New answers tagged

0

As already stated, pressure is effectively the weight of the air above the aircraft. If you were (for example) to double the absolute temperature of the entire atmosphere (from say 300K at sea level to 600K then the atmosphere would double in volume, assuming it’s an ideal gas, which isn’t a million miles from the truth, and pressure altitudes would ...


0

By definition temperature is not factored in to calculation of pressure altitude. Pressure altitude is always the indicated barometric altitude with 29.92 used as a barometric offset. Temperature will affect the altitude of aircraft flying at pressure altitude though.


2

Because Pressure altitude is a measure of the weight of the air above you. Temperature does not affect that. Heating the air just makes it expand. It still weighs the same.


3

The picture you have displayed is correct. But, your understanding of what it is saying is incorrect. The picture is explaining the reason your Indicated Altitude will change with temperature for the same True Altitude. And, your True Altitude will change with temperature (a potentially dangerous situation) for the same given Indicated Altitude. Your ...


10

Because air pressure is not constant over wide areas. Weather provides us with high and low pressure areas, and you may not know the pressure at your destination when departing. Indeed, it may have changed en route. OTOH, barring a major earthquake, the field elevation is not going to change significantly. In point of fact, I DO almost always set the ...


19

Good question. The reason is things fail. If you set the altimeter to show field elevation, but the altimeter is faulty, you could end up flying differently from the rest, leading to loss of separation or worse. But if you set the QNH, and then the reading is within 75 feet of the field elevation, you're good to go. 3. Altimeter Setting Procedures 3.1.3 If ...


2

Airspace classes and locations are defined by regulation in 14 CFR 71, which references JO 7400.11E - Airspace Designations and Reporting Points. Here's an example of the definition of class D airspace, at KEUG (Eugene, Oregon): ANM OR D Eugene, OR Mahlon Sweet Field Airport, OR (lat. 44°07'29''N., long. 123°12'43''W.) That airspace extending upward from ...


3

Airspace boundaries are not defined by altimeter settings or Indicated Altitude. Like the field elevation, they are at True Altitude. This is defined as the actual height above the 19-year average level of the sea surface. Some boundaries are defined by the height above the surface (field elevation) which is in turn at True Altitude. The MSL vertical ...


Top 50 recent answers are included