3 questions...
Thread Starter
Joined: Jul 2003
Posts: 14
Likes: 0
From: Europe
3 questions...
Hi guys, 3 questions that I don't succeed to understand, and in which I don't agree with the answer given. Can anyone help me?
thanks a lot
1)An aircraft is in straight and level flight and has a CL of 0.42 and a 1 degree increase in angle of attack would increase the CL by 0.1. The aircraft experiences a gust which increases the angle of attack by 3 degrees, what load factor would the aircraft be subject to?
2)If the maximum force acceptable is 50lbs and the design limit g of the aircraft is 6g, what is the stick force/g that must be achieved to permit the aircraft to be manoeuvred to its design limit?
3)At a true airspeed of 300kts what turn radius would be achieved in a 45 degree bank if g = 10m/s squared
in this one I've answered 9000m but it was said the right answer is 2387...why?
thanks a lot
1)An aircraft is in straight and level flight and has a CL of 0.42 and a 1 degree increase in angle of attack would increase the CL by 0.1. The aircraft experiences a gust which increases the angle of attack by 3 degrees, what load factor would the aircraft be subject to?
2)If the maximum force acceptable is 50lbs and the design limit g of the aircraft is 6g, what is the stick force/g that must be achieved to permit the aircraft to be manoeuvred to its design limit?
3)At a true airspeed of 300kts what turn radius would be achieved in a 45 degree bank if g = 10m/s squared
in this one I've answered 9000m but it was said the right answer is 2387...why?
Joined: May 2002
Posts: 379
Likes: 4
From: Sale
My guesses are:
1. 3 degrees would add 3 * 0.1 to CL giving a CL of 0.72 instead of 0.42. This is an increase of 0.72 / 0.42 = 1.7 ish.
2. 50 lbs total max force. 6g max LF therefore stickforce gradient is 50/6 = 8.3lbs/g
3. use r = V(squared) / (g x tan (angle of bank)
The important bit to remember is to have the same units i.e. convert knots to m/s i.e. 300 kts = 300 kts x 1852 m / 3600 secs = 154 m/s. This gives the right answer.
I think that's all correct, but it's been a while since I used my brain.
FIS
1. 3 degrees would add 3 * 0.1 to CL giving a CL of 0.72 instead of 0.42. This is an increase of 0.72 / 0.42 = 1.7 ish.
2. 50 lbs total max force. 6g max LF therefore stickforce gradient is 50/6 = 8.3lbs/g
3. use r = V(squared) / (g x tan (angle of bank)
The important bit to remember is to have the same units i.e. convert knots to m/s i.e. 300 kts = 300 kts x 1852 m / 3600 secs = 154 m/s. This gives the right answer.
I think that's all correct, but it's been a while since I used my brain.
FIS
