84 votes

Do pilots adjust the aircraft's flight path to allow for the curvature of the Earth?

Aircraft altitude is measured (inferred) by atmospheric pressure. The aircraft is usually flown at an altitude that maintains constant ambient pressure (by pilot or autopilot, as the case may be). ...
  • 99.3k
76 votes

Do pilots adjust the aircraft's flight path to allow for the curvature of the Earth?

There is no adjustment needed as the aircraft will naturally follow the curvature of the earth without any input from the pilot. This is because the aircraft flies through the atmosphere which also ...
  • 35.8k
75 votes
Accepted

What are some of the differences between piston engines used in aircraft and automobiles?

The engine in a typical light airplane (say a Cessna 172 or a Piper Cherokee) has a lot in common with the engine in a classic 1960s VW Beetle (Type 1): Both engines are horizontally opposed four-...
  • 67.9k
65 votes
Accepted

Would a slower speed and lower altitude reduce fatal incidents?

I'd like to answer this question by debunking the premise of the question: that most plane crashes happen when planes fall out of the sky, and that it's like rock climbing where the higher you are, ...
  • 6,503
61 votes

Would a slower speed and lower altitude reduce fatal incidents?

It would likely create a more deadly situation. In aviation altitude is your friend. Generally speaking altitude in the case of an emergency buys you time to work the problem. Generally you want to ...
  • 98.1k
51 votes

Was the transatlantic crossing for Concorde too short to reach optimal cruising altitude?

The simple answer is that the Concorde had no single assigned altitude, it was allowed to climb freely above ~FL450; this is discussed in depth in episode 166 – Flying the Concorde (worth the listen ...
  • 98.1k
46 votes

Is there a place where altitude while flying is negative?

There are quite a few airports near sea level since many larger cities are located near the sea. There are even some airports below sea level. Amsterdam Schiphol is somewhat famous for it (at least ...
  • 51.3k
42 votes
Accepted

What is the difference between "flight level" and "altitude"?

Flight levels use QNE or pressure altitude, while altitude references QNH or local pressure adjusted to sea level pressure. Altitudes are used at low levels and flight levels at higher levels. The ...
  • 35.1k
42 votes
Accepted

Why are listed times of useful consciousness so low?

In short: acclimatization, both chronic and acute. During your Tibet-trip, you had probably spent days at high altitudes, allowing your body to acclimatize to the lower oxygen partial pressure (...
  • 3,000
39 votes
Accepted

Why is 0 ft a valid target altitude for an autopilot?

Quite simply, it's because sometimes you fly below sea level. There's a couple stories out there of aircraft navigation systems acting a bit odd due to their flight below sea level. For example, there ...
  • 2,399
34 votes
Accepted

How does an aircraft descend without its nose pointing down?

A plane descends when it does not have enough thrust to maintain its altitude. A plane can descend with its nose pointed up or down so long as there is not enough thrust to maintain altitude. Altering ...
  • 98.1k
32 votes
Accepted

How was altitude calculated before the invention of the altimeter?

In my opinion the measurement referred to in your question could have come from either an "aneroid barometer (or barograph)" and/or from a "triangulation calculation." In this ...
  • 26k
31 votes
Accepted

On Air France 447, what would have been the lowest altitude to initiate recovery after the stall developed?

For the stalled flight to recover, the nose needs to be pointed in the airstream, and then the aircraft pulled up with load factor below the ultimate load. From the accident report: The recordings ...
  • 60.7k
30 votes

Do pilots adjust the aircraft's flight path to allow for the curvature of the Earth?

There isn't an adjustment for altitude. An aircraft flying level at a given altitude and trimmed for level flight will stay at that altitude. That means the flight path will have a gentle nose-down ...
  • 12.6k
27 votes
Accepted

What is the maximum altitude ATC would deal with?

There are many examples of aircraft with high service ceilings. While most commercial aircraft have service ceilings of FL410 and rarely fly even that high, many business jets have a service ceiling ...
  • 70.3k
27 votes

Why cruise at 7000' in an A319?

The only reason for your flight to operate at such low altitude is because it is cheaper for them to do so. As you said it is due to weather, other route/altitude may not be available. They can ...
  • 8,018
27 votes
Accepted

Is there a place where altitude while flying is negative?

Short answer If you just wanted to know some places below sea level then there are plenty of related collections for places and airports and there is little interest to copy them here. But actually ...
  • 68.6k
26 votes
Accepted

What is the minimum altitude needed to return to the takeoff airport in a 737 after dual engine failure?

Most modern airliners have L/Ds of 18 to 22:1 (sorry I couldn't find a direct reference). So from one nautical mile, 6076 ft, in the air you can glide around 18 to 22 nm in still air. Departure climb ...
  • 117k
25 votes
Accepted

How do aircraft altimeters calculate altitudes accurately while airborne?

Altimeters are calibrated to a standard atmosphere model (International Standard Atmosphere, ISA). What the altimeter shows you is the vertical distance between the altitude equivalent to your ...
  • 3,000
25 votes
Accepted

What might have been the reasons for this low flight altitude?

Looking at the route your plane took, this low altitude flight was likely to avoid the polar jetstream. This is a band of wind that blows west to east in roughly the area the first half of your flight ...
  • 2,703
25 votes
Accepted

Which source to use when reporting the current altitude to ATC?

When asked for altitude, you report the altimeter reading, utilizing the correct barometric pressure entered into the Kollsman window. ATC separates traffic based upon indicated altitude. The ...
  • 17.6k
25 votes

Is air to air refuelling possible at "cruising altitude"?

The main limitation is that the receiver needs to have enough excess thrust available to be able to precisely maintain formation on the tanker. Near the service ceiling, you typically don't have a lot ...
  • 45k
24 votes

Was the transatlantic crossing for Concorde too short to reach optimal cruising altitude?

Concorde had a 10,000fpm climb and a max altitude of 60,000ft, so time to climb was not a problem. It had an optimum cruise altitude that varied with weight, so as it burned fuel it climbed higher to ...
  • 18k
23 votes

Why are listed times of useful consciousness so low?

At lower altitudes, "useful" consciousness doesn't end when you are unable to act. Rather, what happens is that your ability to make sound decisions and carry them out effectively degrades: for ...
  • 4,703
22 votes
Accepted

Why was I getting an uncomfortable feeling in an R22 at 3,000 feet?

Typical height for helicopters is 500-1,500 AGL, and almost all flights are conducted in this regime. Below 1,500 AGL the surface is quite close and the ground moves by fairly quickly, so you have a ...
  • 16.6k
22 votes

Do pilots adjust the aircraft's flight path to allow for the curvature of the Earth?

This is more of a physics question rather than an aviation question. While other answers have addressed the question from the aerodynamics point of view, let me try answering it from a physics ...
  • 39.4k
22 votes
Accepted

How exactly can an airship lose lift?

The reason is a temperature difference between the lift gas and the surrounding air, and probably water uptake by the hull when descending through clouds. A given mass of hydrogen will create a ...

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