Look! Up in the sky! It’s a bird! It’s a plane! Well, it may also be a helicopter.

In addition to birds and planes, Philadelphians and people in surrounding areas may also see their fair share of helicopters, since the aircraft has the ability to take off and land vertically — without needing a runway — and to hover for an extended period of time.

Following last week’s fatal helicopter crash in New York City, an Inquirer reader contacted Curious Philly, our Q&A forum that allows readers to send us questions, wondering why so many helicopters regularly fly over Philly, and why he can see aircraft flying so close to his rooftop.

According to the Federal Aviation Administration handbook, a helicopter is often chosen "to conduct tasks that were previously not possible with other aircraft or were too time -or work-intensive to accomplish on the ground.”

In Philly, those uses include medical transports, police and military operations, news crews, and tours.

According to Sterling Helicopter, a Philly heliport based near Penn’s Landing along the Delaware riverfront, the heliport sees about 3,000 to 4,000 landings each year. At minimum, that racks up an average of eight landings a day for the heliport.

Dawn Fithian, Sterling Helicopter’s office manager and CFO, said these landings typically fall under public service — emergency medical services, police, and military.

Philadelphia is a medical hub, with multiple hospitals receiving trauma victims via helicopter.

The Philadelphia Police Department has four helicopters that are deployed daily for patrol and special events, according to a spokesperson for the department.

Companies also offer helicopter tours of major cities, like Philadelphia and New York.

And television and radio stations also often use the aircraft to report on traffic situations, breaking news, and more.

However, although they can be spotted in the city, a helicopter flying over a densely populated area — like Philadelphia — must be flown at an altitude of 1,000 feet above the highest obstacle or building, according to FAA regulations.

To put that height into perspective, the tallest building in Philadelphia is the new Comcast Technology Center in Center City at 1,121 feet.

Additionally, outside of the city, in areas over open water or sparsely populated, helicopters may not be flown closer than 500 feet to any person or thing.