Flight phase

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Flight phases: 0-taxiing, 1-take-off and initial climb, 2-climb, 3-cruise, 4-descent, 5-landing approach, 6-final approach, 7-landing, 8-taxiing

The flight of an aircraft is divided into the following flight phases :

  • Start and shortly after take-off ( takeoff and initial climb );
  • Climbing (engl. Climb );
  • Cruise (engl. Cruise );
  • Descent (engl. Descend );
  • Landing (. English approach ) - divided into:
    • Initial approach (engl. Initial approach );
    • Between the approach (Engl. Intermediate approach );
    • Final approach (engl. Final approach );
  • Landing (engl. Landing ) - consist of: intercepting (the stabilization period), touchdown, the thrust reverser or brakes and ultimately rolling, until reaching the parking position.

Further possible flight phases during or during the landing procedures are:

In a broader sense, the flight phases also include:

  • Flight planning or pre-flight (engl. Flight preparation )
  • the preparation on the ground (English ground preparation ),
  • the rollers (engl. taxi ), the movement of the aircraft from the parking position to the starting point on the runway or after landing back to the park position,
  • Flight follow-up (ger .: post-flight operations )

Transitions

In the case of large jet aircraft flying at an altitude of approx. 10 km, the following flight phases are exemplified:

When taking off, the aircraft accelerates to V R (speed at the point of rotation ) and then raises the bow. After taking off, it accelerates to V 2 (safe rate of climb). After reaching 1500 ft above ground, the initial climb ends and the flight path becomes a little flatter.

Now the climb begins. The flatter trajectory allows the engine power to be reduced a little and the aircraft to accelerate to the climb speed. Usually only 250 kn are allowed up to FL 100 . The point at which the climb has ended and the cruise takes place is called the top of climb (TOC; literally: the highest point of the climb).

The engine power can be reduced a little for cruising, as no additional energy is required to gain altitude. During the cruise, the flight altitude is often changed again to a higher flight level at intervals of 1 to 2 hours ( step climb , literally: stepped flight ), since the aircraft has become lighter due to the fuel consumption and therefore at an even higher altitude - because of the thinner air - can fly more economically. At the end of the cruise is the top of descent (TOD; literally: highest point of the descent). Here the descent begins.

Since a jet aircraft uses significantly less fuel at high altitudes than at low altitudes, the pilots endeavor to remain at cruising altitude as long as possible. However, the aircraft must not remain at its cruising altitude beyond the top of descent , otherwise it would have to descend too steeply. It would become too fast and exceed the load limits of its structure. The increasing speed during descent can be slowed down by deploying spoilers , but this again consumes energy, so that the aircraft does not fly energy-efficiently. Flying additional circles or detours would also enable a further decrease in altitude, but would be uneconomical. The most economical descent is carried out with minimum fuel consumption, wherein the engines to idle (engl. Idle ) are reduced. The top of descent is calculated and displayed by the flight management system . If this is not available in the aircraft, then it is an important task of the pilot to calculate or at least estimate this point. There are various rules of thumb for the pilot .

The descent changes to the landing approach at the Initial Approach Fix (IAF) and this to the final approach at the Final Approach Fix (FAF).

Air traffic control

Different bodies are usually responsible for air traffic control during the various phases of the flight. Take- off and landing are monitored and controlled by the aerodrome control, call sign: TOWER, abbreviation: TWR . Since the climb is usually identical to the departure, it is checked by departure control ( call sign: DEPARTURE, abbreviation: DEP ). The cruise, which usually makes up the longest part of the flight, is monitored by area control . The descent is monitored by the approach control , call sign: APPROACH or ARRIVAL or RADAR, abbreviation: APP or ARR.

Accidents

In the different phases of the flight, accidents occur with different frequencies. In relation to the duration of the flight phases, the distribution of fatal accidents is concentrated in the first and last flight phases. The following table shows the distribution of fatal accidents and fatalities on board in the period from 2004 to 2013 by flight phase. The proportions of the flight phases in the flight duration are estimated values ​​for a flight of 1.5 hours.

Accident frequency in different phases of the flight
  Flight duration (in%) Fatal accidents (in%) Fatalities on board (in%)
roll - 10 0
begin 1 8th 7th
Initial climb 1 6th 3
Climb 14th 8th 12
Cruise 57 10 20th
descent 11 3 3
Landing approach 12 8th 15th
Final approach 3 22nd 22nd
landing 1 25th 18th

Individual evidence

  1. ^ Fatal Accidents and Onboard Fatalities by Phase of Flight. In: Statistical Summary of Commercial Jet Airplane Accidents. Boeing, July 2017, p. 20 , accessed February 20, 2018 .