Madder
7th Sep 2010, 16:47
Hi guys
I do a bit of reading/brushing up just to stay sharp, and I do so by picking up Bristow's "Ace the Pilot Technical Interview". Before purchasing the book I was well aware that it contained some errors/untrue statements, and I found a few.
So I guess you just have to be that much sharper when you read it :8
So far I generally think that its a nice study aid for brush-up, and I know that a lot of my friends has used or are using it.
Perhaps we could make it better by using this thread to come up with our wrong-findings or simply ask explanatory questions, that be as well for any similar interview study book.
I have a few myself:
1) Regarding CS/VP propeller he gives the following statement, of course taken from a larger context:
"A variable-pitch propeller maximizes the propeller's efficiency through a large speed range by maintaining a constant blade angle of attack that thereby produces a constant thrust value."
In a sentence above this one, he states the complete opposite using almost the same words.
What are your thoughts on that statement?
- My own would be that a CS prop changes its propeller PITCH constantly to maintain a given revoultion setting, correcting either for increased/decreased airspeed or MP.
- I just started wondering if the statement was correct in the sense that when the factors airspeed or MP are changed, in effect the propeller AOA also changes, and to maintain a given RPM setting it changes it's pitch to maintain that AOA creating the same amount of propeller drag giving the same resistance to maintain the set number of revs.
2) What is the TRUE defintion of induced drag?
Bristows:"Induced drag is caused by creating lift with a high angle of attack that exposes more of the aircraft's surface to the relative airflow and is associated with wing-tip vortices."
My own is that ID is the vertical (rearward) compontent of Lift, opposing thrust, cannot remember if it includes vortex generated drag?
Please correct all my wrongs, as I have probably been "overthinking" the issues...:ugh:
I do a bit of reading/brushing up just to stay sharp, and I do so by picking up Bristow's "Ace the Pilot Technical Interview". Before purchasing the book I was well aware that it contained some errors/untrue statements, and I found a few.
So I guess you just have to be that much sharper when you read it :8
So far I generally think that its a nice study aid for brush-up, and I know that a lot of my friends has used or are using it.
Perhaps we could make it better by using this thread to come up with our wrong-findings or simply ask explanatory questions, that be as well for any similar interview study book.
I have a few myself:
1) Regarding CS/VP propeller he gives the following statement, of course taken from a larger context:
"A variable-pitch propeller maximizes the propeller's efficiency through a large speed range by maintaining a constant blade angle of attack that thereby produces a constant thrust value."
In a sentence above this one, he states the complete opposite using almost the same words.
What are your thoughts on that statement?
- My own would be that a CS prop changes its propeller PITCH constantly to maintain a given revoultion setting, correcting either for increased/decreased airspeed or MP.
- I just started wondering if the statement was correct in the sense that when the factors airspeed or MP are changed, in effect the propeller AOA also changes, and to maintain a given RPM setting it changes it's pitch to maintain that AOA creating the same amount of propeller drag giving the same resistance to maintain the set number of revs.
2) What is the TRUE defintion of induced drag?
Bristows:"Induced drag is caused by creating lift with a high angle of attack that exposes more of the aircraft's surface to the relative airflow and is associated with wing-tip vortices."
My own is that ID is the vertical (rearward) compontent of Lift, opposing thrust, cannot remember if it includes vortex generated drag?
Please correct all my wrongs, as I have probably been "overthinking" the issues...:ugh: