# How is it possible that an indirect flight is shorter than a direct one?

Got a very odd result from Kayak when searching for some flights. It claims that the indirect route, including stop-over time, is faster than the direct one. Is this even possible or an error?

Going direct from YUL to PLS takes 7 hours and 5 minutes while making a 1 hour and 21 minute stop in Toronto shorten the duration to 6 hours and 35 minutes as shown above. Flights all on Air Canada.

Now basic geometry says the shortest path on a plane is a straight line but since the earth is curved, it must not be so but could the difference be so great as to eclipse a 1h21m layover? Notice the return leg has a 7 hour layover, so it is indeed faster to go direct.

• Different planes are probably used. May 15, 2018 at 23:36
• Which dates did you search for? It's easier to reproduce then. May 16, 2018 at 0:05
• I tried finding the nonstop flights directly on aircanada.com, and it only gave me flights with 1 or 2 connections. So i assume it's a data glitch at Kayak and those nonstops are actually connecting flights (actually, i found exactly those times on aircanada.com, with a connection in YYZ). May 16, 2018 at 0:28
• Not sure I understand the remark about the earth's curvature at the end. Even non-stop flights tend to follow the great circle route where possible so that should not make a difference. May 16, 2018 at 5:14
• @Henrik Oceanic flights do not follow the great circle path, but one optimized for winds. May 16, 2018 at 16:32

Looks like a bug. Actual nonstop time between YUL and PLS would be a about 4 hours. https://www.travelmath.com/flying-time/from/YUL/to/PLS

Apparently Air Canada has a non-stop from PLS to YUL on Tuesdays (AC1801) which has an official flight time of 4:05. There is no non-stop the other way. The outbound AC1802 flies through ZSA, so it's a YUL-ZSA-PLS-YUL route.

Another word of caution: "direct" does NOT mean "non-stop". Airline marketing speech has corrupted the term "direct" to just mean that all legs of the flight have the same flight number. It does NOT mean that there are no stops, that it's the same plane, or that it's the same crew. If you want no stops, you need to specifically look for the term "non-stop". It's entirely possible that Air Canada would package an YUL-YYZ-PLS flight as a "direct" flight by giving both legs the same flight number. However, in this case it seems to be an honest error

• Air Canada doesn't seem to do that trick, but they do have direct one-stop flights that share a flight number, e.g. on the YYZ-YVR-SYD route. Same aircraft, same crew. May 16, 2018 at 4:53
• Found the result again and its the data FlightHub sends to Kayak. When looking up the flights on AC, there is only the YYZ-PLS segment.
– Itai
May 17, 2018 at 0:03

I had a similar issue on Kayak recently. It was showing a direct LAS-CDG flight which surprised me a lot. It turned out to be a flight with a connection in SLC. The two legs had the same flight number, but different aircraft.

As Kayak retrieve offers from partner sites, it apparently happens that some of the information is sometimes lost in transit (either between the airline and the partner site, or between the partner site and Kayak), and a flight with a stop (which actually looks more like a connection than a stop since the aircraft was different) is shown as non-stop.