Lift off Speed
- Thread starter dtreid
- Start date
Dan Cullman
New member
You'd better not be watching your instrument panel at this time. You should be looking down the runway and the environment you're getting ready launch into. It'll fly when it is ready.
Dan
Dan
kitepilot
New member
'nuff said...Dan Cullman said:
Things to remember:
Airspeed is the result of AOA.
The stall happens when the wing exceeds the 'Critical Angle Of Attack' (regardless of IAS).
More weight will demand a higher IAS at the same AOA to generate enough lift to hold altitude (which also means that you will stall at a higher IAS with more weight but *STILL* at the same 'Critical Angle Of Attack').
The 'attitude' of the aircraft (how high/low the nose is over the horizon) is *NOT* necessarily an indication of your AOA, but most times they are equivalent.
AOA can be safely (and grossly) oversimplified to equate to 'attitude of the aircraft' at the takeoff moment (and in still air).
The 'attitude' of a taildragger aircraft on the ground is roughly consistent with an 'at the edge of stall' AOA, but not stalled.
In a '3-point' takeoff, you just accelerate the airplane until all three wheels leave the planet at the same time (just above stall), without changing the 'attitude' (or AOA).
That's also why a '3-point landing' will place the wheels in the runway at the same time (with the aircraft still barely flying) while a 'full-stall' landing will contact the tail wheel before the mains make contact.
With that said (and addressing what I believe it to be a more 'reasonable' question), getting off the ground is one thing, climbing above obstacles right after it is a total different thing, and 'climbing to cruise altitude' is an entirely different subject.
So lets break it down:
When do you get off the ground?
Whenever she feels like it...
You *WILL NOT* make an airplane fly from the cockpit.
That steering wheel in front of you is not the 'Anti-gravity' control.
That's the reason why you *KNOW* (you do, don't you?) the length of the runway and the performance of your aircraft given atmospheric, runway surface and loading conditions; so you can say: "If I am not flying when I go by this beer can, I'm pulling the plug..."
And *ALWAYS* remember: the fact that you are airborne doesn't mean that you are flying!
Ground effect!
Ground effect!
Ground effect!
And climbing 'at the edge of stall' is generally a bad idea too!
No 2 takeoffs are alike (taking off from Leadville CO requires a different planning that taking off from Vero Beach FL) but I normally accelerate to 'climb-over-the-first-obstacle' speed under ground effect. Less wear and tear, bumping and grinding.
If you know your aircraft, you don't *NEED* to see the airspeed indicator, you know your speed in your nose, your trim, your power settings and your overall 'feel' of the aircraft. But there is no harm to glance down and validate against it.
Remember that gauges can fail, and it sucks to break an aircraft because you have a frozen needle!
In a *VERY* short runway, I regularly climb over the obstacle not slower than 55, and that's until I clear the trees.
If that engine coughs climbing at 55, you are riding a piano to the ground...
After that, I just climb at a higher airspeed as I am gaining altitude, to keep visibility over the nose and to keep the engine cool.
In a 'normal' (documented) aircraft, you could extract from the manual the IAS at which the aircraft was tested, but in the case of the Crusair (where every bird is its own), I'd take it to altitude and stall it (mine just doesn't), and then explore several scenarios of climb rates and IAS.
Don't forget to test emergencies too, $H!T happens!
ET
Man, have you seen what soapboxes are going for lately...
blimpy
New member
On normal take offs, I use 60, and climb out at 85.
You can use 2nd notch of flaps and get it off earlier, but you'll want to accelerate in ground effect
to a decent airspeed before climbing out. And what Dan Said !
This is handy for soft/rough fields where it is pretty much SOP.. although with lots of loose sharp rocks
you gotta think that through.
But mix this with high density altitudes and you need to heed dan's advice, and know your plane. :wink:
You can use 2nd notch of flaps and get it off earlier, but you'll want to accelerate in ground effect
to a decent airspeed before climbing out. And what Dan Said !
This is handy for soft/rough fields where it is pretty much SOP.. although with lots of loose sharp rocks
you gotta think that through.
But mix this with high density altitudes and you need to heed dan's advice, and know your plane. :wink: