Carrier route record

F9DTW→RDU

Frontier Airlines · Detroit to Raleigh

Flights: 111
Period: July 2025 to June 2026
Share of route: 7%
Carriers: 3

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.

Frontier on DTW to RDU lands a B−, 3 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 111 flights, with a median arrival 9 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Frontier on DTW to RDU from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

80.4%

Arrivals under 15 minutes late, of 107 completed flights

Avg delay

63 min

Across delayed arrivals only, not all flights

Cancelled

3.60%

National rate is 1.81%

Whole route

83.8%

Every carrier on DTW to RDU, 1,525 flights

These figures cover 111 flights between July 2025 and June 2026. The median arrival is 9 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.

Carrier by carrier

Frontier against every carrier on DTW to RDU

Frontier flew 111 of the 1,525 flights on DTW to RDU, about 7% of it. Its 80.4% on time is 3 points worse than the route as a whole, which runs 83.8%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Delta at 84.2% to Frontier at 80.4%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on DTW to RDU
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines	1,337	84.2%	63 min	1.20%	B
Spirit Airlinesthin sample	77	83.1%	76 min	0.00%	B+
Frontier Airlines (this page)thin sample	111	80.4%	63 min	3.60%	B−

Departure window

When Frontier runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 111 flights.

5am–8am2 flights—
8am–11am62 flights77.4%
11am–2pm11 flights—
2pm–5pm2 flights—
5pm–8pm33 flights80.0%
8pm–5am1 flights—

Scale runs 70% to 85%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is the strongest at 80.0% on time. The full set of windows spans 3 points.

Across the year

Frontier on DTW to RDU through the year

Jul–Sep 202528 flights—
Oct–Dec 202544 flights86.0%
Jan–Mar 202619 flights—
Apr–Jun 202620 flights—

Scale runs 80% to 90%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 80.4% on time across 111 flights.

Split by quarter, Frontier on DTW to RDU logged 28 flights in Jul–Sep 2025, 44 flights in Oct–Dec 2025, 19 flights in Jan–Mar 2026 and 20 flights in Apr–Jun 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 80.4% annual figure is the one to use.

Delay causes

Why Frontier runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 49% of the 1,326 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Late-arriving aircraft
49%
Carrier
32%
National Airspace System
16%
Extreme weather
3%

49% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 1,326 reported delay minutes here, that single category outweighs weather by 16 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 1,326 reported delay minutes.

Cancellations run at 3.60%, against 1.81% nationally. That is about one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and stage length

What a delay here costs

7.5% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.

The 501 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

The return leg is a different operation and performs like one: it runs 87.3% on time across 111 flights, 7 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 7 points of difference.

One caution: this is a thin sample. 111 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.

What to do with this

Booking Frontier on DTW to RDU

Put together: the delay figures matter less here than the 3.60% cancellation rate. A late arrival costs you about an hour; a cancelled flight costs you the day. Book the 5pm–8pm departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 107 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures