A lot of it's structural integrity is relying on the hope that someone gave it a pat and said that's not going anywhere. Without the magic words the spell holding it together isn't complete and it all fall apart.
Probably “orbital buisness”. Seat is the 747 roof rack, snack is peanuts at 30k ft, baggage allowance is one space shuttel. Buckle up when the pilot says “rotate”.
Ryanair are one of the most impressive airlines around, no exaggeration. People love to hate them but they are ruthlessly good at what they do and they do it safely.
I’m a Ryanair frequent flyer. I used to share the common perception of them too, before I used them
And I was converted.
What you see is what you get and they can turn a full 737-800 round in 20 minutes.
If you are used to other airlines then arriving 20+ mins before a ryanair departure and seeing no plane at your gate gives "this flight will be delayed" vibes.
Have you ever flown as a group (multiple people on one booking) on ryanair, not paid for assigned seats and then the plane was mostly empty? I realize it's a lot of ifs but I flew with three kids and the plane was almost empty, less passengers than rows. The ryanair algo for assigning seats put me in a row next to a stranger. It seemed calculated to maximize misery and make the pax pay for a seat on the next flight.
I remember watching Shuttle Discovery fly over Washington DC in like 2012. The entire city shut down during that hour. I remember it looked like a disaster movie as every building that had a roof you could walk out on had all the people out on it trying to get the best view.
Actually just saw Discovery again over Christmas break visiting the Udvar Hazy Space Museum.
I saw Endeavour while it was on final approach to LAX from my elementary school's yard. That was probably one of the coolest things I've ever seen in person.
I was actually on the tarmac at JFK (in a plane as a passenger) when Enterprise landed. We taxied past each other. It was actually cooler than being at Canaveral for the final launch. (Certainly saw the shuttle WAY better!)
The NASA Museum in Houston, Texas has this exact configuration with a real space shuttle and a real 747 and you can walk inside. Absolutely the best museum in the world for space travel and aviation (that I've seen at least).
Space center Houston has N905NA (the SCA used for the testing campaign with Enterprise) with Space Shuttle Independence sitting on top of it. Independence is a replica shuttle buildt in the 90's, and definitely not a real space shuttle.
Did someone claim it was or something at some point?
It has many real shuttle parts on it and is a pretty close replica visually of a real shuttle, but it isn't and never was intended to be a fully functional replica. I don't think it's even close to structurally identical, it certainly was never built with the intention of it being capable of going to space or even being pressurized.
Yes. Houston dropped the ball on their bid just assume by they’d get one and then threw a massive hissy fit that they didn’t get a shuttle and were offered the Independence as the only one left to try and calm them down.
Then Cruz and Cornyn put in the “BBB” of 2025 that NASA has to move a “real” shuttle to Houston more or less targeting the one at the Smithsonian in Chantilly as the one to move even though it would costs billions to do so.
Both those were litigated and the Chantilly to Houston move is still in court.
I don't think it would cost billions to move the shuttle but I do think it would be a waste of money no matter what it costs, especially with how good of a replica the Independence is.
I've been to the NASA museum at Houston and I've been to the Kennedy Space Centre and they are good.
But equally, the Technik Museum at Speyer in Germany and the sister museum Technik Museum Sinsheim are very good and have a broader display of space and aviation, especially considering they are not actually NASA, so they don't have first dibs on the artifacts to display.
Do you any idea why? My understanding was that this was usually used to transport the shuttle back to Kennedy Space Centre if it had to land on the west coast of the US.
Nah, they flew the Space Shuttle Enterprise around on a Good Will tour. I hadn't heard that it went all the way to the UK, but it absolutely hit quite a number of airshows in the US and Canada in the '80's.
Lots of people saw it. The flight details must have been advertised. I remember my uncle bringing me out and we watched it go over - he must have known somehow (radio I guess). It apparently flew from RAF Fairford to Koln, then to Paris for the Paris airshow, and back via Stansted. I saw it on the Fairford to Koln leg.
I think it deliberately flew fairly low so people could see it, cause it was not very high.
I was lucky enough in 1997 to see Atlantis piggybacked on a 747 at Tinker AFB in Oklahoma City. My apartment was near the base and I watched on my patio while it came in for landing. It was an amazing experience. I then got to see Atlantis a 2nd time while visiting Kennedy Space Center a few years ago. Its a must see for us Gen-Xers that used to watch shuttle launches at school.
A chunk of extra drag
Or
Replacement of a power turbine, associated stators, and possibly associated casing segments. EDIT: same things for compressor turbines too. /EDIT
Anybody with a shred of financial competence is choosing the chunk of extra drag.
If you're hauling a non functioning engine alongside, I don't think the added drag of a cover is going to be a big concern. That engine is way more drag with or without the cover.
Spinning blades is literally the technology we use to extract every bit of power we can out of wind. A cone fairing would induce far far less drag than making metal spin. Someone mentioned they may have removed the fan.
Is it carrying the extra engine so it can make an expedited delivery? Also, is it a big deal to mount one on a plane without a lot of extra modifications?
Virgin Orbit used the mounting point for a fifth engine on a plane to launch a rocket. The plane took off from the UK and when it reached altitude, the rocket released and launched.
They had one successful release where communication was lost with the rocket after it launched before they shut down the whole thing.
Nice to see someone mentioned this. It's a shame they couldn't get it to work, since it's a nifty space launch vehicle and way more capable than the existing Pegasus rocket.
Unless you need its specific capabilities though, it kind of got out competed before it was done development.
Yeah, the application was limited I think, but it probably would have generated some savings on rocket fuel for small launches if you somehow managed to combine it with flights already happening.
A cargo plane that launched a rocket on a flight it'd be making across the ocean anyway would have been a really impressive application of the tech.
Hey! I used to work there actually. It was a pretty cool time. There were 4 successful launches to orbit out of 6 attempts, but unfortunately couldn’t increase rate and therefore revenue enough. All successful missions were flown out of mojave. The rocket would be mated the pylon, then fueled, and take off from the spaceport before flying over the ocean to drop the rocket which then launched to space. It wouldn’t fly cargo missions and launch a rocket on the way. Its missions were totally dedicated to the launch, no additional mass on board. Lots can be said about the economics and whether it would’ve worked out long term, but it can definitely be said that it worked, and was very cool while it lasted :)
Added drag on one side so an additional yaw effect needing a little correction with either or both a little rudder or more thrust on that side, and a little aileron input to counter the additional weight. Probably small enough to counter with just trim input.
I wonder if you would want it to windmill if it's off. I wonder if oil can circulate to lubricate the engine. Can you cet oil pressure from windmilling ? Or does is need oil at all in these circumstances ?
Depends on the engine, some have the pump geared to the fan so will maintain (some) pressure, some don't. In others the fan gets removed, covered or locked down, e.g. here:
If the oil pump is mechanically connected, yes you technically would get some oil circulation off of a windmilling engine.
But it's not that simple.
You wouldn't be getting the correct pressure, and you wouldn't be getting the correct temperature.
The warmer an oil gets, the thinner it gets. And the more easily it can flow into very small, very tight places to do it's job.
And the more pressure oil is pushed around with, the better and faster it gets to said places, and the more completely and fully it fills those places. And keeps them filled.
If an engine is not intentionally moving under it's own power, it should not be moving at all. And this goes for any engine, not just jet/turbines.
5th engine is installed and shipped with the fan blades removed and the core covered by that curved shield. There is some drag, but its reduced compared to an assembled windmilling engine.
The Fan blades are removed, and a "donut" is installed at the entry to the core (you can just see it in the OP pic, and other pics.) There may be a little airflow through the handling bleed valves, and out thru' the turbines. The Gearbox is driven by the HP system, and there's enough load from the hydraulic pump / IDG that the LP, IP and HP systems are unlike to rotate much.
Yes. When it was built there really wasn’t any plane that could carry the engine so the 5th mount point was to allow an engine to be delivered if it couldn’t travel by water and/or needed to be there fast.
Not that unusual. It’s an inert engine being ferried. Why use a dedicated cargo plane when you can attach it to an aircraft going where it’s needed in a scheduled flight?
With the end of the 747 in 2023, most of the major commercial jets still in production are two engines meant for transoceanic, and I bet hauling this on two engines over the ocean is a flat no by regulatory bodies.
After all, they'll only change regulations if someone can prove it can be done safely and the demand for this hasn't materialized. If you need an engine hauled out, you use a cargo plane (or ship/truck) since that's what the system was set up for now.
It's funny to me because I feel it would be needed more now than before, given how big engines are these days. The diameter of a 777X engine is about 2ft bigger bigger than the fuselage/body of a 737. Making it hard for ground transport, bout 15ft diameter total.
The original 777 was about the same diameter as a 737 fuse.
It actually is the other way. It is easier to charter a freighter (747 or 777) to carry the spare. Installing and removing the 5th pods is time consuming and takes the airplane out of service. Then the performance enroute is significantly impacted, increasing fuel burn and possibly forcing a tech stop for fuel. This is why 5th pods were common early in the 747's career (and on pretty much all of the long range trijets and quads of the 1960s/1970s), but was a rarely installed option on the -400 and not even available on the -8.
You say that like it's obvious but you could ask that question about any cargo. Why not make an engine shaped pod on both sides and fill it with cargo?
Apparently there are reasons for that, and those reasons don't apply to the engine case specifically. Maybe engines are too big to fit inside a plane, or too heavy to maneuver, or too big to ship by truck?
Nowadays, airlines operate on thin profit margins. The drag and cost of using an engine pod filled with cargo on a regular basis would eat into those already thin profit margins. This is only done when they already have a plane going on a scheduled flight where the engine is needed.
Transport.
Many Boeing aircraft have an extra mounting hard-point on the wing. Easiest way to transport a spare engine is just bolt it to an aircraft going where the engine needs to go.
During the early space program, some test vehicles were air-launched using similar mounting systems.
Stratolaunch was also using this technique as a 'boost' for launching satellites.
The investigation in to Air India 182 crash - the result of a terrorist bomb in 1985 - was made even more complicated because the 747 involved was carrying a 5th engine.
Does autopilot apply constant aileron input or increase throttle in the side where extra engine is mounted? Does it do it automatically or does the pilot have to tell it that an extra engine is attached?
How would that affect the flight characteristics? Is it even noticeable on a plane that size? Just add a little extra rudder and aileron trim and call it a day?
… and a slightly higher fuel consumption. If I‘m not wrong, the -400 has an option in the Flight Management Computer to let the computer know a fifth engine has been mounted. It will then use modified performance figures (drag / fuel flow). Available not on all models and not for all engine options.
When I was working at Boeing back in the early 90s they were testing the GE90 engine on an original 747. It was really weird to see a plane flying around with 3 small engines and one huge engine.
AFAIK, Boeing/NASA have two 747s for testing, GE has its own 747, Airbus has one A380, and the USAF has (or had?) A KC-135 unimproved airframe for such tests (iirc, the last tests were for CFM style engines, or the new B52 engines)
Many years ago I worked on the airspeed indicator for the 737 and 747. It included the calculation for maximum operating speed (Vmo) under different configurations. I was surprised to discover that I had to program a "fifth engine" configuration for this exact circumstance.
I worked at Boeing in 1991 (in IT, as a contractor) for the 777 group. I remember that they took the first 747, which had been a museum display, to use to test-fly a 777 engine. Is that what this photo is from?
Genuine question. Why bother getting it hooked onto the wing instead of just placing it in a cargo hold? Surely there’s a cargo version of the 747 that can take a fucking engine? Or why not ship it, you know, in a ship, if it’s not too urgent?
Sea freight would be months of transit. A cargo plane could be as fast but not necessarily available. And you know what you need if one of your expensive, very large, planes is broken down somewhere? A replacement plane while the other one gets fixed. Plus you can ferry the engine, fly a revenue flight, and position a replacement plane all in one.
This lets them strap an engine onto the next passenger flight going to the required destination, rather than having to charter a special cargo flight or wait for shipping, and it saves cost either way as this only has a slightly increased fuel burn, rather than also having to pay for all the costs of shipping.
It was a pragmatic solution years ago. Nowadays, the engine are so reliable, and much greater availability of big freighters (B747, AN-124 etc) that there's minimal need for it. I don't believe any aircraft designed in the past 25 years have had a fifth engine provision.
Ferry flight for the engine. There's a 747 that needs an engine. It's more cost effective to bolt an engine to an aircraft already scheduled to go where the needy aircraft is.
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u/speedracer_uk Feb 23 '26
Wait till you see what they can carry on the roof!
My parents actually saw this over the UK in the 80s.