Requirement 4: Missed Approach Climb
JAR 25.121 Climb: One-engine-inoperative.
(d) Discontinued Approach. In a configuration in which VS does not exceed 110% of the VS for the related all-engines-operating landing configuration, the steady gradient may not be less than
2·1 % for two-engined aeroplanes,
2·4 % for three-engined aeroplanes, and
2·7 % for four- engined aeroplanes, with -
(1) The critical engine inoperative, the remaining engines at the available take-off power or thrust;
(2) The maximum landing weight; and
(3) A climb speed established in connection with normal landing procedures, but not exceeding 1·5 VS.
(4) Landing gear retracted.*
* Number (4) of § 25.121 (d) exists only in JAR 25 but not in FAR Part 25.
The missed approach is similar to the second segment situation where one engine of the aircraft is inoperative. The thrust of the remaining engine(s) has to be enough to climb again as required. The second segment climb equation is expanded by the mass ratio determined already in the landing field calculation:
The climb gradient can simplified similar to the second segment:
background of mass relation
statistics of aspect ratio
next: calculation of takeoff thrust to weight
The takeoff thrust to weight ratio of the aircraft must be above the pink line to fulfil the requirement for the missed approach condition. (Bear in mind: Thrust means climb rate.)
|Aircraft||Airbus A 300-600B||Airbus A 310-300||Airbus A 340-300||Antonov AN 124||Boeing B 737-600||Boeing B 777||McDonnell Douglas MD11||Tupolev TU 204|
Takeoff weight [ - ]
|0.308 - 0.324||0.290 - 0.356||0.220 - 0.240||0.231||0.307||0.292 - 0.304||0.299 - 0.309||0.341 - 0.413|
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