Whats the difference between gas and electric air planes?

First off, I assume you mean Nitro when you say gas. Gas planes are another matter altogether.

Nitro planes typically will be stronger built as they usually fly faster and suffer higher stresses. (Not counting crashes) The engines vibrate more on Nitro planes so the firewalls will need to be stronger and better secured. Electric planes may often have less ribs and lighter spars and other structures.

For gas planes I believe the stresses are even higher and the engine vibration is worse yet.

Please note that I have flown neither electric or gas planes but this is what I have observed. I am expecting to be corrected if I'm wrong.

Dave,
You are sure to open up a can of worms herw with this question, but I can tell you my personal pros and cons of each based upon my experience.

First glow fuel/gas
Pros....heavier sturdier airframe, longer flight times (for the most part), allows those who like to fool around with engines to work on them and experiment with different things (fuel blends/props, etc), fairly wide power range, does not need or require the use of expensive battery chargers (but some of us use these field chargers to allow us to fly all day without the need to return home to charge up)

Cons...can be cantankerous and finicky to get needle valve setting where they should be, difficult to tune identical engines on multiengine airframes, messy fuel and longer clean up times, need for starter or "chicken stick", heavier airframes with higher wing loading

Next electrics
Pros...extremely clean and quiet, airframes usually light with excellent wing loading, no need to carry extra fuel to field or flight box, no starter required, getting better everyday with a lot of focus on newer battery technology

Cons...lipo batteries are a fire hazard, prolonged charging times between flights unless you have multiple batteries, smaller airframes restricted to flight in light wind conditions, batteries are expensive (expect to pay almost as much for motor, ESC and battery as comparable 2 stroke engine)

I know I did not cover everything here and others will chime in with their own opinions, but these are some examples of my own perspective. In my opinion there is no reason why there cannot be a mixture of the two, but you don't see a whole lot of overlap where I live.
Tommy

what about flight characteristics? Thanks for the info you've already posted!

I prefer Nitro for flight characteristics. More power, can fly in heavier winds, can make minor mistakes and have the power to fly out of it (or crash faster sometimes) Easier to get extra altitude for beginners and be 3 mistakes high. Electrics seem to fly at lower altitudes where being wrong can get expensive quickly.

With modern brushless motors and lipos, there is no power disadvantage with going electric. Electric power in 2M (6+ foot wing span) pattern ships has been around for several years and is becoming more common. These electric ships have power/weight ratios that are comparable to what a YS160DZ puts out (supercharged 1.60 cu.in. port injection.) The also have flight times that equal nitro setup. I've even heard of an electric 40% IMAC type ship (~12 ft wing span) that was fully 3D capable, normally you'd use a 150cc twin gas engine on that class of ship. So performance isn't an issue.

There are however many poorly performing electric setups. Often these are RTF "toys" that are terribly underpowered. But this isn't the fault of the electric, it is the designer/manufacture fault for putting that crappy setup on that plane.

As for general flight performance, that is plane dependent. A Cub will fly like Cub, etc. Electric, glow, doesn't matter.

The kicker with electric is the cost. I recently compared running a 1.60 cu. in. glow vs a comparable electric. The electric motor/speed controller ran about the same as the glow setup, so that’s about a wash. It is the LiPo batteries that are pricey. It is difficult to find any comprehensive testing, but most figures I've seen show between 100 to 400 flights per pack before the pack is wore out. At 400 flights, the cost of the pack vs a comparable quantity of glow fuel (enough for 400 flights) is about a wash, or maybe slightly in the electric favor. The break even was around 350 flights, and I'm unsure the pack could last that long. Now factor in three packs so I can fly three times an hour, chargers, etc. and the price is several thousand vs $700 for a years supply of glow fuel. And lots could make this even worse. LiPo packs are not terribly durable and rough handling (or a crash) could easily destroy the pack… it would be like burning dozens of gallons of glow fuel because of a "crash" or bad charge.

The plus side is all the vibration that comes with glow would go away with electric. 90% of the repairs I have to make on my 2M ship are engine/exhaust/vibration related. So there is a value there I'm willing to pay for, but I'm not sure I'm ready to risk the possible costs.

Hobby LiPO use is insignificant to the market. But consumer markets like laptops, PDAs, cell phones, etc. are huge and will keep pushing LiPo costs down. I expect that in the years to come large electrics will be as common as glow/gas, but the pack cost must come down.

Cheers.

Not an issue.

An F3A aerobatics competion ship with electric power has the same power and weight as a glow powered one. From what I have seen so far, the electric is more reliable. The equipment to get a largish electric model in the air is expensive but the running costs ("fuel", etc) is OK.

Electric pylon racers are very close to glow speeds.

Small electrics fly very well too and they are not expensive. Small planes are more sensitive to wind but, on the positive side, you can fly them in smaller areas, and they are easy to transport and store.

A good electric model (read: not a toy) will cost more than a comparable one up front...

The best example so far that i have seen in real life is in helicopters...because we dont have any electric plane guys (other than me and some others guys' suped up strykers, but those are still toys to play with in between flights on our glow planes) where i fly..

A guy at our feild has a joke (a 90 sized electric helicopter) the frame alone is about 1000 bux...so pick something in the 90 glow helis thats around 1000 (Tehre are a few) now you can finish out a glow heli for about 800 more at that size (digital servos, good gyro)

But the kicker comes in the fact that the 2 batteries he needs to fly (2 at once) are $400 a peice. The charger to charge them was $800. The motor was $600. The esc, another $250 ....so thats $2050 extra before you even buy 5 digital servos and a good gyro...ouch...

The advantage for him though, is he does arial photography/video...and there is almost no vibration in that bird, and he can fly for about 40 minutes on a charge...vs 10-15 on a tank of gas...

So it really comes do to paying more now, or paying more later....

The thing about electrics is that you only get one flight out of them before it's time to head home and recharge. If you have more than one battery that's not really a problem, or if you have a car charger, but the down time in between flights gets really annoying.

That's why I like nitro a lot better, a gallon of fuel and you can fly multiple flights back to back. If you have a quick way to change the battery for your Rx and Tx you can fly all day back to back without much pause in between.

The thing I don't like about glow planes is the fact that they are very messy. You ALWAYS get greasy film on your aircraft. They also can be a little finicky at times, but it's really not too much of a problem.

Electrics are nice because you can put the battery on, and go fly. No starting, tuning, anything.

All in all, I enjoy nitro more. But I'm a tinkerer and enjoy engines, and I don't have a working electrical port in my car for a car charger. So I only get one flight out of my electrics. But I must say, a Zagi 400 is one of the most fun planes I own, and it's an electric.

My advice to you would be to choose a plane based on its flying characteristics, and if you have the option of electric or glow, choose whichever powerplant you feel is most practical for your application.

I fly both, electric and glow. Electric power is viable up to about 40 size. After that, it can be costly. And, saying that glow power is more reliable or faster etc. is a myth. I've seen electric powered H9 Twist and pattern models fly the pants off even the 4 stroke powered models. But like I said, there is a cost factor once you get to this size. So far, there isn't a brushless motor setup (batteries, esc and motor) for $109 thats comparable to an OS .46 AX glow engine. And, no matter what you start with, the beginning costs are a bit high since you have no equipment whatsoever. Like I said, I fly both. I have everything from a small 20 inch span flying wing up to 90 size glow powered models and just about everything in between. All depends on what mood I'm in. Generally, I take both electric and glow models to the field. Another myth, you only fly one battery pack on electric and have to go home to charge. Complete BS. I will take with me my Poly4 charger which will charge 4 lipoly packs at the same time. While I'm flying one pack, theres one on the charger fully charged. I have flown all day long on 4 packs (fly one pack and the other 3 are charging) numerous times last year. So, I'm not fully an electric zealot or a nitro nazi, I fly'em both no matter what the power plant is.

Dave...

How much does the charger and each battery cost? Just wondering.

There are lots of options, depending on your requirements. Just like you can buy a YS 170 or a cheap .10.

You should be able to get a charger for charging 2 or 3 cell (2S or 3S) LiPos for $30 or so. A LiPo pack for a parkflyer size plane would be around $30 to $50. (That is just rough estimates.)

My charger cost me around $200 but it will charge anything that is currently available. For a large plane, you could pay several hundreds for a battery pack.

Glow fuel is not free either.

I did not start with electrics because of the cost. Other advantages weighed more in my case. I expect to build a glow plane within a year or so. I already have an engine or two and I want to try out that side of the hobby too.

Ditto… Chargers and packs vary wildly in cost.

As for charger, you can get a real simple charging module for under $50, a decent charger with readout for about $100, and some nicer high end chargers for $200+. The kicker here is if you have three packs, and want two on charge, one in plane, you need to buy two chargers, or get a dual output version.

Battery cost depends on capacity, number of cells, cell type, etc. In my case, a pack for a F3A 2M pattern ship was going to run between $700-$1,100 per pack. This may sound silly high, but I spend about $800/year now on glow fuel for ~400 flights, so I can almost make it work, but just not quite yet. But, a 30" wing span plane could easily be fine with a $50 or under pack. So it really depends on what size of plane, or more precisely the motor current and desired runtime, as to which pack is needed and the cost.

I'm not convinced electric is cheaper than glow on small planes under 40 sized. I think that the total cost is low enough that it doesn't matter a whole lot if they are 20% more or whatever. But I'll admit I've never looked into that size real close.

Cheers.

True! Very true! What if we judged glow engine powered planes by the performance of a typical .049 powered RTF toy?

I'm all gas. (ask anyone) But thats because I've been in the hobby for nearly 30 years, and all of my tools, my equipment and so forth all all geared toward building and flying nitro models.
However, A good friend of mine likes electric models. I do most of his test flying for him. (he is a little older, 68, and his reactions are not that great, and he started late in life, so he never reached a very high skill level ) Anyway, I have really been very impressed with the new elcetric motors and the new lipo batteries.
But switching to electric would be very expensive for me. Buying batteries, chargers, micro servos , smaller airborne equipment and such would be needed. It would be like starting over.
But if you ARE just starting, then it really might be something to consider. They are quieter and can be flown in smaller fields. Someone mentioned that they require lighter winds. I suppose that is true. However, I have flown the Hobby Lobby Mig 15 , ( nearly 100 mph ), in some pretty stiff breezes. So, I think they handle the wind pretty good, at least the faster ones.

the difference between gas and electrics is that one uses an extension cord for power to fly.

Couldn't agree more! Example: I am currently building an Airfoil Z Yak (3d Foamy). This plane builds at an all up weight of 14 to 17 ounces. Brushless Motor was $65, the ESC was $35 & 3cell lipo was about $50. So there'a $150 to fly a 1 lb plane with authority. I allready had the lipo compatible charger or that would have been another $80. While the OS .46AX will fly the wings off of a 5 to 7 lb plane. At $114.99 Tower Hobbies price. Now sure I have to feed it fuel in order for it to do that, but since reading our club by-laws & finding that we are a non-profit organization, that makes my fuel Tax Deductable.

The one other difference I notice between my nitro planes & my electrics that no-one ever seems to mention when this question comes up is the throttle response feel. With a combustion engine of any type fuel, you can feel the throttle & roll out the powerband. Not so with electrics IMO, they have a sort of all or nothing feel to them, which of course is not the case. You do have throttle management control it just has a much different feel to it. I preferr my nitro planes much better, but I like the little brushless Foamies to play around with. A much cheaper Airframe to learn to fly 3D on.

We're having our semi annual 1/2A (.049) pylon race this May,, your welcome to bring a "toy" up and see how well you can keep up!! requires a Cox .049

LOL I have a scratch built 1/2A Reno Racer that my Dad built years ago hanging from Elena's ceiling in her room with a hand polished .049 in it. Nothing like a 100 mph "Toy" !! 2 channels, Ailerons & elevator, Tune till it screams & hold on tight! Talk about "Pucker-factor"[X(]

It wasn't my intention to dis serious 1/2 A planes. When I said RTF toy, I was talking about something like a Cox EZ-Bee. I am a small plane enthusiast myself, and my smallest plane is a TD .020 powered Pocket Rocket, which I will fly in wind that grounds some of the bigger planes.

Okay I'll stop the quotes here,,BLE I didnt figure you were dis'in 1/2A , but we do get a lot of it "you mean those squirrely little planes" and I 'd hate to have all these beginners get a bad taste for .049s based on a general statement..we have a 1/2a trainer plane plan as a sticky over in our forum,, and I'm the one around here that throws it in every now and again about how everybody just has to start off with a big ole .40 trainer,,which in itself can be somewhat intimidating I have lots of 2 and 3 channel planes that were $5 worth of balsa R/E or A/E some with throttle, its usually wide open anyway till you run out of fuel and belly in...nothin like it....Rog
I started out with a GWS pico stick in the local schoolyard on saturday mornings,,the invite still stands

rog, I gotta pass on that invite. I know that thing is too fast for me! That's why it hangs from the ceiling. It's a beautiful hand built bird & I just couldn't ever forgive myself if I was to crash it. Too much sentimental value for me in that plane.

To all those that replied to my “Toy” post…I wasn’t referring to all small planes as being “toys.” Indeed, I’ve seen some very powerful and well performing small models. I even have a small ~30" span plane that does over 300MPH (but it's not electric.) What I was eluding to was the many RTF packages found in the LSH and elsewhere that come with some brushed electric setup with NiMH batteries. Most of these I’ve seen really suck and fall into the “toy” category as far as I’m concerned. But it is not the electric part per se that is at fault, it is the specific setup they choose for that model which sucks.

You can get 1HP+ motors with speed controllers for about $275. This is more $ than just the OS46AX glow engine, but there is other stuff you need with the glow such as tank, lines, servo, glow plugs, etc. At the glow engine will reduce the life of on board equipment such as servos, RX, etc, due to vibration. When all is considered, it think motor vs motor is about a wash, even at this size. The kicker is cost per flight, i.e. battery costs and life vs glow fuel.

Cheers

That question is bound to head in the same direction as "which is better" about the same subject. One of the half-dozen perennial emotional circular 'arguments'.

The "diference" is that gas planes are powerd by internal combustion engines deriving their power from a conventional liquid fuel as it's energy source, and electrics are powered by electric motors sourcing their energy from an onboard storage battery.

Most RC fliers will be influenced by or biased toward whichever one captures and excites their imagination to most interest them than any logical aspect of the pros and cons of operation. That's the one for YOU to buy/play with/clique you will most happily fit in with.

I see lots of people who do both electric and liquid fuels. Like this one guy who does electric 3D, electric gliders, EDF, glow aerobatics, gas aerobatics, turbines (I may have missed something).

Different power sources have their advantages in different applications.