This question originally appeared on Quora. 
Answer by Tim Morgan, Ruby on Rails Developer, Private Pilot
James Bond is flying a DC-3, a two-engine piston-driven aircraft that was a popular airliner in the 1940s. The villain is flying an Aermacchi SF.260TP, a turboprop version of the popular SF.260, which is a nimble aircraft used by many European countries to transition fighter pilots from piston aircraft to jet aircraft. SF.260s do not carry guns, but some SF.260TPs (such as this one) are weaponized and used as a cheap close air support (CAS) aircraft.
So the SF.260TP, being smaller and powered by a turboprop engine instead of a piston, is faster and much more maneuverable than the DC-3. This necessitates using what fighter pilots call "boom and zoom" tactics against the DC-3. The SF.260TP cannot remain at the DC-3s six o'clock, "in the saddle," for an extended period of time, without sacrificing a ton of precious energy. (You never want to be slow in a dogfight; energy is life.) So as you can see, the pilot performs fast passes and barrel rolls to preserve his energy while giving himself multiple opportunities to be in the saddle.
The SF.260TP fires on the DC-3 and ignites a fire in the left engine. Bond, being the well-trained pilot that he is, responds by cutting fuel to the left engine. He does this by retarding the mixture knob all the way back. Since the DC-3 has two engines, it has six engine knobs total:
The black knobs are the throttles, and control manifold pressure. The white knobs are the propeller controls, and control RPM. The red knobs are the mixture controls, and control the amount of fuel flowing into the engine. By retarding the left engine mixture all the way back, he shuts down the engine by starving it (and the fire) of fuel.
The SF.260TP continues its boom-and-zoom while the now-single-engine DC-3 bleeds off airspeed and altitude. Bond needs a plan. The next time the SF.260TP saddles up, Bond advances the left engine's mixture knob all the way forward.
This returns a full flow of fuel to the left engine, giving the fire plenty to burn. The left engine bellows with smoke, obscuring the adversary pilot's view. The adversary pilot cannot remain at the DC-3's deep six, in firing position, while maintaining visual contact. He is forced to drop "out of plane" to a non-firing position.
Meanwhile, Bond does another tricky thing: He slows his DC-3 way down. We see him reach for the DC-3's "Johnson bar" style flap lever, a giant lever in between the pilots' seats:
And we see the DC-3's flaps go down:
This is our clue that Bond is slowing the plane down. The flaps provide an extra margin of maneuverability at low speeds. The adversary pilot should at this point disengage and come around for a shot at a different angle, maybe a deflection shot from above, out of the path of the smoke, but instead he insists on letting his speed drop along with the DC-3's.
The DC-3 is a slower aircraft than the SF.260TP, and has a slower stall speed. We get a brief shot of the SF.260TP's airspeed indicator as the airplane slows down:
The SF.260TP's stall speed is 80 knots, and the needle is winding down. Here's a shot of the airspeed indicator from a DC-3:
The red line on this dial is down at 60 knots, giving the DC-3 the ability to fly 20 knots slower than the SF.260TP.
Bond's next trick is to put the DC-3 into a hard left turn. Here's the thing about the stall speed indications on those airspeed dials: They apply only to straight and level flight. Stall speeds increase as bank angle increases. An airplane in a 60° bank has increased its stall speed by 40%.
The left turn was also a particularly adroit decision: Remember that only the right engine is generating thrust, meaning the airplane can turn more tightly to the left than it can to the right, challenging the SF.260TP's ability to keep up in the turn.
So the DC-3 and the SF.260TP are low and slow in a hard left turn. The SF.260TP's stall warning light comes on, warning the pilot that he cannot sustain this turn much longer:
The adversary pilot has no choice but to abandon the turn and accelerate. Unbeknownst to him though, Bond has flown his DC-3 to a narrow canyon pass, which the adversary pilot could not see behind the thick wall of smoke. When he pulls up out of the smoke and prepares to overtake the DC-3, he is greeted by the sight of the canyon wall, and flies in for a much much closer look.
Some notes for my fellow pedants out there: A few knowledgeable Quorans have rightly been pointing out that the scene is not entirely factually accurate, as is often the case in movies. The above deconstruction is based on what the movie presents to you as the truth of the matter, and not would have happened in real life. As others have pointed out, trying to recreate this dogfight in real life would result in a few nasty surprises:
- The DC-3, when flying with one engine inoperative, would have experienced an asymmetric force caused by the non-centered placement of the operating engine, causing the DC-3 to tend to yaw to the left. This would require Bond to apply right rudder to compensate. The slower the DC-3 flew, the greater the force would be, and the more "right boot" Bond would have had to put in to keep the airplane flying straight. Flying slow enough, there would not be enough rudder authority to keep the airplane centered. This is called the minimum controllable airspeed, and is 76 knots in the DC-3. So, in summary: If you were to find your nearest DC-3, shut down the left engine, and slow it down to 60 knots or so, you would discover you can't keep it flying straight. Attempt to make a turn, or even just keep it under control, and you may very well discover the airplane has a tendency to "want" to flip over, at which point you will regret having followed these instructions you found on some random Quora answer.
- Now, that being said, nowhere in the movie do they establish that the DC-3 was flying below Vmc (min. controllable airspeed). In the shots of the SF.260TP's airspeed indicator you can see it drop to 80 knots, but that's still above the DC-3's Vmc. The turn would have been very difficult for Bond, but maybe not impossible. There is a different issue that does render the whole thing moot, however, and that's...
- The stall speed for the SF.260TP depicted may not be accurate. In reality, the stall speed is probably much more comparable to the DC-3, around 60 knots. The SF.260TP is not certificated in the United States, so official data on its important airspeeds is not easy to find. Chances are, recreating this dogfight in real life, you'd find that the SF.260TP could hold with the DC-3 in the turn just fine, and in fact could hold the turn longer because it's a more powerful airplane and wouldn't bleed off speed in the turn like a single-engine DC-3 would. But, in the end, the dogfight wasn't decided by who could hang on in the turn longer; it was decided by Bond forcing the adversary pilot to fly into a canyon wall, and no amount of performance advantage could save the SF.260TP at that point.
- I realize I start by saying "never get slow in a dogfight" and then explain how Bond does exactly that. It only works because the adversary pilot insists on slowing down with Bond. Were he a smarter pilot he would preserve his energy (his "E" as fighter pilots call it). Whomever has more "E" can set the terms of a dogfight: He can choose to attack and escape on his own terms, with the other aircraft being unable to give chase. He can disengage when the terms are unfavorable and re-engage at his leisure.