David Folkenflik

So the Black Hawk helicopter was on what they call a check ride in which the crew is being tested, other use of night vision goggles and flying by instruments. And they were flying along this familiar corridor along the Potomac while the American Airlines CRJ regional jet was approaching for a landing at Reagan National Airport. Investigators say cockpit voice recordings.

So the Black Hawk helicopter was on what they call a check ride in which the crew is being tested, other use of night vision goggles and flying by instruments. And they were flying along this familiar corridor along the Potomac while the American Airlines CRJ regional jet was approaching for a landing at Reagan National Airport. Investigators say cockpit voice recordings.

So the Black Hawk helicopter was on what they call a check ride in which the crew is being tested, other use of night vision goggles and flying by instruments. And they were flying along this familiar corridor along the Potomac while the American Airlines CRJ regional jet was approaching for a landing at Reagan National Airport. Investigators say cockpit voice recordings.

indicate that an air traffic controller seemed concerned that the helicopter was flying toward the path of the incoming plane and asked the Black Hawk pilots to fly behind it. Here's NTSB Chair Jennifer Homendy.

indicate that an air traffic controller seemed concerned that the helicopter was flying toward the path of the incoming plane and asked the Black Hawk pilots to fly behind it. Here's NTSB Chair Jennifer Homendy.

indicate that an air traffic controller seemed concerned that the helicopter was flying toward the path of the incoming plane and asked the Black Hawk pilots to fly behind it. Here's NTSB Chair Jennifer Homendy.

Homendy says the mic in the helicopter cockpit was keyed open for just a second or two, but the pilots may have missed the key words, passed behind the. That's critical instruction that had the pilots actually heard and followed, this disaster might have been averted.

Homendy says the mic in the helicopter cockpit was keyed open for just a second or two, but the pilots may have missed the key words, passed behind the. That's critical instruction that had the pilots actually heard and followed, this disaster might have been averted.

Homendy says the mic in the helicopter cockpit was keyed open for just a second or two, but the pilots may have missed the key words, passed behind the. That's critical instruction that had the pilots actually heard and followed, this disaster might have been averted.

Yes. You know, Hamidi says the helicopter pilots might not have been receiving correct information about their exact altitude. Hamidi says a radio altimeter, which uses radio waves bounced off the ground to measure the aircraft's altitude, and information gleaned from a flight data recorder were in conflict and showing different altitudes.

Yes. You know, Hamidi says the helicopter pilots might not have been receiving correct information about their exact altitude. Hamidi says a radio altimeter, which uses radio waves bounced off the ground to measure the aircraft's altitude, and information gleaned from a flight data recorder were in conflict and showing different altitudes.

Yes. You know, Hamidi says the helicopter pilots might not have been receiving correct information about their exact altitude. Hamidi says a radio altimeter, which uses radio waves bounced off the ground to measure the aircraft's altitude, and information gleaned from a flight data recorder were in conflict and showing different altitudes.

Hamendi says it's still not clear why there was erroneous or conflicting data, and the investigation is still in its early stages. But she says this is definitely something the NTSB is focusing on.

Hamendi says it's still not clear why there was erroneous or conflicting data, and the investigation is still in its early stages. But she says this is definitely something the NTSB is focusing on.

Hamendi says it's still not clear why there was erroneous or conflicting data, and the investigation is still in its early stages. But she says this is definitely something the NTSB is focusing on.

Well, investigators did say that the crew of the American jet did pull up aggressively just before the impact, indicating that they likely saw the helicopter at the very last moment.

Well, investigators did say that the crew of the American jet did pull up aggressively just before the impact, indicating that they likely saw the helicopter at the very last moment.

Well, investigators did say that the crew of the American jet did pull up aggressively just before the impact, indicating that they likely saw the helicopter at the very last moment.

In addition, they did confirm the Blackhawk crew was likely wearing night vision goggles, and they acknowledged there is some concern in an area with a lot of aircraft lights and city lights that it could have been difficult to see the airplane. Chair Homendy says the NDSB will conduct a visibility study to try to determine what the pilots could and could not see.

In addition, they did confirm the Blackhawk crew was likely wearing night vision goggles, and they acknowledged there is some concern in an area with a lot of aircraft lights and city lights that it could have been difficult to see the airplane. Chair Homendy says the NDSB will conduct a visibility study to try to determine what the pilots could and could not see.