Squawk 7700 transmission — ACA857

2025-08-25 21:21 UTC· EGLL CYYZ· Air Canada· B77W

ACA857 (Air Canada) was operating from EGLL to CYYZ on 2025-08-25. SkyMeter recorded a 7700 transponder transmission at 21:21 UTC. Code 7700 indicates a general emergency declaration (e.g. engine, medical, smoke). A sustained transmission is normally accompanied by ATC priority handling. Trace data at the event: 35975 ft AGL, 445 kt GS. Approach stability score: 96/100. Scores in this band are observed on roughly 50% of approaches at this runway and represent the centerline of normal operations. METAR at the time reported 6 kt wind, 5 kt crosswind component. Detection algorithm and known limitations: see SkyMeter methodology.

Pilot review data

  • 35975 ft AGL at event
  • 445 kt ground speed
  • 0 fpm vertical
  • Approach stability 96/100
  • 6 kt wind
  • 5 kt crosswind component

Flight context

  • ACA857
  • Air Canada
  • B77W
  • EGLL → CYYZ
  • 2025-08-25 21:21 UTC

All events on this flight

Squawk 7700 transmission 21:21:51 UTC · · 35,975 ft AGL · 445 kt GS
Squawk 7700 transmission 21:21:50 UTC · · 36,087 ft AGL · 445 kt GS

Automated analysis. Events shown on this page (such as go-around, unstable approach, or runway events) are heuristic classifications produced by algorithms from publicly broadcast ADS-B data. They are intended to surface flights of interest for further review — they are not findings of fact, and they do not determine pilot fault, regulatory compliance, or the cause of any occurrence. Coverage gaps and sensor noise can affect accuracy. Only the relevant civil aviation authority or accident investigation body can make official determinations. How we detect events · Dispute or correct this data

SkyMeter · trace data observed via ADS-B