The crews of both a United Airlines Boeing 737 and a California National Guard Black Hawk had each other in sight and one of the helicopter pilots declared “no factor” before a TCAS resolution advisory sounded and prompted the 737 crew to pause their descent to John Wayne International Airport near Los Angeles last week. The incident made headlines as being reminiscent of the collision between an Army Black Hawk and a regional jet in Washington that killed 67 people last year, but if any of the pilots or controllers directly involved in this incident were concerned they didn’t express it over the radio. ADS-B data showed the helicopter 525 feet below and 1,422 feet laterally from the 737 as they passed perpendicular to one another.
In an animation put together by VASA Aviation, controllers advised both crews of their relative positions and in all cases the pilots responded that they had the other aircraft in sight. As the two passed each other a controller told the helicopter crew the airliner was 600 feet above them and had them in sight. One of the helicopter pilots responded “We have them as well. No factor.” Another controller then told the United crew that the helicopter traffic was “no factor” but by then the RA had gone off. The incident came a few days after the FAA ordered an end to allowing helicopters and other aircraft to maintain visual separation at airports where there is mixed traffic. It’s not clear whether those new rules were applied in this case because a controller can be heard telling another crew to “maintain visual separation.” The animation is below.
After the 737 had landed a controller expressed concerns about the loss of separation. “Did you get a traffic call reference the helicopter or did they restrict your altitude or anything?” the controller asked. One of the United pilots responded that “we had an RA” and the controller acknowledged it. “We’re gonna be addressing that, because that was not good,” the controller said on a transmission recorded by atc.com. The 737 pilot then confirmed that the controller “did not restrict our altitude,” although before the two crossed paths a controller did tell the airline crew to “fly and maintain 2,000.” Meanwhile the Black Hawk pilot thanked controllers “for all their help” and bid them a “great night.”
The new rules were put in place in response to the collision of an Army Black Hawk and an American Eagle regional jet at Reagan National Airport in January of 2025. The Guard said its helicopter was following procedures. “The aircraft was returning to Los Alamitos airfield along an established Visual Flight Rules (VFR) route at an assigned altitude while in communication with air traffic control,” the Guard said in a statement. “A thorough review will be conducted in coordination with the appropriate agencies.” The FAA confirmed it’s investigating the incident.
500’ vertical separation is normal separation between IFR and VFR traffic so this sounds like a nothingburger to me. Typical FAA to ignore the real issues like we had in DC with opposing routes at nearly the same altitude and now worrying about things that aren’t an issue.
Russ, you have my permission (for what it’s worth) to edit Voyager’s post to correct “thugs” to “things”. I doubt seriously he meant to cast aspersions on anyone involved.
Yes, correct. Unfortunately, I see no way to correct a post made here unlike most other forums. So, autocorrect errors get memorialized forever.
Fixed
Sounds like the Resolution Advisory they got was simply a do-not-descend command, which they had already been instructed to stop at 2000. Doesn’t sound this this was a close of a call is it might appear.
These used to really tick me off because it requires paper work. All RAs for airlines must be written up in their safety reporting system. So you have to remember time, altitude, position etc then spend time in the hotel room or after your trip to write it up and submit it.
How come the helicopter had so many pink markings? California, perhaps?
Aircraft’s 2D tracks converge regularly and thankfully the 3D keeps them apart. It seems conceivable that since the flight paths can be predicted minutes before intersecting, that a “Reduce 10 knots” call could be made to an aircraft when the vertical margin will be less than 1000’. That could provide a second option to mitigate a collision if for any reason errors occur in the vertical separation.
Question? At 200knots, how long does it take to travel 1422 feet?
AI Answer:
At a speed of 200 knots, it takes 4.21 seconds to travel 1,422 feet.
Ok. So can you turn your airplane from any angle to miss another aircraft that you just found out about without knowing his speed, altitude and direction of travel, climb rate, decent rate, etc…?
If you have 4.21 seconds before impact at 200 knots, how much time do you have to respond with the combined speeds of both aircraft, assuming that creates even less time?
how long does it take you to roll in to a 30 degree bank, assuming you see the intruding aircraft in time and the other aircraft also makes the appropriate turn, climb, descent, etc…
Take it from an old timer. If another aircraft is within 3 miles and 500 feet, that aircraft is a factor, even if you clearly see and can currently avoid the aircraft. The TCAS knows it and is giving you a warning. Yes, it is a factor.
Don’t tell the controller no factor in such situations because the controller will turn his attention somewhere else while the bogey is still in range and may be unpredictable and then you as the pilot could become distracted with other duties at a critical moment.
Once the other aircraft is passed, ok, now you can say “No Factor” or we avoided him for the moment would be better terminology.
The tower’s response after United’s check in is odd(cleared to land, maintain 2000). I have never been cleared to land but restricted to an altitude, those two instructions are in conflict with each other. It appears that United was still leveling off when the RA triggered, so the future looking feature of the TCAS system saw a conflict.