747SP numbers vs operators

[AnotherFSO]

Hi all.

Just some idle musing...

If I'm reading Wikipedia correctly, its SP operator numbers seem a tiny bit muddled -- it lists 45 former operators, but one of those is also listed as being one of two current operators. And while it mentions the NASA/DLR Sofia observatory, it's not included in the list of former operators.

Putting all that together there seem to have been 47 former and current operators, yet only 45 SPs were built. Obviously, some of those airframes went through multiple owners/lessees.

Wikipedia also says that 17 airframes are currently "stored or otherwise preserved". That's 38% of the 45 built. Somewhat amazing.

Anyway, I just thought it interesting that such a low-number aircraft has had so many operators. Are there any other similar examples?

[Gne]

Any idea how many are still in service?
Gne

[AnotherFSO]

Wikipedia lists one airframe with the Las Vegas Sands Corporation, and two with Pratt & Whitney Canada as engine testbed aircraft.

[Rebus]

Worked on a couple owned by middle eastern Royal families, lets just say they were opulent. One even had anti missile systems built into the engine pylons.

[Rebus]

Worked on a couple owned by middle eastern Royal families, lets just say they were opulent. One even had anti missile systems built into the engine pylons.
Also worked on Iranian SP, a bit of a **** heap.

[Asturias56]

Good product in a very niche market

[Jhieminga]

I don't know how regularly this site is being updated these days, but it could be a good starting point for some reading: https://www.747sp.com/
I guess the fact that it was/is an offshoot of a more succesfull product has influenced its career. I can think of a couple of other low-numbers types, but none with this many operators. As Asturias56 said: within its niche market it did very well.
Edit: there are 58 different operators listed on that website.

[rog747]

Both Pan Am and Iran Air worked together with Boeing to push for the 747SP design, and Boeing had sought an attempt to compete with the DC-10 30 (up to a point).
The idea for The 747SP came from a joint request between Pan American World Airways and Iran Air who were looking for a high capacity airliner with enough range to cover Pan Am's New York-Middle Eastern routes and Iran Air's planned Tehran-New York route.
The Tehran-New York route when launched was the longest nonstop commercial flight in the world.
Iran Air had plans (before the 1979 Revolution) to launch 747SP services to SYD and LAX.
Both airlines took simultaneous deliveries and entered SP service in 1976.
The SP's were still being delivered with Upper Deck First Class lounges.

The 747SP had a much simpler single piece flap system, and these did not require the "canoe" fairings, rather than the immense and complex triple slotted Fowler flaps of the larger 747.

SAA SP's were soon to follow in service also in 1976, enabling them to now fly non-stop around the bulk of Africa, and Syrian Arab Airlines took a pair.

Braniff ordered a total of 4 747SP airframes but only actually took delivery of 3 of those.
Braniff suffered from high oil fuel prices, the economic recession, traffic downgrowth and withdrew from its Pacific routes.
As a result Braniff would withdraw the 747SP and the fleet was soon offered for sale.
One was quickly sold back to Boeing, one to Pan Am, and another sold on to Aerolineas Argentinas.
The 4th Braniff 747SP was NTU and eventually Boeing sold it to CAAC as N1301E.

Taiwan's China Airlines took 4.
CAAC would order 3.
Korean Air 2 (The last SP's delivered)

TWA and Qantas came a while later to the SP game in 1980/1981, and both airlines did not end up using their SP's on the dedicated routes as was originally envisaged.

[SpringHeeledJack]

I flew from Tokyo to Dallas once on an American Airlines 747SP, or was it United ? The take-off was pretty sporty if I recall, but as I had the mother of all hangovers who knows! I suppose the only comparable aircraft built for very niche markets were the British wonders from Hawker-Siddeley and Vickers back in the 60's.

[treadigraph]

Always partial to the SP, still remember the first time I saw one, Pan Am inbound Heathrow via Ockham which passed over my school as I strolled to breakfast - May or June '76... Whenever I see an A380 heading my way, I'm reminded of the SP, a relatively short body wearing grown-ups' wings...

Good safety record, looks like three write offs, no fatalities and only one (ZS-SPF) came close to being a serious accident - plus the China Airlines loss of control.

[Mooncrest]

The UAE government flew at least one SP. I saw it once or twice at Leeds Bradford doing circuits and bumps some years ago. The training captain on board was Mike Webster who worked for British Airways so I assume Captain Webster was either freelancing or BA had an arrangement for training and probably maintenance with UAE. Likewise, Captain Webster did training jollies on the UAE 707 and Air Hong Kong 747. I guess he knew his stuff!

[l.garey]

Not so niche maybe. Could be useful on long, thin routes. For example I flew in Air China 747SP B-2452 Beijing-Sharjah-Frankfurt-Gatwick in 1991. It looked like most other 747s from inside!
Laurence

[Groundloop]

I was scheduled to take my one and only flight on an QF SP back in early 1980 as SYD-LAX-SFO. However it was substituded with a brand new -400 at the last minute so I missed out on the chance. However as the 400 had only an SP load on board it was VERY comfortable - lots of room to stretch out!

[Asturias56]

We took a PanAm SFO-HK flight on a hot summers day and possibly the longest takeoff run I've ever experienced - a calendar rather than a clock was needed . But the flight was fine if very very very long

[Self loading bear]

Aircraft type with relatively much operators:
Short Brothers Belfast C1 10 built 4 operators.

Super Guppy 5 built 5 operators

CL-44 39 built, 46 operators!

Bristol Freighter/Wayfarer 214 built, 86 operators.

Boeing B777-200LR 61 built 22 operators and growing when Mammoth starts to redeliver.

[megan]

TWA and Qantas came a while later to the SP game in 1980/1981, and both airlines did not end up using their SP's on the dedicated routes as was originally envisagedWhat routes did Qantas envisage using the SP on rog? Did fly on their SP Sydney to Los Angeles, also flew on the Pan Am SP in the early days Los Angeles to Sydney, had to make an unexpected stop in Nandi for a splash of fuel as the winds were against us, stayed on board for the half hour it took to accomplish, told the early engines were not quite there with fuel efficiency.

[AnotherFSO]

Two Sydney Morning Herald advertisements -- one from Pan Am on 16 Feb 1984, and one from Qantas less than a week later on 21 Feb 1984.

https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/689x984/panam_smh19840216_38cffca16518a41dfda320c067f625b4745f7e1f.j pg


https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/774x1038/qantas_smh19840221_7a8c40c79992088131261011760a8a07a1b15b46. jpg

[rog747]

What routes did Qantas envisage using the SP on rog? Did fly on their SP Sydney to Los Angeles, also flew on the Pan Am SP in the early days Los Angeles to Sydney, had to make an unexpected stop in Nandi for a splash of fuel as the winds were against us, stayed on board for the half hour it took to accomplish, told the early engines were not quite there with fuel efficiency.

Contrary to some popular belief, QANTAS did not acquire the Boeing 747SP for the SYD-LAX route but originally to serve Sydney-Wellington profitably as the weather in Wellington was erratic and the runway too short for 747-238B's.
The airline's original plan was to use them to connect Sydney to New Zealand's capital, Wellington - located on the southern tip of the North Island of the New Zealand.
Wellington had a short runway that made operations by the existing 747s impossible.
In addition, the airport was frequently affected by erratic winds and poor weather. QANTAS's original intent was to use the 747SP's ability to operate on shorter runways to serve Wellington with more profitable payloads despite the operational limits placed by the airport authorities for safety reasons.
With a shorter fuselage but essentially the same power as the regular 747-200, they were known for their brisk performance.
The SP's were ordered in 1980 and had Rolls Royce RB211 524 B2, then D2/D4 engines.
These aircraft were originally ordered by Iran Air but their export was banned following the Iranian Revolution and were purchased by Qantas while still on the Boeing production line.
VH-EAA "City of Gold Coast Tweed" and VH-EAB which was first named Winton, then renamed "City of Traralgon" were both delivered in 1981.

The first QANTAS 747SP (VH-EAA) flew QANTAS Flight 55 Sydney to Wellington, but had to divert to Auckland due to poor weather at Wellington.
Only QANTAS captains were allowed to land the 747SP at Wellington as the first officer monitored the approach which was conducted at 125 knots to insure that the landing could be made using the markers painted on the runway. Landing too fast, too high, or too long, was a mandatory go-around.

It wasn't until 1984 that the airline's 747SPs were used on the Sydney to Los Angeles route.
They did expand to other Pacific destinations prior to then, such as to HNL.
They were occasionally seen at LHR.
Both aircraft were used by the airline's Australia Asia subsidiary for politically-sensitive service to Taipei.
Both were listed for sale in 1990, and again in 1997.
The SPs were withdrawn in late 2001 and sent to Marana, Arizona, and were scrapped there.

Trans World Airlines operated three Boeing 747SPs between 1980 and 1986.
TWA's 747SP's were intended for the Persian Gulf and Asia, I don't remember if it was for Iran or Saudi Arabia, and they ordered three 747SPs for 1980 in anticipation of being awarded the new long range routes which did not materialize, so they ended up flying the SPs on Transatlantic routes mainly out of LAX, JFK or BOS.....primarily the LHR, Rome, Tel Aviv, and Cairo flights, and they flew some other Transatlantic services such as to Paris and Athens, depending upon the season...

They were ordered in anticipation of increased non stop service to the Middle East which never materialised.
TWA had to keep them for a few years so they just filled in where they could be most useful - often on 747 routes that were difficult to fill up.
That said they made ideal aircraft substitutions because they were underutilised and had flight deck commonality with TWA's large fleet of B747-131's, and could therefore be seen pretty much anywhere the TWA B747's went...
TWA did not need the extra range of the 747SP and disposed of the airplanes as quickly as practical: two went to AA (for use on their newly awarded DFW-Tokyo route....the SPs flew this route for years until AA took delivery of MD11s) and one was sold to an individual in the Gulf for use as a private aircraft.


When Pan Am completed the sale of its Pacific Division to United Airlines in 1986, its 11 747SPs formed part of the deal and were not seen in Pan Am’s colours again.

[mustafagander]

Hey rog,
The QF SPs had C2 engines. The D4s were over the thrust limit certified. It actually gave QF a place to hang D4s which were getting a bit tired and could no longer make the D4 spec.
Originally the WLG operation forbade any derate or assumed temp operation so all T/O was full thrust. Imagine keeping the beast under control when your initial altitude limit was 3,000ft and you had a light SP??? Exciting!!! Flap limit speeds were a challenge.
One very frisky aircraft even at high TOW. The fuel feed configs at max TOW were simply a nightmare for the FEO.

[AnotherFSO]

https://www.youtube.com/watch?v=jHZEh7zVJcA

https://www.youtube.com/watch?v=0wUADZgZvaQ

[rog747]

Hey rog,
The QF SPs had C2 engines. The D4s were over the thrust limit certified. It actually gave QF a place to hang D4s which were getting a bit tired and could no longer make the D4 spec.
Originally the WLG operation forbade any derate or assumed temp operation so all T/O was full thrust. Imagine keeping the beast under control when your initial altitude limit was 3,000ft and you had a light SP??? Exciting!!! Flap limit speeds were a challenge.
One very frisky aircraft even at high TOW. The fuel feed configs at max TOW were simply a nightmare for the FEO.

How simply wonderful to hear the stories from someone who was 'there' and flew it too.
Thank you so much for sharing.
I was trying my best to ensure the RB211 Info I gave was correct as I could, as I kept reading variations on the engine types fitted from new build and then my source said that in 1982 the pair of SP's had the B or D variant engines fitted.

I flew on SAA SP's a few times - once was just the JNB-CPT hop and I was lucky to be sat upstairs in Biz Class. A lovely flight.

Thanks again.

and to AnotherFSO - what awesome video clips !!!

[BigBoreFour]

I was scheduled to take my one and only flight on an QF SP back in early 1980 as SYD-LAX-SFO. However it was substituded with a brand new -400 at the last minute so I missed out on the chance. However as the 400 had only an SP load on board it was VERY comfortable - lots of room to stretch out!

Did you mean perhaps 1990?

Was the 747SP the first aircraft to fly the Pacific (LAX-SYD) non-stop? Did Pan Am do it first with that aircraft? The Pan Am - Qantas Pacific advertisement 'war' was certainty interesting back then!

[WHBM]

I did notice over the years various press articles about the 747SP which turned out to be (maybe) inaccurate - possibly either hopeful PR people or journalist misunderstandings.

The original Pan Am purchase was described as for their round-the-world flight, where it was stated that the Transatlantic sector needed an aircraft bigger than a 707, while the operation onward across Asia needed something smaller than a 747. In the event I don't think the SP was ever assigned to the round-the-world.

The different aerodynamic relationship between the back of the upper deck (original 747 length) and the wing leading edge was "discovered" to give an unexpected benefit, and led to the 747-300 and -400 having the upper deck extended to get the same benefit. I always thought Boeing were pretty good with aerodynamics, and can't quite relate to them suddenly discovering this after the event,

The Qantas SP was indeed originally said to be for serving Wellington. Qantas (international only then) was moving to an all-747 fleet, their last 707 ran Wellington, after which they chartered an Air New Zealand DC8 to cover their rigorously controlled 50% of flights on the route. There had likely been criticism they didn't use their own metal.

American bought the ex-TWA SPs for their Dallas to Tokyo route, but ended up using them on the very short Boston to London route they acquired from TWA. American were really short of intercontinental aircraft when they first bought the TWA London Heathrow network, and seemed to use one of everything for a while.

The SAA SP fleet were really just an insurance against losing their landing rights at Sal on European flights when the Portuguese colony got independence. In the end this didn't happen before the -400 came along, which could do without it anyway, and SAA, like other operators, ended up at a bit of a loss for what to do with them..

[treadigraph]

Didn't Clay Lacy set a round the world record in an ex Pan Am SP with United? And another one in a GIII?

[tdracer]

The different aerodynamic relationship between the back of the upper deck (original 747 length) and the wing leading edge was "discovered" to give an unexpected benefit, and led to the 747-300 and -400 having the upper deck extended to get the same benefit. I always thought Boeing were pretty good with aerodynamics, and can't quite relate to them suddenly discovering this after the event,

Boeing originally didn't intend for the upper deck to be used for passenger seating - so if was faired in as soon as practical after providing room for the flight deck, crew rest, lav, and a few seats for cargo handler types for the freighter version.
When they shortened the fuselage for the SP, they pleasantly discovered that the upper deck 'fairing' provided favorable 'area ruling' as the upper deck now merged into the wing - which provided better transonic drag characteristics. When the 747 was originally designed (mid 1960s), the area rule concept was still quite new and novel, and so wasn't considered in the original design. I think the B-1 design was the first aircraft (early 1970s) that really took advantage of area ruling.

The 747SP gives a good example of how the large commercial aircraft business has changed. Back then, production runs of a particular aircraft design were quite a bit smaller than what's typical today - so when Boeing sold an aircraft, the price was set such that about 50% went to actually building it, and the other ~50% covered the development costs and cert, and hopefully left a bit over for profit. As a result, although the 747SP wasn't exactly a cash cow, it reportedly at least paid for itself, and aircraft like the 727 (~1,800 produced) were real cash cows.
Today, the development and cert costs have soared (despite all that went wrong with the 737 MAX cert, it's far more difficult and costly to certify a new design that in was even 30 years ago), and the pricing pressures mean that the built price is a much higher percentage of the overall sales price. As a result, in order to pay back all the development and cert costs - and have some profit left over, you need to sell a lot of that aircraft design.
As an example, Boeing didn't make any money on the 777-200LR (61 delivered). However, the -200LR paved the way for the 777F, which shares much of the design, and the 777F has been a commercial success (over 260 delivered and more than 50 unfilled orders).

[Bug]

I flew in QANTAS 747SP Melbourne - Denpasar - Singapore in about early 90's, so late in their career with QANTAS they were on other and short routes.

[Bug]

I flew Melbourne - Depasar - Singapore on a QANTAS SP, in about early 90's. It was by then a bit tired looking.
Was surprised they used an SP for that route. Not sure if it was a one off or regular.

[megan]

I think the B-1 design was the first aircraft (early 1970s) that really took advantage of area ruling.The first aircraft to use area ruling was the Ju-287 bomber in 1944. When the area rule was re-discovered by Whitcomb, it was made available to the U.S. aircraft industry on a secret basis for military programs from 1952, the beautiful Grumman F-11 Tiger was the first area rule to fly 1954, the F-102 was disappointing in that it was unable to reach Mach 1, a redesign using area rule produced the second area rule aircraft, the F-106 in 1956.

It is said in some quarters that the flap canoe fairings are an area rule application.

[Fris B. Fairing]

From 1959, trans-Tasman flights were operated by Electras of Air NZ (then TEAL) and Qantas. When Qantas disposed of their Electras in 1967, the Wellington service was operated by Air NZ with Electras in Air NZ livery with added Qantas titles. When Air NZ retired their Electras in 1972, only their DC-8s could operate into WLG whereas Qantas 707s could not. With the imminent retirement of the DC-8s in 1981, neither airline would have an aeroplane able to operate into WLG. Qantas purchased two SPs for this specific purpose. The WLG problem was eventually solved in 1985 by the introduction of the B767-200 by Air NZ and Qantas. The Qantas SPs were then utilised exclusively on the longhaul routes for which they were designed. The greatest irony is that towards the end of their service, the Qantas SPs were routinely used on what was effectively a one-hour domestic shuttle between Sydney and Brisbane.

[treadigraph]

It is said in some quarters that the flap canoe fairings are an area rule application.

Weren't the conical fairings on the CV-990 wings an aera rule addition to reduce drag? It was certainly no slouch, if I remember the fastest subsonic airliner.

[Asturias56]

"The large anti-shock bodies (https://en.wikipedia.org/wiki/Anti-shock_bodies) on the upper trailing edge (https://en.wikipedia.org/wiki/Trailing_edge) of the wings, to increase the critical Mach by reducing transonic drag. The inboard shock bodies, which were larger, were also used for additional fuel tankage"

Don't think it was anything to do with the area-rule although they are associated with it

they were invented by Whitcomb & Kuchemann https://en.wikipedia.org/wiki/Anti-shock_body

"he extension beyond the trailing edge was considered secondary to the body on the wing surface, which slowed the supersonic flow to give a weaker shock and acted as a fence to prevent outward flow. The extension was only long enough to prevent flow separation.[5] (https://en.wikipedia.org/wiki/Anti-shock_body#cite_note-Aviation-1958-5): 52  Whitcomb stated that the anti-shock body was no longer required on the top surface of a wing when the supercritical airfoil (https://en.wikipedia.org/wiki/Supercritical_airfoil) was introduced[8] (https://en.wikipedia.org/wiki/Anti-shock_body#cite_note-8) because they both decreased the strength of, or eliminated, the shock and its attendant drag."

Generally thought to only give a modest effect overall

[mustafagander]

Hey Megan,
As I understand it the B747 canoe fairings were simply sized to cover the very complex mechanism for the flaps. They cost a lot in skin friction drag as I am reliably informed. TDRacer likely knows. There was a lot of stuff crammed into those fairings. The SP did not have nor need canoe fairings. The flaps were extremely simple to reduce weight and drag. The concept was that if a full sized B747 could operate out of a field an SP could too with simple flaps coz it was so much lighter and over thrusted.
The SP flaps were really easy to cock up when setting the T/O flaps. Unfortunately the F20, usual T/O setting, on the SP, was not in the same position on the flap gauge for the other B747s. In fact F10 on the SP was about the same position on the dial for F20 on the others. HF anyone?? Yes, many crews owned up to departing with F10 on the SP.

[WHBM]

When Air NZ retired their Electras in 1972, only their DC-8s could operate into WLG whereas Qantas 707s could not. With the imminent retirement of the DC-8s in 1981, neither airline would have an aeroplane able to operate into WLG. .
I didn't know Wellington was good for the DC8 but not the 707. It's a surprising way round, because I always thought the 707 wing was better. Douglas had multiple goes at getting the DC8 wing right from the original arrangement, including a wholesale redesign for the DC8-62, but the ANZ fleet was DC8-50s. Boeing had invested in their own wind tunnel in the 1950s, in Seattle (TDR can probably tell us about it), but Donald Douglas would only buy time on NASA etc tunnels.

A UK business colleague had previously spent some years sent over to run the New Zealand office. He had all the stories about turbulent approaches into Wellington. He said more than once participants in national business meetings arrived from elsewhere with injuries and bleeding from being rolled around against the cabin wall on approach. He said it was accepted as a fact of New Zealand life. If I'm not mistaken they have never had an accident there.

[FlightlessParrot]

A UK business colleague had previously spent some years sent over to run the New Zealand office. He had all the stories about turbulent approaches into Wellington. He said more than once participants in national business meetings arrived from elsewhere with injuries and bleeding from being rolled around against the cabin wall on approach. He said it was accepted as a fact of New Zealand life. If I'm not mistaken they have never had an accident there.

In the 1980s the radio had travel reports in the morning: road closures, congestion, that sort of thing. Sometimes Wellington Airport was closed, but often it was described as "marginal." As a then-nervous passenger, I think that is the last status I'd like to hear:

Captain Speaking: Well, it looks pretty sporty down there, but we'll give it a try--you never know. Hold on tight.

[megan]

As I understand it the B747 canoe fairings were simply sized to cover the very complex mechanism for the flapsArea Ruling is a means by which wave drag is reduced. Wave drag is a component of the aerodynamic drag on the aircraft wings and fuselage moving at transonic and supersonic speeds, due to the presence of shock waves. Wave drag is independent of viscous effects and tends to present itself as a sudden and dramatic increase in drag as the vehicle increases speed to the critical Mach number.

Aera ruling aims to make the sectional volume of the aircraft to smoothly increase from the nose and smoothly decrease at the tail. Some exmples.

F-102

https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/500x226/ar1_91b2ae7660467cec09d5fffa3c70c3942f77fb97.png

F-106 - the F-102 redesigned with area ruling producing a 25% increase in speed

https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/510x224/ar2_8711bf2dfbf86ace69b5146b7d113f769d530d90.png

Concorde - having the "bump" reduced to fall inside the ideal line would have meant reducing the cabin diameter over those points, you can't satisfy all design criteria.

https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/838x374/ar_54fc1bd66aca8fe89e742e053d4f2baba55b7946.png


At the time of the 747 design area rule was well known and we have no idea of what was in the aerodynamic department minds. Positioning the under wing engine pods forward of the leading edge is another nod in the direction of area rule, But that positioning of engine pods was a feature on the B-47 and B-52 prior to Whitcomb coming out with his theory. The question is why Boeing adopted that particular feature, besides engineering issues such as wing bending relief etc. Did the post war Operation "Paperclip" give them some insight to what became Area Rule from the German research, or was the podded engine placement Area Rule effect just a serendipitous outcome resulting from other engineering concerns.

Whitcomb published his area rule paper in 1953 and it was classified "Restricted", in 1958 it was made public. His paper here,https://ntrs.nasa.gov/api/citations/20050019402/downloads/20050019402.pdf

[Rebus]

Area Ruling is a means by which wave drag is reduced. Wave drag is a component of the aerodynamic drag on the aircraft wings and fuselage moving at transonic and supersonic speeds, due to the presence of shock waves. Wave drag is independent of viscous effects and tends to present itself as a sudden and dramatic increase in drag as the vehicle increases speed to the critical Mach number.

Aera ruling aims to make the sectional volume of the aircraft to smoothly increase from the nose and smoothly decrease at the tail. Some exmples.

F-102

https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/500x226/ar1_91b2ae7660467cec09d5fffa3c70c3942f77fb97.png

F-106 - the F-102 redesigned with area ruling producing a 25% increase in speed

https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/510x224/ar2_8711bf2dfbf86ace69b5146b7d113f769d530d90.png

Concorde - having the "bump" reduced to fall inside the ideal line would have meant reducing the cabin diameter over those points, you can't satisfy all design criteria.

https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/838x374/ar_54fc1bd66aca8fe89e742e053d4f2baba55b7946.png


At the time of the 747 design area rule was well known and we have no idea of what was in the aerodynamic department minds. Positioning the under wing engine pods forward of the leading edge is another nod in the direction of area rule, But that positioning of engine pods was a feature on the B-47 and B-52 prior to Whitcomb coming out with his theory. The question is why Boeing adopted that particular feature, besides engineering issues such as wing bending relief etc. Did the post war Operation "Paperclip" give them some insight to what became Area Rule from the German research, or was the podded engine placement Area Rule effect just a serendipitous outcome resulting from other engineering concerns.

Whitcomb published his area rule paper in 1953 and it was classified "Restricted", in 1958 it was made public. His paper here,https://ntrs.nasa.gov/api/citations/20050019402/downloads/20050019402.pdf
Wasn't the wasp waist designs of some military jets from the 50's and 60's to do with area rule?

[Jhieminga]

Positioning the under wing engine pods forward of the leading edge is another nod in the direction of area rule, But that positioning of engine pods was a feature on the B-47 and B-52 prior to Whitcomb coming out with his theory. The question is why Boeing adopted that particular feature, besides engineering issues such as wing bending relief etc. Did the post war Operation "Paperclip" give them some insight to what became Area Rule from the German research, or was the podded engine placement Area Rule effect just a serendipitous outcome resulting from other engineering concerns.

One reason I have read (cannot remember the source I'm afraid) is that they were unable to calculate the effects of the underslung engine pods on the flow field around the wing, which led to them placing the engines a significant distance away from the wing, both in a vertical and horizontal sense, hoping to keep the (negative) effects to a minimum. It wasn't until the advent of CFD that they were able to get a better grip on these effects and this enabled installations like the first CFM56 equipped Boeing 737 generation, the Boeing 777 with its GE90 engines and later variations thereof.

[WHBM]

The DC8 pod positioning looked similar to the 707 (apologies to the knowledgeable here but "looked similar" is as tech as I get), but the DC8-62 re-engineered both wing and pod positioning quite substantially, coming about 8 years later. So it appeared that the pods were generally seen as the way to go, but the detail needed a fair bit of refinement.

[tdracer]

The initial reason for putting the engines in pods out in front of the wing was - interestingly enough - structural. Turns out that the engines can be used as 'tuned mass dampers' to reduced/eliminate flutter concerns. This had the additional benefit of giving physical isolation between the engines, so that something like an uncontained failure was unlikely to damage another, adjacent engine.
Boeing then discovered - using the Boeing Transonic Wind Tunnel (BTWT) referenced earlier - that it was important to put the engine well below wing - otherwise you would get 'interference' drag where the jet exhaust combined with the airflow around the wing to create areas of trans-sonic and supersonic flow (i.e. high drag). I don't ever recall hearing any reference to the engine pod placement with respect to 'area ruling'.
Way back when we were doing initial development of the 767, they did some BTWT testing that showed serious interference drag at cruise (as in ~2% of total aircraft drag). The setup for this testing was interesting - they did a 'blown nacelle', where high pressure air was piped up through the wing and strut and exhausted out carefully crafted core and fan nozzles (I was involved in some of the blown nacelle testing). Flow vis showed there was a 'pinch point' on the inside of the strut where the combination of fuselage, nacelle, and strut resulted in something of a nozzle effect with big shocks forming. They discovered that by reshaping the strut they could open that space up enough to make the resultant interference drag unmeasurable.

Megan - your points about area ruling are good, but remember the aircraft you referenced were designed to fly much faster than (subsonic) commercial aircraft. What wasn't well understood in the 1960s is how applicable area ruling could be in the low transonic region.

[Groundloop]

Originally Posted by Groundloop
I was scheduled to take my one and only flight on an QF SP back in early 1980 as SYD-LAX-SFO. However it was substituded with a brand new -400 at the last minute so I missed out on the chance. However as the 400 had only an SP load on board it was VERY comfortable - lots of room to stretch out!

Did you mean perhaps 1990?

Sorry. Was Feb 1990 - slip of the finger on the keyboard!

[BigBoreFour]

https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/462x683/img_1217_e7003535d7ea1c6c88367247b3c07535557681ef.jpeg


Putting its range to good use it seems. San Fran to Hong Kong (Kai Tak I’d imagine) seems the longest when I looked at great circle distance.
Was the return via Bangkok or Singapore?
United did the JFK-NRT route using the -200 with the -7R4G2 motors. I’m guessing that pushed the limits.
Wonder how the numbers compared between using that and the SP on a similar leg?

The good old days as they say. I bet they served cocktails as well. Gotta make 14+ hours flights worthwhile..

[megan]

Wasn't the wasp waist designs of some military jets from the 50's and 60's to do with area ruleThat was the first purposful application of the concept.

Even the swept wing contributes to area rule, but as we all know the swept wing was introduced for all together other reasons. Another serendipitous occurence.your points about area ruling are good, but remember the aircraft you referenced were designed to fly much faster than (subsonic) commercial aircraftAlthough the aircraft may be subsonic there may very well be sonic, or near sonic, airflow somewhere on the airframe, typically seen on the upper surface of the wing as a line stretching out along the span. Wave drag becomes of importance at .7 to .8 Mach where supersonic flow somewhere on the airframe will induce wave drag. The aim of area ruling is to alliviate, or reduce, the possibility of supersonic flow being created.

Whitcomb began exploring applications of his area rule to subsonic commercial transports during the late 1950s. He quickly discovered that making relatively minor changes to the external shape could significantly reduce the drag these aircraft experience. Compared to the radical "waisted fuselage" shaping required for supersonic flight, subsonic aircraft could be made far more efficient simply by placing elongated pods along the wing trailing edge. Whitcomb referred to these pods as "antishock bodies" like those shown in the wind tunnel model pictured below. Also note the large bulge above the forward fuselage that Whitcomb found further improves transonic aerodynamics. This concept was later adopted for the Boeing 747.

https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/550x375/sub_76c44b33bbcc1a865589099c0770b2bba0749344.jpg

[Asturias56]

"San Fran to Hong Kong (Kai Tak I’d imagine) seems the longest when I looked at great circle distance."

yes Kai Tak - I have it taking 14:30 in 1978 - I think they showed 5 movies on the pull-down screen - it was a very long flight - even in First!

[Kiwithrottlejockey]

The Qantas SP was indeed originally said to be for serving Wellington. Qantas (international only then) was moving to an all-747 fleet, their last 707 ran Wellington, after which they chartered an Air New Zealand DC8 to cover their rigorously controlled 50% of flights on the route.

Boeing 707s never operated into or out of Wellington. Air New Zealand did operate the DC8 on Wellington services from the retirement of the Lockheed Electras until QANTAS introduced the 747SP to trans-Tasman flights into and out of Wellington. The introduction to service by both QANTAS and Air New Zealand of the Boing 767 saw the end of 747SPs on the Wellington route as the two airlines went their own separate ways and ended code-sharing on Wellington services.

[Sotonsean]

Boeing 707s never operated into or out of Wellington. Air New Zealand did operate the DC8 on Wellington services from the retirement of the Lockheed Electras until QANTAS introduced the 747SP to trans-Tasman flights into and out of Wellington. The introduction to service by both QANTAS and Air New Zealand of the Boing 767 saw the end of 747SPs on the Wellington route as the two airlines went their own separate ways and ended code-sharing on Wellington services.


We haven't learned much from your post. You have described more or less the "exact same" information that was made in Post 29, dated the 13 April 2023 at 05.23.

[Fris B. Fairing]

We haven't learned much from your post. You have described more or less the "exact same" information that was made in Post 29, dated the 13 April 2023 at 05.23.
Well at least we agreed.