To: Nick Lappos
Quite possibly you have proven my point. In Georgia Tech… How about your design section at Sikorsky. In calculating the loads on the rotorhead do they deal with centripetal force or centrifugal force? Go over to the technical school and ask them how they teach aerodynamics of the helicopter. I’m sure they are still using the blue book and it deals with centrifugal force just as I quoted above. How about when you get into a conversation with your fellow pilots and the subject of rotor dynamics comes up do you address centripetal force or centrifugal force?
I may not have your engineering background but I have over the years worked in engineering departments as a design supervisor and a senior project engineer as well as many other engineering capacities. I asked a lot of questions and kept my eyes and ears open. In almost every case when a new engineering graduate was hired they came in thinking that based on their schooling (UCLA, USC, U of M and many others to include Stamford and MIT) they were capable of designing the entire aircraft, helicopter or spacecraft. However their first job was very menial and they were told that college taught them how to think but at (Douglas, Boeing, Hughes, etc., etc. they would do it their way which did not relate to what the new engineer had learned in college.
That is why I made the comment above about selling their textbooks back to the bookstore or to a new student. They have very little relevance to what goes on in industry. At Douglas we had professors working during the summer and most of them were non-productive because they didn’t understand that Douglas was not the same as the university. The only productive professors were from Long Beach State and that was because their aero department taught the Douglas design handbook and in the drafting classes they taught the Douglas drawing system. Graduates of that program would have a good job waiting for them at Douglas because they did not require indoctrination and training.
I had a summer hire working for me at Douglas and he received a Masters in Aero-Astro Engineering from MIT. He was at that time working on a PHD at Stamford. I asked him to make a few changes on a drawing and he stated that he never had any drafting classes at MIT. At MIT he was told that when he went to work he would have other people to do the drafting. Is that how they taught in the engineering courses at Georgia Tech?
One final question. If a blade separates from the rotorhead what is the force that sends it flying off the rotorhead. What causes the resultant imbalance? Is it an imbalance of centripetal force or is it the result of the imbalance of centrifugal forces. How about when a tipcap fills up with water and the water freezes. Is it centripetal force that causes the imbalance or, is it centrifugal force?
I think you and the others that are deeply involved in engineering studies all think I am an idiot for addressing centrifugal instead of centripetal force. And, that every one else that feels that way is also an idiot because some author of an engineering text says that it is a non-force and you believed him. I think he (the author) would do the engineering student community a good service if he stated that centripetal force is a non-force and that it is the reaction to centrifugal force. It would be much easier to understand the concept.
[ 30 November 2001: Message edited by: Lu Zuckerman ]