That ain't no airplane. Look.

5 seconds sound clip from the Back to the Future movie soundboard.

You can hear this line at 00:32:06 in the Blu-ray version of the movie.

Quote context

[...]

(TIRES SQUEALING)

(SCREAMING)

(DELOREAN CRASHING)

- What is it? What is it, Pa?

- Looks like an airplane without wings.

- That ain't no airplane. Look.

(SCREAMING) (2)

- Children!

- Listen... Whoa.

(COWS MOOING)

[...]