NASA is testing lightweight planes with folding wings

[DelJo63]

Yes, the Grumman F-14 inherited the moving wing technology from the Rockwell B-1

 

[mbrowne5061]

Sorry, your into the politics, the small passenger capacity was a design issue for supersonic airframe design.

I'm not referring to passenger capacity of a single flight. I am referring to being blocked from dozens of routes that could have supplied the concord with tens of thousands of more passengers a year, all because Boeing couldn't get their own supersonic passenger plane off the ground - literally. This would have changed the economics of commercial supersonic flight entirely - the competition from Boeing, not an Airbus-BAE monopoly over all supersonic flight.

If you limit the routes, you limit the number produced because you handicap your ability to reduce unit cost through economies of scale, and this reduces the overall demand for the plane because it costs more than expected. For a modern example, see Airbus' Dreamliner. Its so large that a lot of airports couldn't even accept it without extending their runways (not always an option, depending on local geography), and this compounded with bad timing as the rest of the airline industry started moving away from wide-body passenger designs. The Dreamliner likely would have died in its first few years of production if it wasn't for Emirate air and the backing of the Qatar royal family. It still may die if the overall situation between Qatar and the rest of the Middle East doesn't improve - but that is neither here nor there.

Being able to alter the available lift surface in flight will be a huge innovation. I am more curious about the actual Shape Memory Alloy itself. Does it only have two positions to select from, or can it respond over a continuous profile of ranges based on how much energy is input into the material? I hope it is the later, because have only two positions, 'up' and 'down', seems like it won't be worth the increased complexity. Now, if you could have the system automatically adapt to the optimal amount of lift surface based on current reynolds and mach numbers of the air flowing over the wings itself, that would be amazing. The fuel savings alone would make it worth it.

 

[DelJo63]

I'm not referring to passenger capacity of a single flight. I am referring to being blocked from dozens of routes that could have supplied the concord with tens of thousands of more passengers a year,...

It's still $$/seat profit proposition and the SST lost money unless it was at 100% capacity. The volume of sales produces a better gross (the McDonald's sales plan), but a fuselage with larger capacity would have been much much better. More destinations is a fractional increase when the profitability is low to start with.

 

[DelJo63]

BTW: this is the very change that the DC3 made to commercial aviation - - higher capacity and lower costs compared to the Boeing 247.

DC3: b-247:
Crew of two and at least 12 passengers. ---- 247: 10 passengers
Range: 1,491 miles - - - - - - - - - - - - - - - - - Range: 745 miles (1,200 km)

 

[captaincranky]

Basically because all aviation has been diverting away from biplanes since 1909:

​

The closest thing to a biwing is the FA-18 with the stubby winglets along the nose of the fuselage

View attachment 84004

The FA-18's winglets are a bit of a moot point, since it, and all modern fighter aircraft have lifting bodies anyway. Although they do likely have a use in helping to guide airflow

The U-2 which you've mentioned is in reality, a turbojet powered glider. It's subsonic, with the same extremely high aspect wings you'd find on a hobby glider. Lockheed's "Skunk Works" are responsible for both it, and the fabled SR-71. I think the U-2 has outlived the SR-71, and is still being used by NASA for high altitude research. Ostensibly cost is a factor, since I've read it costs about $50,000 just to start the SR-71's engines. (Dunno what exact costs were included in that estimate though)./

BTW: this is the very change that the DC3 made to commercial aviation - - higher capacity and lower costs compared to the Boeing 247.

DC3:View attachment 84011 b-247:View attachment 84010
Crew of two and at least 12 passengers. ---- 247: 10 passengers
Range: 1,491 miles - - - - - - - - - - - - - - - - - Range: 745 miles (1,200 km)

My father used to drag me down behind Philly International to watch the planes take of and land. Don't know if I remember either one of those tail draggers, but the field was loaded with DC-7s, The "Viscount, with its really whiny turboprop engines, and possibly the most beautiful commercial airliner of all time, the Lockheed "Super Constellation". ("Connie", for short)

 

[captaincranky]

In the Movie "The Final Countdown" The Jets used in that movie could position the wings all the way back and thus have full throttle and high speed flight. Yet those would be considered folding wings..

The center piece of "Topgun" was the Grumman F-14 "Tomcat". It was released in 1986. The plane itself entered active service in Sept, 1974. "The Final Countdown", falls somewhere in the middle, with a 1980 release date. BTW, tgo the best of my knowledge, your posted photo is an F-14.

The Navy's F-14s, I believe have all been retired in favor of the FA-18, which doesn't have movable wings.

In any case, the swing wing F-111 "Aardvark" preceded the Tomcat by several years: https://en.wikipedia.org/wiki/General_Dynamics_F-111_Aardvark

Rockwell's B-1B "Lancer" also has variable sweep wings

Any of that, biplanes included, seems to be missing the point by a bit, since the story, (as much as I've been able to assimilate), is dealing with wings the vary the tip configuration, more so than sweep.(And please feel to correct me if I've misinterpreted that). And again AFAIK, the idea of "angled winglets or tips", is mostly to trap airflow at the narrowest area, partly to prevent tip stall, which is a big issue with a highly tapered wing planform.

 

[mbrowne5061]

... I think the U-2 has outlived the SR-71, and is still being used by NASA for high altitude research....

They still fly A U-2 today, but its not the same as the original. The Original U-2 was retired, and a few decades later launched the U-2S "Dragonlady". Used in recon in uncontested airspace, and some have kicked around the idea of using it as a targeting platform - paint lasers on ground targets from 60,000 feet for surface and air fighters to engage with at will.

 

[DelJo63]

The Navy's F-14s, I believe have all been retired in favor of the FA-18, which doesn't have movable wings.

The 'upgrade' to the FA-18 was a cost & maintenance decision, not in better aerodynamics or avionics. Even the initial costs highlight this difference: F-14 @ 40millon/per vs FA-18 @ 18millon/per. The F-14 has almost twice the maintenance hours than the F-18 is far more complicated to effect even simple R/R activities.

The sweeping wing design is automatic in the F-14 while the Russian Mig-23 & SU-24 are manual only.

 

[tipstir]

F-14's were the best for it's time..Cost me a lot to the American Tax payers.. But USAF wants more speed from their jet fighters..

 

[DelJo63]

F-14's were the best for it's time..Cost me a lot to the American Tax payers.. But USAF wants more speed from their jet fighters..

That's the laugh; the F-14 could reach mac 2.4 while the FA-18 only mac 1.8. The primary deployment of both were Navy however. The F-15 Eagle and F-16 Falcon were USAF.

 

[captaincranky]

That's the laugh; the F-14 could reach mac 2.4 while the FA-18 only mac 1.8. The primary deployment of both were Navy however. The F-15 Eagle and F-16 Falcon were USAF.

The F-15 is the fastest one of the bunch by a good margin. However, there's always been some contention as to who are the better pilots. The Navy pilots claim they are, due to the whole carrier landing and launch dynamics. Remarking with some scorn about how Air Force pilots have a 2 mile long runway to work with.

Which brings us back to the Tomcat's swing wings. To get that Mach 2.4, the wings needed to be fully swept back. But to land the sucker, the wings need to be fully extended, or otherwise you'd never be able to make those tight carrier landing turns.

Delta wing aircraft are notorious for wanting to go in a straight line, and not being very receptive to turning on a dime.

All those performance numbers are gleaned.empty, and unarmed. I was told, or heard in the movie (?), that fully armed and fueled, the F-14 "was a real slug", when it got shot off the carrier.

In any case, earlier jets didn't have the thrust to support supersonic speeds without retractable armament, along with full (stationary), delta wings.

The F-102 is a prime example of this:

I don't believe I'm hearing myself say this, but about 32 years ago ( ) someone I worked with who was in the Air Force Reserve, invited me to the base's, "Dart Out" ceremony, when they retired the Darts, and replaced it with the F-16.

The dart made its pass, pulled vertical, going almost out of sight in the process. The F-16 pulled vertical, and I counted at the very least, 12 vertical rolls before it did go out of sight. Progress!

That was at this base: https://www.goang.com/locations/new-jersey/Atlantic-City-Air-National-Guard-Base

 

[DelJo63]

In any case, earlier jets didn't have the thrust to support supersonic speeds without retractable armament, along with full (stationary), delta wings.

The F-102 is a prime example of this

The Camarillo Airport [IATA: none, ICAO: KCMA,FAA LID: CMA] Coordinates

34°12′50″N 119°05′40″W
was originally established in 1942 ... auxiliary landing field with a 5,000 ft (1,500 m) runway, which was later extended to 8,000 ft (2,400 m) in 1951 to accommodate what by then had developed into Oxnard Air Force Base. At the base, Aerospace Defense Command directed the 354th, 437th, and 460th Fighter-Interceptor Squadrons successively.

The East end of the runway (still) has three revetments and I've personally seen TWO F-102 Darts scramble with full afterburners from them, as Hiway 101 runs parallel to the runway and only a few 100 yards to the north. The Dart was a deathtrap on landing as it was easily over controlled and induced into a fatal snap-roll at low altitude. Have a personal friend who worked on the 102 flight simulators wired to train the pilots to use small stick corrections.

 

[DelJo63]

Oops; 460th interceptor squadron flew F-106s


Max speed Mach 2.31 (2455km/h; 1325kt/1525mph) at 12,200m (40,000ft)
Range 4347km (2346nm/2700mi) with maximum fuel in external tanks at 982 km/h (530kts/610mph) at 12,500m (41,000ft)