This is most comprehensive aircraft maintenance check for the airplane, also known as a Heavy Maintenance Visit (HMV). 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.

A cost sometimes associated with chartering a private jet. If the aircraft is sitting on the ground waiting for a return leg, the client will be assessed a daily minimum charge for keeping the aircraft out of rotation. Also, very short flights that would mathematically cost less based on flight time may be priced out based on the daily minimum.

Is similar to ACMI and Wet leasing however usually without the cabin crew. The lessee will provide the cabin crew. This can only be done if the cabin crew receives SEP (Safety and Emergency Procedures) training by the lessor, in order to be acquainted with the differences of the airplane.

A room equipped for recreation and relaxation. In order to adhere to strict duty times, pilots sometimes will require a day room, especially common on same day round trip flights.

DNL or Ldn. The average noise level over a 24 hour period except that noise occurring at night (between the hours of 10PM and 7AM) are artificially increased by 10 dB. This weighting reflects the added intrusiveness of night noise events attributable to the fact that community background noise typically decreases by 10 dB at night. Under Federal Aviation Regulation (FAR) Part 150, the FAA has established Ldn/DNL as the cumulative noise exposure metric for use in airport noise analyses, and has developed recommended guidelines for noise/land use compatibility evaluation.

Term used for a leg of a trip that is transporting no passengers or cargo. Also known as an empty leg. This is usually the return from dropping or the departure to a pickup. Find dead heads on the Empty Legs page of JetRequest.com.

A segment of a round trip that is scheduled to be flown with no passengers. Typically these legs can be chartered for a significant discount. Also known as Empty Leg. Find dead legs on the Empty Legs page of JetRequest.com.

The process of estimating one's current position based upon a previously determined position, or fix, and advancing that position based upon known speed, elapsed time, and course.

Dead Stick Landing refers to the process of landing an aircraft with the engines and/or propellers shut down. The aircraft is effectively gliding into its landing position.

A measure of the sound pressure of a given noise source relative to a standard reference value is the sound pressure level (SPL). This reference pressure is typical of the quietest sound that a young person with good hearing is able to detect and is measured in decibels (dB).

When there are freezing conditions and precipitation, it is critical that an aircraft be de-iced. Failure to do so means the surface of the aircraft's wings will be too rough to provide for the smooth flow of air and thereby greatly degrading the ability of the wing to generate lift, possibly resulting in a crash. If large pieces of ice separate once the aircraft is in motion, they can be ingested into turbine engines or impact moving propellers and cause catastrophic failure. Thick ice can also lock up the control surfaces and prevent them from moving properly. Because of this potentially severe consequence, de-icing is performed at airports where temperatures are likely to dip below the freezing point.

Aircraft with a wing plan in the form of a triangle. It is named for its similarity in shape to the Greek uppercase letter delta.

Altitude in terms of the density of the air; it is corrected for non-ISA (International Standard Atmosphere) atmospheric conditions. On a very hot day, density altitude at an airport (especially one at a high elevation) may be so high as to preclude takeoff, particularly for helicopters or a heavily loaded aircraft.

The angle that an aeroplane's wings make with a horizontal plane. A larger dihedral angle gives greater roll (lateral) stability at the cost of efficiency. If the wings angle upwards, it is called the dihedral angle. Downward angled wings are said to have an anhedral angle.

Expenses that are incurred while the aircraft is flying. These costs can include fuel, fuel burn, fuel additives, lubricants, maintenance labor, maintenance parts, engine restoration cost, major periodic maintenance, propeller overhaul, APU maintenance overhaul, landing and parking fees, crew expenses, small supplies and catering. Same as Variable Operating Cost.

A lighter-than-air craft that can be steered and propelled through the air. (See also airship)

A couch on some private jets. Usually seats 2 or 3 passengers and has seatbelts for each.

Department of Defense

Department of Defense Flight Information Publications. Used for flight planning.

Flight that takes place inside only one country. Find aircraft available for your domestic charter flights on the Empty Legs and Transient Aircraft pages of JetRequest.com.

Occurs when a flight goes from Point A to Point B to drop off passengers, returns to home base empty, then returns to Point B empty, and picks up passengers for a return to Point A. This is done when the air charter itinerary reveals it is more costly to keep the plane away from home base than to perform the double rotation. (also called Double Round Trip)

Occurs when a flight goes from Point A to Point B to drop off passengers, returns to home base empty, then returns to Point B empty, and picks up passengers for a return to Point A. This is done when the air charter itinerary reveals it is more costly to keep the plane away from home base than to perform the double rotation. (also called Double Rotation)

One of four aerodynamic forces. The resistance to the motion of a body passing through a fluid, esp through air: applied to an aircraft in flight, it is the component of the resultant aerodynamic force measured parallel to the direction of air flow.

Is the lease of the basic aircraft without insurances, crew, maintenance etc. Usually dry lease is utilized by leasing companies and banks. A dry lease requires the lessee to put the aircraft on his own AOC and provide aircraft registration. A typical dry lease starts from two years onwards and bears certain conditions as far as depreciation, maintenance, insurances etc. are concerned. This depends on the geographical location, political circumstances etc. There are generally two types of dry leases, an Operating Lease and a Finance Lease.

Certificate held by an air charter operator that both publishes a schedule and provides non-scheduled air charter service.

The amount of time legally allowed for the aircraft crew to perform flights and flight related duties in a 24 hour period. These duty limitations are put in place to avoid pilot fatigue. The time varies slightly based on factors such as domestic flights, international flights, and weather delays. Domestic Flight time: 8 hours in a 24 hour period. This can be increased to 10 hours with the use of a co-pilot. International Flight time: 12 hours in a 24 hour period. However, once the aircraft lands in the US, the 8 hour rule takes precedent. Duty time: 14 hours in a 24 hour day. This includes pre-flight and post flight operations of the aircraft. If a pilot can receive 10 hours of rest in between flights, he or she become new again, and their flight time clock re-sets itself to zero. The rule is a maximum of 8 hours in a 24 hour period. If the pilot flies beyond the 8 or 10 hour limit due to weather, the rest period increases to 16 hours instead of the normal 10 hours. Also, pilots can fly only six consecutive day in a row before they are required to take 24 hours off.

The portion of the day when a crew member is on duty in any capacity, not just in-flight. This can be a constraint on long day-trips as there are FAA-imposed limits on the amount of time allowed on duty. Duty time: 14 hours in a 24 hour day. This includes pre-flight and post flight operations of the aircraft.