danger of turboprop aircrafts

[NovaBoy]

I fear for my life everytime they make me fly the King Air

[rigpiggy]

What makes you say that?

Which way does the aerofoil face on most non the tails?

Just because a lot of them point down a bit, doesn't mean that you need to be outside the back of the envelope, let alone 'dangerously' out the back of the envelope in order for them to provide upward lift.

During normal operations of an aircraft, it's perfectly possible that a tail will generate lift. You might not need as much positive lift as you might need downward force at some point in the flight, but you might encounter a lifting tail.

Remember, the more downwards force the tail generates, the more upwards force the wing needs to generate, and the less efficient your plane is. Ideally you'd have a tail that generates neither up nor down force. But that plane would be uncontrollable.


Some examples:

source: https://en.wikipedia.org/wiki/Center_of ... t_aircraft

This data strongly suggests that a CoG can be put behind the CoL of the main wing, which almost guarantees that the tail will have to lift.
Note the 'almost', as there are some extra forces due to drag on the fuselage which may create a nose up or nose down moment and could theoretically cancel out the need for a positive tail lift, but it seems highly unlikely they would be big enough to actually do so.

So the CoG position is located as indicated above. The CoL of a wing is usually located around the 25% MAC position. That leaves ample margin to determine with some degree of certainty that the 737, 767 and 747 will generate upwards lift on the tail at some point.


Or, see the discussion here: viewtopic.php?t=87966

Remember swept wing jets have area far behind the cg supplying upward
where do you measure the cg?

[‘Bob’]

On the MEAN AERODYNAMIC CHORD.

Swept wings are literally why we use MAC.

[YYCAME]

I guess it's only a matter of time until AI bots start posting on forums and learning from the responses as a way to train them.

[W5]

Personally I thought it was the noise. (Darts anyone?)

[tsgarp]

Reminds me of Olivia Chow talking about turboprops when she was fighting the bridge to the CYTZ…