How to calculate de VS?

How can you calculate all your Speeds?
Ad the trim?

Hello! I am not sure whether you are referring to vertical speeds, or V-Speeds. I’ll answer both, as well as your trim question.

Vertical Speed:
For climb, I will pitch for speed. This means I will set throttle to an appropriate climb power (usually 80-92% depending on aircraft and weight) and then adjust the vertical speed until my preferred IAS (in air speed) is maintained. For descent, without getting into more complex calculations (posts of which can be found in this community), start your descent when the distance to your destination is three times that of your cruise altitude divided by 1000 (for instance, cruise altitude = 30,000. 30,000 /1000 is 30. 30 times 3 = 90. Start your descent 90 NM from your destination.) and descend at a rate around -2,200 fpm.

This is highly subjective, and depends on aircraft, and weight. For rotation speed (Vr), it will be in the ballpark from 110-160 depending on aircraft and weight. A fully loaded 777 will be around 150. A near empty CRJ will be around 110. To find V1 without using a performance calculator program, subtract 5 from Vr. To find V2, add 5 to VR. Note that again, these speeds are highly subjective and far from 100% accurate. These are meant to be used as a rough estimate.

In real life for most aircraft have a takeoff trim range, and their flight computers will punch out an actual takeoff trim setting, for instance: 5.6° UP. However in Infinite Flight, you don’t necessarily need to set a takeoff trim setting, and degrees wouldn’t help you anyways since Infinite Flight uses percent rather than degrees for trim. The only aircraft I set takeoff trim for are the CRJ’s, for which I would recommend a takeoff setting of 10-20% nose up. When using trim to remove control pressure there isn’t a way to calculate it, and you just need to either trim up or down depending on your situation until it feels correct.


Vertical Speed: For climbing, I usually set it around 2000’/min to 3000’/min, depending on the aircraft, and then decrease it as I climb higher. For descending, I use IF assistant to calculate vertical speed, all I need is to calculate altitudes at my waypoints. I use the STAR/APP charts to find altitudes at certain waypoints and use the nautical miles in between to calculate waypoints without altitudes listed, and then IF Assistant does the rest.

V-Speeds: You can find many performance charts online for different aircraft. Using the Auto-generated V-speeds on IF Assistant works well for taking off, too. I will include some below that I use.

Trim: I use between 25% and 35% trim (since IF uses % instead of degrees), depending on the aircraft and weight. The trick to not have the nose pitch up or down while disengaging the autopilot is to make the pink bar next to the trim disappear. This means that your elevators are trimmed appropriately.

I hope this helps!


Do you mean at what vertical speed you have to descend?

Or an even easier calculation :take your Flight Level and decvide by 3 to get your distance to go (DTG) of when to start your decent: ie 30000FT = FL300. 300/3 = 100nm DTG.


@David_Lockwood that actually works really well. I didn’t even think of it that way. Usually I’d multiply the end result by 1.1 to get a little more leeway, which would be pretty much the same calculation as FL/3.


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