Electric planes

[Buckminster]

This is the boys toys thread. Real men go here:
VTOL Supersonic aircraft

 

[cybertrucker]

Since this thread title doesn't specify range at all I recommend you start a thread about long range electric planes only if you're so motivated. This thread is just fine as it is.

You might be the first person to ever describe a 737 as "long range".....hahaha, congratulations!


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[JRP3]

You might be the first person to ever describe a 737 as "long range".....hahaha, congratulations!


.

You are unfortunately not the first person to create a false narrative, I didn't describe the 737 at all, or even mention it ....hahaha, congratulations! You also seem to have no interest in contributing anything to this thread other than complaints.

 

[daniel]

You might be the first person to ever describe a 737 as "long range".....hahaha, congratulations!

Compared to any electric plane that will ever be built, the 737 is extremely long-range, capable of flying all the way across America, in any direction, with reserve left over.

 

[daniel]

This is the boys toys thread. Real men go here:
VTOL Supersonic aircraft

I don't read threads that start with Joe Rogan videos, and I can't imagine who would. Listening to Joe Rogan is kind of like having a load of fresh cow manure dumped into your ears.

Oh, and I believe the military already has supersonic VTOL airplanes. The real kind, not the make-believe futuristic electric kind. I'll bet there are forums for aficionados of military aircraft with extensive discussions of them. Minus the make-believe part.

As for Elon, he is prone to exaggeration and flights of fancy.

 

[cybertrucker]

You are unfortunately not the first person to create a false narrative

no, you don't get to make up narratives then accuse others of false narratives.

Here is a recap:

The main problem with batteries is, landing weight is the same as take-off weight.

Which means EV planes should weigh close to the weight of an ICE plane with empty tanks. I am not even sure today we are anywhere close to that in terms of gravimetric density for even the highest energy density LiOn battery with Co & Ni.

The above statement is true and highlights the problem with the low energy density of batteries with respect to aviation.

Then, several commenters tried to say this person was wrong. Note the phrasing with "all" and "always" as well as leading off with "what are you talking about?"

What are you talking about? All the airplanes I have flown are designed to land with a full tank.

Or look up any regional turboprop specifications, maximum landing weight is generally very close to maximum takeoff weight. As in 95% full tank.

That is correct, as an Aerospace Engineer that has certified multiple platforms and systems that are directly applicable to this, we always end up certifying max landing weight very close to max TO weight except with special conditions. It's not as efficient really because the lighter an aircraft gets through it's flight plan the lower AOA needed to maintain lift and therefor the CoD reduced make for more efficient flying, but it can be accounted for just fine.

So I simply stated some facts agreeing with the original commenter:

"The best selling Jet Airliner of all time is the 737. Currently, the most common example is the Next Generation 737-800.

Max Takeoff weight 174,000 pounds.

Max Landing weight 146,000 pounds.

That is a SIGNIFICANT difference"


So you can have your opinion, but you can't have your own facts.


.

 

[JRP3]

So you can have your opinion, but you can't have your own facts.

Here's a fact: I never mentioned the 737 or it's range, or any plane weight or range. You're having an argument in your own head divorced from reality.

 

[petit_bateau]

Please can we have sensible well-informed non-bickering posts. Please

 

[JRP3]

We managed to for the last 14 years. Guess what changed?

 

[cybertrucker]

Here's a fact: I never mentioned the 737 or it's range, or any plane weight or range. You're having an argument in your own head divorced from reality.

I was responding to Electroman, Etna, and MadScientist.

If you don't like what we were saying that's fine, but if you want to join this portion of the conversation insults probably aren't going to win you any friends.

 

[cybertrucker]

See the Pipistrel Taurus Electro. I have one. It's got a 40 kW motor (actual peak output is something like 33 kW), which is enough to climb at a decent clip up to soaring altitude. Battery runtime is something on the order of 20-25 minutes. It's got battery power for 8,000' of climb - enough for a few launches to 2,000' or a full day of flying if you're able to find some thermals.

that's pretty cool !

 

[Etna]

Here is a recap:

Let's try with a recap of mine. My job for the past 25 years has specifically been the design of new airplanes, jets and turboprops. My answers may be sometimes a bit obtuse or overly complicated, and not always correct, but I will try my best to explain what the deal is.

This fixation on maximum landing weight being an issue for electric airplanes, which I frequently read on various forums, is a total mystery to me because it is a problem that does not exist, and worse, even if existed it would not be a problem either. So it's a double strike.

The problem does not exist because there are many very successful airplanes that have their maximum landing weight equal or extremely close to their maximum takeoff weight. That is the case of virtually all general aviation airplanes except the largest ones (all that I have flown as a private pilot), for example the incredibly successful Beechcraft Bonanza has a maximum landing weight equal to its maximum takeoff weight of 3805 lb. It is also the case of the majority of short range turboprops. One example I gave earlier in this thread is the ATR-42 which is more dominant in its market space than the 737 is in its market space. Its maximum landing weight is 40344 lb versus 41005 lb maximum takeoff weight, or a 98.3% ratio that I would qualify as extremely close. This is similar to other extremely successful airplanes like the De Havilland Twin Otter (98.4%) and simply represent the approximate fuel burn of taking off, flying the pattern and landing immediately.

So having a maximum landing weight at or very close to the maximum takeoff weight does not prevent an airplane from becoming extremely successful. It. Is. Not. A. Problem.

It is actually the way this is done for airplanes having technical similarity with electric airplanes: not very large and not going very far.

You provide an example for the 737-800, I can tell you that the large difference between its maximum landing weight and maximum takeoff weight is not the reason it is such a successful design. The ratio of the two is 83.9% which is about the same as the A321 at 83.2%. It is just the way it is done for that particular category of airplanes, as it allows the aircraft structure - including the landing gear - to be designed a little bit lighter, since these airplanes rarely fly less than an hour on a typical mission.

One could also modify an existing widebody to operate ultra-short-haul flights. A cool example is the Boeing 737-100SR designed for Japan Airlines. It had a ratio of maximum landing weight to maximum takeoff weight of 94%, a huge difference when compared to the 747-400 at 72%.

Electric airplanes must be significantly heavier than their ICE counterparts for a long list of reasons, and and the maximum landing weight "issue" is actually not on that list of reasons, because their ICE counterparts having similar characteristics (size and range) already have their maximum landing weight at or near their maximum takeoff weight.

 

[petit_bateau]

One could also modify an existing widebody to operate ultra-short-haul flights. A cool example is the Boeing 737-100SR designed for Japan Airlines. It had a ratio of maximum landing weight to maximum takeoff weight of 94%, a huge difference when compared to the 747-400 at 72%.

Great post.

One typo - I'm sure you mean the 747-100SR.

The fate of those Japanese models is instructive: high speed rail killed their economic niche, and increasingly high speed rail is driven via renewable electrics. Will this be the first generation of aero engineers to witness a shrinking market (absent post-war stuff).

 

[Etna]

Great post.

One typo - I'm sure you mean the 747-100SR.

The fate of those Japanese models is instructive: high speed rail killed their economic niche, and increasingly high speed rail is driven via renewable electrics. Will this be the first generation of aero engineers to witness a shrinking market (absent post-war stuff).

Thanks, yes a typo, I meant the 747-100SR.

 

[daniel]

The fate of those Japanese models is instructive: high speed rail killed their economic niche, and increasingly high speed rail is driven via renewable electrics. Will this be the first generation of aero engineers to witness a shrinking market (absent post-war stuff).

The high-speed trains in Spain when I lived there (circa 2000) are not nearly as fast as the ones in Japan or France, but still it was faster to take the train between Seville and Madrid than to fly, given the time to get to the airport, go through security, factor in delays (the Spanish trains always arrive a few minutes early) and get out of the airport. Any place that has a sensible public transportation system, which includes electric intercity trains, will have no significant commercial market for short-distance planes. Island-hopping would be their only niche. I took a floatplane from Seattle to San Juan Island and I'd have paid a significant premium to fly electric, but I'm rabidly anti-gasoline. Most people will take the cheapest flight. Maybe some day that route could be operated by an electric plane? (A 50-minute flight on a very small plane.) (And it was a lot of fun!)

 

[cybertrucker]

Let's try with a recap of mine. My job for the past 25 years has specifically been the design of new airplanes, jets and turboprops. My answers may be sometimes a bit obtuse or overly complicated, and not always correct, but I will try my best to explain what the deal is.

This fixation on maximum landing weight being an issue for electric airplanes, which I frequently read on various forums, is a total mystery to me because it is a problem that does not exist, and worse, even if existed it would not be a problem either. So it's a double strike.

The problem does not exist because there are many very successful airplanes that have their maximum landing weight equal or extremely close to their maximum takeoff weight. That is the case of virtually all general aviation airplanes except the largest ones (all that I have flown as a private pilot), for example the incredibly successful Beechcraft Bonanza has a maximum landing weight equal to its maximum takeoff weight of 3805 lb. It is also the case of the majority of short range turboprops. One example I gave earlier in this thread is the ATR-42 which is more dominant in its market space than the 737 is in its market space. Its maximum landing weight is 40344 lb versus 41005 lb maximum takeoff weight, or a 98.3% ratio that I would qualify as extremely close. This is similar to other extremely successful airplanes like the De Havilland Twin Otter (98.4%) and simply represent the approximate fuel burn of taking off, flying the pattern and landing immediately.

So having a maximum landing weight at or very close to the maximum takeoff weight does not prevent an airplane from becoming extremely successful. It. Is. Not. A. Problem.

It is actually the way this is done for airplanes having technical similarity with electric airplanes: not very large and not going very far.

You provide an example for the 737-800, I can tell you that the large difference between its maximum landing weight and maximum takeoff weight is not the reason it is such a successful design. The ratio of the two is 83.9% which is about the same as the A321 at 83.2%. It is just the way it is done for that particular category of airplanes, as it allows the aircraft structure - including the landing gear - to be designed a little bit lighter, since these airplanes rarely fly less than an hour on a typical mission.

One could also modify an existing widebody to operate ultra-short-haul flights. A cool example is the Boeing 737-100SR designed for Japan Airlines. It had a ratio of maximum landing weight to maximum takeoff weight of 94%, a huge difference when compared to the 747-400 at 72%.

Electric airplanes must be significantly heavier than their ICE counterparts for a long list of reasons, and and the maximum landing weight "issue" is actually not on that list of reasons, because their ICE counterparts having similar characteristics (size and range) already have their maximum landing weight at or near their maximum takeoff weight.

when you cite examples of niche, poorly selling, and discontinued aircraft (or ones that got beat by trains), it doesn't really help your point.

 

[Etna]

when you cite examples of niche, poorly selling, and discontinued aircraft (or ones that got beat by trains), it doesn't really help your point.

Beechcraft built and sold over 17000 Bonanza, far more than Boeing sold 737s. And it is still in production.

 

[daniel]

when you cite examples of niche, poorly selling, and discontinued aircraft (or ones that got beat by trains), it doesn't really help your point.

I think the point is that the tiny niche market of very small short-hop planes is the only one where electric planes have a hope of competing. That and the hobbyist market, where factors other than cost and load weight predominate. There will never be an economically viable commercial electric plane with the range and passenger capacity of a 737.

The difference between takeoff and landing weight is not the issue. The weight of batteries is the issue.

 

[cybertrucker]

Beechcraft built and sold over 17000 Bonanza, far more than Boeing sold 737s. And it is still in production.

Now you are just cherrypicking a flying Porsche sold to doctors and lawyers.

When it comes to commercial aircraft that have to make economic sense the distance between your examples and a successful aircraft design is enormous.

747-100SR.....29 sold
ATR................400 sold

vs

737.................10,000 sold



.

 

[winfield100]

Let's try with a recap of mine. My job for the past 25 years has specifically been the design of new airplanes, jets and turboprops. My answers may be sometimes a bit obtuse or overly complicated, and not always correct, but I will try my best to explain what the deal is.

This fixation on maximum landing weight being an issue for electric airplanes, which I frequently read on various forums, is a total mystery to me because it is a problem that does not exist, and worse, even if existed it would not be a problem either. So it's a double strike.

The problem does not exist because there are many very successful airplanes that have their maximum landing weight equal or extremely close to their maximum takeoff weight. That is the case of virtually all general aviation airplanes except the largest ones (all that I have flown as a private pilot), for example the incredibly successful Beechcraft Bonanza has a maximum landing weight equal to its maximum takeoff weight of 3805 lb. It is also the case of the majority of short range turboprops. One example I gave earlier in this thread is the ATR-42 which is more dominant in its market space than the 737 is in its market space. Its maximum landing weight is 40344 lb versus 41005 lb maximum takeoff weight, or a 98.3% ratio that I would qualify as extremely close. This is similar to other extremely successful airplanes like the De Havilland Twin Otter (98.4%) and simply represent the approximate fuel burn of taking off, flying the pattern and landing immediately.

So having a maximum landing weight at or very close to the maximum takeoff weight does not prevent an airplane from becoming extremely successful. It. Is. Not. A. Problem.

It is actually the way this is done for airplanes having technical similarity with electric airplanes: not very large and not going very far.

You provide an example for the 737-800, I can tell you that the large difference between its maximum landing weight and maximum takeoff weight is not the reason it is such a successful design. The ratio of the two is 83.9% which is about the same as the A321 at 83.2%. It is just the way it is done for that particular category of airplanes, as it allows the aircraft structure - including the landing gear - to be designed a little bit lighter, since these airplanes rarely fly less than an hour on a typical mission.

One could also modify an existing widebody to operate ultra-short-haul flights. A cool example is the Boeing 737-100SR designed for Japan Airlines. It had a ratio of maximum landing weight to maximum takeoff weight of 94%, a huge difference when compared to the 747-400 at 72%.

Electric airplanes must be significantly heavier than their ICE counterparts for a long list of reasons, and and the maximum landing weight "issue" is actually not on that list of reasons, because their ICE counterparts having similar characteristics (size and range) already have their maximum landing weight at or near their maximum takeoff weight.

@Etna
I notice you are from Canada,
have you ever flown a Lazair ultralight, or an Aerolite 103 electric?