Welcome to the Home Page for:

ENAE 631


The objectives of this course are to provide an introductory treatment of the aerodynamic theory of rotary-wing aircraft, including basic performance, control, and basic rotor dynamics. Prerequisites are a understanding of elementary aerodynamics and dynamics. Students should have taken two courses in aerodynamics at the undergraduate level. Students should also have an elementary background in computer programming.

Office Hours
Assessment Method
Homework Policy
Homework Problem Sets
Technical Essay
History of Rotorcraft
Specialist Topics
Course Outline


Prof. J. Gordon Leishman, Room 3179C,

Office Hours:

Open. Unavailable Tuesday and Thursdays until 11am (Reserved for ENAE 488A students). Only by prior appoinments on Fridays. Otherwise, you are welcome to come and see the instructor at anytime during regular office hours, workload permitting. Call or email first!


Students may use email as a means of interacting with the instructor. Make sure you have a computer account. Class announcements will often be made by email. Click here to email: J. Gordon Leishman.

Please do not send homework assignments by email (see homework requirements below).

Assessment Method:

  1. Homework (70%)
  2. Technical Essay (15%)
  3. Final Exam (15%).

Homework Policy:

Homework Problem Sets (posted here when made available)

Homework #1. Posted 9/1/05. Due 9/13/05.

Homework #2. Posted 9/16/05. Due 9/27/05.

Homework #3. Posted 10/7/05. Due 10/17/05

Homework #4.  Posted 10/18/05. Due 11/1/05

Homework #5. Posted 11/17/05. Due 11/24/05

Homework #6. Posted 11/29/05. Due 12/08/05

Download Introductory Slides for ENAE 631 here:

Technical Essay:




The ideas of vertical flight can be traced back to early Chinese tops, a toy first used about 400 BC. Amongst his many elaborate drawings, the Renaissance visionary Leonardo da Vinci shows what is a basic human-carrying helicopterlike machine. His sketch of the "aerial-screw" or "air gyroscope" device is dated to 1483 but it was first published nearly three centuries later. Da Vinci clearly did not build his machine, except perhaps for some small models, but his idea was clearly far ahead of its time. Read more....

  1. Article on Breguet Quadrotor
  2. Article on Cornu Helicopter

Specialist Topics:

  1. Singles versus tandems versus coaxials
  2. Vortex ring state
  3. BERP rotor.
  4. Tail rotors

Course outline (not necessarily covered in order stated):

1. Introduction: A History of Helicopter Flight

2. Fundamentals of Rotor Aerodynamics

3. Blade Element Analysis

4. Rotating Blade Motion

5. Basic Helicopter Performance

6. Conceptual Design of Helicopters

Go back to the Rotorcraft Aerodynamics main page