Introduction
Anytime someone thinks WW2, they always remember the Mustang. Some of the best pilots flew it, the 1960's Ford car was originally named after it, and it earned a healthy respect in the air. One word comes to mind when flying it though: Janus. The two-faced guardian of doorways really does apply here. For the Mustang does have two faces: one of beauty, and one of fright. Though which you see often depends on what you're doing in it. The D model is one everyone knows as the "airplane that won the air war over Europe". While many would contest this (me included) it is a fact that the P-51D was key to long range bomber escort. A lot of what's below is from the P-51B article, as the two aircraft handle pretty closely. Though there are a few huge differences you need to know about.

Takeoff Characteristics
You'll want to use flaps, probably two notches or more depending on how it's loaded. With a full-up bomb load and full fuel, you guessed it; use full flaps. The sole oddity of the P-51 is that it needs a bit longer run to get in the air than most because of the high-speed wing. Torque is high enough to cause zig-zagging if you don't watch it. Add in a good boot of right rudder and she'll keep straight. Around 100mph the tail comes up and she'll swing a little. Go easy on the rudder and you'll do fine. At 125mph she can be pulled off the dirt and will readily fly, provided you didn't load it down. Even by taking only rockets you'll need an extra 30mph to get in the air. A good general rule of thumb is to wait for the tail to come up, wait five more seconds, and then lift off. It should be humming along at 150mph or more, which means you won't have to fight it to get in the air. Pull the gear up right after getting airborne, but leave the flaps down until airspeed is at least 200mph. The controls stay rather soft after takeoff no matter what you do, so wait till she's fast before pulling any stunts.

Slow Speed handling
There's quite a bit of adverse yaw, and it will stall readily so don't reef on it. Aileron and elevator input are both slightly slow initially, while the rudder is only soft close to neutral. Accelerating is as easy as leveling it off and waiting a minute. As usual, speed can be picked up quickly by lowering the nose a bit. Adverse yaw is a bit of a problem when quick reversals are needed, but goes away with added speed. It won't snap-to your commands at low speeds, so wait until you've above 250mph before getting into a fight. Stay completely away from vertical maneuvers until you've got more speed, and avoid hard turns. One thing you'll notice quickly is that it's mushy in pitch response until you really accelerate.

With the D model a new problem comes up; a load of adverse yaw. Look closely at any -51D and you'll notice two big differences between it and it's older brother. One: a bubble canopy which provides excellent visibility. Two: it's a lot "thinner" than it's brother. This thinning out is a lack of rear deck area behind the cockpit. Since the bubble canopy installation required them to cut down the side area, the fuselage sides are a lot shorter. Also, there's a gas tank right behind the cockpit. What we have here is a headache waiting to happen. One fairly new -51D pilot once said: "On a fly-by I tried following the rest of my squadron into a wing-over, and she nearly swapped ends on me! Later I asked my CO about it, and he said 'nuts, I forgot to tell you about that fuselage tank!". When that tank is full the center of gravity (CG) is very much behind the wing. Not where you want it to be!

At low speeds this makes for an airplane that flies almost as if you were balancing the thing on a bowling ball. In pitch it becomes rather unstable, and it'll yaw around readily without much input from you. Throw a pair of drop tanks on it and you can cruise around for almost days at a time. Unfortunately it also turns the -51D into a wallowing pig.

Moderate Speed handling
Running along at 300+mph it's a dream to fly. Fast aileron and elevator response make it a very sharp-handling aircraft. While the rudder stays crisp from 220mph right through 400mph. Vertical maneuvers, hard turns, and violent snap-rolls are all possible with merely a thought. At low to mid altitudes is where it really shines, displaying rather easy handling in dogfights. Thanks to the large gunsight you can get on target fast; which the control harmony only adds to. Accelerated stalls can happen, but require a lot of effort on your part to pull off. The trick to driving a Pony is to keep fast; once you get too slow it'll change faces on you. Mushy pitch response is almost gone by 270mph, which nearly gives the impression of flying on rails.

Remember with the fuselage tank full handling is a lot sloppier. She'll slide around in a turn, wallow somewhat in pitch, and generally not like you until you burn that fuel off. Before you try it in combat practice with full tanks offline, where it's a bit safer. Get a feel for the difference between a full fuselage tank and an empty one. And don't forget the -51D pilot's mantra..."Burn the fuselage tank down to a quarter, then switch to drop tanks". Trust me, you'll get a lot better performance out of it by doing it this way. Don't let the automatics handle your fuel in this plane, do it manually!

High Speed handling
Ailerons stay somewhat crisp through 350mph, after which they start to get stiff. Elevator response is right-damn-now fast clear through 400mph, while the rudder is still a little soft around neutral. At medium or high altitude is where this Mustang should be; between 7 and 25,000 feet you can tangle with anyone and come out on top, especially if you don't fight stupidly. Conserve your speed through turns, use the vertical a lot, and you'll quickly find it's a killer. Above 400mph everything gets very stiff, especially the ailerons. Elevator feel, and the aircraft's response to it, both get heavy but not to an alarming point. Once you cross the 400mph mark, avoid steep dives at any cost so you won't pull the wings off it. At very high speeds, up near Vne, the elevator gets very stiff and makes pulling out rather tricky. Whether heavy or light on fuel it handles mostly the same. Though adverse yaw is still present clear up to around 370mph, thankfully it isn't much.

Stall & Spin
A power-off stall in a Mustang could be done on a trainee without any trouble; it stalls that docile. Power-on stalls approach a snap-roll in speed, but hardly require any special measures. Just remember that it has a high-speed wing, so you need more speed before you can recover from the stall. 220mph works just fine, and pull it out easy. Spins can get fairly vicious if you aren't watching it, and never forget it needs more speed on the pull-out. Use standard technique to get out of a spin, and the aircraft recovers promptly. Accelerated stalls are almost a mirror of those found in the Fw-190A; the left wing dumps and it'll snap-roll on you. Thankfully there's enough warning; the wing will start to tip when you get close to the accelerated stall. Avoiding one with that kind of advance notice is really easy.

Nasty Habits & Quirks
Her accelerated stall is the only real worry. Quirks include a little mush in pitch at moderate speeds, the soft rudder near neutral, and a need for speed. Do not stall or turn-fight this aircraft, it wasn't built for it. To be successful you need to keep it fast, and unless you're landing keep it above 300mph. High altitudes don't pose much of a problem. Rudder input, as mentioned, is a little soft near the middle. Don't take that as "pound the pedals" though, just use a bit more rudder than normal and it'll do fine. As for the mushy elevator, it takes some getting used to. While nearly every aircraft has a razor-sharp elevator response near 250mph, pitch has a little mush to it. Only when you go past the 300 mark will that go away. Yet another problem that was introduced with the high-speed laminar-flow wing. If you add 30mph to the speed you do everything in any other aircraft, you'd be about dead on. Landings can be a touch hairy until you get used to the fast landing speed; 160mph with two ticks of flaps isn't a strange thing. Yes, I'm going to remind you about that fuselage tank again. It makes the aircraft do really strange things when full (100% fuel load taken) and there are ways to get around it. As noted above, burn off the fuselage tank first and then switch off to automatic fuel handling. If you don't do this, you'll end up with an aircraft with an aft-CG condition. That makes the tail rather heavy, which induces a LOT more accelerated stalls than you'd normally see. A slight pitch change with that tank empty isn't a bad thing, but when full? Yeow!

Personal Notes
A half-dozen guns give you a real chance of killing on the first burst. Get used to shooting from 350+ yards too, cause you can make kills that far out. Shooting at medium to low speeds in a fight will happen, and you need to be aware of a small hiccup. Because of both the mush in pitch below 270mph, and the adverse yaw, shooting ain't easy. As you can probably imagine; if shooting is a bit of a trick, fighting can get pretty hairy. Hence the reason you keep this Pony moving at a rather fast clip. High speed eliminates adverse yaw, the mush, and allows for a larger number of maneuvers to be pulled. Scissors, hammerhead stalls, and a whole variety of stunts can be performed at will. My personal favorite is a high yo-yo leading into a fast high-speed scissors. It really shows off both the roll rate and degree of control the pilot has. Diving to bounce an enemy plane, or to run away, is where the P-51D got the nickname "Runstang". It's so fast in a dive that hardly anyone can catch it. As hard as this might seem, do not get into a spin. I wouldn't call the Pony D a nasty spinner, it's just a fast one. And although other aircraft will pop out of a spin, this one won't. It'll "stick" in the spin for a second before finally coming under control. If you hesitate or start a pull-out at this point, it'll drop right back into the spin again. Laminar-flow wings make low speeds the regime of Dweebs, not pilots or aces. The slower you go the more unstable it gets, eventually it'll go ape if you aren't watching it. Hence the reason it was tagged by a few pilots as Janus. At high speed, or even moderate speeds, it's a dream to fly. But like the Yak-9U if you get it low and slow, she'll bite you square on the ass. Especially the D model. It's a little more slick than the B, and a lot less stable because of the bubble canopy. Stay above 320mph unless you're landing and odds are you'll have a blast.