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Inacio
May 20, 2013





how does the MB-339 have such tiny tiny intakes compared to... pretty much anything else, and can still do 500 knots and 48,000ft?

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azflyboy
Nov 9, 2005


rscott posted:

Where are you supposed to wash your hands after dropping a duece in one of those?

Hand sanitizer.

The Q400 has a "normal" lavatory, but since the sink has issues with the lines freezing, a lot of those airplanes just have hand sanitizer instead of running water.

It's exactly as disgusting as you imagine, to the point where the FDA actually banned an airline with Q400 from serving ice or food because the flight attendants couldn't wash their hands. That was solved by a hilarious kludge of a "hand wash station" that converted one of the coffee warmers in the galley into a water tank, and then used plastic tubing and a dish washing container as a sink, which clogs if anyone so much as looks at it funny.

Bombardier also put the lavatory directly behind the first officers seat (the bulkhead behind the FO is also the lav wall), and since the lav is essentially a flushing porta potty with horrible seals, the flight deck tends to smell horrific in the summer if the lav isn't drained every single leg.

Inacio
May 20, 2013



azflyboy posted:

Hand sanitizer.

The Q400 has a "normal" lavatory, but since the sink has issues with the lines freezing, a lot of those airplanes just have hand sanitizer instead of running water.

It's exactly as disgusting as you imagine, to the point where the FDA actually banned an airline with Q400 from serving ice or food because the flight attendants couldn't wash their hands. That was solved by a hilarious kludge of a "hand wash station" that converted one of the coffee warmers in the galley into a water tank, and then used plastic tubing and a dish washing container as a sink, which clogs if anyone so much as looks at it funny.

Bombardier also put the lavatory directly behind the first officers seat (the bulkhead behind the FO is also the lav wall), and since the lav is essentially a flushing porta potty with horrible seals, the flight deck tends to smell horrific in the summer if the lav isn't drained every single leg.

i always thought the Q400 looked cool as heck and you ruined it for me. thanks

e.pilot
Nov 20, 2011

MR. FUSION


Inacio posted:

i always thought the Q400 looked cool as heck and you ruined it for me. thanks

There’s a lot more than just the lav that should ruin that plane for you.

azflyboy
Nov 9, 2005


e.pilot posted:

There’s a lot more than just the lav that should ruin that plane for you.

I will say that when it works, it's a pretty good airplane.

Most of the issues with it stem from Bombardier wanting to cut corners and keep the same type certificate as the smaller Dash 8 models. That means you end up with controls that are needlessly duplicated (we have both condition levers and a set of buttons to control the prop RPM, and several of the electrical switches are automatically overridden by the airplane), controls that do nothing (there's a switch for the ice protection system that's not actually connected to anything), or systems that are totally unsuited to an airplane that size (the heating was designed for an airplane half the size, and the autopilot has zero yaw authority and often confuses left and right), so there's basically more workarounds than actual procedures for most things. The radar is also terrible, which is fun when you're capped at FL250 and there's storms.

It's also impossible to land consistently well, since the fuselage is long enough that there's not a whole lot of flaring you can do without whacking the tail on the runway.

The FMS on the Q400's I fly is also quirky as hell, since the software we run is unique to about 35 airplanes worldwide, so there's quite a few bugs that got fixed in the rest of the Q400 fleet, but we have to live with because Universal won't fix it for that few airplanes.

That said, the ability to do 350kts on just under 2000lbs an hour is impressive, the cabin is pretty quiet when the NVS is working, and since the props act like giant airbrakes at idle, it gives us the flexibility to do stuff like maintain 200kts until about a 5 mile final, then go to idle, extend the flaps, and cross the threshold at about 110kts.

Other than constantly having to add rudder trim, it's actually a lot of fun to hand fly, but it's absolutely an airplane that will beat you up and take your lunch money if you aren't on top of your game and don't understand what it can and can't do.

PhotoKirk
Jul 2, 2007

insert witty text here



Charged batteries weigh the same as depleted ones. Is this going to lead to more wear and tear on the landing gear?

(Not a pilot, just a dude who like to watch airplanes)

simplefish
Mar 28, 2011

So long, and thanks for all the fish gallbladdΣrs!



azflyboy posted:

I will say that when it works, it's a pretty good airplane.

Most of the issues with it stem from Bombardier wanting to cut corners and keep the same type certificate as the smaller Dash 8 models. That means you end up with controls that are needlessly duplicated (we have both condition levers and a set of buttons to control the prop RPM, and several of the electrical switches are automatically overridden by the airplane), controls that do nothing (there's a switch for the ice protection system that's not actually connected to anything), or systems that are totally unsuited to an airplane that size (the heating was designed for an airplane half the size, and the autopilot has zero yaw authority and often confuses left and right), so there's basically more workarounds than actual procedures for most things. The radar is also terrible, which is fun when you're capped at FL250 and there's storms.

It's also impossible to land consistently well, since the fuselage is long enough that there's not a whole lot of flaring you can do without whacking the tail on the runway.

The FMS on the Q400's I fly is also quirky as hell, since the software we run is unique to about 35 airplanes worldwide, so there's quite a few bugs that got fixed in the rest of the Q400 fleet, but we have to live with because Universal won't fix it for that few airplanes.

That said, the ability to do 350kts on just under 2000lbs an hour is impressive, the cabin is pretty quiet when the NVS is working, and since the props act like giant airbrakes at idle, it gives us the flexibility to do stuff like maintain 200kts until about a 5 mile final, then go to idle, extend the flaps, and cross the threshold at about 110kts.

Other than constantly having to add rudder trim, it's actually a lot of fun to hand fly, but it's absolutely an airplane that will beat you up and take your lunch money if you aren't on top of your game and don't understand what it can and can't do.

Those are... quite the quirks

Safety Dance
Sep 10, 2007

Five degrees to starboard!


PhotoKirk posted:

Charged batteries weigh the same as depleted ones. Is this going to lead to more wear and tear on the landing gear?

(Not a pilot, just a dude who like to watch airplanes)

In aggregate over the lifespan of an aircraft, yeah. In reality, there'd be a tradeoff between fitting sturdier gear than an equivalent fossil fuel plane and increasing the maintenance requirements on landing gear (inspection every so many cycles, replace components every so many cycles, etc). Electric planes are for the most part still prototypes, so there are plenty of kinks to iron out as battery density improves.

MrYenko
Jun 17, 2012

#2 isn't ALWAYS bad...


PhotoKirk posted:

Charged batteries weigh the same as depleted ones. Is this going to lead to more wear and tear on the landing gear?

(Not a pilot, just a dude who like to watch airplanes)

That will matter more for range than for any wear on the gear. Electric airplanes make the most sense for operations where you’re flying a relatively short distance on a predictable route very frequently. You trade range capability and versatility for radically lower operating costs. It’s not going to replace IC airplanes, but it will replace them in specific niches.

evil_bunnY
Apr 2, 2003



Electrics planes are going to be flight school specials and parachute buses until the next battery tech leap.

Charles
May 9, 2004

zoom-zoom


Toilet Rascal

Imagine an electric medevac

Platystemon
Feb 13, 2012



If the Earth’s natural history had not given us oil, we would use renewable hydrocarbons for things like flying machines.

Platystemon fucked around with this message at 21:07 on Jun 1, 2020

Sagebrush
Feb 26, 2012





Gravy Boat 2k

Yep. Hydrocarbons like gasoline and diesel have practically the highest energy densities of any chemical fuel. Aside from a few dangerous and toxic experimental compounds, the only fuels that do better are nuclear.

azflyboy
Nov 9, 2005


simplefish posted:

Those are... quite the quirks

Most of the times I get a jumpseater who doesn't know the Q400, I get told some version of "drat, you guys are busy" at the end of the flight.

It doesn't help that the airline I fly for has over-proceduralized the crap out of the airplane, so we get things like the pilot monitoring having eleven separate tasks to complete between 1000 and 500AGL on approach, all while they're supposed to be monitoring the pilot flying.

MrChips
Jun 10, 2005

FLIGHT SAFETY TIP: Fatties out first

Biscuit Hider

A neat video:

https://www.youtube.com/watch?v=424oXB6-44Y

joat mon
Oct 15, 2009

I am the master of my lamp;
I am the captain of my tub.


Inacio posted:



how does the MB-339 have such tiny tiny intakes compared to... pretty much anything else, and can still do 500 knots and 48,000ft?

Both sides feed the single 50s era turbojet in the sub 10,000 lb aircraft.

joat mon fucked around with this message at 22:56 on Jun 1, 2020

rscott
Dec 10, 2009


azflyboy posted:

Hand sanitizer.

The Q400 has a "normal" lavatory, but since the sink has issues with the lines freezing, a lot of those airplanes just have hand sanitizer instead of running water.

It's exactly as disgusting as you imagine, to the point where the FDA actually banned an airline with Q400 from serving ice or food because the flight attendants couldn't wash their hands. That was solved by a hilarious kludge of a "hand wash station" that converted one of the coffee warmers in the galley into a water tank, and then used plastic tubing and a dish washing container as a sink, which clogs if anyone so much as looks at it funny.

Bombardier also put the lavatory directly behind the first officers seat (the bulkhead behind the FO is also the lav wall), and since the lav is essentially a flushing porta potty with horrible seals, the flight deck tends to smell horrific in the summer if the lav isn't drained every single leg.
This is great lmao

PainterofCrap
Oct 17, 2002

Hey bebe





So is Patrick Smith's story of the cargo DC-8's exploding lavatory:

https://www.askthepilot.com/essaysa...ploding-toilet/

azflyboy
Nov 9, 2005


rscott posted:

This is great lmao

The actual execution of the FDA crackdown was hilarious.

The airline in question had been operating Q400's for fifteen years at that point, and had passed all of the FDA inspections with zero issues. Suddenly, in the summer of 2016, the FDA realized that "wash your hands in the terminal between flights" is nowhere near compliant with food safety standards, and banned the airline from serving ice or pouring drinks. The ban on serving unsealed food didn't matter, since the Q didn't have anything except packages of cheez-its on board anyway.

After trying unsuccessfully to argue with the FDA, the airline tried using bottled water and a big tupperware container, which technically met the requirements but was completely unworkable, which lead to the current "repurpose a coffee warmer as a sink" solution. Since the airline in question was in the middle of contract negotiations with the pilot group, we all thought it was completely hilarious to watch management try and insist that food safety standards somehow didn't apply "because airplane".

To this day, no one is quite sure why the FDA suddenly realized they had a problem, but the best guess is that a disgruntled employee blew the whistle, since the timing corresponded with mass layoffs of the HR and training departments.

Cat Mattress
Jul 14, 2012

I don't find this sort of thing funny


Sagebrush posted:

Yep. Hydrocarbons like gasoline and diesel have practically the highest energy densities of any chemical fuel. Aside from a few dangerous and toxic experimental compounds, the only fuels that do better are nuclear.

How about hydrogen? Wikipedia gives liquid and compressed hydrogen about thrice the energy density of jet fuel.

Platystemon
Feb 13, 2012



Cat Mattress posted:

How about hydrogen? Wikipedia gives liquid and compressed hydrogen about thrice the energy density of jet fuel.

Hydrogen has high energy for its mass, but it’s voluminous, it leaks like a Trump staffer, and cryogenic storage presents its own challenges.

Rockets sometimes use it, but it’s more common to use hydrocarbons, especially for the first stage that constitutes a disproportionate amount of the rocket’s bulk and fuel consumption. “Rocket propellant 1”, more commonly referred to as RP‐1, is basically kerosene with stricter standards for composition. Jet fuel is also basically kerosine.

CrazyDutchie
Aug 5, 2005


Cat Mattress posted:

How about hydrogen? Wikipedia gives liquid and compressed hydrogen about thrice the energy density of jet fuel.


Hydrogen has been a bit of a no-no due to some negative publicity.

Ola
Jul 19, 2004



CrazyDutchie posted:


Hydrogen has been a bit of a no-no due to some negative publicity.

Dang, hydrogen can catch fire? Better stick to hydrocarbons then, we don't want stuff that can catch fire.

Cat Mattress
Jul 14, 2012

I don't find this sort of thing funny


CrazyDutchie posted:


Hydrogen has been a bit of a no-no due to some negative publicity.

That was not using hydrogen as a fuel, though; it was using it as lifting gas due to sanctions preventing them from using helium.

We're seeing hydrogen fuel cells in consumer cars already, like the Mirai.

The main difference with fossil fuels is that with fossil fuels, despite extraction and refining, you get out more energy than you put in. With hydrogen, you get out less energy than you put in, so they're for energy storage, not energy generation. But the same is true of batteries. And it's not like batteries don't catch on fire either; as Boeing and Samsung found out.

CarForumPoster
Jun 26, 2013


Inacio posted:



how does the MB-339 have such tiny tiny intakes compared to... pretty much anything else, and can still do 500 knots and 48,000ft?

Not very knowledgable about intake design but my guess would be the combination of it being a turbojet (no big fan in a big shroud for bypass air) and it being subsonic.

PhotoKirk posted:

Charged batteries weigh the same as depleted ones. Is this going to lead to more wear and tear on the landing gear?

(Not a pilot, just a dude who like to watch airplanes)

Landing gear are specified for a plane based on requirements including the weight the plane is when it lands and the number of landings you need to make at that weight (and >100 other things that accompany critical safety items). Landing gear have a ton of requirements in my experience in military aviation compared to similar complexity mechanical systems like hydraulic pumps. They also tend to have extremely tight materials/processing/manufacturing requirements though that could be specific to the plane I was working on. Less so than an engine but more than other critical safety items of similar complexity. Even if they use an all or partially off the shelf solution in the end, it'll be one that has been evaluated against those requirements.

Inacio
May 20, 2013



Cat Mattress posted:

We're seeing hydrogen fuel cells in consumer cars already, like the Mirai.

does japan/the us have enough hydrogen gas stations to support owning a hydrogen car? huh

also yeah planes

Platystemon
Feb 13, 2012



Hydrogen for land transport is an accounting trick on a level with We regret to inform you that Star Wars has not yet turned a profit.

There is no significant free hydrogen on this planet. We cannot make free hydrogen on any significant scale through biological processes.

The options are to pump natural gas into a chemical plant and use energy to make it into an inferior fuel in a process called “steam reforming”, or to produce it via electrolysis, making it a very leaky battery.

sanchez
Feb 26, 2003


Cat Mattress posted:

We're seeing hydrogen fuel cells in consumer cars already, like the Mirai.

These things rely on hydrogen generated from natural gas and sold at an exorbitant price from a network of sparse unreliable stations that occasionally explode. It's pretty terrible really, you're better off with an EV or a Prius.

Sagebrush
Feb 26, 2012





Gravy Boat 2k

Cat Mattress posted:

How about hydrogen? Wikipedia gives liquid and compressed hydrogen about thrice the energy density of jet fuel.

Liquid hydrogen and compressed hydrogen require a huge amount of infrastructure to transport, store, and load into a vehicle. With gasoline all you need is a bucket and a funnel. The extreme convenience of a fuel that is dense and liquid and relatively non-volatile at room temperature, which can be stored in a sheet metal box instead of a carbon fiber pressure vessel, outweighs the theoretically higher energy density of hydrogen.

luminalflux
May 27, 2005



Inacio posted:

does japan/the us have enough hydrogen gas stations to support owning a hydrogen car? huh

Apparently because I saw one here in SF the other day.

Phanatic
Mar 13, 2007

Please don't forget that I am an extremely racist idiot who also has terrible opinions about the Culture series.


Cat Mattress posted:

How about hydrogen? Wikipedia gives liquid and compressed hydrogen about thrice the energy density of jet fuel.

The volumetric energy density of hydrogen is awful. If you want it to be liquid, you need big tanks and cryogenic temperatures. If you try compressing it, you need really thick heavy tanks.

Hydrocarbons are a really good energy storage medium.

Midjack
Dec 24, 2007






Biscuit Hider

Inacio posted:

does japan/the us have enough hydrogen gas stations to support owning a hydrogen car? huh

also yeah planes

No and they never will. Hydrogen vehicles are a science fair display.

wolrah
May 8, 2006
what?


Platystemon posted:

Hydrogen has high energy for its mass, but it’s voluminous, it leaks like a Trump staffer, and cryogenic storage presents its own challenges.
The BMW Hydrogen7 (in)famously would start venting gas due to inability to maintain cryogenic temperatures within 18 hours of being parked, and if left alone would entirely empty its 45 gallon hydrogen tank in under two weeks. It also got <5 MPG on hydrogen, so even if you filled up and just started driving you'd only get a bit over 200 miles before needing to refuel. Also that huge hydrogen tank took up half the trunk.

I used to be a big believer in hydrogen as a transition fuel but the storage problem combined with the need for all new infrastructure makes it really hard to fit in to any scenarios other than a few niche fleet applications in locations where hydrogen is readily available at low enough prices to be worth the hassle.

The Real Amethyst
Apr 20, 2018

When no one was looking, Serval took forty Japari buns. She took 40 buns. That's as many as four tens. And that's terrible.

ATR72 > Dash 8.

Sagebrush
Feb 26, 2012





Gravy Boat 2k

if only there were some way to take all that hydrogen and bind it up with something else that would make it easier to handle. you'd want it to be some compound that would stabilize it, make it into a dense room-temperature liquid or gel, but not totally stable -- ideally it would be relatively safe when sealed up but still reactive enough that you could trigger a rapid release of the stored energy with some simple technique like shock or electricity.

maybe someday!

Nebakenezzer
Sep 13, 2005

The Mote in God's Eye



wolrah posted:

I used to be a big believer in hydrogen as a transition fuel but the storage problem combined with the need for all new infrastructure makes it really hard to fit in to any scenarios other than a few niche fleet applications in locations where hydrogen is readily available at low enough prices to be worth the hassle.

(ahem)

Airships.



A dumb chemistry question: would it be possible to combust petrochemicals and *not* have the products produce so much CO2?

Midjack
Dec 24, 2007






Biscuit Hider

Nebakenezzer posted:

(ahem)

Airships.



A dumb chemistry question: would it be possible to combust petrochemicals and *not* have the products produce so much CO2?

No. Ideal hydrocarbon combustion in oxygen yields carbon dioxide and water, you'd have to do something with the CO2 after it was formed.

Safety Dance
Sep 10, 2007

Five degrees to starboard!


Sagebrush posted:

if only there were some way to take all that hydrogen and bind it up with something else that would make it easier to handle. you'd want it to be some compound that would stabilize it, make it into a dense room-temperature liquid or gel, but not totally stable -- ideally it would be relatively safe when sealed up but still reactive enough that you could trigger a rapid release of the stored energy with some simple technique like shock or electricity.

maybe someday!

Alas, that exists but the product of that chemical reaction is literally heating the planet!


Nebakenezzer posted:

A dumb chemistry question: would it be possible to combust petrochemicals and *not* have the products produce so much CO2?

The unfortunate reality of hydrocarbons is they contain hydrogen (good at burning, produces water when oxygenated!) and carbon (produces CO2 when oxygenated ). So, like, for every gram of hydrocarbon-based fuel you burn, you produce a known quantity of carbon dioxide (assuming the fuel burns completely).

The big problem with hydrocarbons is they're just sitting in the ground waiting to be used. That makes them cheaper than other chemical fuel sources.

bull3964
Nov 18, 2000

DO YOU HEAR THAT? THAT'S THE SOUND OF ME PATTING MYSELF ON THE BACK.




Midjack posted:

No. Ideal hydrocarbon combustion in oxygen yields carbon dioxide and water, you'd have to do something with the CO2 after it was formed.

Or, ideally, the CO2 that went into your fuel to begin with was pulled from the environment.

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Unreal_One
Aug 18, 2010

Now you know how I don't like to use the sit-down gun, but this morning we just don't have time for mucking about.


Midjack posted:

No. Ideal hydrocarbon combustion in oxygen yields carbon dioxide and water, you'd have to do something with the CO2 after it was formed.

I mean, you can get carbon monoxide if you really want, but that's less energy output and possibly worse for the environment than CO2.

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