Why Gas Engines Are Far From Dead - Biggest EV Problems

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

Voidhawk9

Well-Known Member
HBA Supporter
Joined
Mar 26, 2012
Messages
322
Location
Timaru, NZ
But its all depend on mission. You cant simulate c152 behavior on high efficiency airframe..
I think BJC nailed it. :D

Why would you want to simulate C-152 behaviour? Sure it's easy enough to fly and does its job fine, but it handles like a soggy noodle and isn't very efficient. We can do a lot better than a design from 60+ years ago today. :)
 

PMD

Well-Known Member
Joined
Apr 11, 2015
Messages
242
Location
Martensville SK
I think BJC nailed it. :D

Why would you want to simulate C-152 behaviour? Sure it's easy enough to fly and does its job fine, but it handles like a soggy noodle and isn't very efficient. We can do a lot better than a design from 60+ years ago today. :)
We CAN make much more efficient airplanes (but we seldom do), but there will always remain a market for things that fly with such benign handling that any idiot could survive reasonably well. Personally, I think they make a terrible trainer, since they are cramped, noisy and far too easy to fly, but that doesn't address the 90% or higher portion of the market. Always remember the disaster that the Tomahawk was in the marketplace.
 

Vigilant1

Well-Known Member
Lifetime Supporter
Joined
Jan 24, 2011
Messages
4,966
Location
US
Sure it's easy enough to fly and does its job fine, but it handles like a soggy noodle and isn't very efficient. We can do a lot better than a design from 60+ years ago today. :)
"Efficiency" comes in many forms. In most airports in the US, if somebody wants to "efficiently" convert dollars into rental aircraft time, there's no airplane on the ramp that will best a C-152. It isn't hard to sketch out a more aerodynamically efficient plane, but (according to the market) nobody in 5 decades (including Cessna) has come up with a more aerodynamically efficient plane that can also take the bashing that occurs in primary flight training. The C-152 takes those lumps and keeps going.
Since this thread is about EVs, how do those slick Electro Pipistrelles stack up to a lowly C-152 where it counts (the bottom line). Not well.
 
Last edited:

PMD

Well-Known Member
Joined
Apr 11, 2015
Messages
242
Location
Martensville SK
"Efficiency" comes in many forms. In most airports in the US, if somebody wants to "efficiently" convert dollars into rental aircraft time, there's no airplane on the ramp that will best a C-152. It isn't hard to sketch out a more aerodynamically efficient plane, bit (according to the market) nobody in 5 decades (including Cessna) has come up with a more aerodynamically efficient plane that can also take the bashing that occurs in primary flight training. The C-152 takes those lumps and keeps going.
I have no first hand experience, so this is more of a question than an answer: I have seen a LOT of Diamond 20s powered by Blowtax engines with well over 10,000 TTAF. SOMEONE seems to be getting good training service from them (and they are a very efficient airframe).
 

BJC

Well-Known Member
HBA Supporter
Joined
Oct 7, 2013
Messages
11,257
Location
97FL, Florida, USA
This comment
Yup. Take one high efficiency airframe, deploy draggy flaps, spoilers and a drogue chute, and end up with C152 behavior
about the C152 is wrt the lack of aerodynamic efficiency of the C152, not the value of it.

I owned an A152 and had a great time flying it. Yes, it is forgiving, and some think that a forgiving airplane makes a poor initial trainer. My view is that a pilot should continue to improve his skills after getting his pilot certificate, regardless of what his initial training was in. And flying a 152 precisely, right at the limits of its performance capability, takes more skills than required for a PP certificate. FWIW, my training and early flying was in Champs and Cubs, and I had a Pitts S-1S before the Cessna.

As V1 pointed out, the C152 has proven itself as a cost-effective trainer, many of which have logged over 15,000 hours in training service. People who want to fly economically, and don’t have a place to properly keep a fabric airplane, should consider a C152.

BJC
 

TFF

Well-Known Member
Joined
Apr 28, 2010
Messages
13,058
Location
Memphis, TN
Every new trainer in skew it’s shot at the 150. They pretty much loose in the basic category of initial information raining. Diamond only has two things. They make new ones and they have glass in panels. Cessna is not interested in making new ones and because used prices are so reasonable, they will be hard to knock off. You can go buy 4 150s for a used Diamond. That’s a fleet. A fleet that is proven.

There is someone at the airport that is learning in his own aircraft. SR20. I was watching first landing practice. Cringe. They will be great if they don’t tear it up. Only fools give their teens a Ferrari as their first car. Cool to be the kid but it probably will be a total.
 

PMD

Well-Known Member
Joined
Apr 11, 2015
Messages
242
Location
Martensville SK
I think TFF has hit it on the head. There are so many cheap 150s and 152s out there, how does a new design compete? I would give Diamond more than two advantages, though. As a trainer, their maintenance record and costs seem (again, I have been out of the plane fixing business since Christian Dries was in short pants) pretty decent, but outside of the training part, the speed, range, etc. of the Rolls/Conti 240 airplanes is completely out of the C152 class in every way.
 

Dan Thomas

Well-Known Member
Joined
Sep 17, 2008
Messages
5,351
I think TFF has hit it on the head. There are so many cheap 150s and 152s out there, how does a new design compete? I would give Diamond more than two advantages, though. As a trainer, their maintenance record and costs seem (again, I have been out of the plane fixing business since Christian Dries was in short pants) pretty decent, but outside of the training part, the speed, range, etc. of the Rolls/Conti 240 airplanes is completely out of the C152 class in every way.
When I was looking after the flight school fleet, for a time we had two 150s and two 172s. There was about ten bucks per hour difference in total operating costs between the 150 and 172. The O-200 needed cylinder/valve work at mid-time, the O-320 did not. The O-200's TBO was 1800 hours, the O-320's 2000. The students spent more of their dollars climbing in the circuit or to altitude for upper air work. Their circuits were bigger because of that and so they got less practice per hour. We ended up selling them both and getting more 172s.

One warm day two of our instructors, with the 150 at gross, took off to do some practice themselves. Density altitude was at 5000 feet or better. Airport was at 2975. They couldn't get above about 2000 AGL; the airplane simply wouldn't climb anymore. There was nothing wrong with it, either. It was just being a 150. We also had a 7EC Champ, with an O-200 in it. It would take off shorter, climb faster, and cruise faster than the 150. I wondered if the 150's McCauley prop was the issue, so I looked at the TCDS and found that the Champ's Sensenich prop was listed as an eligible prop for that 150. Part number, diameter and ptich, everything exactly. I installed it and went flying; no improvement for the 150.

The old 150s without that back window were better performers. That sharp drop-off behind the cabin added plenty of drag, and the inboard ends of the flaps, being out in the open, generated vortices. More drag. The back window also allowed the fuselage to flex more, and you could find cracks at the upper corners of the bulkhead at the bottom of the window. There's a service bulletin on it.
 

BJC

Well-Known Member
HBA Supporter
Joined
Oct 7, 2013
Messages
11,257
Location
97FL, Florida, USA
The 150's with their 85 - 90 HP Continental O-200's are marginal in hot weather or with two adults aboard.

The Lycoming O-235's in the 152's do better than the 150's in all categories, especially with the STC'ed Sensenich propeller. The Cessna (McCauley) prop is inefficient, and limits, by design, max RPM to 2550. Install a Sensenich that will rev to 2800, (even though the STC limits it to 2550) and performance is much better. Mine increased Vmax by 10 knots, improved RoC, and shortened TO distance. As expected, fuel burn increased too.


BJC
 

Dan Thomas

Well-Known Member
Joined
Sep 17, 2008
Messages
5,351
The 150's with their 85 - 90 HP Continental O-200's are marginal in hot weather or with two adults aboard.
Yup. I flew an Alon Aircoupe, one of the last versions of the Ercoupe, with a C-90. Same power-to-weight ratio as a 150, if you figured on getting 100 HP out of that O-200. That Aircoupe could run circles around the 150. Shorter takeoff, better climb, better cruise.

Jan Carlsson, our resident prop expert, uses 85 hp for figuring props for the O-200.
 
Last edited:

Voidhawk9

Well-Known Member
HBA Supporter
Joined
Mar 26, 2012
Messages
322
Location
Timaru, NZ
Sure, C-150s are cheap, we use one locally for training for that reason. But that same cheapness, along with being tired and worn-out (looking or otherwise) is also a turn off to a lot of prospective GA pilots. They don't last forever. Sure you can refresh and rebuild them, but that detracts from the cheapness.
They also cost more in time (thus money) due to their low performance. It simply takes longer to climb to altitude where a lot of training takes place.
 

BJC

Well-Known Member
HBA Supporter
Joined
Oct 7, 2013
Messages
11,257
Location
97FL, Florida, USA
Sure, C-150s are cheap, we use one locally for training for that reason. But that same cheapness, along with being tired and worn-out (looking or otherwise) is also a turn off to a lot of prospective GA pilots. They don't last forever. Sure you can refresh and rebuild them, but that detracts from the cheapness.
They also cost more in time (thus money) due to their low performance. It simply takes longer to climb to altitude where a lot of training takes place.
All true.

What are you planning to replace it with, that will not turn off a lot of prospective GA pilots?


BJC
 

PMD

Well-Known Member
Joined
Apr 11, 2015
Messages
242
Location
Martensville SK
What are you planning to replace it with, that will not turn off a lot of prospective GA pilots?
Since we are talking about an airplane that does not exist, but COULD, I will take a bit of license with the answer and show my own strong bias: A fastback 150 fuselage available with either tricycle or airplane (i.e. conventional = taildragger) landing gear and a 110 real HP diesel weighing in at 912 or at worst case 0-200 numbers. I would even go so far as to suggest the landing gear should be convertible as supplied, able to something such as unbolt the nosewheel, turn mains around, bolt on a tailwheel in provided lugs (that could double as glider tow point for higher HP version). while for my own interests think the AA-1 series of airplanes made far better trainers, the world at large seems to want something more benign. I particularly like that the 150/2 has enough flaps that when deployed make the pilot DO something different to handle new configuration. Oh: and make the new 150 fueselage a few inches wider!!!! The final bit of kit would be 2 glass screens that could be set up to mimic steam gauges or latest glass displays as different training wants and needs could be met.
 

PMD

Well-Known Member
Joined
Apr 11, 2015
Messages
242
Location
Martensville SK
And that is the point.
I think the key here is to appreciate that the training industry can pick from a few thousand old or very old airplanes for peanuts in Capex. The Da20 seems to be a viable alternate...except of course for cost. Even the Pa28 fallback with corrosion issues bubbling to the surface from a half century of sitting around are not really a good alternative. And, as pointed out, 172s are still there, so other than going with something far newer, the pretty much define the only real alternative to the C150/2. To your point: the 152 with Lyc power is probably a lower overall cost, but once again, the capital expenditure of small startup or marginal training operations means Continentals under the hood.

And, to get back to the subject of the thread: this is what will also kill electrics for the vast majority of small flight training operations. A fleet of three represents a million dollar investment - because they are new. Then one has to consider the dispatch limits due to charge time. Finally: how are insurers going to regard such a dangerous energy storage medium as LiPo batteries?? (yes, they live with gasoline now - but more of a known problem).
 
Last edited:

BJC

Well-Known Member
HBA Supporter
Joined
Oct 7, 2013
Messages
11,257
Location
97FL, Florida, USA
The Da20 seems to be a viable alternate...except of course for cost.
Another issue with the DA20, at least here in Florida where much of the flight training is done, is that the canopy makes the cockpit unbearably hot most of the time. They are nice airplanes, otherwise.


BJC
 

PMD

Well-Known Member
Joined
Apr 11, 2015
Messages
242
Location
Martensville SK
Another issue with the DA20, at least here in Florida where much of the flight training is done, is that the canopy makes the cockpit unbearably hot most of the time. They are nice airplanes, otherwise. BJC
As a repeat offender Grumman/American owner, I can understand that. Obvious answer is to move all flying training to YXE.
 
  • Like
Reactions: BJC

Sockmonkey

Well-Known Member
Joined
Apr 24, 2014
Messages
1,880
Location
Flint, Mi, USA
Natural gas and propane both contain carbon, which means emitting CO2 upon combustion. I thought we were trying to find ways around that?
Yeah, but propane doesn't crank out out as much of the other nasty combustion by-products gasoline does. That also makes the inside of your engine lasts longer because it's not putting corrosive gunk into the oil.
Batteries will continue to improve because there's already a lot of other stuff they're good for with a ready market for mass production so there's always a constant incentive to keep making better ones. So eventually, we are going to hit the point where most cars are electric. Hard to say just how soon because you can't predict breakthroughs.
If I were making an electric plane, I'd make it a plank with the main spar being a hollow battery compartment to distribute the weight across the span.
Steam could be viable for cars if they were mass-produced enough to lower the cost. All the little refinements to make them as convenient as gasoline engines came too late to survive against cars like the model-T, but with the current emphasis on reducing pollution, they can meet emission standards just because they're more fuel efficient, and burn whatever fuel they use much more cleanly.
 
Top