Old Plane Designs, Built Today...

khenleydia · Wed Jun 26, 2013 6:47 am

There is such a push over recent years to make planes more fuel efficient, safer, more reliable and more comfortable, that it made me wonder what tech from today could do for planes from yesterday? Keep in mind, I am not 'dreaming' of what it would be like. I wonder in what 'factual' ways could the planes be improved, however keeping the overall same design.

I will use the example of the Boeing 377 (based off of the B-29)...
- Engines: Updated from the C-130 or A400?
- Skin: Composite aluminium or carbon finer?
- Landing gear: Same or somehow squeeze a 4 or 6 wheeled setup?
- Flight deck: 2 person of course, but systems fly-by-wire or?

In the end, I am curious, what overall effect this would have on the plane itself. Would it just make it more expensive, but overall the same abilities? In the 377 case, I don't expect much to help with speed because its design likely limits that, but with better engines and being lighter, wouldn't it likely fly a lot further?

I find it interesting to learn or understand more of what our advances in technology could help improve.

Thanks!
KhenleyDIA

LH707330 · Wed Jun 26, 2013 7:07 am

One of the biggest drivers of efficiency is that planes are designed as a complete package where all components are designed to work together. Changing things afterwards typically results in an inferior result, even for the same technology level. Your hypothetical reskinned 377 with T56 or TP400 engines would be hugely overpowered, which means it would probably burn more than the original corncobs.... Moreover, at some point you have a ship of Theseus.

Now a 707 with GTFs, that would be cool....

SASMD82 · Wed Jun 26, 2013 7:19 am

The 707 that is still built as 737. Very old but updated model. And still selling like hot cakes.

anfromme · Wed Jun 26, 2013 1:08 pm

Quoting LH707330 (Reply 1):
Now a 707 with GTFs, that would be cool....

You could do away with two of the four engines, then - and would definitely need a new landing gear, given the required ground clearance of the GTFs...

There were actually a few attempts to re-engine the 707. In the late 70s, Boeing tested a 707-700, which was basically a -320 with CFM56 engines. They abandonded that programme, though, allegedly because it posed too much of a threat to the then-new 757.
Some RC-135 eventually got CFMs in the late 1990s/early 2000s; in 2001 or so, there was the 707RE programme from P&W, using JT8D-219; I believe this was then used as a basis for a JSTAR engine upgrade.

I think that these kinds of retrofits only really make sense on military airplanes that, once purchased, can remain in service for 30+ years. For commercial airlines, where fuel cost is much more of an operating factor, the alternative to using a four-engined 707 (or A340, for that matter) is not to put new engines under its wings, but to use a plane that can fulfil the same mission profile with just two engines.

afterburner33 · Wed Jun 26, 2013 1:15 pm

I would have thought that something like the Nimrod MRA4 would have come close to a situation like this.

Also I remember reading a quote from a USAF officer who said that so many components of most B-52s still flying today had been replaced over the last 50 years that they were pretty much a modern Ship of Theseus.

Of course such a thing is probably more likely on military equipment than commercial, given the much tighter economic margins...

gregarious119 · Wed Jun 26, 2013 1:48 pm

I watched a special about this company on The Aviators a while ago:

http://www.baslerturbo.com/

They convert old DC-3's into 0 hour new frames for cargo companies. I would LOVE to take a ride on one of them one day...

cschleic · Wed Jun 26, 2013 4:09 pm

Quoting SASMD82 (Reply 2):
The 707 that is still built as 737. Very old but updated model. And still selling like hot cakes.

This came to my mind first, too. Interesting how things go in cycles. Reduce to two engines, change the wing and landing gear, and you have a 737-900ER, complete with the new rear emergency exits like some 707's had. The basic fuselage design is going on 50+ years now. With the number of 737's selling, they'll still be flying when the fuselage is a 100-year old design.

The Lockheed C-130 first flew in 1954, and they're still being built.

LH707330 · Wed Jun 26, 2013 4:32 pm

Quoting anfromme (Reply 3):

I'm not sure losing two engines would work with that wing structure. If you take the MRJ engines, they would be about the right size, and -40% on fuel burn.

The ironic thing about the CFM56 upgrade is that it became popular on the DC8 after most of the 707 R&D was done. IIRC, the -700 was built as the E-8, the Navy versions that came from the factory with CFM56s.

Quoting cschleic (Reply 6):
This came to my mind first, too. Interesting how things go in cycles. Reduce to two engines, change the wing and landing gear, and you have a 737-900ER, complete with the new rear emergency exits like some 707's had.

There was a thread a while back comparing the 707-100 and the 737-900ER, similar tube size but much less weight.

DarkSnowyNight · Wed Jun 26, 2013 4:36 pm

Quoting khenleydia (Thread starter):
- Engines: Updated from the C-130 or A400?

Sure. But it's too much power for that frame. Better to cut it to just two at that point.

Quoting khenleydia (Thread starter):
- Skin: Composite aluminium or carbon finer?

Possible, but very cost and engineering prohibitive to the point of being an effective impossibility.

Quoting khenleydia (Thread starter):
- Landing gear: Same or somehow squeeze a 4 or 6 wheeled setup?

Not necessary. The 377 was roughly between the A319 & A320 in terms of size. So, no need of adjusting the MLG Wheels, although perhaps new wheels with multirotor brakes will be good...

Quoting khenleydia (Thread starter):
- Flight deck: 2 person of course, but systems fly-by-wire or?

Doable, but expensive. At that point, it becomes worth it to add FBW (hell, hydraulic control surfaces at all!) too, so do that.

Aesma · Wed Jun 26, 2013 4:46 pm

Interesting subject, I'm in a debate at the moment on wikipedia over the Iranian HESA Saeqeh, is it a new plane or a modified F-5. To me it's the latter, what do you think ?

http://en.wikipedia.org/wiki/HESA_Saeqeh

http://en.wikipedia.org/wiki/Talk:HESA_Saeqeh#aircraft_built

Quoting afterburner33 (Reply 4):
I would have thought that something like the Nimrod MRA4 would have come close to a situation like this.

Or the Breguet Atlantic.

ADent · Wed Jun 26, 2013 5:13 pm

DC-8s were re-engined and flew for years in passenger and cargo service.

There are some old planes built today. The Bonanza has been in production 66 years, same as the DHC-2 Beaver.

maxpower1954 · Wed Jun 26, 2013 5:14 pm

The DC-8 Seventy Series (re-engined Sixty Series with CFM-56s, starting in 1981) is easily the most successful program updating a commercial airframe.

Aircellist · Wed Jun 26, 2013 5:45 pm

Ah, my dream plane would then be a reengined or remade Lockheed L-1449 or L-1649 Super Starliner…

exFWAOONW · Wed Jun 26, 2013 5:48 pm

Quoting khenleydia (Thread starter):
I will use the example of the Boeing 377 (based off of the B-29)...
- Engines: Updated from the C-130 or A400?
- Skin: Composite aluminium or carbon finer?

Why worry about the thin skin when so much of the weight is in the structural frame supporting the skin? Newer aluminum alloys might be lighter, but to take advantage of it would require re-designing the frame and everything attached to it. Reducing the weight would require smaller engines, smaller wings, etc. At what point is it no longer a 377?

FlyCaledonian · Wed Jun 26, 2013 6:06 pm

One I've wondered about is the 727. I know it was replaced by the 757, but that was a jump in size from the 727-200. Now the last 727 was built in 1985, after the 737-300 was in production. What sort of plane would have been a 727 twin, using the 727-100 and 727-200 fuselage lengths. and the T-tail just updated for lack of engine, with two rear mounted CFM engines?

N14AZ · Wed Jun 26, 2013 6:30 pm

The An 2 and the Chines airframes built in licence comes to my mind. If I remember correctly, I saw a Y 5 with kind of winglets in a Chinese newspaper.

txjim · Wed Jun 26, 2013 6:39 pm

Quoting LH707330 (Reply 1):
. Moreover, at some point you have a ship of Theseus.

Extra points for that reference! As an engineer, I would state that if the ship was at the same rev level, it was the same ship! (anything to avoid the dreaded "Class 1 change")

[Edited 2013-06-26 11:46:06]

AAMDanny · Wed Jun 26, 2013 6:54 pm

IIRC.... The A330/A340 ran off the back of the A300 project, cabin doors, fuselage cross section etc, I believe the AFT fuselage was reworked and newer, more efficient wings where added but the fuselage was of the same design

AviationAddict · Wed Jun 26, 2013 7:06 pm

Quoting LH707330 (Reply 1):
One of the biggest drivers of efficiency is that planes are designed as a complete package where all components are designed to work together. Changing things afterwards typically results in an inferior result, even for the same technology level.

Isn't that basically what happened with the Dornier 328 vs. the J328? The plane was designed as a turboprop but when jet engines were added the overall performance actually suffered a bit.

flyingturtle · Wed Jun 26, 2013 7:27 pm

The Stout Bushmaster 2000 takes the cake.

A re-engined, improved and re-made Ford Trimotor. To be sold in the 1960ies.

http://en.wikipedia.org/wiki/Stout_Bushmaster_2000

DAvid

HBGDS · Wed Jun 26, 2013 7:59 pm

Piper tried to market the 'Enforcer" in the 1970s, a souped up Mustang designed for counter-insurgency (read "Vietnam." That went kaplunk.
http://en.wikipedia.org/wiki/Piper_PA-48_Enforcer

alberchico · Wed Jun 26, 2013 8:14 pm

The Chinese MA600 is a license produced modernized version of the an-24 which was designed in the 1950's

http://en.wikipedia.org/wiki/Xian_MA600

Even the iconic Piper Cub is still available in a modernized version. Why would you even want a glass cockpit in a Cub is another story....

http://en.wikipedia.org/wiki/CubCrafters_Carbon_Cub_SS

Revelation · Wed Jun 26, 2013 8:15 pm

Quoting SASMD82 (Reply 2):
The 707 that is still built as 737. Very old but updated model.

That statement is inaccurate at best, and inflammatory at worse. The original 737 had next to nothing in common with the 707. The 737NG is radically different than the Classic. If you feel otherwise, feel free to explain it's radically different range/payload characteristics.

Antidote · Wed Jun 26, 2013 8:16 pm

I'd love to see an updated Caravelle - surely one of the most graceful airliners ever.

LH707330 · Wed Jun 26, 2013 8:24 pm

Quoting flyingturtle (Reply 19):

Quoting HBGDS (Reply 20):

You learn something every day.... Now a 2400 hp Mustang would be quite a hoot to fly!

khenleydia · Wed Jun 26, 2013 8:49 pm

Wow... Some people have certainly had some thoughts about this before and other people don't understand the general curiosity about this...

Overall, doing any of this of course would cost a lot of money and seriously, it would serve no real purpose. I get that.

Like I tried to explain at the start though, with all the new advances in technology, what could we do to a plane, like the 377, but keep the core of what it is, or at least what it looks like.

Quoting exFWAOONW (Reply 13):
Reducing the weight would require smaller engines, smaller wings, etc. At what point is it no longer a 377?

I imagine it would be a Boeing 377X.

I like the way you are thinking though. If the plane was built and made so much lighter, it could likely use smaller engines. Of course, depending on how the rework would be done, and how much fuel it could carry, would this be a plane that could fly x2 or x4 the distance as the original 377? It, I would assume, would be a lot more dependable.

Thanks everyone for thinking about all of this. It is interesting to realise just how close a 707 is to a 737.

KhenleyDIA

ExL10Mktg · Wed Jun 26, 2013 9:14 pm

Quoting Aircellist (Reply 12):

Ah, my dream plane would then be a reengined or remade Lockheed L-1449 or L-1649 Super Starliner…

I too would love the concept, but I assume you mean a 1049 (the Super Constellation) not a 1449. The latter was a design study (stretched 1049 with new wing and turboprops) but none were ever built.

They did, however, build 4 model 1249s -- 2 for the Air Force and 2 for the Navy. Standard 1049 but with turboprops.

seabosdca · Wed Jun 26, 2013 9:23 pm

Quoting FlyCaledonian (Reply 14):
What sort of plane would have been a 727 twin, using the 727-100 and 727-200 fuselage lengths. and the T-tail just updated for lack of engine, with two rear mounted CFM engines?

A very poor competitor to a 737-800. Heavier, with less capacity. Its only advantage would have been better field performance.

N62NA · Wed Jun 26, 2013 9:28 pm

Quoting Revelation (Reply 22):
The 737NG is radically different than the Classic.

Well then at what point does a 737 cease being a 737?

Revelation · Wed Jun 26, 2013 9:55 pm

Quoting N62NA (Reply 28):
Well then at what point does a 737 cease being a 737?

When the FAA refuses to certify it as a 737.
Note that all the MD-80/90s were DC-9s according to the FAA, yet the 737 wasn't certified as a 707.

kc135topboom · Wed Jun 26, 2013 11:14 pm

Quoting khenleydia (Thread starter):
I will use the example of the Boeing 377 (based off of the B-29)...
- Engines: Updated from the C-130 or A400?

The USAF was way ahead of you. They flew two turbo-prop YC-97Js back in 1955. The YC-97Js was originally a KC-97G which had its refueling equipment and 4 Pratt & Whitney R-4360 Wasp Major engines removed, and replaced with 4 Pratt & Whitney YT-34-P-5 turbo-prop engines. The USAF tail numbers were 52-2693 and 52-2762

AF.jpg" target="_blank">http://en.wikipedia.org/wiki/File:YC-97J_USAF.jpg

The YT-34-P-5 produced about 5230 shp. The YC-97J program was dropped in favor of buying the KC-135A.

The Aero Spacelines B-377-SG Super Guppy was powered by T-34-P7WA turbo-prop engines. The two Super Guppys were rebuilt from the two YC-97J aircraft. The later four B-377-SGT Super Guppy Turbine aircraft were rebuilt from C-97 and B-377 airplanes. The SGs flew for NASA, and the SGTs flew for NASA, then Airbus, and two returned to NASA, one is still flying.

There was a joke at one time about Airbus airplanes learning to fly on the back of a Boeing.

Viscount724 · Wed Jun 26, 2013 11:34 pm

Quoting maxpower1954 (Reply 11):
The DC-8 Seventy Series (re-engined Sixty Series with CFM-56s, starting in 1981) is easily the most successful program updating a commercial airframe.

Some would argue that that the Convair 340/440 conversion to Convair 580 with Allison 501 turboprops was equally if not more successful than the DC-8-70 series CFM56 conversion program. If memory correct, 170 Convair 340/440s were converted to 580s compared to 110 -60 series DC-8s that became -70s. Another 38 Convair 240s became Convair 600s, and 27 340/440s became 640s, both with R-R Darts.

I would guess that more Convair 580s are flying today than -70 series DC-8s, and many of those Convairs were originally built in the early to mid-1950s, 15 to 20 years before the -60 series DC-8s.

zippyjet · Thu Jun 27, 2013 12:20 am

This reminds me of a concept design by Boeing back in the day. There was a design where they mated a 747 design to the three holer 727 and it would have been a 727 widebody complete with three aft tail mounted engines like the 727 but have the bubble whale hump of a 747.

Also Boeing and MD were mounting UDF reverse propfan engines on the tails of DC-9 and 727's.

N62NA · Thu Jun 27, 2013 12:31 am

Quoting Revelation (Reply 29):
When the FAA refuses to certify it as a 737.

The FAA operates with strange logic sometimes (and this is one of them). I believe the FAA has given the 787 a common type rating with the 777. Wow!

RayChuang · Thu Jun 27, 2013 12:35 am

One project that Boeing seriously looked at was replacing the three JT8D turbofans on the 727-200 with two PW2037 turbofans. Had that gone ahead, the 757 would likely never get built, and 727 production would likely have continued almost to 2000 as the plane switches to a 767-style two-crew cockpit (among other improvements). And European airlines would have expressed far less interest in buying the A320, since many European airlines already flew the 727 by the late 1960's and a more environmentally-friendly 727 model would have kept the European airlines buying 727's.

seabosdca · Thu Jun 27, 2013 12:44 am

Quoting RayChuang (Reply 34):
And European airlines would have expressed far less interest in buying the A320, since many European airlines already flew the 727 by the late 1960's and a more environmentally-friendly 727 model would have kept the European airlines buying 727's.

I strongly doubt this. An A320 would have equaled the capacity of a PW2037-powered 727 while being far lighter and more efficient. Boeing would have been under exactly the same pressure to develop the 737NG that it actually faced.

cptkrell · Thu Jun 27, 2013 12:55 am

Quoting ExL10Mktg (Reply 26):

Turboprop Super Connie photo in your post brings back memories. I was lucky enough to win the Airliners International model contest in late 1990's with a kitbash of said beast, however I chose the Navy's other prototype, the R7V2 (picture the same airframe with Lockheed Electra style turbo nacelles) and dressed it in latest TWA livery. The designation of the Super Connie in your picture is YC-121F, I believe. The airframe of one of the 121-F's was actually salvaged and operated by Flying Tigers for a while (albeit without turbo prop power).

RE: KC135TopBoom's Rep 30; Boeing also played around with REALLY updating the Stratocruiser. I have pictures of Boeing artist renderings of more radical Strats with turbos, swept wing Strats with turbos, and a super-super stretch 377 with turbos. They also proposed building a swept wing jet Stratocruiser. Building a model of that was a trip, with the Boeing B-47 wings, tail, tandem center landing gears, etc. Regards...jack

rwessel · Thu Jun 27, 2013 12:58 am

Quoting N62NA (Reply 33):

The FAA operates with strange logic sometimes (and this is one of them). I believe the FAA has given the 787 a common type rating with the 777.

A common type rating, which has to do with the requirements of the *pilot* flying the aircraft, is completely separate from the certification of two different aircraft designs, which has to do with how the requirements of the *aircraft*.

panam330 · Thu Jun 27, 2013 1:26 am

Quoting FlyCaledonian (Reply 14):
One I've wondered about is the 727. I know it was replaced by the 757, but that was a jump in size from the 727-200. Now the last 727 was built in 1985, after the 737-300 was in production. What sort of plane would have been a 727 twin, using the 727-100 and 727-200 fuselage lengths. and the T-tail just updated for lack of engine, with two rear mounted CFM engines?

Wasn't one of the 757's proposed designs basically a T-tail twin 727?

Viscount724 · Thu Jun 27, 2013 1:31 am

Quoting RayChuang (Reply 34):
And European airlines would have expressed far less interest in buying the A320, since many European airlines already flew the 727 by the late 1960's and a more environmentally-friendly 727 model would have kept the European airlines buying 727's.

Only about 11% of the 1,831 727s delivered (1,832 built) went to customers in Europe. By the end of the 1960s, 59 had been delivered to European customers, and 2 carriers accounted for 40 of those -- LH (27) and AF (13). The other 19 were split between 5 carriers: Sabena, Olympic, TAP (5 each), Transair Sweden (3), Icelandair (1).

cptkrell · Thu Jun 27, 2013 1:37 am

Quoting panam330 (Reply 38):

Correct. There were published renderings and scale drawings of same in Aviation Week & Space Technology (IIRC). I have those ferreted away somewhere. One version had the engines in rear a'la DC-9 and one version had underslung wings as per final design. Regards...jack

N62NA · Thu Jun 27, 2013 2:01 am

Quoting rwessel (Reply 37):
A common type rating, which has to do with the requirements of the *pilot* flying the aircraft, is completely separate from the certification of two different aircraft designs, which has to do with how the requirements of the *aircraft*.

Which brings us right back to square one re: today's 737-900ER vs the 737-100.

Aircellist · Thu Jun 27, 2013 2:05 am

Quoting ExL10Mktg (Reply 26):
Quoting Aircellist (Reply 12):

Ah, my dream plane would then be a reengined or remade Lockheed L-1449 or L-1649 Super Starliner…

I too would love the concept, but I assume you mean a 1049 (the Super Constellation) not a 1449. The latter was a design study (stretched 1049 with new wing and turboprops) but none were ever built.

They did, however, build 4 model 1249s -- 2 for the Air Force and 2 for the Navy. Standard 1049 but with turboprops.

I meant the one with the new wing, the Starliner (1649), and the one with turboprops.

About the 1449: sorry, I'm not home and my reference books are far away! The 1249 (or YC-121F) one you have pictured is, I believe, one of the two I had in mind.

From the Lockheed aircraft book from René J. Francillon, I remember that the 1649 had better performances than the equivalent 1049. But, no aircraft was made with both the new wing and the turboprop. I guessed that the 1449 referenced in Wikipedia

would have been that one… Mixed references. Thanks for the picture and for clearing up things.

Also, I agree that a redone Caravelle would be nice.

bohica · Thu Jun 27, 2013 2:53 am

Quoting Aircellist (Reply 42):
I agree that a redone Caravelle would be nice.

I would like to see a redone Trident. Call it the Trident Four. 3 LEAP or GTF engines, stretched fuselage to handle 225 pax in 2 class seating, TATL range. A true 757 replacement.

I know it will never happen but one can dream.

UA735WL · Thu Jun 27, 2013 4:41 am

Quoting antidote (Reply 23):

That would make for a classy RJ...just replace the RR Avons with FADEC CF34s- Would make longer CRJ routes a lot more fun!

(Interesting sidenote- the RR Avon is actually still in production...as a "utility" engine for use as a pump or generator)

Cheers,

Jonas

Revelation · Thu Jun 27, 2013 5:29 am

Quoting N62NA (Reply 41):
Which brings us right back to square one re: today's 737-900ER vs the 737-100.

From an aircraft/systems point of view there is enough traceability/consistency between the two for the FAA to certify the 747 NGs to be derivatives of the 737 Classics and in turn 737 Jurassics. There's really no point in arguing otherwise, it's all documented extensively.

The original point of discussion was that the 737 was a derivative of the 707 and there have been threads here that thoroughly debunk that. They do share a common fuselage diameter, and perhaps a few system elements, but that's about it.

ExL10Mktg · Thu Jun 27, 2013 5:54 am

Quoting cptkrell (Reply 36):
Turboprop Super Connie photo in your post brings back memories. I was lucky enough to win the Airliners International model contest in late 1990's with a kitbash of said beast, however I chose the Navy's other prototype, the R7V2 (picture the same airframe with Lockheed Electra style turbo nacelles) and dressed it in latest TWA livery. The designation of the Super Connie in your picture is YC-121F, I believe. The airframe of one of the 121-F's was actually salvaged and operated by Flying Tigers for a while (albeit without turbo prop power).

Quoting Aircellist (Reply 42):
About the 1449: sorry, I'm not home and my reference books are far away! The 1249 (or YC-121F) one you have pictured is, I believe, one of the two I had in mind.

The picture is of the R7V2. If you notice, it says United States Navy on the fuselage. YC-121-F was the Air Force designatoin. They each had 2 prototypes (with the L-188 Electra style exhaust nacelles as pictured, so I don't quite get the point of the first quote above.)

Aircellist · Thu Jun 27, 2013 10:28 am

Quoting ExL10Mktg (Reply 46):
The picture is of the R7V2. If you notice, it says United States Navy on the fuselage.

Thanks for the precision.

… And it's a good thing that at one point, identifiers were unified, for the Navy and the Air Force

art · Thu Jun 27, 2013 10:45 am

eg Twin Otter, Rekkof 100 so can be done (could have been done with the latter but too late now, I guess).

cptkrell · Thu Jun 27, 2013 12:34 pm

Quoting ExL10Mktg (Reply 46):

You'll note that the Turbo Connie pictured in reply 26 does not have the Electra-style nacelles, but the simpler tubular, or what I'd call "Bristol Britannia-style" turbine nacelles.

You're right though about me mixing up the designations, R being USN and YC being AF versions. Too many dead cells; sorry. For interest, the first R7V-2 (construction no. 4131) was the fastest air screw driven transport of the time with a cruising speed of 435-440 mph. Early in 1956 it attained a speed of 479 in rapid descent testing over California. Pretty far-out for the time. All best...jack

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