Climb gradient and FPA?

[Dirk98 354]

"Maintain minimum climb gradient of 6

[3-2-1-Now 126]

Absolutely!For 3 degrees you take half your GS and x 10, so for 6.4 you take x24.e.g. GS = 200 kts, so 0.5x200 = 100 x 24 = 2400 ft/min is the minimum rate of climb you need (approx).Best regards,Robin.

[Dirk98 354]

Thanks Robin! But now, how do I connect it to the required minimum climb gradient of 6

[ErnieAlston 33]

>Thanks Robin! But now, how do I connect it to the required>minimum climb gradient of 6

[Dirk98 354]

Ernie, thanks for the answer, but how can they be essentially the same, if one is mesured in % percent and the other in degrees? Do you mean to say a climb gradient of 6.4% equals 6.4 degrees? How is it measured then?Thanks,Dirk.

[michal 44]

>For your purposes the climb/descent gradient and flight path>angle are essentially the same.Sorry, but this patently false information. Degrees and gradient expressed in % are not the same. In fact 1% of gradient is equal about 0.57 degrees so in his case 6.4% is equal to an angle about 3.6 deg.Dirk, this is a minimum requirement only, there is no need to fly exactly 6.4% (3.6 deg). Most airplanes in normal situations will very easily exceed this climb gradient. Even Cessna 172 loaded with 4 people should easily meet it. Only when your takeoff is from high altitude airports or temperatures are high you should start worrying. Also I am curious which airplane you fly in FSX allows you to see FPA directly on the PFD. Only airplane equipped with the Flight Path Marker (e.g. the latest G1000 with synthetic vision) gives you this feature. I don't think there are any transport aircraft (without HUD) that have this capability.Michael J.http://img142.imageshack.us/img142/9320/apollo17vf7.jpg

[XWRed5 0]

I'm amazed no one has answered this poor chaps question, especially since it's basic trigonometry....6.4% means you go up 6.4m for every 100m you move along, giving you a right angled triangle.The tan of the angle you are looking for is equal to the opposite over adjacent, i.e. 6.4/100. The arc tan of this will give you that angle.I make it 3.661935576degs, or 3.7degs for government work.As previous posters have already mentioned, that's a minimum gradient and I wouldn't recommend you fly at exactly that, you'll get quite close to the ground.Also as previously mentioned, 3degs is about half your ground speed times 10, e.g. @140kts 3degs is approx 700fpm.I would suggest that you simply set climb power and maintain V2 + whatever increment you deem appropriate (10 or 15 is common) until about 1000ft above the airfield, then start accelerating and cleaning up. That would see you safe just fine.Hope this helps,Ian

[Dirk98 354]

>I'm amazed no one has answered this poor chaps question,>especially since it's basic trigonometry....>>6.4% means you go up 6.4m for every 100m you move along,>giving you a right angled triangle.>>The tan of the angle you are looking for is equal to the>opposite over adjacent, i.e. 6.4/100. The arc tan of this will>give you that angle.>>I make it 3.661935576degs, or 3.7degs for government work.>>As previous posters have already mentioned, that's a minimum>gradient and I wouldn't recommend you fly at exactly that,>you'll get quite close to the ground.>>Also as previously mentioned, 3degs is about half your ground>speed times 10, e.g. @140kts 3degs is approx 700fpm.>>I would suggest that you simply set climb power and maintain>V2 + whatever increment you deem appropriate (10 or 15 is>common) until about 1000ft above the airfield, then start>accelerating and cleaning up. That would see you safe just>fine.>>Hope this helps,>>Ian>Thanks Michael, thank you Ian. Forget about the quote with the required gradient of 6.4%, I used it only as an example from CLACTON SID. I wanted to understand the connection.This sounds rather intimidating, Ian. (I forgot it too long ago at school):>The tan of the angle you are looking for is equal to the>opposite over adjacent, i.e. 6.4/100. The arc tan of this will>give you that angle.I make it 3.661935576degs, or 3.7degs for >government work.Anyway, if I just memorize this shortcut:>In fact 1% of gradient is equal about 0.57 degrees so in his case 6.4% is equal to an angle about 3.6 degwill it be precise enough for simulation purposes only? :)Many thanks, guys.Dirk.

[Dirk98 354]

>Also I am curious which airplane you fly in FSX allows you to>see FPA directly on the PFD. Only airplane equipped with the>Flight Path Marker (e.g. the latest G1000 with synthetic>vision) gives you this feature. I don't think there are any>transport aircraft (without HUD) that have this capability.>>Michael J.Michael, it's EJets by Wilco/Feelthere. Very good and enjoyable package with some horrible parts in autoflight in the turns, climbs and decents. Don't know what to blame FDE or the logics. I hope most of these issues (in the first hand) will be addressed first. Shame, when I see how the plane behaves in the turns, leveling off, flc etc. I lose any interest. very fast But I know there's a great potential, there's very nice and clear avionics package, panels are good and the vc is fine. I recall the developer was supposed to get back to work from vacation this week. :)

[michal 44]

>>In fact 1% of gradient is equal about 0.57 degrees so in his>case 6.4% is equal to an angle about 3.6 deg>>will it be precise enough for simulation purposes only? :)Yes, but in fact real pilots never do such calculations (in terms of degrees). SIDs typically come with a gradient table that show what climb rate is required for a given horizontal speed or they use Jeppesen tables. And most pilots (specially jet pilots) know that they will easily exceed the minimums therefore don't even bother to perform calculations. No mental arithmetic, no fancy trigonometry, no formula memorization is required in cockpit.Michael J.http://img142.imageshack.us/img142/9320/apollo17vf7.jpg

[Dirk98 354]

>Yes, but in fact real pilots never do such calculations (in>terms of degrees). SIDs typically come with a gradient table>that show what climb rate is required for a given horizontal>speed or they use Jeppesen tables. And most pilots (specially>jet pilots) know that they will easily exceed the minimums>therefore don't even bother to perform calculations. No mental>arithmetic, no fancy trigonometry, no formula memorization is>required in cockpit.>>Michael J.Cool, thanks, Michael. :)