737 MAX 10

[GON]

Why the condescension? It’s doesn’t make ME think that at all.

It’s a chart about DOMESTIC flying. Why would they include international widebody flying in a chart about domestic flying?

MIT has a bunch of data if you want to make your own chart with average seats per departure for the Total Operating Fleet. Sounds like that’s what you’re looking for. United was #2 in 2019, only behind Hawaiian.

Airline Data Project

If one wants to fix the pilot shortage and airport congestion, the solution is quite simple. End federal subsidies of regional airports .

One of many examples I can site, when I lived in Pennsylvania for four years. There were six regional airports within 100 miles of where I lived. And I lived in a town of 200 people. All five of these airports had regional flights multiple times per day. Eliminate the federal subsidies, a large amount of gates, landing rights, and pilots are free up for mainline flights.

 

[Just a civilian pilot]

As a passenger Air Canadas first A320's weren't great.

I flew them a tremendous number of times from LAX to YUL when my company was headquartered in MTL.

Air Canada seemingly ordered them without APU's and during long parks at gate you'd get no AC.

Lots of then had metal boxes on the floor that intruded into your legroom and or ability to store a carry on item completely under the seat.

More later, but for now....

We do not start the APU until 10 minutes prior to push so it would be because the gate AC was not on or was weak.

The APU is very powerful ( heat and cooling ).

Got to go flying

 

[Astro14]

Why the condescension?

It’s a chart and article about domestic flying. Why would they include international widebody flying in a chart about domestic flying?

MIT has a bunch of data if you want to make your own chart with average seats per departure for the Total Operating Fleet. Sounds like that’s what you’re looking for. United was #2 in 2019, only behind Hawaiian.

Airline Data Project

No condescension.

That slice of the data is a gross misrepresentation of what is actually going on.

The “biggest” airplanes on the graph are the ones flown by discount airlines with no big airplanes and one class of seats.

The “smallest” airplanes, again, by number of seats, are flown by the airlines that offer better seating, including economy plus and first class, on their domestic airplanes and that actually own big airplanes.

 

[350Rocket]

As a passenger Air Canadas first A320's weren't great.

I flew them a tremendous number of times from LAX to YUL when my company was headquartered in MTL.

Air Canada seemingly ordered them without APU's and during long parks at gate you'd get no AC.

Lots of then had metal boxes on the floor that intruded into your legroom and or ability to store a carry on item completely under the seat.

The Sunwing flights we took a this past February smelled like kerosene fumes when we boarded (especially the outgoing flight on the max). They said they had to idle the engine longer than normal. I don't know if they had an apu or not.
A few years back the last time we went on vacation, when we landed (in a 737ng) they kept the seatbelt lights on while idling at the gate "because the apu was not working and they didn't want to kill the AC on us". I can't remember what airline it was, but it was a common one.

 

[UncleDave]

The Sunwing flights we took a this past February smelled like kerosene fumes when we boarded (especially the outgoing flight on the max). They said they had to idle the engine longer than normal. I don't know if they had an apu or not.
A few years back the last time we went on vacation, when we landed (in a 737ng) they kept the seatbelt lights on while idling at the gate "because the apu was not working and they didn't want to kill the AC on us". I can't remember what airline it was, but it was a common one.

All airports always smell like kerosene to me, but aircraft air conditioning is interesting in that sometimes its powered by bleeding air off the engines, and sometimes electrically, often times by both at different times every flight.

There have long been claims some models contaminate bleed air. (DC9 lawsuit?) It's always interesting to know and Im sure a 737 pilot would know as they have to control all these subsystems.

I cant recall often sitting at a gate with engines running for very long??

 

[Nuclear_42]

All airports always smell like kerosene to me, but aircraft air conditioning is interesting in that sometimes its powered by bleeding air off the engines, and sometimes electrically, often times by both at different times every flight.

There have long been claims some models contaminate bleed air. (DC9 lawsuit?) It's always interesting to know and Im sure a 737 pilot would know as they have to control all these subsystems.

I cant recall often sitting at a gate with engines running for very long??

Most modern airliners have 2 air conditioning packs. They’re usually run with engine bleed air. 1 pack per engine or both packs on a single engine if needed. Also the A/C packs can be run with APU bleed air. The only jet with electric packs is the 787 along with electric engine start. The 787 essentially got rid of 90% of pneumatic systems.

 

[350Rocket]

Most modern airliners have 2 air conditioning packs. They’re usually run with engine bleed air. 1 pack per engine or both packs on a single engine if needed. Also the A/C packs can be run with APU bleed air. The only jet with electric packs is the 787 along with electric engine start. The 787 essentially got rid of 90% of pneumatic systems.

When the fumes were really bad bad in the 737 max 8, it was cold winter outside in Toronto, so no Ac on. Would they have had to leave it idling because the APU was broken?

 

[Nuclear_42]

When the fumes were really bad bad in the 737 max 8, it was cold winter outside in Toronto, so no Ac on. Would they have had to leave it idling because the APU was broken?

The packs provide all cooling and heating as well as cabin pressurization. Even when it’s cold outside. In this case you’re off the gate on engine power. The engine bleed air systems are supplying the packs. The fumes could be from many things engines, pneumatic systems, packs themselves, or even from nearby odor unrelated to the aircraft. The APU on most aircraft supply electric and pneumatics. They could be partially inop or completely inop.

 

[Astro14]

When the fumes were really bad bad in the 737 max 8, it was cold winter outside in Toronto, so no Ac on. Would they have had to leave it idling because the APU was broken?

I think you're misunderstanding what a pack does. The packs are air conditioning compressors. They are powered by bleed air from the engines, or high pressure air off the APU. The packs feed air into a manifold that then supplies the cabin. The manifold temp is managed by mixing in hot bleed air, if the engines are running, to provide different temperatures in different parts of the airplane. Cockpit, cabin zones, etc.

Pack outlet temperature depends on the inlet temperature, the bleed air mix, and the desired cabin temp. So, it's not like your car. We don't press the AC ON button. We run packs if we have engines or APU running, and the packs provide conditioned (heated or cooled) air to the cabin.

If the packs aren't available - then the station usually hooks up external air, that is fed into the cabin air manifold normally used by the packs. Cool air in the summer. Hot air in the winter.

The air in the airplane is coming from outside, the packs suck it in, just like the external air handlers suck it in, from the gate area - and lots of things nearby can cause odors and fumes. Deicing fluid, tractors and ground support equipment exhaust, airplane engine exhaust.

I'm actually a fan of our all new electric (BEV) fleet of ground support equipment - it does a lot to reduce the fumes from constantly running diesel exhaust around the gate area.

 

[nthach]

The Sunwing flights we took a this past February smelled like kerosene fumes when we boarded (especially the outgoing flight on the max). They said they had to idle the engine longer than normal. I don't know if they had an apu or not.
A few years back the last time we went on vacation, when we landed (in a 737ng) they kept the seatbelt lights on while idling at the gate "because the apu was not working and they didn't want to kill the AC on us". I can't remember what airline it was, but it was a common one.

If the APU isn’t working, that’s already cause to can the flight. A working APU is on the minimally required equipment list to dispatch a plane, IIRC. It’s the only way the engines can start without a ground bleed air cart.

 

[E365]

If the APU isn’t working, that’s already cause to can the flight. A working APU is on the minimally required equipment list to dispatch a plane, IIRC. It’s the only way the engines can start without a ground bleed air cart.

There’s a lot of factors/situation involved, but sometimes you can fly without an operating APU. In some applications, the APU can even have certain parts of it deferred, such as just the pneumatics. I flew a bunch of MD80/90s with APU pneumatics deferred, and just the electrical generator operating. And maybe vice-versa(?). Can’t remember…

When I flew CRJs, those APUs were inop frequently, especially the CRJ200. The CRJ900 was much better. “Huffer Cart” (External HP air) starts were pretty common. Often would do a huffer cart start at the gate, then do a “cross bleed” start on the other engine, out on a taxiway. Spool up the operating engine to provide enough bleed air to start the other.

I fly a 737 now and that APU is almost flawless. Don’t think I’ve ever seen one NOT start and run perfectly

 

[350Rocket]

If the APU isn’t working, that’s already cause to can the flight. A working APU is on the minimally required equipment list to dispatch a plane, IIRC. It’s the only way the engines can start without a ground bleed air cart.

About 5 years ago on another flight to Cuba, they actually told us when we landed in Cuba that they were leaving the one engine on because the APU wasn't working. Maybe it died during the flight.

 

[Astro14]

About 5 years ago on another flight to Cuba, they actually told us when we landed in Cuba that they were leaving the one engine on because the APU wasn't working. Maybe it died during the flight.

Or maybe there wasn’t the ground support equipment in Cuba needed for air conditioning, power, and engine start.

An APU is a very expensive gas turbine engine. Far cheaper to provide conditioned air and ground power to an airplane than run that little turbine for an airplane that is sitting on the ground. But not every airport has that kind of infrastructure.

We actually try and shut them down within minutes of arrival - to save wear and tear on them.

We will dispatch an airplane without an APU if it’s going to a place where ground conditioned air, ground power, and a pneumatic start system is available. Usually all plugged in within seconds of setting the parking brake at the gate. That’s the standard at our hubs. Not every outstation has that, though many do, and that’s when captain and dispatcher will have a conversation.

The other time an APU matters is in really bad weather. The electrical system on most airplanes uses APU generator as a third electrical power source during a triple-redundant auto land. So, if the forecast is for very low visibility (fog in London, for example), then an operating APU becomes more important.

 

[Cujet]

The air in the airplane is coming from outside, the packs suck it in, just like the external air handlers suck it in, from the gate area -

One minor clarification, conventional air conditioning packs don't suck in air and then provide it to the cabin.

The air comes from the engine or APU's compressor section.

The compressed air is compressed further, the heat is removed via a heat exchanger (looks much like an automotive intercooler) and then expanded through a turbine, where it exits at about -35F. Hot bleed air is then immediately mixed in, to melt the ice that forms.


The picture below is a vast simplification of what happens. For nerdy types like me, it's a fascinating process.

TLDR, what ever air the APU or engine is drawing in, is what reaches the cabin.

 

[mk378]

At the gate when a ground air conditioning unit is in use, the air is from the intake of that machine near the ground. It goes through the cabin once then exits through the open door.

 

[97prizm]

With the end of 747 production I thought the plan was to not stack so many people on a plane anymore?

With demand picking up faster than expected several airlines are pulling their Airbus A380s back out of storage.

 

[Astro14]

One minor clarification, conventional air conditioning packs don't suck in air and then provide it to the cabin.

The air comes from the engine or APU's compressor section.

The compressed air is compressed further, the heat is removed via a heat exchanger (looks much like an automotive intercooler) and then expanded through a turbine, where it exits at about -35F. Hot bleed air is then immediately mixed in, to melt the ice that forms.


The picture below is a vast simplification of what happens. For nerdy types like me, it's a fascinating process.

TLDR, what ever air the APU or engine is drawing in, is what reaches the cabin.

Great point. Thanks. The pack inlets and outlets are for the cooling air flow.

But still, the APU and engines suck in the fumes around the gate area.

 

[Just a civilian pilot]

Airbus A320 APU is very reliable.

In 21 years, only had problems starting it once ( three attempts then 1 hour wait to cool starter ).

 

[E365]

RyanAir just ordered 150 MAX-10s (with 150 options).

228 seats vs. 180/182 on United/Delta

Ryanair orders at least 150 of Boeing's largest 737 Max planes

Boeing is planning to ramp up production of the best-selling planes to meet an increase in demand.

www.cnbc.com

 

[CKN]

RyanAir just ordered 150 MAX-10s (with 150 options).

228 seats vs. 180/182 on United/Delta

Ryanair orders at least 150 of Boeing's largest 737 Max planes

Boeing is planning to ramp up production of the best-selling planes to meet an increase in demand.

www.cnbc.com

Leg room is getting down right unbearable on airplanes-even for those of us that fall right at average in height.