Налобный фонарь нужен у точки разворота.

Literally, налобный means forehead/head-mounted and comes from лоб = forehead.
So налобный фонарь is a headlamp or head torch.

Also, фонарь by itself can mean things like lamp, lantern, or flashlight, depending on context. In this phrase, the whole expression clearly means a lamp worn on the head.

Not exactly. Нужен is the short-form adjective of нужный, which means necessary / needed.

In Russian, this short form is commonly used as the predicate:

• фонарь нужен = a headlamp is needed
• мне нужен фонарь = literally a headlamp is needed to me, which English translates as I need a headlamp

So even though English often uses a verb need, Russian often uses this adjective pattern instead.

Because нужен agrees with фонарь, and фонарь is masculine singular.

Compare:

• фонарь нужен — masculine singular
• лампа нужна — feminine singular
• освещение нужно — neuter singular
• фонари нужны — plural

So the form of нужен matches the gender and number of the thing that is needed.

In the present tense, Russian normally omits the verb to be.

So:

• Налобный фонарь нужен
  literally looks like Headlamp needed, but it means A headlamp is needed.

This is completely normal Russian grammar.

That is a very natural question. Russian often leaves out the person if it is:

• obvious from context, or
• not important, or
• meant as a general rule/instruction

A fuller version could be:

• Мне нужен налобный фонарь — I need a headlamp
• Вам нужен налобный фонарь — You need a headlamp

But in your sentence, the idea is more general: a headlamp is required/needed at that location.

Here у means something like by, near, or at.

So:

• у точки разворота = by / near / at the turnaround point

English often uses at, but Russian у usually gives a sense of being in the vicinity of something rather than inside it or directly on it.

Because the preposition у requires the genitive case.

The noun точка changes like this:

• nominative: точка
• genitive: точки

So:

• у точки = by / near the point

This is just a standard preposition + case pattern:

• у дома — by the house
• у дороги — by the road
• у точки — by the point

Because it depends on точка.

The phrase точка разворота means literally point of turnaround:

• точка = point
• разворота = of turnaround / of turning back

So this is a noun + dependent genitive construction, very common in Russian:

• центр города — center of the city
• начало маршрута — beginning of the route
• точка разворота — turnaround point

It is a very natural expression, especially in contexts like:

• routes
• races
• hiking instructions
• navigation
• procedures where something turns back

It literally means the point where the movement reverses direction. In English, turnaround point is a good match.

Yes. Russian word order is flexible, and changing it usually changes emphasis, not the basic meaning.

For example:

• Налобный фонарь нужен у точки разворота. — neutral
• У точки разворота нужен налобный фонарь. — emphasizes the location
• Нужен налобный фонарь у точки разворота. — emphasizes the fact that it is needed

The original order is perfectly natural.

Russian has no articles.

So налобный фонарь could mean:

• a headlamp
• the headlamp

And у точки разворота could mean:

• at a turnaround point
• at the turnaround point

Which one sounds right in English depends on the context, not on a separate word in Russian.