify it right now. Good to know they're as good as they claim. Sent from my SM-G973U using Tapatalk
  9. So land slightly less than 3 point attitude? Sent from my SM-G973U using Tapatalk
  10. Thanks fellas! Sent from my SM-G973U using Tapatalk
  11. Love your channel man Sent from my SM-G973U using Tapatalk
  12. We do tend to make a mess of things. For better or for worse. Lol Sent from my SM-G973U using Tapatalk
  13. Seat adjustment is on the starboard side, next to the seat and behind the emergency undercarriage lever. It looks like a handle jutting out of the seat towards the instrument panel at 45°. Other than that welcome from an American learning the Spit for the first time. I'm not sure where, but I found an abbreviated startup which might come in handy for you so I figured I'd share. Startup(from left to right) Set takeoff trim Pitot heat on Fuel pump on Throttle cracked Carb intake full forward Magnetos on Fuel cock on Booster and starter switches uncovered Primer unscrewed Prime as needed Brakes full on Depress starter and booster coil Mixture once the engine catches Cover ignition switches and screw primer And boom you're flying in less than a minute. Things had to be simple when you were scrambling 4-5 times per day during the Battle of Britain. Sent from my SM-G973U using Tapatalk
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