Supercharging

[Ted]

Okay I get it. I need to quit looking at aircraft engines in the same was as auto applications. In auto apps I KNOW supercharging is much better then turbos unless you go twin turbos in imports.

That isn't an accurate statement. Superchargers and turbochargers both have their benefits. My Mitsubishi is twin-turbo'd, and while a supercharger would have less lag, the turbos work very nicely.

Of course, the roots blowers they use in most auto applications aren't particularly efficient (although they are fairly reliable).

Can anyone name a plane that is supercharged?

There were a number of Commanders that had GSO/IGSO engines. The S stands for supercharged.

Which is a ridiculous statement.

So you're telling me that transport category aircraft are still being produced with big radials? I was pretty sure that the 747 had jet engines on it.

The R3350 was the most advanced radial in it's time, and the PRT in combination with the turbocharging and supercharging was the most advanced, efficient power available for an aircraft.

Didn't disagree with that statement. However, the total cost of an aircraft isn't just fuel consumption. It's speed, reliability, dispatchability. The lower failure rates and overhaul requirements of turbine engines ended up making enough sense that radials stopped being produced.

Furthermore, when you look at efficiency numbers for the turbines up at altitude (where they should be spending their time and do spend most of it), they're pretty good. Sure, the R-3350 was still more efficient, but not enough so to make up for the added maintenance. There is nothing more expensive than an airplane you can't fly.

The P2V operated with both R3350's and turbojets on the wings; it had avgas-powered J34's. The J34's, however, burned far too much fuel; each consumed as much fuel independently as both R3350's combined, and didn't put out nearly the power. Fuel consumption tripled upon lighting them off; hence, they were used for takeoff, with hydraulic doors blocking the inlet in flight to reduce drag...where they became mostly dead weight.

I'm familiar with the P2V. And you should be familiar with the fact that it wasn't really intended to spend its life up at high altitudes where turbines make sense. But I don't think you would typically cruise around in a 747 at 5,000 ft hunting subs.

Certainly turbine engines have advanced reliability and performance. We don't fly large radials high into the flight levels today; we fly turbines, and we generally fly turbofans, not turbojets. Technology takes us higher and faster, but I don't see many turbines being installed on piston airplanes these days. We're not going to see them replaced. Your'e not likely to see the O-320 replaced with a turbine motor any more than the 0-470, or even the TSIO-520. In a few rare cases, perhaps, but not many.

Correct, because on those airplanes turbines don't make any sense. My 310 wouldn't do very well with PT-6s.

We were talking about the R-3350s here. And in that realm, yes, they weren't as good of a solution to the problem of how to power these aircraft.

 

[Skylane81E]

Can anyone name a plane that is supercharged?

Comander 680FLP to name one post war example.

 

[Tom-D]

Didn't disagree with that statement. However, the total cost of an aircraft isn't just fuel consumption. It's speed, reliability, dispatchability. The lower failure rates and overhaul requirements of turbine engines ended up making enough sense that radials stopped being produced.

Would you rather have an engine that has basically 1 rotating part or an engine that has a multitude of parts that reciprocate ?

I'm familiar with the P2V. And you should be familiar with the fact that it wasn't really intended to spend its life up at high altitudes where turbines make sense. But I don't think you would typically cruise around in a 747 at 5,000 ft hunting subs.
When you consider the design date of the P2V, you will find that there were no really dependable turbine engines to place on it.

We were talking about the R-3350s here. And in that realm, yes, they weren't as good of a solution to the problem of how to power these aircraft.

When you had to work on the 3350 you knew why it should go away. I'll wager there is nobody here that has changed the lower rear cylinder on one, except me. I'll bow down and pay homage to any one who can do it in less than 24 hours.

 

[DouglasBader]

I'll wager there is nobody here that has changed the lower rear cylinder on one, except me.

You'd lose that bet.

So you're telling me that transport category aircraft are still being produced with big radials? I was pretty sure that the 747 had jet engines on it.

I'm pretty sure I didn't say a thing about transport category aircraft, nor about aircraft still being produced.

Being type rated in and having flown the 747 for a number of years now, I'm fairly sure it has turbofan engines, too. It's also irrelevant.

I'm familiar with the P2V. And you should be familiar with the fact that it wasn't really intended to spend its life up at high altitudes where turbines make sense. But I don't think you would typically cruise around in a 747 at 5,000 ft hunting subs.

Again with the 747. How is this relevant? I've flown both the P2V and the 747, which is also irrelevant. We can go on all day with the irrelevant, but that doesn't address your comment. Point of fact, however; the P2V was replaced by the P3, which is being replaced by the P8, which is a Boeing 737.

A 747 would be a bit of overkill, don't you think?

Since when do you cruise around at 5000' hunting submarines? That's a little high.

The P2V had both R3350's and turbojet engines.

There are airplanes still flying with R-3350s...just not turbo-compound 3350s. P2V, for example.

The P2V-5 and P2V-7 uses R-3350 turbo compound engines. They're still in use today. The -4 was the first airplane to use the turbo compound engine, in fact.

DC-6s are still operating, but no DC-7s, no 1649 Connies, very few C-119s.

DC-6's are in use, and Butler is still running a DC-7 on contract in Oregon, on fires.

 

[j1b3h0]

I stand corrected on the P-2V. What is the number of such airplanes currently flying?

 

[Shorrick Mk2]

However, it wasn't long before the turbo-compound engines developed a reputation for ventilating the cowling - what with all the moving parts and high power per cu.in. Which is why one almost never sees those kind of airplanes around anymore. DC-6s are still operating, but no DC-7s, no 1649 Connies, very few C-119s.

There's a flying 1049 based in Switzerland

 

[kgruber]

Bleed air on a turbine engine isn't quite the same thing as supercharging on a piston engine.

Again, your ignorance of King Airs shows.

90, A90, B90 do not use bleed air for cabin pressurization.

 

[j1b3h0]

There's a flying 1049 based in Switzerland

I'll have to look it up, but I think only the 1649 used turbo-compound engines.

 

[rainsux]

> supercharged

There is a STC for supercharging the O-470 in the C182. Apparently they are working on other models:

http://www.forcedaeromotive.com/

 

[DouglasBader]

Again, your ignorance of King Airs shows.

Oh, good Lord, no! Please say it isn't so. Again?

I was Director of Maintenance for a King Air operation, as well as a pilot there. We flew the 200, and had a BE9L. The BE9L was such junk that I refused to work on it, and had it done elsewhere.

Perhaps we should have sent it to you.

 

[kgruber]

Oh, good Lord, no! Please say it isn't so. Again?

I was Director of Maintenance for a King Air operation, as well as a pilot there. We flew the 200, and had a BE9L. The BE9L was such junk that I refused to work on it, and had it done elsewhere.

Perhaps we should have sent it to you.

The five striper coughs up another belly laugh. I feel sorry for the people who have to fly with you.

 

[Sac Arrow]

This is entertaining!

 

[LJS1993]

That isn't an accurate statement. Superchargers and turbochargers both have their benefits. My Mitsubishi is twin-turbo'd, and while a supercharger would have less lag, the turbos work very nicely.

Of course, the roots blowers they use in most auto applications aren't particularly efficient (although they are fairly reliable).



There were a number of Commanders that had GSO/IGSO engines. The S stands for supercharged.



So you're telling me that transport category aircraft are still being produced with big radials? I was pretty sure that the 747 had jet engines on it.



Didn't disagree with that statement. However, the total cost of an aircraft isn't just fuel consumption. It's speed, reliability, dispatchability. The lower failure rates and overhaul requirements of turbine engines ended up making enough sense that radials stopped being produced.

Furthermore, when you look at efficiency numbers for the turbines up at altitude (where they should be spending their time and do spend most of it), they're pretty good. Sure, the R-3350 was still more efficient, but not enough so to make up for the added maintenance. There is nothing more expensive than an airplane you can't fly.



I'm familiar with the P2V. And you should be familiar with the fact that it wasn't really intended to spend its life up at high altitudes where turbines make sense. But I don't think you would typically cruise around in a 747 at 5,000 ft hunting subs.



Correct, because on those airplanes turbines don't make any sense. My 310 wouldn't do very well with PT-6s.

We were talking about the R-3350s here. And in that realm, yes, they weren't as good of a solution to the problem of how to power these aircraft.

Like I said in imports I really like turbo setups. However in domestic applications and especially in older muscle I'd rather have a Weind or KB any day.

 

[DouglasBader]

The five striper coughs up another belly laugh.

You wear five stripes? Impressive. You really should seek work in India. They'd love you. Call yourself "commander kgruber," and your'e in.

I wear greasy BDU pants and an oil soaked shirt. With all those stripes, I bet you're fast.

 

[Shorrick Mk2]

I'll have to look it up, but I think only the 1649 used turbo-compound engines.

1049s used TC from version C onwards.

 

[Ted]

Would you rather have an engine that has basically 1 rotating part or an engine that has a multitude of parts that reciprocate ?

Exactly.

When you consider the design date of the P2V, you will find that there were no really dependable turbine engines to place on it.

That makes sense. Certainly turbines had leaps and bounds worth of improvements in reliability and efficiency early on.

When you had to work on the 3350 you knew why it should go away. I'll wager there is nobody here that has changed the lower rear cylinder on one, except me. I'll bow down and pay homage to any one who can do it in less than 24 hours.

I'd believe you fully.

I'm pretty sure I didn't say a thing about transport category aircraft, nor about aircraft still being produced.

So we agree that aircraft that came with R-3350s mostly still have them. Well, that's on the cover of Duh magazine.

Being type rated in and having flown the 747 for a number of years now, I'm fairly sure it has turbofan engines, too. It's also irrelevant.

*sigh* Well, depending on the variant you have JT9Ds, CF6s, or RB211s, and probably some other variants I'm forgetting. That's up until you get the 747-8, which has the GEnx in it. Although they're all varying form of turbofans, I believe "jet" would still be an appropriate term. Note I didn't say "turbojet" which would be referring to, say, a CJ610.

The P2V-5 and P2V-7 uses R-3350 turbo compound engines. They're still in use today. The -4 was the first airplane to use the turbo compound engine, in fact.

DC-6's are in use, and Butler is still running a DC-7 on contract in Oregon, on fires.

Yes, you're making lots of irrelevant points. Planes that were made with engines do still have those engines on them. But clearly the large piston engines weren't reliable and economical enough to convince airlines to keep buying them.

 

[Tom-D]

But clearly the large piston engines weren't reliable and economical enough to convince airlines to keep buying them.

Considering the cost of diesel fuel, (basically what the jets burned then) and the cost of 115/145 aviation fuel, and the speed of the 707 the days of the recipe were numbered.

 

[Ted]

Considering the cost of diesel fuel, (basically what the jets burned then) and the cost of 115/145 aviation fuel, and the speed of the 707 the days of the recipe were numbered.

Tom, maybe you can confirm or deny this story. I have heard that Wright engines had made a guarantee to the airlines that their engines would cost less in total operating costs than jets. This guarantee ultimately put them out of business, because they weren't. Do you know if that story is true?

 

[Tom-D]

Tom, maybe you can confirm or deny this story. I have heard that Wright engines had made a guarantee to the airlines that their engines would cost less in total operating costs than jets. This guarantee ultimately put them out of business, because they weren't. Do you know if that story is true?

The demise of the company came at their own hands believing they would always have a market, and did until the military when all jet, and they had nothing to offer.

I have never heard of that story before.

 

[DouglasBader]

But clearly the large piston engines weren't reliable and economical enough to convince airlines to keep buying them.

We generally don't see radios with vacuum tubes in them these days, either. What's your point?

 

[Ted]

We generally don't see radios with vacuum tubes in them these days, either. What's your point?

My point's been pretty clear. Yours has been the unclear one.

 

[Tom-D]

We generally don't see radios with vacuum tubes in them these days, either. What's your point?

Point is, they are still radios.

Name one thing in today's economy that was not an evolutionary thing.

 

[DouglasBader]

My point's been pretty clear. Yours has been the unclear one.

Not really. You keep rabbiting on about radial engines not being on modern airliners. You've whined on about radial engines vs. the 747 in an ASW role for god only knows what reason.

You've accurately described the fact that the 747 doesn't use radial engines, also for some unknown, mysterious reason apparently known only to you.

You mumbled something about turbofan engines being inappropriate on ASW aircraft (inefficient B747's and all that) for some other mysterious reason, although the current ASW offering is an aircraft powered by turbofan engines.

What then, is your point?

Name one thing in today's economy that was not an evolutionary thing.

Brussel sprouts, but that's also irrelevant.

As is the evolution of radial engines to turbofan engines. Obviously we use turbofan engines. Obviously modern aircraft aren't equipped with radial engines. So what?

 

[Tom-D]

Not really. You keep rabbiting on about radial engines not being on modern airliners. You've whined on about radial engines vs. the 747 in an ASW role for god only knows what reason.

You've accurately described the fact that the 747 doesn't use radial engines, also for some unknown, mysterious reason apparently known only to you.

You mumbled something about turbofan engines being inappropriate on ASW aircraft (inefficient B747's and all that) for some other mysterious reason, although the current ASW offering is an aircraft powered by turbofan engines.

What then, is your point?



Brussel sprouts, but that's also irrelevant.

As is the evolution of radial engines to turbofan engines. Obviously we use turbofan engines. Obviously modern aircraft aren't equipped with radial engines. So what?

pretty ugly post don't ya think? Just saying, did your ego get stepped on some where along this thread?

 

[DouglasBader]

pretty ugly post don't ya think?

No, and yes, I really do think.

Ego? No.

Still waiting to find out what his point is. He keeps babbling on about reciprocating engines being replaced by turbines. To quote him, "duh."

Thanks, captain obvious. The point?

 

[kyleb]

Hey Everybody!!! A circular firing squad!

;-)

 

[Tom-D]

He keeps babbling on about reciprocating engines being replaced by turbines.

Well actually they were, prove me wrong by showing us 1 major airline buying a reciprocating powered aircraft.

the market is jet or turboprop. even the beavers and otters are being converted to Garrett and P&W-PT6.
I have 2 really good friends that converted their Beavers to P&W-PT6 and their maintenance cost are 10% of what they were running the P&W 985.

 

[Henning]

Didn't disagree with that statement. However, the total cost of an aircraft isn't just fuel consumption. It's speed, reliability, dispatchability. The lower failure rates and overhaul requirements of turbine engines ended up making enough sense that radials stopped being produced.

Right, when you have a commercial mission operating costs don't hurt you, down time and missed missions kills you. OTOH, for me to have one, the turbine needs a self supporting job, besides, I can't stand the choking stench of kero.

I wonder if I can find a 4360 with a contra rotating hub and prop?

 

[Tom-D]

Right, when you have a commercial mission operating costs don't hurt you, down time and missed missions kills you. OTOH, for me to have one, the turbine needs a self supporting job, besides, I can't stand the choking stench of kero.:no nod:

Yeah but they will start at -40 with out preheat.


I wonder if I can find a 4360 with a contra rotating hub and prop?

Yes contact the Pueblo aviation museum they had one for sale, bring your RR flat car to haul it away.

 

[N801BH]

Brussel sprouts,

YUCK..............

I was enjoying this lively thread till you said the BS word..


Carry on Mr MasterBader....

 

[Everskyward]

90, A90, B90 do not use bleed air for cabin pressurization.

Kgruber is right about the pressurization system in the old 90s.

The King Air Model 90 was conceived as a turboprop upgrade to the piston-engine Queen Air in 1961. The first straight 90 aircraft was powered by Pratt & Whitney PT6A-6 engines, and assigned se- rial number LJ-1. That was 1964, and it marked the beginning of a long evolutionary production run that continues today.

Two years later, Beech introduced the A90 model, improved with a higher altitude 4.6 PSID cabin, reversible propellers and PT6A-20 engines. In 1968, the B90 entered production featuring a 4 ft. longer wingspan and a higher 9,650 lb. takeoff weight.

Next came the C90 in 1971, starting with serial number LJ-502. The big change was the elimination of the single engine-driven supercharger pressurization system, and introduction of the dual engine bleed air environmental system.

http://www.raisbeck.com/nls/radar/RADAR_April_2011.pdf

 

[DouglasBader]

Well actually they were, prove me wrong by showing us 1 major airline buying a reciprocating powered aircraft.

Of course major airlines aren't operating aircraft with radial engines. Again, to quote Dupuis, "Duh." What's that got to do with the price of tea in China?

What's the point?

I was enjoying this lively thread till you said the BS word..

There are children in China with no brussel sprouts.

Not one of them is complaining.

the market is jet or turboprop. even the beavers and otters are being converted to Garrett and P&W-PT6.
I have 2 really good friends that converted their Beavers to P&W-PT6 and their maintenance cost are 10% of what they were running the P&W 985.

For those who can afford that market, yet.

I flew a M18T for several years; the east-bloc version of the 1820 that was on it had been replaced with a PT6A-45R. I preferred it. Less noise, less vibration, more power available if I needed it, and I could haul more with the aircraft...and it had reverse. I flew a garret powered version, which suffered a failure in flight on a fire, and that didn't impress me at all.

I've been doing a lot of wrenching on the radial versions lately, especially at night (hence remaining covered in oil). Two are sitting here new, in the crate, waiting to go on.

Turbine engines have their place. I've operated them all over the world, and of course I enjoy their reliability, smoothness, power, and capabilities. Nothing replaces the soul of a shaking, leaking, loud, hot radial, however. Radials are a rarity these days, and nostalgia for them is far better than the reality of them being the main stay. Yes, we know that radial engines are historic items and few of them are in use. Yes, we know that the P2 was replaced as the primary ASW aircraft a long time ago, and the airplane that replaced it is being replaced itself. Progress happens. So what?

 

[Ted]

Right, when you have a commercial mission operating costs don't hurt you, down time and missed missions kills you. OTOH, for me to have one, the turbine needs a self supporting job, besides, I can't stand the choking stench of kero.

Operating costs are still important for commercial operators, although dispatchability trumps all.

Also, when you take a look at the SFCs of various modern turbines (made within the past 40 years) at their designed operating altitudes, they are pretty efficient. The local Cheyenne owners point out that, if you're going on a trip long enough that you actually spend most of it at FL220 or so, the Cheyenne is cheaper per mile than a Navajo.

 

[Tom-D]

For those who can afford that market, yet. (snip) Progress happens. So what?

Those who can't afford the change are closing the business, and retiring because they can't compete.

The last old Beaver that I was servicing just went in for overhaul and conversion, when it comes back to service it will have a new owner, a new service route, where the customers can expect regular deliveries.

 

[Henning]

Operating costs are still important for commercial operators, although dispatchability trumps all.

Also, when you take a look at the SFCs of various modern turbines (made within the past 40 years) at their designed operating altitudes, they are pretty efficient. The local Cheyenne owners point out that, if you're going on a trip long enough that you actually spend most of it at FL220 or so, the Cheyenne is cheaper per mile than a Navajo.

Operating costs are billable, down time is not.

 

[Morne]

We generally don't see radios with vacuum tubes in them these days, either. What's your point?

I have a Collins KWM-2...

 

[DouglasBader]

Touche'.

Does it work?

 

[Morne]

Yep. Even have a separate S-line receiver to make duplex easier.

 

[denverpilot]

Yep. Even have a separate S-line receiver to make duplex easier.

Nice!