EFB Performance Landing Dispatch

[ElNull]

I got the following output from the EFB -> Landing Dispatch:

Landing limit weight is 192776 KG

Dispatch related information:
Field limited weight is 269887 KG
Landing climb limited weight is 262706 KG
Approach climb limited weight is 238181 KG
Tire speed limited weight is 269887 KG
Brake energy limited weight is 269887 KG
Go-around limited weight is 230031 KG
Required go-around gradient is 2.50%
Most favorable runway limited weight is 269887 KG

Landing climb gradient at limit weight is 9.05%
Approach climb gradient at limit weight is 4.76%

I have two questions:

1) Am I correct in assuming that all of the above are Regulated Landing Weights (RLW) used only for dispatch performance calculation? (not during flight)
2) What is the difference between Approach/Landing climb limited weight and the Go-around limited weight?

[FlyingStone]

Dispatch is only used for dispatch, inflight for inflight - different rules and safety margins apply for what you need to satisfy prior dispatch and what before commencing an approach once you are airborne.

Go-around limited weight is what is limited by the selected (2.5% in your case) go-around climb gradient. Approach climb likely refers to the CS25 certification requirement of 2.1% climb gradient during a go-around with OEI (assuming you're flying a twin), and similarly for the landing climb - 3.2% with all engines operating.

[ElNull]

Originally Posted by FlyingStone

Dispatch is only used for dispatch, inflight for inflight - different rules and safety margins apply for what you need to satisfy prior dispatch and what before commencing an approach once you are airborne.

Go-around limited weight is what is limited by the selected (2.5% in your case) go-around climb gradient. Approach climb likely refers to the CS25 certification requirement of 2.1% climb gradient during a go-around with OEI (assuming you're flying a twin), and similarly for the landing climb - 3.2% with all engines operating.

Thanks for the clarification. I understand that the Approach and Landing climb gradients are fixed regulatory values used to demonstrate that the aircraft meets a minimum certification climb performance requirements.

The Go-Around, on the other hand, represents the 'operational limit' determined by the specific airport or procedure, but it must still meet at least the 2.5% minimum climb gradient. Is that correct?

[Chesty Morgan]

And for clarity the approach climb limit is OEI in the approach configuration whilst the landing climb limit is in landing configuration AEO.

[ElNull]

Originally Posted by Chesty Morgan

And for clarity the approach climb limit is OEI in the approach configuration whilst the landing climb limit is in landing configuration AEO.

Yes, I’m aware of the differences between the Approach climb and Landing climb assumptions and their respective gradients. My question was specifically about the Go-Around limited weight (standard gradient 2.5%). How it differs in purpose or application from the Approach and Landing climb limits.

[FlyingStone]

Landing climb weight assumes AEO and landing configuration (flaps and gear extended) - think a hydraulic malfunction where gear and flaps are stuck, but you have to do a go-around.

I think the 2.1% approach climb gradient required is similar to the 2.4% requirement during 2nd segment after takeoff - you'll have sufficient performance to fly away, assuming no obstacles in your way. The go-around climb gradient ensures you can do this safely in IMC, and have sufficient obstacle clearance along the way, which is done by satisfying the MACG requirement from the instrument approach chart.

[wof]

Originally Posted by ElNull

I got the following output from the EFB -> Landing Dispatch:


I have two questions:

1) Am I correct in assuming that all of the above are Regulated Landing Weights (RLW) used only for dispatch performance calculation? (not during flight)
2) What is the difference between Approach/Landing climb limited weight and the Go-around limited weight?

I’ve always thought the Approach and Landing Climb Limit weights were something we only check at dispatch, not during flight. Then I came across the 787 Overweight Landing checklist, which actually asks you to refer to those weights when deciding flap settings for landing and go-around. Hmm?