You can buy TM40 Aerial Ace from the Technical Machine Shop located in Konikoni City. You will also be able to buy another four TMs from this same shop: TM09, TM47, TM51 and TM78.
Konikoni City is located on Akala Island. You will gain access to the city once you complete the Lush Jungle trial.
Getting TM40 Aerial Ace (Step-by-Step)
While playing through the main story, you will first enter Konikoni City from the south.
Step 1: From the southern entrance, walk north along the main street.
Step 2: Continue walking north along the main street and head to the second stall on the left side. You’ll see a signpost with a CD-disc icon in the front.
Step 3: Talk to the stall’s vendor in order to access the Technical Machine Shop. Select “Buy” from the menu.
Step 4: Select Aerial Ace, which is the second item from top to bottom. It will cost 10,000 PokéDollars.
Aerial Ace Details + Use
|Aerial Ace Move Details
Aerial Ace is a damage-dealing move that bypasses accuracy checks.
Because of its low base power, Aerial Ace isn’t viable in competitive play. Brave Bird and Acrobatics are better alternatives as physical, Flying-type moves.
In a main story playthrough, on the other hand, Aerial Ace is a good early game move.
With 60 base power, Aerial Ace will deal decent damage with a Flying STAB. The secondary effect, bypassing accuracy checks, is also a nice advantage.
Combined with its early availability, Aerial Ace is a very good option for physical Flying-type Pokémon. Although later in the game Aerial Ace becomes replaceable with better moves.