Just my opinion before reading the answers and FAR 1.1. I would have said a missile is not an aircraft. I have to change my opinion. Reading the FAA definitions of aircraft, rcoket and unmaneed aircraft, I would say a missile could fit all three definitions.

According to the ICAO definition, not all missiles are aircraft: take ballistic missiles. A ballistic missile is like a space rocket and derives its support from engine thrust, air just gets in the way.

This only really tells half the story - now we need a sampling of definitions of "missile" to see where it overlaps with "aircraft". Is it necessary that a missile must "derive support from the atmosphere" and "fly"? A rocket propelled grenade, for example, uses fins for stabilization but not lift - a self-propelled rocket need not derive any support at all from the atmosphere. I'd say the Venn diagram of aircraft and missiles has incomplete overlap - there are non-aircraft missiles and non-missile aircraft.

Any machine that can derive support in the atmosphere from the reactions of the air But missiles don't do that. They get no support whatsoever from the air.

{ Setting aside the types of missiles that have aerodynamic wings, and hence aren't missiles but are sometimes referred to as missiles or missile variants. }

@Chris No, missiles can support themselves while flying horizontally the same way that space rockets gain a horizontal component and otherwise steer: by pointing the exhaust. This is very common, even on small missiles.

"reactions of the air" doesn't necessarily mean "lift" like wings, think about hot air balloons, they don't have wings but they are still aircraft.

@user71659 Some missiles have thrust vectoring, yes. They also have lift. Look at a typical missile that has exhaust on one end, far from the CG. If you redirect part of that downward far enough, you could in principal provide enough vertical thrust to hold the missile up. But that would also give a very very very large nose-down pitching moment. It's also very very inefficient- pitching the missile slightly to produce lift is much much more efficient. Thrust vectoring is great for changing attitude- it's not a replacement for aerodynamic forces!

@Chris Look at a typical missile. There's no wings. Where is this magic lift coming from? Missiles work like space rockets: they take a steep upwards initial trajectory to gain the height they need, then go forward. You're wrongly imagining that non-cruise missiles fly flat at some point: they don't. I think what you don't understand is that small missiles cannot fly for a more than a minute. A Sidewinder has 40 seconds max, 10-20 seconds is typical.

@Chris - that's wrong. Missiles are simply rockets.

@ocirocir. if you define the sentence that way, then, sure, literally every single thing that has ever been in the air or near the air is an aircraft. "reactions" has a pretty clear sense in physics/engineering though.

@ocirocir MRBMs and ICBMs are clear counterexamples to your claim that "all missiles are aircraft". The majority of their flight is outside the atmosphere.

Why doesn't someone simply telephone the ICAO and/or EASA and ask them for clarification of whether they mean aerodynamic lift here they say that - ? Youse guys are all pilots, you could easily phone.

@user71659 The lift is coming from the fuselage. It's not an efficient airfoil, but it doesn't have to be with the speeds missiles travel at! "A Sidewinder has 40 seconds max." What's your point? 40 seconds of downward acceleration would make it lose about 26000 feet if it wasn't supported by vertical lift. Have you read at all about how missiles work? For example, here's a paper describing how missile flight control systems work. You'll notice terms like "angle of attack" and "aerodynamic lift!"

@Fattie The paper I linked in the last comment might be interesting to you as well.

@Chris Wrong: 20 seconds of free-fall is 6,000 feet. A Sidewinder is about 190 lbs with 4000 lbs thrust. In order to get some decent lift, you need an AOA of around 6-8 degrees (page 47). Sin(6 degrees)*4000 lbs = 400 lbs, so your thrust is not only supporting you, but accelerating. Lift is enough to care about for pointing, which your article is about, but it isn't how a missile supports itself. It's by pointing the rocket thrust.

@user71659 20 seconds of free fall is 6430 feet, 40 seconds (as I said to begin with) is 25740. What do you mean by "decent" lift? You only need 190 pounds of lift, by your own logic! (In reality, missiles can develop a lot more lift than this- they pull high-g maneuvers). Many missiles would initiate a climb by directing their thrust upward. This seems counterintuitive, but it creates a large nose-up pitching moment, and the resulting large angle of attack gives a lift equal to many times the weight.

@user71659 Quote from the paper I linked: "This feature is common to tailcontrolled missiles. The tail must develop a negative force at the aft end of the missile in order to pitch the nose up and develop a positive AOA. The initial negative kick by the tail moves the center of gravity in the negative direction before the AOA increases and develops positive lift to accelerate the missile in the desired direction." Thrust vectoring in tail-controlled missiles is used for attitude control- aerodynamic forces dominate the accelerations in directions perpendicular to the longitudinal axis.

All of this discussion regarding the lift of the wings of the missiles is completely irrelevant. Again, hot air baloons ARE aircraft and they don't have any wings. This discussion would have sense if the question was "are missiles airplanes?"

@ocirocir If missiles worked off of buoyancy we'd be comparing them to balloons instead. Missiles have a fair amount in common aerodynamically with airplanes- thus the comparison.

@Fattie Not all missiles are rockets. Some are jets. Some of the modern jet missiles are even turbofans.