Can somebody help me with this?
Although the discribed image is quite visible, I cannot get my head around the structure of the sentence which I put here in brackets. It seems to me unfinished.
Unfortunately, I do not have the original text and could rely only on audio: https://voca.ro/1jYF9XNStdVJ

And one more point about the verb "to crinkle". Can "white walls CRINLE a hilltop" or should be there another verb?
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"With the ships looking like toys I take position well to the left of the CO, while the other three Spitfires which I have to lead clamber into formation behind me...
...A disturbance of colour on the horizon is growing steadily nearer. From navigational logic it's just where I expected it to be. We are changing formation. Each section of four aircraft has now become a tightly packed arrowhead. (As the apex of the left hand arrow might outstretch elliptical wings, that overlapped by other wings, for three profile Spitfires are sliding downwards beside me.) Two islands like two autumn leaves floating on the water grow larger and larger. The steep cliffs of the smaller and nearer which must be go over a Malta line, beyond it, rush towards us. White walls crinkle a hilltop."

Question

Can somebody help me with this?
Although the discribed image is quite visible, I cannot get my head around the structure of the sentence which I put here in brackets. It seems to me unfinished.
Unfortunately, I do not have the original text and could rely only on audio: https://voca.ro/1jYF9XNStdVJ

And one more point about the verb "to crinkle". Can "white walls CRINLE a hilltop" or should be there another verb?
____________________
"With the ships looking like toys I take position well to the left of the CO, while the other three Spitfires which I have to lead clamber into formation behind me... 
...A disturbance of colour on the horizon is growing steadily nearer. From navigational logic it's just where I expected it to be. We are changing formation. Each section of four aircraft has now become a tightly packed arrowhead. (As the apex of the left hand arrow might  outstretch elliptical wings, that overlapped by other wings, for three profile Spitfires are sliding downwards beside me.) Two islands like two autumn leaves floating on the water grow larger and larger. The steep cliffs of the smaller and nearer which must be go over a Malta line, beyond it, rush towards us. White walls crinkle a hilltop."

Answer

The recording clearly says "crinkle."

This might be a regional or archaic use of crinkle to indicate an uneven appearance.

Answer

As a native speaker, this is a challenge to imagine.
He is describing the way a formation of fighter planes shift and move into various shapes.
(I am guessing World War 2?)
And "Crinkle" is the wrong verb. What are you trying to express? Perhaps I can give you a different verb.

Answer

Also, I'll add that "crinkle" is usually an intransitive verb ["my face crinkled"], but as here, it can be used as a transitive verb ["a smile crinkled my face"].

Answer

"Crinkle" is probably an unusual verb to use here. The effect is metaphorical (as is much of this writing). But grammatically, it's certainly a complete sentence. Anyway, "Crinkle" here has the definition: "to form small creases or wrinkles in the surface of something".

Honestly it's beyond my powers to visualize the sentence in parentheses. But perhaps my correction of the text below will help you. I'll also give you the sentence with commas where I would have placed them. Perhaps that will help.

If you transcribed this from the audio clip, I'd say you did an excellent job. I'm not sure I could have done any better. However, I was able to find the original text and so have a couple of corrections below:

"As the apex of the left hand arrow my outstretched elliptical wings are overlapped,"

[My punctuation of the whole sentence: "As the apex of the left hand arrow, my outstretched elliptical wings are overlapped by other wings, for three profile Spitfires are sliding downwards beside me.

"The steep cliffs of the smaller and nearer which must be Gozo with Malta lying beyond it, rush towards us."

Text is here: https://books.google.ca/books?id=v8d1DwAAQBAJ&pg=PT73&lpg=PT73&dq=%22A+disturbance+of+colour+on+the+horizon+is+growing+steadily+nearer.%22&source=bl&ots=ye9K46JwMa&sig=ACfU3U2L9wKAKmRTW2vc5QuSd29U-Qtd0w&hl=en&sa=X&ved=2ahUKEwiAos_0q4bzAhWJct8KHUa3BdAQ6AF6BAgCEAM#v=onepage&q=%22A%20disturbance%20of%20colour%20on%20the%20horizon%20is%20growing%20steadily%20nearer.%22&f=false

Answer

I would say it was poetic usage.

The white walls look similar to crinkled paper against the hills i.e. not in straight lines.