A320 Single Engine Missed Approach

[JABBARA]

I tried to review all posts, if I am not missed, one important and controversial point is not mentioned at all.

That is: Go around gradient value calculated with the tool (e.g Flysmart now on I will mention as FSA) at the hand of pilot calculating landing performance HAS NO USAGE from the perspective of pilot
It can never be compared with the design gradient of Missed Approach procedure, which is defaulted as 2.5 % if the terrain along the path is not requiring more.
This is correct, regardless what the calculated value is either 2.1 % (minimum as approach climb gradient for two engine airplane) or 15%
As a requirement of Procedure Design Gradient (PDG) of ICAO DOC 8168 Part I or 2 (also known as PAN-OPS), the MAP gradient has NO interest with the number of engine of the airplane and how good their performance while going around or flying Missed approach Procedure

Whereas, Approach Climb Gradient (see note) is a requirement stated by CS 25 or FAR 25
These two docs guides the manufacturer how they should make their plane to be good enough to comply with the certification standards which are safe enough to carry human species. Those docs have no interest in which terrain condition the plane will fly the missed approach. This gradient requirement confines the manufacturer to advertise their airplane to the customer as "this airplane can land with this weight at this condition".
I mean, regulation says "hey Mr/Mrs manufacturer, when you are praising your plane in terms of landing weight you cannot tell fabulous numbers; your max number (weight) which you can advertise should not be more than the weight which can hinder an MOMENTARY (valid only for a fraction of second) 2.1% gradient (two engine airplane). (I remind, as you aware, this is only the one of the landing weight requirements of many, probably most difficult one to visualize)

MOMENTARY is the important point, no FSA (or likewise) calculated GA gradient is a continuous gradient. That is impossible because whatever the number is, let's say 5% that is only valid for that altitude and ambient conditions, as you climb your TAS will increase (accelerate, even for fixed CAS) and Thrust will decrease. Conclusion, an airplane in this scenario, cannot maintain a straight climb path; It starts with 5% but 2000 feet above it may be 1.5%. Therefore this 5% even as even greater than PDG (2.5%), cannot guarantee that following MAP is flyable


Note for only for those gents who may be away from some definitions: Shown GA gradient after the calculation by FSA is more limiting of either Approach Climb Gradient or Landing Climb Gradient (according to Airbus, for two engine plane always the second, LCG, is limiting)

Limiting(in terms of ACG) means the max permissible weight where you can start the approach, assuming either then or at the go around
one engine failed (out of whatever number was there)



There are more controversial things about engine 10 min usage limit as well, but later if required