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View Full Version : ATR 72 - QRH Graph - Max Landing Weight (KG) limited by Max Brake Energy (8.3 MJ)


Tikoloss
20th Jul 2015, 07:24
Hi there!

I guess only ATR pilots may understand this one... But any help would be appreciated.

Anyone seen the Graphs added by ATR in their QRH page 4.67 (Dec 14 - 500)?

I have some issues understanding the latter...

It involves Landing Elevation, ISA deviation and weight of Aircraft all in normal conditions for various Flaps settings such as Flaps 30-15-0.

Lets say that I operate at sea level for Take-Off and Landings and in the ISA+10 to ISA+20 range.

Extract from the graphs:

1- Normal Conditions FLAPS 30 - Vref - Dry or Wet Rway - no wind (*never exceed certified MLW)
- Landing Elev: 0FT
- ISA+10: 24700 (Which corresponds to a landing weight greater than the MLW of 22350)
- ISA+20: 24200
2- Normal Conditions FLAPS 15 - Vref - Dry or Wet Rway - no wind
- Landing Elev: 0FT
- ISA+10: 22200
- ISA+20: 21900
3- Normal Conditions FLAPS 0 - Vref + 5Kt - Dry or Wet Rway - no wind
- Landing Elev: 0FT
- ISA+10: 18800
- ISA+20: 18500

Below the graphs are some corrections for wind, effect of reversers etc which either increase or decrease the weight obtain from the table.

My question is, what does those graphs actually show us?

- Should I have an aircraft that is heavier than what is given in the table, would it mean that I wont have enough brake energy to stop the latter upon landing? If so, why haven't they given an added information regarding the distance at which the latter may stop?

This gets really confusing for me, as two pages prior to those graphs are some tables showing us the landing distance in meters at sea level with a 30 degree flap setting.

In the emergency checklists they never ask to refer to those graphs for the landing should there be a problem. Does it mean that there are here only as additional information?

- Also, in the last graph with Flaps 0, this corresponds most of the time to weights below our ZFW! What then?

Any information would be greatly appreciated.