How to dertermine climb gradient

[dts 0]

hehe - I entered the distance to be 2100 m as per the chart. But you make a fair assumption - that would probably be illegal in most countries... lol....

check your chart, doesnt it say 21000m not 2100m

[janpitor 2]

Hi once again,I don´t see why you couldn´t use the go-around table at PD.12.6 of FCOM 1. It says gradients in % with one engine inoperative and flaps 15. Whenever you have flaps 15 or less, you will have the same or higher gradient and you will suffice the requirement. This may be not legal IRL (honestly, I don´t know) but it is safe.Jan

[3-2-1-Now 126]

Beware lower flap settings (e.g. Flap 5 vs. 15) giving better climb - not necessarily! You have reduced lift for a start. Check the charts.@michal: I find it easier to remember - others might too.Best regards,Robin.

[mas618 17]

 

check your chart, doesnt it say 21000m not 2100m

I Should be thrown from the NGX at FL370 over the pond, with a palm tatooed across my face... No parachute... Forgive me my ignorance everybody! I can now put virtual obstacles ala Granitus Cumulus in TOPCAT out of LOWI.

[janpitor 2]

Beware lower flap settings (e.g. Flap 5 vs. 15) giving better climb - not necessarily! You have reduced lift for a start. Check the charts.

If you do not alter your configuration, the best gradient is always achieved with lower flap setting. Only the required airspeed is then higher (increasing lift and decreasing AOA, thus reducing drag even more). The problem is acceleration, because this reduces your overall gradient. So it is the best to stay on take-off flaps until clear of the obstacles/required gradient.

[G550flyer 1,014]

1

[G550flyer 1,014]

For years flight sim has been plagued with the inability to calculate aircraft climb performance. Normally, real world aircraft purchased will come with a flight and performance manual based on the options chosen at purchase. The performance manual may be further developed at a nominal fee. Every aircraft I've flown had a performance manual that provided the capability to calculate full performance based on conditions. Now days operators may purchase FMC/FMS options that will provide performance calculations.Most performance manuals will have a conversion chart to convert gradients.You are probably familiar with the climb limit chart. This is a climb limit chart for the -700 with flaps 15.Only issue is that this chart is based on second segment climb and is usually based on 2.4%. This chart will give me the max weight that i can attain and meet the 2.4% based on conditions.In the FAA, the min is 3.3 or 200 fpnm. The next chart you maybe accustomed to is the obstacle limit chart.Notice that this chart tops out at 1000ft. In this case you will need extra charts to figure if you can make a published gradient, or an obstacle that's higher than 1000ft. At purchase, you can have the company provide extra charts($) giving you the capability to make these calculations. Some operators will purchase 3rd party software that will make calculations for you. Some will have a company evaluate different airports and calculate weights based on varying conditions. My company uses Jeppesen. Jeppesen provides single engine departure procedures. These procedures provide a engine out route to be flown in the event of an engine failure. The data provides max gross weights based on temps and runway conditions. This data allows a higher takeoff gross weight than what can be attained from the performance manual. We also use a program that allow you to calculate weights based on runway, SID, and obstacles for planning purposes.Here are some example of performance manual charts that can be obtained from the manufacturer.This is a SID TAB chartThis chart allows me to account for the distance from lift off to an obstacle, allowing reduced climb rate required. Obstacle distance is based from the departure end.This 2 part chart allows me to calculate the actual climb gradient capability at a given weight.Close and distant obstacleI even have charts for en-route climb capability.Hopefully, programs like TOPCAT will give us the capability to actually figure out what climb gradients the aircraft will perform. We even have all engine climb gradient charts that I can quickly figure if I can make an ATC climb gradient. The FMC will calculate this info also. The FMC, software, and performance manual gives me the capability to calculate max weights in all situations. This is critical when it comes to safety, range and fuel.