Unable to take off due to weight from SJU in 737?
Posted by mjltmjlt@reddit | aviation | View on Reddit | 38 comments
Leaving SJU for ATL on 737. Full flight returned to the gate and wasn’t cleared for takeoff due to weight…headwind of 6 mph and longer runway was apparently closed for construction. Anyone experience anything like this before?
bears-eat-beets@reddit
I've been completely loaded at Denver, but the temperature rose so fast that by the time we got to the runway, the new METAR came out and we were overweight.
eagleace21@reddit
Its crazy how quickly your performance drops up here in CO with temperature, pesky density altitude :P I have had a few high weight takeoffs in single engine pistons out of COS that I was under the limit but still felt like I wasn't going to get off the runway...and then that sluggish subsequent climb
WedNiatnuom@reddit
Happened to me on a 787 headed for São Paulo. They had it loaded assuming a temperature at takeoff, but it was still 10 degrees hotter than they figured for. Took an extra hour or so at the gate for them to sort it out.
EducationalCookie196@reddit
I was non-revving once and the snow intensity picked up a little bit, and we returned to the gate solely for the purpose of kicking me off :)
Independent-Reveal86@reddit
That seems a bit pointless. They would’ve burned your weight in fuel taxiing back to the stand.
duprass@reddit
This past summer DCA was in north flow with a wet runway and we were about to push in a 737. Our central load planning comes back and says we need to bump all the standbys. Okay, sucks but done.
We rerun the takeoff data on our end and it looks good for Runway 1, bleeds off full blow. Then as we are about to push, ops and the gate agents frantically get our attention and say we need to pull 20 more people. Huh? Time out.
Turns out, a crane on a barge up the Potomac went up, and it hit our takeoff weight by something like 5000lbs. Anyway the whole time we are trying to get this figured out, with the gate freaking out, I called up clearance delivery and asked how long of a wait it would be to takeoff 19 wrong way. He says “maybe 30 minutes.”
Done. This has taken much longer than that anyway. Off we go, push back and wouldn’t you know it? Nobody else could take Runway 1 either an we were like number 8 for takeoff “wrong way” on runway 19.
adamwhereartthou@reddit
Yes. Heat+weight flying from SLC to AMS a couple of years ago. Just asking some to change flights and a delay though
GoldenKnightz@reddit
Not in San Juan, but this happens frequently.
Mike__O@reddit
No, I fly a proper narrow body-- the 757
masteroffdesaster@reddit
never any performance issues
JaiBoltage@reddit
I was on a flight from Maui to SFO. While taxiing out, we had to return to the gate. ATC had not given us the route we anticipated. We had to take on more fuel and de-board the standbys on the flight.
WanderinPilot@reddit
In the airline business, aircraft performance is all centered around weight. I can’t speak for the 73, but our airbuses can’t get their full structural takeoff weight on 10 in SJU. Instead, the flight will be limited to a certain weight based on the weather conditions to ensure adequate performance. Sounds like for whatever reason your flight was planned right on the edge of the performance envelope (likely in order to not bump passengers, which is fair) and the real conditions differed enough from those planned to put you over that max weight. Just a few knots of wind, a degree or two of temperature, or even a slight air pressure difference can knock that max weight down a few hundred pounds.
Another factor is the flight could have been heavier than planned and it wasn’t caught until it was too late. Ideally not something that happens but unfortunately I’ve seen it. Maybe more pax and bags onboard than planned. Maybe the pilot added extra fuel without checking the plan and assumed it was fine. Maybe the ramp just over fueled by a few hundred pounds.
Speculation is difficult because any number or combination of shenanigans can take a flight planned close to max and put it over. Those of us in dispatch (flight planners) try not to get backed into a corner like that but sometimes even with best efforts the math is against you from the start.
Go_Loud762@reddit
Yes, but that should have been caught way before you got to the runway.
Madmaxdriver2@reddit
Things like wind and temp change from programmed on taxi out all the time. This is what I get paid to do. Make sure that the numbers match the environment just b4 takeoff.
Go_Loud762@reddit
I so hope that you are smart enough to dispatch the flight with a margin.
Do you plan the departure with actual temp/+5 degrees? Do you plan a variable wind compent? Do you plan with a worst case scenario?
According to OP, this happened in SJU. The weather there is pretty damn consistent with winds from the east. OP also said that the long runway, 10, was closed. That leaves 8 for departures, which is 8,000 feet long.
Seems to me that 8,000 feet in a 737 with no climb restrictions should be fine.
Now, there is a lot we don't know about this flight because OP doesn't know and/or hasn't told us. BUT! Flying from SJU to ATL isn't that far and an 8,000 foot runway should be adequate for departure.
As a dispatcher, what is your gut feeling about this flight?
FlyingSceptile@reddit
8 is the long one. 10 is the shorter one.
Wondering if because 10 hugs the coast a bit more, if there could be terrain concerns on the engine failure also limiting takeoff weight? Just a thought. Either way, like you said, they should not have left the gate unless they had this sorted.
theothergrapedrink@reddit
I’m not sure if it’s the reason but there is a low offshore VFR corridor that runs along that coastline that’s relatively busy, 500ft or below
Accurate-Principle94@reddit
Rwy08 and Rwy26 were notam closed pretty much all day today. And SJU was using Rwy10 all day for T/O and landing. Also, oceanic airspace was pretty saturated today as ATC had closed most of the oceanic routes due to hurricane Melissa. Maybe OP’s flight had a longer route that required more fuel. So that and the crappy performance that you usually our on Rwy10, limited OP’s flight.
mjltmjlt@reddit (OP)
Would happily answer more about this flight and conditions as a passenger if it would be helpful.
mjltmjlt@reddit (OP)
That was my thought…maths?
Go_Loud762@reddit
Maths is hard, mkay.
Mike734@reddit
It’s a regular occurrence departing Maui in the mornings for Seattle. Sometimes all we needed was 9 knots and all we had was around 5. Sometimes all we had to do was wait a little longer. Rarely did we return to the gate.
mjltmjlt@reddit (OP)
It was a nice education in the margins for me as a reasonably frequent (but not quite yet million) flier.
YMMV25@reddit
Lol, 737s.
At least it’s not an A321 though. For that the Y pax have to get out and push the first 2000ft.
ForsakenRacism@reddit
Getting cleared for takeoff has nothing to do with it. The pilot would have asked to not take off and return to the gate. Something probably changed with the weather or conditions where they became overweight
mjltmjlt@reddit (OP)
Nah, pilot did not ask to return and I did not say anything about being cleared for takeoff.
ForsakenRacism@reddit
No the pilot definitely asked to return. Like 100%
mjltmjlt@reddit (OP)
Gotcha, makes sense. Appreciate the insight.
Loafer34@reddit
Happened to me on a not super full flight out of Jackson Hole. They ended up offering people a night at a very nice resort if they were willing to get off the plane and take one the next day. Unfortunately I had to get home for work but people accepted the vouchers pretty quickly.
ak_kitaq@reddit
Alaska Air doesn’t leave ADQ without going back to the ramp to ask the handlers to spread the fish out in the cargo hold (it’s inevitably all on one side of the plane)
mjltmjlt@reddit (OP)
Love it
OnigiriEnthusiast@reddit
Love me a good load of cod wad
f9pilot@reddit
Delta? I don't know what they do but Delta does SJU very differently than every one else. Rumor is they don't pay for some performance data so they have restoration there.
mjltmjlt@reddit (OP)
Yeah, Delta
dj6586@reddit
Yeah LAS-LHR on a BA 777, really hot July day, we were parked on taxiway for an hour before they told us we couldn't take off safely. Back to the gate for another hour while they offloaded half our bags to get under weight. Another hour after that taxiiing back to the runway. Then what felt like another hour on the roll.
OnigiriEnthusiast@reddit
It might have been really close, and the hourly weather report changed just enough to disqualify it. Reduced headwinds, hotter, etc.. Definitely unfortunate and I'm sure the crew was just as frustrated as you are
mjltmjlt@reddit (OP)
They were, for sure, timed out. Knowing the captain was doing everything and it’s a terrible time for ATC and everyone made it easier to take. But holy crap, that was a first.
airport-codes@reddit
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