199 views

### What does account for a high coffin corner of a plane?

The Coffin corner is the altitude at which a plane's stall speed is close to Mach 1, the speed of sound (but still below, at the critical Mach number). What accounts for a coffin corner at higher ...
8k views

### What prevents a small plane like a Cessna or Piper from flying as high as a jet?

Obviously taking oxygen in consideration. What prevents a small plane from being able to fly at a much higher altitude? I know some business jets can fly up to 40,000 ft. Does it have to do with the ...
2k views

### Can the plane Celera 500L be eight times more fuel efficient than a jet of similar size and capacity?

Celera 500L (see Otto Aviation site for more details) is a plane with a single propeller powered by a piston diesel engine. The constructor claims it is 8 times more fuel efficient than a jet of about ...
272 views

### What happens in an F-16 once the aircraft exeeds its service ceiling?

What exactly is the sequence of events that would unfold as an F-16 attempts to exceed its service ceiling? The scenario is simply full afterburner and attempting to simply climb higher and higher (at ...
420 views

### What happens if an aircraft goes above maximum altitude? [duplicate]

We all know what happens when a plane goes overspeed... but what happens when a plane goes above their max. altitude? And why are planes certified maximum altitudes anyway? Is it because there won't ...
171 views

### Can planes go to space? [duplicate]

What are the reasons why planes can't go into space? https://thehumble.co.uk/aircraft-with-forward-swept-wings/
220 views

### Why is the F-16's service ceiling 50,000ft? [duplicate]

What defines the service ceiling for aircraft, in particular the F-16? I suppose, as with almost everything, this depends on the aircraft, the engine type, etc. While I'm fine with a comprehensive ...
751 views

### Calculating the maximum altitude of a drone [duplicate]

Is there an equation to find the maximum altitude that a drone or quadcopter can fly to ?
841 views

### Can a commercial aircraft theoretically reach 60,000ft? [duplicate]

As per this question: Altitudes above 60,000 feet are class E airspace. That means that, if you are lucky enough to have an aircraft that flies that high, once you get there you could theoretically ...
145 views

### What is the background of the maximum altitude formula?

This question What determines the maximum altitude a plane can reach? has a formula at Peter Kämpf's answer : $$\rho_{min} = \frac{2\cdot m\cdot g}{(Mach^2 \cdot c_L)_{max}\cdot a^2\cdot S}$$ Does ...
808 views

### What should be the minimum time spent in cruise (for e.g. a B737)?

Having a short sector to fly, it would not be convenient to climb all the way up to the best cruise altitude, since the time in climb would burn more fuel than that necessary for a flight at lower ...
471 views

### May planes be flown above the maximum certified altitude?

Let's take the 737NG as an example. The 737NG has a maximum certified altitude (MCA) of FL410. However, looking at the MCP, the maximum altitude that can be set is 50,000ft. And the pressurization ...
6k views

### What are the limiting factors for high altitude planes (e.g: U2 or SR71) preventing them from going higher?

I'm curious as to why planes like the U2 Dragon Lady and the SR71 Blackbird couldn't fly higher. What physical constraint set their operational ceiling? Pilots wore spacesuits, so that wasn't the ...