A huge garage-type building for airplanes.

The cost incurred when keeping an aircraft in a hangar. Costs vary based on the size of the hangar a particular jet will require.

The direction in which an aircraft is pointing measure clockwise in degrees from North. Note that this is not necessarily the same as the aircraft's track because of wind.

A wind which is blowing in the opposite direction to the direction of movement or flight.

An aircraft with a minimum takeoff weight of 255,000 lbs. They are typically configured for 12 to 18 passengers. See examples of Heavy Jets on JetRequest.com.

HMV. This is most comprehensive aircraft maintenance check for the airplane, also known as a D Check. This check occurs approximately every 4–5 years. This is the check that, more or less, takes the entire airplane apart for inspection. This requires even more space and time than all other checks, and must be performed at a maintenance base. Often, older aircraft being phased out of a particular airlines' fleet are stored or scrapped upon reaching their next check due to the high costs involved in comparison to the aircraft's value.

The elevation above a certain ground reference point, commonly the terrain elevation.

A rotor craft with one or more sets of powered blades. See examples of Helicopters on JetRequest.com.

Helicopter landing pad. Used for takeoffs, landings and occasionally for parking of helicopters.

An airport for helicopters. In includes the area of land or water used for the landings and takeoffs, as well as the buildings, structures and grounds.

An airport that is located a good distance above sea level, such as in Tibet. At high altitude airports, planes might need longer runways, have to fly with a smaller payload, or have a dramatically slowed down approach.

Heavy Maintenance Visit. This is most comprehensive aircraft maintenance check for the airplane, also known as a D Check. This check occurs approximately every 4–5 years. This is the check that, more or less, takes the entire airplane apart for inspection. This requires even more space and time than all other checks, and must be performed at a maintenance base. Often, older aircraft being phased out of a particular airlines' fleet are stored or scrapped upon reaching their next check due to the high costs involved in comparison to the aircraft's value.

An oval flight pattern with two parallel sides and two turns, flown usually while an aircraft is waiting for clearance to land.

The home airfield and where the aircraft is primarily located when on the ground.

Hotel Accommodation

Designating, of, or traveling at a speed equal to about five times the speed of sound or greater.

Oxygen deprivation sickness caused by flying at high altitudes in an unpressurized cabin or without an oxygen mask. It causes dizziness and affects pilot judgment.