Will I reach the edge of space in a commercial aircraft if I just continue to climb,can you leave 'orbit'?

I mean simply going right through the rated 'ceiling' of an aircraft, and just going up up up. I'm sure I went extreamly high (8,000 ft? - can't recall) in a C152 once, but where does it all end? Commercial aircraft with loads of speed & power go much higher, so does the oxygen run out (failing the engines) before one can break the earth's gravity? Or do the engines stall and you return to earth (possibly at a rate of descent close to / greater than the Vne of the airframe)?

Crazy question, but my idle mind throws many of them at me each and everyday.

Yes, in a commercial aircraft, the aircraft's engines will run out of oxygen before you get into space. And there's no way that any commercial aircraft can carry enough velocity to enter orbit.

Some military aircraft can fly MUCH higher than commercial aircraft and get awfully close to the edge of space. The best example is the SR-71 Blackbird, which could reach an altitude of 85,000 feet. That's close to 17 miles up and the air is very thin there. The last SR-71 was retired in 1990 and one is displayed at the National Air and Space Museum at Dulles Airport, near Washington. A link for information on the SR-71 is posted below.

One other note on gravity: You can't really "break" Earth's gravity , as it is felt throughout space for millions of miles. After all, the moon is held in orbit by Earth's gravity (as well as some of its own). Therefore, getting outside the atmosphere means that you will fall back into it, and that is a very tricky proposition in any aircraft. Even the Space Shuttle can have serious problems re-entering the atmosphere.

I don't think a commercial aircraft's engines can handle the lack of oxygen so the power trails off and hence cannot break through the ceiling. Therefore engines stall and a return to earth at Vmax results....

You can't with a conventional aircraft for a couple of reasons.

Firstly, your jet engines would stall as there is not enough air to propel the aircraft along.

Secondly, the higher you go the thiner the atmosphere gets and so the less air is passing over the wings providing lift, so eventually, you would hit a limit where no more lift can be generated.

Most vehicles to get you into spact are missiles of one sort or another. They only have wings to control them at lower altitudes.
They are propelled by rockets which will work at any altitude.

So unless your aircraft is fitted with a rocket or two, then I think you'll have to settle for gravity for a while longer.

At the heights at which you are hinting, the air is too thin for a normal aircraft wing to get any lift - that's why an aeroplane has something called its 'service ceiling' (where the rate of climb is so low as to be insignificant).
I've been to 50,000+ feet in an English Electric Canberra, back in the late 50's, which, as far as I was concerned at the time, seemed near the edge of space (dark blue sky, earth curvature seen). Concorde went higher, and many modern military aicraft go very high, too, and the crew has to wear 'space suits'. But you won't and can't do it your Cessna 152 - maybe 12,000 if you are patient!!

Good points by everyone on this question. The real answer you need is speed. If you can some how generate escape velocity at sea level you can just fly off the surface of the earth. You need to go 25,000 MPH. It is too hard to do this where the air is think so you need to climb where it is thinner. To do this you need a source of thrust that runs good in thick-air and thin air. Most all rockets have their oxidizer mixed with the fuel (either during the burn or within a monolithic fuel like solid rocket boosters). This way they control the exact amount of fuel-air mixture during all phases of the flight.

Normal plane engines don't get past about 40,000 feet. The SR-71 has been way past 80,000 (classified) but uses ram-jet+turbine engines. The a-5 vigilante has the record for air-gulping turbines at a world altitude record of 91450.8 feet.

Commercial airliners do not come even close to escaping the atmosphere, their performance runs out way before oxygen does.

The service ceiling for any aircraft is the highest it can climb to while maintaining a slight climb gradient, even then, it is at the very limit of it's performance envelope.

However, an airplane DID make it to space, it was the X-15 rocket plane, but it was a sub-orbital shot.

To actually break the pull of gravity you must achieve Escape Velocity, on Earth this is 11.2 kilometers per second or 40,320 Kilometers per hour or about 25,200 miles per hour. The fastest a jetliner can go is about 580 miles per hour.

If you wanted to leave the solar system (starting from Earth), you would need an Escape Velocity of 42.1 Km/sec or about 94,725 Miles per Hour.

OK Here is what you need, even your Cessna 152 is capable of reaching space. There are two ways well three actually.

First: This is the toughest unless you have it.......Money and lots of it..millions should suffice strap it to the inside of the space shuttle.

2nd: carry on board an oxygen supply big enough to support the combustion of a supercharged engines thirst, for O2.

3rd: Sit in your airplane smoke a really huge reefer, laced with some kind of hallucinogenic......you will be spaced in no time!!!