Near mid-air collision at LAX between American Airlines and ITA [video]

Original Article ↗ Hacker News Discussion ↗

What Happened and Why It Was Dangerous

  • Two jets departed parallel runways at LAX; the right‑runway departure (American) climbed straight, while the left‑runway departure (ITA) incorrectly turned left into its path.
  • Commenters estimate separation of ~1000 yards and <5 seconds to collision based on GPS‑based analyses (from other videos).
  • The American crew reportedly saw the conflicting traffic themselves and initiated an avoidance maneuver (change in climb and left deviation) without waiting for ATC.
  • The near-collision occurred during the tower–departure frequency handoff, complicating who heard which warning when.

Procedural Error Theories

  • Widely discussed hypothesis: ITA had the correct SID but for the wrong runway—using a “left‑runway” RNAV path while departing from the “right‑runway” side, a known failure mode when runway assignments change.
  • Visual orientation (a runway labeled “right” appearing on the left from the cockpit’s perspective) plus distraction/tiredness are suggested contributing factors.
  • One commenter notes takeoff clearances (“RNAV xxx, cleared for takeoff”) exist as a final runway/SID cross‑check, which apparently still failed here.
  • Some speculate the event might have been less severe had ITA immediately complied with “turn right heading 270” and American promptly stopped its climb, but this is acknowledged as uncertain.

ATC Communications and Timing Ambiguities

  • Disagreement over timing: tower appears to warn American (“traffic, stop climb”) before visible maneuvers, but American later says they had no tower heads‑up.
  • Explanation offered: American had switched off tower and had not yet checked in with departure when tower issued the warning.
  • Several caution that VASAviation’s track/radio synchronization is approximate and archived audio has gaps removed, so second‑by‑second reconstruction is imprecise.
  • Some think controllers could have been more forceful and proactive with ITA, but others emphasize the primary error was in the cockpit, not ATC.

Debate on “Primitive” Voice/Radio System

  • Many non‑pilots are struck by poor audio, party‑line AM channels, and reliance on spoken callsigns.
  • Defenders argue:
    • Voice is fast, heads‑up, and well‑matched to short, time‑critical instructions (“turn right immediately”).
    • Backward compatibility with old aircraft and global ubiquity of VHF AM make radical change extremely hard.
    • Shared frequencies let all nearby aircraft hear urgent calls and self‑separate if needed.
  • Others highlight weaknesses: garbled audio, overlaps that erase both transmissions, nonstandard phraseology (with JFK/Air China cited as an example), and the training burden for new pilots.
  • Suggested enhancements (not currently standard) include: digital/HD audio in parallel, data side‑channels with caller ID and alerts, better overlap handling, controller–FMS integration to detect mismatched flight plans, and automatic linkage between aircraft position and “correct” ATC frequency.
  • Pilots and controllers note that digital tools already exist (ADS‑B, CPDLC, ACARS, D‑ATIS, XM weather), but they are not suited to fast, tactical vectoring.

Staffing, Pay, and Systemic Risk

  • Multiple comments raise the context of the ongoing US government shutdown: air traffic controllers are reportedly working without pay, sometimes needing side jobs, with concerns about stress, fatigue, and attrition.
  • Some express reluctance to fly under these conditions and question why controllers keep showing up (citing expectations of back pay and fear of being fired, though recent political statements make back pay less certain).
  • Others stress that, despite incidents like this, commercial aviation remains extremely safe, though near mid‑airs are expected to get more public attention as monitoring tools and interest grow.

TCAS and Other Technology

  • Conflicting claims appear about TCAS behavior:
    • One commenter says TCAS alerts are inhibited at low altitude in steps (no alerts, then TAs only, then RAs without descents, then full).
    • Another states TCAS II gives warnings down to ~100 m AGL and they were above that, but resolution advisories are suppressed below ~1000 ft.
  • Consensus is that TCAS might have generated some form of alert, but its effectiveness in such a fast, low‑altitude crossing is uncertain.
  • ADS‑B, already required in the US, is noted as not directly helpful for preventing this particular type of departure‑procedure mix‑up.