Ace Cdn

with a 3 hour delay the temperature probably dropped and that is probably why they were able to do it nonstop.

CloudsBelow

There is no way an A319 would need a fuel stop LAS-YUL even at 40'C and MTOW.

I do agree with your frustration about paying a premium for non-stop and having a possible diversion. Glad it worked out in the end.

CloudsBelow

No. The flight was delayed from 1115a to 2p which is a hotter time.

Eastbound transcons needing to stop for fuel are Very rare. Remember though, LAS-YUL is close to 2000nm. I suspect the OP was on a 320/321 and maybe at full load, no helping winds, high temps, and some clearance issues out of LAS (Statosphere is pretty high!! (kidding) might have required the plane to go out at less than MTOW. . . . Or the captain just made a math error!!

tyberius

Temps going up rather than down, considering it was an 11:15am flight rather than a late afternoon flight.

As well, the changes in flight path happened over about 30-45 minutes, rather than as bookends over a 3 hour delay.

The delay was based on inbound equipment being late, blamed on the strike by the checkin agent, and then once we were boarded, there was a short delay with the flight path, then delay in getting fuel, pilot said there was only one fuel truck available, had to wait for another plane to get fueled up, then for us to get fueled up. Overall combined between 2-3 hours somewhere in delays but the announcements were fairly close.

tyberius

I think the plane was full, I didn't look in the back of the bus but a few "Elite Member X" and "Elite Member Y" were called up to the gate which I assumed were op-ups, and probably meant full plane.

g46r

It's not over MTOW. It's something called balanced field length.

The regulation requires the twin engine jet transport aircraft at its current takeoff weight able to accelerate to a speed right round rotation - if an engine fails immediately after that moment, able to climb using a single engine thrust at a minimum climb gradient. If an engine fails immediately before that moment, able to stop before the end of the runway with no reverse thrust and worn out brakes.

Therefore the performance for each takeoff is calculated beforehand each and every time, taking into account of runway length, weight, temperature, wind, airport elevation, and runway surface contamination if any. Under high temperature the air is less dense, which means the engine produces less thrust at the same time the rotation ground speed needs to be higher for the wing to generate sufficient lift - it's quite possible that the balanced field length requirement can not be met unless the takeoff weight is reduced - such as offloading some fuel (meaning an extra fuel stop), or kicking off some passengers/cargo.

g46r

You're assuming they fill up the fuel tanks - airliners rarely take off with full tanks. They likely had too much passenger/cargo weight, and no long able to meet the balanced field length requirement if taking (regulatory) enough fuel for the LAS-YUL flight under the atmospheric condition.

Ace Cdn

since he was posting in the evening I assumed it was an evening flight so that was my error.

Symmetre

It is possible that the decision to continue to YUL resulted from a change in wind direction or intensity. That would allow a runway switch (LAS has one long (14,000 ft) runway, and three fairly short ones).

An A320 at MTOW in 40 degree temps can eat up a lot of concrete before it becomes airborne. If confined to a shorter runway, it may not have been able to load enough fuel for a direct YUL flight - switching to the longer strip would change that.

ewok22

This happens in LAS all the time when the temps climb's over 40c and it's the control tower that usually has the final say as take off weight. They use a formula.

3 options normally occur in the situation of over weight 320
a) they offer overnight accomodation and $300 when no one takes it they raise it to overnight accomodation and $500 normally it takes 8 pax to lighten the load enough.
b) they loose the weight by loading only enough fuel to get them to a airport on there route that has no congestion or temp issues
c) they off load the last pax that checked in and had no status.
I have been on the 320 when all 3 situations occur.

arf04

That I find completely impossible to believe. All airlines use flight dispatchers and flight planners, and the pilots run their own numbers as well. Airbus has published data for a host of different conditions that pilots draw on. The control tower has nothing to do with calculations of this nature.

HangTen

I hope someone remembers this thread when they poke fun at Westjet for having to do a tech stop once or twice a year in PDX when flying YVR to Hawaii when there is a 120mph headwind!

rehoult

You are correct, the control tower would not have the last say. However, as they can dictate the active runway they could certainly impact a decision.

global happy traveller

eat less, carry less LOL....... math error..... that is pretty scary, we dont need another gimi glider

briantoronto

This makes no sense.