By james art 
Investigators have already recovered the voice recorder of the pilot cabin and records of flight data on the American Airlines aircraft, which collided with an army helicopter while the plane landed on Wednesday night at Ronald Reagan National Airport to Washington.
Officials are considering a number of factors in what the chairman of the Transport Safety Council Jennifer Homendi called an “event of all hands of descent”.
Everyone aboard the two aircraft were killed, with employees examining the military pilot’s actions, as well as the control of the air traffic after a helicopter obviously flew on the path of the American Airlines aircraft.
More than 40 bodies have been withdrawn from the Potomak River, as the widespread recovery efforts continue after the most deadly aviation disaster in a generation, said a law enforcement officer to the Associated Press.
Recovery efforts continued on Friday.
The employee is not authorized to discuss details of the investigation and speaks on condition of anonymity.
Investigations to the air accident may take months, and investigators told reporters on Thursday that they would not speculate on the cause.
The Federal Aviation Administration (FAA) has decided to significantly restrict helicopter traffic next to the Reagan National Airport of Washington, an employee of the issue of the Associated Press on Friday said.
Some of the airspace have already been limited due to the constant effort to search and recover through the site of the crash.
But the FAA has decided indefinitely most helicopters from the use of low domestic routes moving under or parallel to the airport flights, the employee said.
Authorities were still looking for the recorder of the helicopter’s black box, Defense Minister Pete Heget said on Friday’s Fridays News Channel.
Other factors in the crash, including the helicopter altitude, and whether the crew uses their night vision glasses are still being investigated, said G -H Heget.
A air traffic controller was responsible for coordinating helicopter trafficking and the arrival and departure of aircraft when a collision happened, according to a Federal Aviation Administration report received by AP.
These duties are often divided between two people, but the airport usually combines roles at 9.30pm after traffic begins to slow down.
On Wednesday, the head of the tower directed that they would be combined earlier.
“The configuration of the position was not normal for the time of the day and the volume of traffic,” the report said.
However, a person familiar with the question said that the tower headquarters tonight was at a normal level.
The positions are regularly combined when the controllers need to pull away from the rest console, while changing the change or when the air traffic is slow, the person said, talking about the state of anonymity to discuss internal procedures.
FAA has long been fighting a shortage of air traffic controllers.
The officials said the terms of the flight were clear as the plane arrived from Wichita, Kansas, bearing, among other, a group of elite young figure skaters, their parents and coaches and four allied greenhouses from the Washington region.
A senior aviation official of the army said that the crew of the helicopter, a black hawk, is “very experienced” and familiar with the overloaded flying that happens every day around the city.
“Both pilots had flew on this particular route before, at night. It was not something new to any of them, “says Jonathan Cosiol, head of the Army Aviation Staff.
The maximum altitude of the helicopter was 200 feet (about 60 meters), said G -n Cosiol.
It was not clear immediately whether it exceeded this limit, but the heget said that the height seemed to be a factor for the collision.
Caziol said investigators should analyze the flight data before making conclusions about altitude.
Reagan National Flights resumed around noon on Thursday.
Wednesday’s crash was the deadliest in the United States since November 12, 2001, when the American Airlines flight crashed into a residential area of Belle Harbor, New York, just after taking off from Kennedy Airport, killing all 260 people on board and five people On The Earth.
The last major fatal catastrophe, including an American trade airline, happened in 2009 near Buffalo, New York.
Everyone aboard the Bombardier DHC-8 Propeller the aircraft was killed, along with one person on Earth, bringing the total number of deaths to 50.
Experts often emphasize that traveling on the aircraft is extremely safe.
The National Safety Council estimates that Americans have a chance 1 of 93 to die in a motor vehicle crash, while the deaths of aircraft are too rare to calculate the chances.