Part 8 of ”Aspects of Aircraft Design and Control”
We are almost done with a series of posts about an aeronautical engineering course I created this year.
Lecture 8 — Longitudinal stability
Project 8 — Designing Canards
The objective of this eighth and final project was to explore the notion of longitudinal stability and the constraints it imposes on aircraft design and operation. The accompanying lecture is focused tightly on the concept of stability and the tools needed to solve the problem.
The lecture tackles the notion of stability in a very progressive and visual way. It is one great virtue of such informal, project-based lectures that they let us focus on the essential only. Here, all subtleties such as tail/wing interaction, their respective efficiencies, vertical offsets, or dynamic effects are left aside, leaving us to work on the very concept of stability un-distracted.
The last part of the lecture is dedicated to answering the question “how can canard aircraft be stable?”, which if done correctly, neatly captures the concept of, and constraints brought by, longitudinal stability.
As a whole, the lecture is short, neat, and leaves me very satisfied.
The project problem can be solved rather easily (only three sets of two simple equations need be solved) but leaves room for experimentation and initiative; the balance was struck in the right place.
I wanted to alleviate the work load on the students, who were caught within multiple deadlines, as well as hasten the publication of the final results (my experience is that when marks cannot be avoided, giving out marks promptly is one of the most effective ways of keeping students motivated and enabling them to improve). Therefore, I proposed that the project be completed in-class within four hours, and the class accepted. Working with a close-by deadline tremendously increases productivity but this comes at the cost of the serenity and slow-pace exploration that characterize true learning. Cutting-off students in their work at the end of the session simply reinforces the teacher-judge/taught-judged cleavage, and everyone’s frustration. I will not do this anymore next year.
All in all, a nicely constructed lecture and project. To me, the session was special in two ways. First, longitudinal stability had been a devouring, partly-unsolved center of interest ever since I studied it in university, and the first topic I ever desired to teach. Second and most important, it was the last session that I would be able to spend together with a class I’ve known for three years and with whom I’ve spent many an interesting or intense experience. Working on the design of a great-looking, terrific-sounding hypothetical aircraft was a nice way to part.