Att bevisa att ett flygplan är flygt med en eller flera motorer som inte fungerar är en del av certifieringsprogrammet. Airbus A380 är certifierad enligt del 25 av FAR (Federal Aviation Regulations, USA) del 25 och JAR (Joint Aviation Regulations, Europe). En av kraven i FAR / JAR 25 är att riktningskontrollen kan bibehållas när två kritiska motorer det betyder under samma vinge) misslyckas.
Följande extraheras selektivt från FAR del 25 (JAR är liknande, det finns vissa skillnader). Betoning av mig.
Controllability and Maneuverability
§25.143 General.
....
b) It must be possible to make a smooth transition from one flight condition to any other flight condition without exceptional piloting skill, alertness, or strength, and without danger of exceeding the airplane limit-load factor under any probable operating conditions, including—
The sudden failure of the critical engine;
For airplanes with three or more engines, the sudden failure of the second critical engine when the airplane is in the en route, approach, or landing configuration and is trimmed with the critical engine inoperative;
...
$ $
§25.147 Directional and lateral control.
a) Directional control; general. It must be possible, with the wings level, to yaw into the operative engine and to safely make a reasonably sudden change in heading of up to 15 degrees in the direction of the critical inoperative engine. This must be shown at 1.3 VSR1 for heading changes up to 15 degrees (except that the heading change at which the rudder pedal force is 150 pounds need not be exceeded), and with—
The critical engine inoperative and its propeller in the minimum drag position;
The power required for level flight at 1.3 VSR1, but not more than maximum continuous power;
The most unfavorable center of gravity;
Landing gear retracted;
Flaps in the approach position; and
Maximum landing weight.
b) Directional control; airplanes with four or more engines. Airplanes with four or more engines must meet the requirements of paragraph (a) of this section except that—
The two critical engines must be inoperative with their propellers (if applicable) in the minimum drag position;
[Reserved]
The flaps must be in the most favorable climb position.
c) ...
...
d) ...
e) Lateral control; airplanes with four or more engines. Airplanes with four or more engines must be able to make 20° banked turns, with and against the inoperative engines, from steady flight at a speed equal to 1.3 VSR1, with maximum continuous power, and with the airplane in the configuration prescribed by paragraph (b) of this section.
f) ...
$ $
§25.149 Minimum control speed.
...
g) For airplanes with three or more engines, VMCL-2, the minimum control speed during approach and landing with one critical engine inoperative, is the calibrated airspeed at which, when a second critical engine is suddenly made inoperative, it is possible to maintain control of the airplane with both engines still inoperative, and maintain straight flight with an angle of bank of not more than 5 degrees. VMCL-2 must be established with—
...
...
$ $
§25.161 Trim.
...
e) Airplanes with four or more engines. Each airplane with four or more engines must also maintain trim in rectilinear flight with the most unfavorable center of gravity and at the climb speed, configuration, and power required by §25.123(a) for the purpose of establishing the en route flight paths with two engines inoperative.