Learn Hardcore German: Das Flugzeug landet heute später.

Flugzeug is neuter, so its definite article in the nominative singular is das.
der would be for masculine nouns (e.g. der Tisch – the table).
die would be for feminine nouns in the singular (e.g. die Tasche) and all nouns in the plural (e.g. die Flugzeuge – the airplanes).

A useful pattern: many neuter nouns ending in -zeug (tool/device) are neuter:

das Flugzeug (airplane)
das Feuerzeug (lighter)
das Spielzeug (toy)

What grammatical role does das Flugzeug have here, and which case is it in?

Das Flugzeug is the subject of the sentence – it is the thing that is doing the action (landing).

Subjects in German take the nominative case, so das here is the nominative singular neuter article.

You can also see this from the verb:

landen is intransitive here – it does not take a direct object, so there is no accusative noun.
The only noun phrase is das Flugzeug, so it must be the subject → nominative.

What form of the verb is landet, and how is landen conjugated?

Landet is:

present tense (Präsens)
3rd person singular
of the verb landen (to land)

Basic present-tense conjugation of landen:

ich lande – I land
du landest – you land (informal singular)
er / sie / es landet – he / she / it lands
wir landen – we land
ihr landet – you land (informal plural)
sie / Sie landen – they / you (formal) land

So in the sentence, landet matches das Flugzeug (3rd person singular).

Does landet mean “lands”, “is landing”, or “will land”?

It can correspond to all three, depending on context. German Präsens covers several English uses:

Simple present:
Das Flugzeug landet immer um 14 Uhr.
The plane lands at 2 p.m. every day.
Present progressive:
Das Flugzeug landet gerade.
The plane is landing right now.
Near future (with a time expression, like in your sentence):
Das Flugzeug landet heute später.
The plane will land later today / is landing later today.

So here, because of heute and später, the natural English translation uses a future meaning: will land or is going to land.

Why doesn’t German use a separate continuous tense (“is landing”) like English?

German does not have a separate grammatical “continuous/progressive” tense. There is only one present tense form (landet) for both:

The plane lands.
The plane is landing.

If you want to emphasize “right now” in German, you usually add an adverb:

Das Flugzeug landet gerade / jetzt.
The plane is landing right now.

But grammatically, the verb form is still just Präsens.

Why is the verb landet in the second position in the sentence?

German main clauses follow the verb-second rule (V2):

The finite verb (here: landet) must appear in the second position of the clause.
“Position” means second element/constituent, not second word.

In your sentence:

Das Flugzeug – first element (subject)
landet – finite verb → must be here
heute später – adverbials (time)

You cannot say: *Das Flugzeug heute später landet. in a main clause; that would violate the V2 rule.
(However, in a subordinate clause with dass you can: …, dass das Flugzeug heute später landet.)

Can I start the sentence with heute instead? For example: Heute landet das Flugzeug später.

Yes, and this is very natural German. Word order in main clauses is fairly flexible as long as the verb is in second position:

Das Flugzeug landet heute später.
Heute landet das Flugzeug später.

Both are correct. The difference is emphasis:

Starting with Das Flugzeug: neutral focus on the plane.
Starting with Heute: you emphasize today (as opposed to other days):
Today the plane is landing later (than usual).

In both cases, the verb landet must stay in second position.

Why is the order heute später and not später heute?

Both heute später and später heute are technically possible combinations of time adverbs, but they feel different and are not equally common:

heute später in Das Flugzeug landet heute später. is the standard reading “today it lands later (than usual)”.
- heute sets the day (today).
- später modifies when on that day (later than normal).
später heute (später heute landet das Flugzeug) is much less common and sounds marked/awkward in many contexts. If used, it tends to mean “later today” as opposed to “earlier today”, but most native speakers would normally rephrase:
- Das Flugzeug landet später am Tag. (later in the day)
- Das Flugzeug landet später heute Abend. (later this evening)

For learners, the safest and most natural patterns here are:

Das Flugzeug landet heute später.
Heute landet das Flugzeug später.

Why isn’t there a comma between heute and später?

Because heute and später are just two adverbs in a row, not separate clauses or items in a list that require a comma.

German does not put a comma between every pair of adverbs. You simply say:

Das Flugzeug landet heute später.
Er kommt morgen früh. (tomorrow morning)
Wir treffen uns heute Abend.

Commas are mainly for separating clauses, some types of infinitive phrases, and elements in certain lists – not for simple adverb sequences like this.

What part of speech are heute and später here?

Both are adverbs in this sentence.

heute = today (time adverb)
später = later (time adverb, the comparative of spät = late)

Together they answer the question Wann? (When?):

Wann landet das Flugzeug? – Heute (und zwar) später.

Note: später is not an adjective here (it is not describing a noun), it is directly modifying the verb landet.

Why is there no preposition or article with heute? Why not am heute?

Words like:

heute (today)
gestern (yesterday)
morgen (tomorrow)

are pure adverbs, not nouns, so:

They don’t take an article: you never say das heute, ein gestern, etc.
They don’t need a preposition to express time.

You simply say:

Ich fliege heute. – I’m flying today.
Er ist gestern angekommen. – He arrived yesterday.

You use am + day name when it’s a noun:

am Montag (on Monday)
am Dienstagabend (on Tuesday evening)

But heute itself is not a noun, so you just say heute, not am heute.

Why is Flugzeug capitalized?

In German, all nouns are capitalized, regardless of where they appear in the sentence.

das Flugzeug – airplane
der Flughafen – airport
die Ankunft – arrival

Even in the middle of a sentence, they stay capitalized:

Das Flugzeug landet heute später.
Ich warte auf das Flugzeug.

Verbs, adjectives, and adverbs are normally not capitalized (unless they are at the start of a sentence or part of a proper name).

Is Flugzeug singular or plural here? How would I say “The planes land later today”?

In your sentence, Flugzeug is singular:

das Flugzeug – the airplane (singular)
verb: landet – 3rd person singular

To make it plural:

die Flugzeuge – the airplanes
verb must also be plural: landen

So the plural version of your sentence would be:

Die Flugzeuge landen heute später.
The planes land later today / The planes will land later today.

Could I use ankommen instead of landen here? What’s the difference?

You could, but it changes the nuance slightly.

landen = to land (physically touch down).
Used specifically for aircraft (and also birds, spacecraft, etc.).
- Das Flugzeug landet heute später.
  Focus on the landing as a physical act.
ankommen = to arrive.
More general; used for all kinds of transport (trains, buses, planes).
- Der Flug kommt heute später an.
  The flight arrives later today.

For a plane, both are possible:

Das Flugzeug landet später. (the airplane lands later)
Der Flug kommt später an. (the flight arrives later)

In schedules and announcements, ankommen with der Flug or die Maschine is very common; landen focuses more on the pilot/aircraft actually touching down.

Could I say Das Flugzeug wird heute später landen instead? Is that more “future”?

Yes, you can:

Das Flugzeug wird heute später landen.

This uses the Futur I tense (wird + infinitive landen), which is formally a future tense.

However, in everyday German:

The present tense with a time expression (Das Flugzeug landet heute später.) is usually preferred and sounds more natural.
Futur I is used when:
- you want to sound a bit more formal, or
- you’re making a prediction or assumption:
  Das Flugzeug wird wohl später landen. – The plane will probably land later.

For talking about scheduled events like timetables, the present tense (landet) with a time adverb (heute, später) is perfectly normal and very common.