Rotation speed
-
Hi, can anybody please share how to calculate the rotation (take off) speed. As we know it can change depending on the loadout and I some time face difficulty getting off the ground due to wrong timing.
Thanks.
-
The probably easiest way is using the Weapon Delivery Planner. It gives you Vr depending on your engine, weight, and chosen takeoff profile (AB/mil, pitch).
-
10 knots prior to liftoff speed when MIL takeoff, 15 knots prior when MAXAB.
Now all you have to do is calculate liftoff speed.
-
WDP but I just rotate at 170 and never have any issues
-
Not sure where I got this, thought it was in Docs folder but can’t find it there. Hopefully this will work.
-
Attachments did not open, post a screenshot if possible.
Thanks for the response.
-
Great, now how to come up with liftoff speed ???
Thanks for the response
-
@StevieG - Alright, will download that too. But I had a lot of other things to learn so I was hopping to do this later.
Thanks for the reply
-
Been doing lift off in various flavours of falcon for as long as its been around, and never calculated Rotation/lift-off speeds. (not saying its the correct procedure), but rule of thumb is AA loadout pull gently and gradually on stick @ 170knots, AG or heavy loadout pull 180knots, and wait for lift-off. Once you are airborne and past 20knots, you can start to pull to get 5deg on the FPM (but note you are likely going to be more than 10d AOA) here. BMS is quite forgiving with the take off speed.
Trying to get focus on and get an exact pull up point is going the cause you yank on the stick, and cause some damage before even getting airborne. Better to do an early/late rotation gently, than an aggressive one at the ‘theoretical’ rotation speed.
-
Hopefully this will work … two jpegs
https://www.dropbox.com/s/25rfwmjqqb5iafh/Approach.jpeg?dl=0
https://www.dropbox.com/s/pnxv8xo5suq6g83/Takeoff.jpeg?dl=0Added file link
-
There’s a chart but it’s practically a straight line. Doing a regression on it it can be turned into a formula: 70 knots plus 3x GW in thousands of pounds. That’s within a couple knots everywhere spot checking. The part we’re missing is subtracting/adding 0.8kt per %MAC for %MAC aft/forward of 35% because we don’t have balance info. I don’t know how much CG is different in BMS for various loadouts.
-
Hi, can anybody please share how to calculate the rotation (take off) speed. As we know it can change depending on the loadout and I some time face difficulty getting off the ground due to wrong timing.
Thanks.
It’s pretty cheesy but I find if you just set your pitch-trim all the way up, your plane will rotate for you … before you can blink your nose will be above 10deg so be ready to control the attitude, and hit the trim-reset switch.
Basically practice for a carrier launch.
-
I do that without even moving my Trim…the nose wheel will just lift at some point, and all you need do is feed in a light back pressure to get a smooth liftoff.
-
Been doing lift off in various flavours of falcon for as long as its been around, and never calculated Rotation/lift-off speeds. (not saying its the correct procedure), but rule of thumb is AA loadout pull gently and gradually on stick @ 170knots, AG or heavy loadout pull 180knots, and wait for lift-off. Once you are airborne and past 20knots, you can start to pull to get 5deg on the FPM (but note you are likely going to be more than 10d AOA) here. BMS is quite forgiving with the take off speed.
Trying to get focus on and get an exact pull up point is going the cause you yank on the stick, and cause some damage before even getting airborne. Better to do an early/late rotation gently, than an aggressive one at the ‘theoretical’ rotation speed.
Noted, Thanks.
-
I do that without even moving my Trim…the nose wheel will just lift at some point, and all you need do is feed in a light back pressure to get a smooth liftoff.
Never noticed this. Gotta give this a try. I heard JF-17 in DCS does this, (It even rotates and achieves a positive rate of climb). I’ll try this. Thanks
-
It’s pretty cheesy but I find if you just set your pitch-trim all the way up, your plane will rotate for you … before you can blink your nose will be above 10deg so be ready to control the attitude, and hit the trim-reset switch.
Basically practice for a carrier launch.
Gotcha. Thanks.
-
There’s a chart but it’s practically a straight line. Doing a regression on it it can be turned into a formula: 70 knots plus 3x GW in thousands of pounds. That’s within a couple knots everywhere spot checking. The part we’re missing is subtracting/adding 0.8kt per %MAC for %MAC aft/forward of 35% because we don’t have balance info. I don’t know how much CG is different in BMS for various loadouts.
Noted, Thanks
-
Never noticed this. Gotta give this a try. I heard JF-17 in DCS does this, (It even rotates and achieves a positive rate of climb). I’ll try this. Thanks
I think most jets do this, when properly trimmed for takeoff - the nosewheel will generally lift off before the jet is actually ready to fly in some cases, but the nosewheel lifting off is your cue to feed in a little back pressure.