Planes Can't Take Off If Temperature is 104+

Kinda scary news in the Las Vegas Review Journal regarding Norwegian Air's suspension of service from Las Vegas because their 787's can't take off with 300 passengers if the temperature is 104 or higher.

Quote: LVRJ Article on Norwegian Air's suspension of service from Las Vegas

...Norwegian's heat issues stem from an unusually high passenger capacity aboard the Boeing 787-8 jetliners that the carrier uses on its Las Vegas routes. Most airlines operate the plane with an average of 200 seats, but Norwegian puts 291 seats for sale on the 787-8 aircraft to keep costs down as part of its low-cost model, Jones said.

"Given the weight of those additional Norwegian passengers and all that accompanies them, the airline this summer found close to 300 people on board, including crew, and its planes "ability to take-off during high-temperature periods was sometimes limited", Jones said.


Norwegian officials are now studying whether to offer flights during the cooler early morning or late night hours from Las Vegas. The carrier might also opt to use planes with engines that are strong enough to take off with high passenger volumes during the extreme Las Vegas heat.

Can't take off!

Quote: Ayecarumba

Kinda scary news in the Las Vegas Review Journal regarding Norwegian Air's suspension of service from Las Vegas because their 787's can't take off with 300 passengers if the temperature is 104 or higher.


Norwegian officials are now studying whether to offer flights during the cooler early morning or late night hours from Las Vegas. The carrier might also opt to use planes with engines that are strong enough to take off with high passenger volumes during the extreme Las Vegas heat.

Buffalo Airways running old piston pushers have a -40 degree rule
-39 degrees or hotter, they fly
-40 or colder, oil just turns into sludge, flights grounded

Vegas and Phoenix and the like are subject to Density Altitude limitations at high temperatures. Often the plane's formulas do not include high weight and temperature operations. Mainly pilots will take off and fly away from their destination to gain altitude and then attempt a climb.

Quote: Ayecarumba

Kinda scary news in the Las Vegas Review Journal regarding Norwegian Air's suspension of service from Las Vegas because their 787's can't take off with 300 passengers if the temperature is 104 or higher.

What's scary about that? All planes have operational limits depending on configuration. A 777 can't fly from MEX to Shanghai with a rather typical 2-class configuration. It can't carry enough fuel due to the additional fuel required for takeoff at 2,200+ meters altitude. So it makes a stop along the way to refuel.

Norwegian could do the same. They could fly from LAS to, say, Toronto or NYC, refuel, and proceed to Europe easy as you please. They could also reduce loads, reschedule for cooler periods (as noted in the piece), or do R&D on JATO adaptations for the 787-8 :)

I doubt it requires that much more fuel for takeoff.
It is all about how much weight you can take off with. If you have to reduce weight, and you keep the same number of passengers, then you have to carry less fuel.

Quote: Dalex64

I doubt it requires that much more fuel for takeoff.
It is all about how much weight you can take off with. If you have to reduce weight, and you keep the same number of passengers, then you have to carry less fuel.

Sure. But that's Norwegian's checked bag and meal policies? How much cargo do they take on? With a full load of 300 people, the only places to reduce mass are 1) luggage, 2) meals and snack (which is negligible if you don't reduce the galleys as well), and 3) cargo.

They could also sell fewer tickets for the same flight. So even though you'd still have the capacity to carry 300 people, you'd only allow 275 to purchase tickets, say. Also, and ideally, you'd take out one flight attendant and save both on mass and salary. But I don't think that adds up.

Long haul low cost airlines have been perennial failures. What changed that is the 787 and its crazy high efficiency operation. So switching to a 777 or an A340 or A330 is not an option. So if the 787 configured with the required density can't do it, you're out of luck.

Conversely, if they're thinking of stops, they might switch to a 737 and offer two frequencies rather than one.

My point was I don't believe you need additional fuel to take off at altitude, as you stated.

Quote: Dalex64

My point was I don't believe you need additional fuel to take off at altitude, as you stated.

All other things being equal, like temperature, weight, winds, etc. you need additional fuel at 2,200+ meters compared to sea level. The air is thinner, so the wings provide less lift at a given speed, ergo takeoff speeds are higher, ergo you need to burn fuel longer on takeoff, ergo you need more fuel for takeoff. Keep in mind when you add fuel, you need to then add fuel to carry that fuel. It's a vicious circle.

It's as simple as the fact that AM made a fueling stop at Tijuana on the way to Asia with the 777. On the other hand, 777 flights from MEX to Paris , both by Aeromexico and Air France, did not require a fueling stop. That's because those flights are shorter, which require less fuel to begin with. So the extra takeoff fuel can be carried without trouble.

When I started reading flight reports on blogs, some mentioned the time of the takeoff roll. Usually it took between 25 and 35 seconds. I'd never timed mine, but I did a couple of times since. An A320 taking off from MEX took 45-50 seconds. You might think fuel for an additional 15-20 seconds can be that much. On cruising altitude it wouldn't be. but on takeoff with a full load of fuel from a standing start, it is quite a lot. Keep in mind engines provide much more power on takeoff than on cruise or landing.

Can you back that up with some documentation?

I mean, if we are all reasoning from our guts here, I would point out that by starting at 2,200m the airplane saves fuel by not having to climb from sea level from that altitude. In either case, the AC still needs to climb from 2,200m to its eventual cruising altitude. Once you are in the climb phase, there is no additional fuel use there.

Here is a post with two example charts - max takeoff weight by temperature, and required runway length.

http://aviation.stackexchange.com/questions/1531/does-temperature-affect-takeoff-performance

none of those charts talk about additional fuel consumption, or limited range due to take off altitude.

The reason for the fuel stops is just because when taking off at that altitude, they weren't able to carry as much fuel, due to decreased max takeoff weight at altitude combined with a longer takoff roll, which might require further reductions in takeoff weight.

I have never seen it described that the aircraft needed extra fuel due to the lengthened takeoff run.

here is another article describing hot and high operations:

http://lasvegassun.com/news/2012/jul/11/why-extreme-heat-makes-life-more-difficult-airline/

it also states, simply, that higher altitude requires lower weight, and instead of reducing passengers, they reduce fuel.

Quote: Dalex64

Can you back that up with some documentation?

https://en.wikipedia.org/wiki/Hot_and_high

Wikipedia has an article with some references to Hot and High airports with Vegas and Mexico City listed as prominent examples.

Probably the absolute worst thing that could happen to Norwegian would be an emergency refueling stop in Iceland.


The planes to Hong Kong used to make emergency stops in Tapei if they were low on fuel. It happened fairly frequently.


Flights from DFW to Sydney on the B747 would stop in Brisbane (only 274 miles closer) because of concerns about range with bad winds.


Probably the worst thing to happen was that the luggage was sent on a later flight as they were concerned about weight. It is more of a nuisance issue than something to be afraid about.