Argument with friend: Passenger airplanes haven't progressed much in 40 years?

DanTMWTMP

Lifer
Oct 7, 2001
15,906
13
81
I told him there were several advances in safety, efficiency, noise, comfort, maintenance, logistics, etc.

He told me that cars have advanced far more in the last 40 years than aircraft. I disagree. We may not see the advances first hand, but under the skin, there were several leaps in engineering to achieve what we have today.

yes. this is inspired from the 787 talk I had with him today.

I guess he's talking about where's our supersonic passenger planes.
 

spidey07

No Lifer
Aug 4, 2000
65,469
5
76
I'd say there are pretty even, with safety being the biggest advancements in both of them.
 

Linflas

Lifer
Jan 30, 2001
15,395
78
91
Your friend is wrong. Just stand beneath the flight path of a 707 or 727 when they take off vs one of today's high bypass turbo fan jets for a fairly dramatic example of the advances just in jet engine technology.
 

Hyperlite

Diamond Member
May 25, 2004
5,664
2
76
Yeah engines have definitely progressed. Short of the 787, the airframes haven't progressed much. But then again, there hasn't been any real revolutionary shift in how cars are manufactured, either.
 

gwai lo

Senior member
Sep 29, 2004
347
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The changes aren't significant, but there have been. For example, the newest 747's have redesigned airfoils that allow for a full 100,000 lbs of gross lift off weight (its either GLOW or payload I don't remember) without significant changes in geometry.

Supersonic passenger planes have a few things going against them, I can't explain the aerodynamics stuff too well. However, from my understanding, anything with turbomachinery (like the huge turbofans on GE's GEnx) don't like supersonic flow. These systems are also the ones with the highest Isps (its like mpg but for planes), so that's one strike against them in the cost v. revenue perspective.

Another issue is that being able to generate large amounts of thrust to overcome to increased drag around Mach one means high exit velocities from the engine. High exit velocities are typically associated with high temperatures as well and temperature gradients are what makes engines loud. I think the relationship is something like noise level scales proportionally with v_exit^0.8. The problem here is that people don't like loud things.

There's also a whole topic about geometry changes in the engines required to operate in different flight regimes.

Flying fast is complicated. :|
 
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darkxshade

Lifer
Mar 31, 2001
13,749
6
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Your friend might be right. I am completely unqualified to make such an assessment but my assumption is based on the fact that passenger cars could be updated and upgraded annually from model to model. This is possible because cars are relatively cheap compared to airplanes so trying out new R&D won't be as costly as trying out a new engine on a new plane for example. The customers are the consumers. Passenger planes are a whole nother ballpark. They are big and costly to maintain. They don't sell millions a year so they aren't able to cost effectively build prototypes to try out new R&D. The customers are airliners and there aren't enough to drive competition as say the millions of customers who buys millions of cars annually which force auto maufacturers to gain marketshare with every upgrade they can get their hands on to gain a competitive edge.
 

nanobreath

Senior member
May 14, 2008
978
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What are the advances in automobiles you are talking about? A lot of those advances can directly apply to airplanes. There is one big difference between automobiles and airplanes. Cars are sold to consumers and need to appeal to them. Airplanes are sold to companies who use them as tools.

What matters to the companies purchasing the planes like fuel efficiency, safety, maitanence costs, etc has most certainly improved.
 

Linflas

Lifer
Jan 30, 2001
15,395
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There have been a lot of "invisible to the public" changes for safety reasons to the cockpit instrumentation and controls as well as a direct result of accident investigations. One example would be ground proximity warnings were significantly beefed up as a result of a 727 crashing into the side of a mountain on final approach to Dulles Airport in 1974 and further enhanced after an L-1011 crashed in the Everglades while the pilots were trying to solve an issue with a warning light. That Everglades crash also resulted in some changes to the autopilot system to make it more obvious to the pilots when the system was engaged/disengaged.
 

KeithP

Diamond Member
Jun 15, 2000
5,662
199
106
Until planes have parachutes, I'm not a fan. Some smaller private jets have them now.

Actually ballistic recovery systems are available for a wide range of aircraft including ultralights. Here is a story about one such device saving a guy in an ultralight.
http://www.lodinews.com/articles/2007/06/13/news/1_plane_070613.txt

As far the argument that "passenger" aviation hasn't progressed as much as the automotive industry in the last 40 years...anyone that would make such a claim is so clueless to what has been going on in the commercial aviation industry and its history that it isn't worth arguing with them.

-KeithP
 

bunnyfubbles

Lifer
Sep 3, 2001
12,248
3
0
Until planes have parachutes, I'm not a fan. Some smaller private jets have them now.

Most fatal plane crashes are events where parachutes would be completely useless - takeoff, landing, or abrupt catastrophic failure (ie no time to be able to put on a chute)
 

Demon-Xanth

Lifer
Feb 15, 2000
20,551
2
81
Avionics and efficiency have been the major advancements. Aircraft are so close to the sound barrier that speed increases over the years have been minor. Going supersonic is a major hurdle that isn't something that can't be overcome, but merely something that can't be overcome at the prices we are willing to pay.

Could we make a 400 passenger mach 2.5 passenger airliner? Yes.
Could we make a 400 passenger mach 2.5 passenger airliner profitable? No.

There was a day in age when flying on a jet was just for the rich. Now it's cheaper than driving in a lot of cases.
 

Arkaign

Lifer
Oct 27, 2006
20,736
1,379
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My best friend is a USAF jet engine mechanic with 20 years experience on both military and private jet engines, mainly GE and Pratt & Whitney.

"Cars have definitely advanced far more than passenger airliners in the past 40 years."
 

darkxshade

Lifer
Mar 31, 2001
13,749
6
81
After thinking about it some more, I don't think it's possible to make a direct comparison. A car is really only about fuel efficiency, horse power and a few other asthetic and enginering qualities that can't be compared to planes. Can we really compare the advancement of say car suspension over 40 years to the advancement of the auto-piloting system? The auto-piloting system is so sophisticated and advanced that a car suspension or anything else about a car can't be compared to directly. Planes also have radars, weather systems, radios and a lot of other trinkets that cars don't need R&D for. The only way to compare is something both has advanced over the years like the alloys used in plane & car construction. I'm no engineer but I think planes have become more sturdier and lighter over 40 years than cars have.
 

Zargon

Lifer
Nov 3, 2009
12,218
2
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there are just not alot of great ways to get that much shit through the air, so the shape isnt going to change much
 

Demon-Xanth

Lifer
Feb 15, 2000
20,551
2
81
I think part of the "last 40 years" part is that compared to cars, between 1930 and 1970 cars didn't progress much. But during the same time aircraft progressed at an absolutely staggering rate. Look back on the history of aircraft and you'll see a number of military aircraft that were obsoleted in a matter of ten years. Piston engined airliners were doomed virtually as soon as the 727 hit it's maiden voyage in 1963.
 

mb

Lifer
Jun 27, 2004
10,233
2
71
40 years ago, airplanes could not take off from a treadmill.

Today, they can.

That is progress.
 

torpid

Lifer
Sep 14, 2003
11,631
11
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You could have the greatest safety belt in the world around your lap in the world's safest seat in the otherwise world's safest plane and you are still going to lose a leg as soon as anything happens that would test those safety mechanisms because the seat in front of you is 1 mm in front of your knee.
 

Gibsons

Lifer
Aug 14, 2001
12,530
35
91
Avionics and efficiency have been the major advancements. Aircraft are so close to the sound barrier that speed increases over the years have been minor. Going supersonic is a major hurdle that isn't something that can't be overcome, but merely something that can't be overcome at the prices we are willing to pay.

Could we make a 400 passenger mach 2.5 passenger airliner? Yes.
Could we make a 400 passenger mach 2.5 passenger airliner profitable? No.

There was a day in age when flying on a jet was just for the rich. Now it's cheaper than driving in a lot of cases.

One of my favorite sayings "Fast, reliable, cheap. Pick two."

Although I guess if we could get fuel at 1 cent per gallon, we'd probably have SSTs all over the place. But we can't, so moot point.
 

darkxshade

Lifer
Mar 31, 2001
13,749
6
81
40 years ago, airplanes could not take off from a treadmill.

Today, they can.

That is progress.


That is a flawed argument, it could be that it was the treadmill that has progressed in the last 40 years but not the plane. ;)
 

foghorn67

Lifer
Jan 3, 2006
11,883
63
91
My best friend is a USAF jet engine mechanic with 20 years experience on both military and private jet engines, mainly GE and Pratt & Whitney.

"Cars have definitely advanced far more than passenger airliners in the past 40 years."

Did he forget about high-bypass?:\
 
Dec 26, 2007
11,782
2
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After thinking about it some more, I don't think it's possible to make a direct comparison. A car is really only about fuel efficiency, horse power and a few other asthetic and enginering qualities that can't be compared to planes. Can we really compare the advancement of say car suspension over 40 years to the advancement of the auto-piloting system? The auto-piloting system is so sophisticated and advanced that a car suspension or anything else about a car can't be compared to directly. Planes also have radars, weather systems, radios and a lot of other trinkets that cars don't need R&D for. The only way to compare is something both has advanced over the years like the alloys used in plane & car construction. I'm no engineer but I think planes have become more sturdier and lighter over 40 years than cars have.

You can compare them from a "40 years ago this was the average/top of the line car, and today this is the average/top of the line car". Then do the same for airlines, and compare/contrast the differences. Whichever has more improvements over their respective spot 40 years ago wins.

IMHO cars and airplanes are about equal, with cars maybe more simply because the refresh cycles are much shorter and less expensive so there are more generations in the same amount of time.

If you care to look at some #'s:

http://en.wikipedia.org/wiki/Boeing_Commercial_Airplanes#Boeing

The 747 just past its 40th anniversary of it's first delivery (and on Jan 21 will be 40 years since it's been in service). So, it's a perfect airplane to represent the tech 40 years ago. Take a look at the tech sheet http://en.wikipedia.org/wiki/Boeing_747#Specifications for it, and compare it to the current tech which is the 787 Dreamliner (specs http://en.wikipedia.org/wiki/Boeing_787#Specifications).*

Cruise speeds are close enough to be the same (787:561-587 mph vs 747:555-594 mph), but top speed is actually down in the 787.

Max range is up on the 787 depending on model (787: 8,200 NM vs 747: 5,300 NM)

Total seating is down (787: 250 vs 747: 452)

Max takeoff weight is down (787: 502,500 lbs vs 747: 735,000 lbs)

etc.

So, basically the 787 can transport less passengers/weight further with higher fuel economy per flight. The real interesting statistic would be per-passenger/seat what the cost is to fly a 747 vs a 787. Obviously this isn't the whole story, but based on those spec sheets we haven't progressed a whole lot in those 40 years.

*I realize this is leaving out safety and control systems like fly-by-wire in newer systems. This is also comparing only one version, and I didn't spend the time to match up the closest spec wise. Maybe I will later.

In the car department, you have a similar thing. Take a look at the VW Golf from first produced in the early 70's to todays Golf. They have similar HP, similar MPG, still carry 5 people, etc.

What I'm really trying to say I suppose is that the only meaningful "improvements" to both autos and airplanes (commercial variants) are in regards to safety and "features". Air conditioning, air bags, ABS, powered windows/locks/steering, etc are now more common "standard features" in most cars. In airplanes you have auto pilots, many improvements in safety, etc. All of this boils down to which has a better:

Cost to transport 1 passenger/x weight from destination A to B, more safely and reliably.
 

The Stig

Senior member
Aug 13, 2007
335
0
0
<--- Work for Fortune 50 aerospace company involved in commercial, military aviation and space program as well. your friend is an idiot.
 

PlasmaBomb

Lifer
Nov 19, 2004
11,636
2
81
40 years ago -

727-100
Cockpit crew.....Three

The 727 was one of the last airliners in service to have a three-person flight crew, including a flight engineer, a crew member whose tasks have been largely automated on newer airliners.

Max. seating capacity...................149
Length.........................................133 ft 2 in (40.6 m)
Wingspan....................................108 ft (32.9 m)
Tail height.....................................34 ft (10.3 m)
Zero fuel weight..................100,000 lb (45,360 kg)
Maximum take-off weight....169,000 lb (76,818 kg)
Maximum landing weight.....137,500 lb (62,400 kg)
Cruising speed...................Mach 0.81
Maximum speed.................Mach 0.90
Range fully loaded....................2700 NM (5000 km)
Max. fuel capacity.....................8,186 US gal (31,000 L)
Thrust....................................65,100 lbf
The 727 is one of the noisiest commercial jetliners.

Lower is better
Economy 6.2 L per km.
Economy per passenger 0.042 L/P/km

787-9
Cockpit crew................................Two
Typical Seating........................250&#8211;290
Length............................................206 ft (62.8 m)
Wingspan.......................................197 ft (60.0 m)
Height...............................................55 ft 6 in (16.92 m)
Zero Fuel weight......................254,000 lb (115,000 kg)
Maximum takeoff weight..........547,000 lb (248,000 kg)
Cruise speed.........................Mach 0.85
Maximum cruise speed..........Mach 0.89
Range.............................8,000 &#8211; 8,500 NM (14,800 &#8211; 15,750 km)
Maximum fuel capacity...............33,428 US gal (126,539 L)
Maximum thrust capability........140,000 lbf

Economy 8.0 L per km.
Economy per passenger 0.028 L/P/km

The 787 has a maximum takeoff weight ~ 4 times that of the 727, has twice the thrust, and carries nearly twice the number of passengers.