Saat turbulensi mulai terasa, pramugari meminta semua penumpang kembali ke kursi mereka.

Yes. Saat means when or at the moment when.

In this sentence, Saat turbulensi mulai terasa means When the turbulence started to be felt / When the turbulence began to be noticeable.

You could also say:

• Ketika turbulensi mulai terasa
• Waktu turbulensi mulai terasa

All three are natural. Very roughly:

• saat = a bit neutral/written
• ketika = also common and slightly formal
• waktu = very common in everyday speech

So they are often interchangeable here.

Because terasa means to be felt or to become noticeable, while merasa means to feel in the sense of someone feels something.

Compare:

• Saya merasa takut. = I feel scared.
• Getarannya terasa. = The vibration can be felt.

In your sentence, the subject is turbulensi, not the passengers. The idea is that the turbulence became noticeable / could be felt, so terasa is the right choice.

If you used merasa, you would need a person as the subject, for example:

• Penumpang mulai merasa turbulensi. = The passengers began to feel the turbulence.

Terasa comes from rasa and often means:

• felt
• noticeable
• perceptible
• sometimes seems or comes across as

In this sentence, mulai terasa means started to be felt or started to become noticeable.

This is a very common Indonesian pattern:

• Rasa sakitnya mulai terasa. = The pain is starting to be felt.
• Dingin sekali, ya. Anginnya terasa. = It’s really cold, huh. You can feel the wind.

So terasa often describes an experience without directly naming who experiences it.

Yes. Pramugari traditionally refers to a female flight attendant.

Related words:

• pramugari = female flight attendant
• pramugara = male flight attendant
• awak kabin = cabin crew, more gender-neutral

So if the person is known to be female, pramugari is fine. If you want a neutral term, awak kabin is often a good choice.

Literally, meminta usually means to ask or to request.

In this sentence, it means the flight attendant asked/requested all passengers to return to their seats. In real-life context, that can function like an instruction, but the word itself is softer than memerintahkan or menyuruh.

Compare:

• meminta = ask, request
• menyuruh = tell someone to do something
• memerintahkan = order, command

So pramugari meminta semua penumpang kembali ke kursi mereka sounds natural and polite.

Because in Indonesian, after verbs like meminta, you can often directly follow with the person and the action.

So this structure is normal:

• meminta semua penumpang kembali ke kursi mereka

It means:

• asked all passengers to return to their seats

You can also say:

• meminta semua penumpang untuk kembali ke kursi mereka

This is also correct. The version without untuk is often more direct and natural.

A useful pattern is:

• meminta + person + verb

For example:

• Dia meminta saya menunggu. = He asked me to wait.
• Guru meminta murid-murid duduk. = The teacher asked the students to sit down.

Semua penumpang is the standard way to say all passengers.

• semua penumpang = all passengers

Penumpang semua can occur in conversation, but it sounds more colloquial and often more like the passengers, all of them. It is not the most neutral choice here.

For a clear, standard sentence, semua penumpang is best.

Other examples:

• semua siswa = all students
• semua orang = everyone
• semua tamu = all guests

Because the meaning is specifically return to their seats, not just sit.

• duduk = sit / be seated
• kembali ke kursi mereka = return to their seats

On an airplane, passengers may already have assigned seats, so kembali ke kursi mereka is more precise. It tells them to go back to the seats they were in before.

A shorter alternative could be:

• Pramugari meminta semua penumpang kembali ke tempat duduk mereka.

That is also very natural.

In Indonesian, mereka can also function like their.

So:

• kursi mereka = their seats

This is normal and very common.

However, Indonesian sometimes avoids possessives if the meaning is already obvious, so you might also hear:

• kembali ke kursi masing-masing = return to their respective seats
• kembali ke tempat duduk masing-masing

Masing-masing is especially useful when you want to emphasize each person’s own seat.

Both are correct, but tempat duduk mereka is often a little more natural in transportation contexts.

Compare:

• kursi mereka = their chairs/seats
• tempat duduk mereka = their seats

On a plane, bus, or train, tempat duduk often sounds slightly more idiomatic because it clearly means seat rather than just chair.

So these are both good:

• kembali ke kursi mereka
• kembali ke tempat duduk mereka

And these are also very natural:

• kembali ke kursi masing-masing
• kembali ke tempat duduk masing-masing

The comma separates the time clause from the main clause.

• Saat turbulensi mulai terasa = time/background clause
• pramugari meminta semua penumpang kembali ke kursi mereka = main clause

So the sentence structure is:

• When X happened, Y happened.

In English, this is similar to writing:

• When the turbulence began to be felt, the flight attendant asked all passengers to return to their seats.

The comma helps the sentence read more clearly. In Indonesian, punctuation is often a bit flexible in casual writing, but the comma here is perfectly normal.

Yes. The original sentence is good, but here are some natural alternatives:

• Saat turbulensi mulai terasa, pramugari meminta semua penumpang kembali ke tempat duduk mereka.
• Ketika turbulensi mulai terasa, pramugari meminta semua penumpang kembali ke kursi masing-masing.
• Begitu turbulensi mulai terasa, pramugari meminta semua penumpang kembali ke tempat duduk masing-masing.

Notes:

• begitu gives more of a sense of as soon as
• tempat duduk often sounds slightly more natural than kursi for transport seating
• masing-masing is very good for their own respective seats

So the original sentence is correct, but there are several natural variations depending on tone and style.