The National Transportation Safety Board (NTSB) released two reports on March 11 on the deadly midair collision between an Army Black Hawk helicopter and an American Airlines regional jet in late January that led to 67 deaths.
The American Airlines jet was descending toward the airport when it was hit on its right side by the military helicopter at roughly 300 feet of altitude, investigators said. The helicopter was flying 100 feet above its maximum allowed altitude and was running a training mission.
“At best, we’re in a situation where we’re threading a needle allowing helicopters to fly down the same airspace as landing aircraft,” Duffy said.
1. Permanent Restrictions Needed on Helicopter Traffic
The NTSB determined that helicopter operations should be banned near two particular runways at DCA and issued an urgent recommendation for the FAA to restrict that air traffic permanently.“We’ve determined that the existing separation distances between helicopter traffic operating on Route 4 and aircraft landing on Runway 33 are insufficient and pose an intolerable risk to aviation safety,” NTSB Chair Jennifer Homendy said during the news conference on March 11.
“We remain concerned about the significant potential for a future mid-air collision at DCA, which is why we are recommending a permanent solution today.”
The NTSB stated that the restrictions would cover the stretch between the Woodrow Wilson Bridge and Hains Point and recommended against helicopters flying along that same airspace when planes are taking off over the river from runway 15.
2. Too Many Close Calls Near DCA for Too Long
Cockpit alerts, known as resolution advisories, have been triggered in high numbers over the past few years because of helicopters and planes flying in close proximity to one another near DCA.These alerts, including “CLIMB, CLIMB” and “DESCEND, DESCEND,” warn pilots to take action to avoid collisions.
Between 2011 and 2014, at least one of these alerts occurred each month because a helicopter was close by, the NTSB stated, according to an analysis of FAA data and voluntary safety reports.
Investigators said there were 85 cases in which a commercial airplane and a helicopter had less than 1,500 feet of “lateral separation” between them while flying at altitudes that were less than 200 feet apart.
3. Problems with Air Traffic Radio Transmissions
There was a critical radio instruction roughly 17 seconds before the collision that was not heard by the pilot and other crew members on the Black Hawk helicopter, the NTSB stated.An air traffic controller told the helicopter pilot to pass behind the American Airlines jet, but the transmission was “stepped on,” meaning that a helicopter crew member attempted to use the aircraft’s microphone within the 0.8-second window when the instruction was given.
This likely would have prevented the crew from hearing the controller’s transmission.
After analyzing the helicopter’s cockpit data recorder, the NTSB determined that “the portion of the transmission that stated ‘pass behind the’ may not have been received.”
4. FAA Lacks Clearly Defined Route Boundaries for Helicopters
There are “no lateral boundaries” in the FAA’s helicopter routes, NTSB investigators stated.A chart showing these routes in Washington includes “no warning for helicopters to operate a defined distance from the shoreline.”
Duffy pointed to the NTSB’s estimate that if a helicopter is flying at its authorized altitude of 200 feet along Route 4, that would give it only 75 feet of clearance from an airplane landing on runway 33 at DCA.
Notably, the midair collision on Jan. 29 occurred after the helicopter pilots breached the altitude ceiling of 200 feet.
5. 1 Air Traffic Controller Working 2 Positions
According to investigators, one air traffic controller was working two positions that night—monitoring the radio frequencies for both the helicopter and the jet, which is allowed under certain conditions. The radio separation also prevents helicopters and jets from hearing each other’s transmissions to and from the control tower.However, that shift handling both positions started at 3:30 p.m. The incident occurred hours later, at roughly 8:50 p.m., according to the preliminary report.
During the NTSB’s March 11 news conference, a reporter asked Homendy if more staffing could have prevented the collision.
“That is part of our investigation and is part of the analysis phase of our investigation,” she said. “Right now, we are collecting facts on air traffic control. In our preliminary report today, we will mention that there were five controllers on position.”
Homendy said there were nine controllers in the tower that night, and some were in the break room.
“We are taking a look at that,” she said. “We do not have any evidence that anybody left.
6. NTSB Relies on FAA to Enforce its Recommendations
While the NTSB is responsible for making aviation safety recommendations, it must rely on the FAA to enforce them. The FAA has instituted rules barring helicopters from the DCA airspace since the days following the crash, including a temporary restriction over six square miles near the airport.After investigating incidents, the NTSB makes safety recommendations, which it releases to the government, the aviation industry, and the public. These recommendations highlight key changes that the board believes are necessary for transportation safety.
Although the NTSB can make recommendations, the FAA issues regulations for airlines, airports, and other parties involved in aviation. Regulatory actions can vary from one presidential administration to another.
