Woah that was close. Ahead of Washington plane crash, near-misses were warning signs

Pilot Mike Slack was in the cockpit during a descent into Ronald Reagan Washington National Airport nearly two decades ago when he noticed something on the runway.

Mr Slack, a licensed pilot and now aviation attorney, was sitting in the right pilot seat as his plane prepared to land on Runway 33 - the same runway the doomed American Airlines flight approached when it collided mid-air with a helicopter this week.

A departing Cessna citation plane was pulling onto the runway to take off. His aircraft quickly aborted the landing, climbed back into the sky and began circling the airport to try again - a flight manoeuvre called a sudden go-around.

"That was one of those moments you go, 'Man that was close and that was tight,'" he told the BBC.

While near-misses at the airport and across the country are far from the norm, and fatal collisions are even rarer, Wednesday's crash, in which 67 people died, has renewed calls to re-evaluate safety protocols and shone a spotlight on air traffic at Reagan National airport.

"When something like this happens, typically it's something that's slipped past many safeguards," said retired air-traffic controller Ron Bazman, whose son, wife and brother have also all worked as controllers. "Rarely is it a smoking gun."

The cause of the collision is still being determined, but media and the White House have zeroed in on actions taken by the helicopter and on air traffic control staffing on the night of the crash as they speculate on what went wrong. It is the worst mid-air collision in America since the 1980s.

MIT aeronautics professor R. John Hansman said that it's important to take stock of safety concerns, but also to recognise that the American aviation system is one of the safest in the world.

"This was terrible," he said, noting there hasn't been a major commercial plane crash since 2009. "But it isn't like the system is falling apart."

Since his comments, a small medical transport plane crashed into buildings in Philadelphia on Friday evening, just two days after the Washington crash. The jet was carrying four crew members, a child patient and the patient's escort, Jet Rescue Air Ambulance said in a statement.

The FAA and National Transportation Safety Board (NTSB) are investigating the crash. In a statement, President Donald Trump said: "So sad to see the plane go down in Philadelphia, Pennsylvania. More innocent souls lost."