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DelayAtlas

Route reliability record

DCATYS

Washington to Knoxville

Flights
1,023
Period
July 2025 to June 2026
Distance
437 mi
Carriers
3
C−GRADE

This route carries a cancellation problem, not just a delay problem: 3.8% of scheduled flights never operate, against 1.8% nationally. Of the ones that do fly, about seven flights in ten arrive on time, worth a C− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 1,023 DCA to TYS flights, with a median arrival 3 minutes early.

Best time to fly DCA to TYS: a 8am–11am departure, ideally on a Saturday. Flights in that window arrived on time 84.6% of the time and Saturday flights 78.3%, against 68.4% for the route overall.

The national on-time rate over the same period is 77.6%, so this route runs 9 points behind the country as a whole. Across a thousand flights that is about 92 extra late arrivals.

Key figures

On time

68.4%

Arrivals under 15 minutes late, of 983 completed flights

Avg delay

100 min

Across delayed arrivals only, not all flights

Cancelled

3.81%

National rate is 1.81%

Best carrier

PSA

67.7% on time across 982 flights

These figures cover 1,023 flights between July 2025 and June 2026. Beyond the headline rate, 16.8% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

Which airline is most reliable on DCA to TYS

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 DCA to TYS
AirlineFlightsOn timeAvg delayCancelledGrade
Envoy Airthin sample2100.0%0.00%A+
Republic Airwaysthin sample3984.2%108 min2.56%B
PSA Airlines98267.7%99 min3.87%C−

Flight by flight

Flights on DCA to TYS

The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.

Departure window

The best time of day to leave

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 27 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am
  • 8am–11am346 flights84.6%
  • 11am–2pm52 flights62.7%
  • 2pm–5pm311 flights59.7%
  • 5pm–8pm191 flights60.9%
  • 8pm–5am123 flights57.4%

Scale runs 50% to 90%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 57.4% on time, against 84.6% for the 8am–11am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8am–11am window is the busiest, with 346 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 32 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.

On-time rate by calendar month71J73F59M74A68M71J57J77A81S69O68N49D
Darker means more delays. Figures are on-time percentages.September best, December worst

December is the weak month at 49.2% on time, against 81.2% in September. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. May was the busiest month here, with 93 flights.

Across the week, Saturday is the strongest day at 78.3% on time and Thursday the weakest at 62.0%. 16 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week66.4Mon70.5Tue66.9Wed62.0Thu67.8Fri78.3Sat68.5Sun
Monday: 66.4 percent on time. Tuesday: 70.5 percent on time. Wednesday: 66.9 percent on time. Thursday: 62.0 percent on time. Friday: 67.8 percent on time. Saturday: 78.3 percent on time. Sunday: 68.5 percent on time

Delay causes

Why this route gets delayed

One category carries most of the weight here. Late-arriving aircraft accounts for 59% of the 31,000 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
    59%
  • Carrier
    21%
  • National Airspace System
    12%
  • Extreme weather
    7%
  • Security
    0%

59% 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 31,000 reported delay minutes here, that single category outweighs weather by 8 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 30,958 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 84.6% on time here.

Cancellations run at 3.81%, against 1.81% nationally. That is about one flight in 25 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 actually costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 16.8% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

At 437 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 8am–11am window matters as much as it does.

The return leg runs 70.6% on time across 1,023 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 1,023 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.

Work out the risk of missing a connection in TYS after this flight

What to do with this

Booking this route

Put together: the delay figures matter less here than the 3.81% cancellation rate. A late arrival costs you an hour and a half; a cancelled flight costs you the day. Book the 8am–11am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 983 completed flights over 12 months sit behind that.

Common questions

DCA to TYS questions

How often is DCA to TYS delayed?

About one flight in three arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 31.6% of the 1,023 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.

How reliable is DCA to TYS compared with the rest of the country?

68.4% of flights arrive on time here against a national 77.6%, a difference of 9 points against it. That is worth a C− on this site's grading scale.

What time of day has the fewest delays on DCA to TYS?

The 8am–11am departure window is the strongest at 84.6% on time. The 8pm–5am window is the weakest at 57.4%, 27 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.

How bad are December delays on DCA to TYS?

December is the weakest month at 49.2% on time, compared with 81.2% in September. Across the year that is 32 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Related

Where to go next

Direction matters. DCA to TYS and TYS to DCA are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Embed DCA to TYS’s on-time badge on your site

Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.

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.