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Flight Reliability

DL 517 · Delta Air Lines

Atlanta → San Francisco (ATL–SFO)90% of its flights flew this route. The rest (DFW–ATL, LAX–BNA) are included in these numbers.

75
Usually Fine
WanderNerd Reliability Score
70%
Arrive within 15 minutes
14 min
Average arrival delay
0.3%
Cancelled
2 min
Median arrival delay

Based on 336 historical flights. Data through May 2026.

What the data says

The late departure is the smart one here.

DL 517 departing between 6–9 PM arrived on time 83% of the time, versus 69% between 3–6 PM.

Sunday scaries are real for this one.

DL 517 arrived on time 78% of the time on Wednesdays and just 57% on Sundays. That gap is worth planning around.

A bit behind the ATL–SFO route.

DL 517 arrived on time 70% of the time, versus 73% across the ATL–SFO route.

Lagging the Delta Air Lines network.

DL 517 arrived on time 70% of the time, versus 81% across the Delta Air Lines network.

The breakdown

On-time by weekday
  • Mon69%(48 flights)
  • Tue74%(49 flights)
  • Wed78%(49 flights)
  • Thu71%(49 flights)
  • Fri73%(48 flights)
  • Sat67%(43 flights)
  • Sun57%(49 flights)
On-time by departure window
  • 3–6 PM69%(311 flights)
  • 6–9 PM83%(24 flights)
On-time trend by month
52%
May

Jun 53% → May 52% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202553%30
July 202565%31
August 202565%31
September 202577%30
October 202574%27
December 202570%30
January 202683%30
February 202682%28
March 202687%31
April 202670%30
May 202652%31
Departures on time
77%
Diverted
0%
Flights flown
335
Months covered
12

Same route, other flights

Keep nerding

Based on 336 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.