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Flight Reliability

DL 3900 · Delta Air Lines

Detroit → SBN (DTW–SBN)

50
A Little Dicey
WanderNerd Reliability Score
61%
Arrive within 15 minutes
38 min
Average arrival delay
1.4%
Cancelled
4 min
Median arrival delay

Based on 365 historical flights. Data through May 2026.

What the data says

The late departure is the smart one here.

DL 3900 departing between 9 PM–12 AM arrived on time 91% of the time, versus 59% between 6–9 PM.

Mondays have been rough.

DL 3900 arrived on time 76% of the time on Saturdays and just 50% on Mondays. That gap is worth planning around.

Lagging the DTW–SBN route.

DL 3900 arrived on time 61% of the time, versus 70% across the DTW–SBN route.

Well behind the Delta Air Lines network.

DL 3900 arrived on time 61% of the time, versus 81% across the Delta Air Lines network.

The breakdown

On-time by weekday
  • Mon50%(52 flights)
  • Tue62%(52 flights)
  • Wed70%(50 flights)
  • Thu67%(52 flights)
  • Fri51%(51 flights)
  • Sat76%(50 flights)
  • Sun55%(53 flights)
On-time by departure window
  • 3–6 PM—(3 flights)
  • 6–9 PM59%(334 flights)
  • 9 PM–12 AM91%(23 flights)
On-time trend by month
77%
May

Jun 66% → May 77% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202566%29
July 202545%31
August 202565%31
September 202573%30
October 202584%31
November 202569%29
December 202552%31
January 202641%29
February 202657%28
March 202647%30
April 202660%30
May 202677%31
Departures on time
61%
Diverted
0%
Flights flown
360
Months covered
12

Same route, other flights

Keep nerding

Based on 365 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.