Week 4 Period: Energy

Altitude and airspeed are one quantity in two denominations, and every manoeuvre is a transaction in it

15 March 2027

Before you arrive#

Read the specific energy section of the notes and attempt the six worked problems. Bring your working, including the ones you got wrong.

In this period#

Altitude is stored airspeed, and airspeed is altitude not yet climbed to. Both are one quantity — specific energy — held in two denominations, and the aircraft, not you, sets the rate at which you exchange between them.

Two things act on the account:

• the engine adds to it
• drag withdraws from it continuously, without asking

Everything else is a transfer between the two columns, and the transfer is lossy in one direction only: altitude converts to speed almost perfectly, speed converts to altitude rather less so.

This is why the answer to being low and slow is not “pull up.” Pulling up spends the denomination you are short of to buy the other one you are also short of, at a poor rate, while drag charges for the privilege. The manoeuvre feels like a solution and is a second problem.

By week 7 you fly a circuit: a sequence of deliberate energy decisions ending with almost none left at a point chosen in advance. Today is where that arithmetic starts.

Afterwards#

Compute the specific energy at every corner of the standard circuit from the published profile. You will use these numbers for the rest of the course.