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Qantas ferried an engine on the wing of a 747 (2016)

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Re: Qantas ferried an engine on the wing of a 747 (2016)

#81

Post by Deritiod »

sofixa wrote: post #80
dorfsmay wrote: post #77

Earlier quoted context omitted.

Right, but what I meant was that it'd be difficult to have a sustainable supersonic flight business given the fuel consumption required at those sppeds. My understanding is that even though Air France and British Airways were charging twice the price of normal first class for Concord, they were losing money on them. I'm surprised there aren't supersonic business jet though.

> My understanding is that even though Air France and British Airways were charging twice the price of normal first class for Concord, they were losing money on them. They weren't, the Concordes were quite profitable until 9/11 and the following slump in international travel ( due to fear, increased controls and inconveniences) and increase in oil prices. > I'm surprised there aren't supersonic business jet though Th…

It was a novelty. The market was small the expectation that it costly but still profitable is easy.

But I wouldn't care for sonic travel besides the novelty.

Price wins

Re: Qantas ferried an engine on the wing of a 747 (2016)

#82

Post by hef19898 »

jsjohnst wrote: post #54
hef19898 wrote: post #21

Earlier quoted context omitted.

Normaly the nose loading is done oy when absolutely necessary. It's a pain, takes ages and is complicated. When possible stuff is squeezed through the fuselage cargo doors. Back the day we did it with a ten foot sea container, never thought it would fit...

> Back the day we did it with a ten foot sea container, never thought it would fit How’d you end up doing it? Roll it on its side? Usually the height of a sea going container is ~2.6m and per the specs I’m seeing online the allowed height through the nose is only ~2.49m. Because they are just taller than they are wide, spec wise it would fit laying on its side, but still curious when doing it for real if that was nec…

They maneuvered it through the side door, with four people, inch by inch, millimeter by millimeter. Working for the airport at the time I didn't touch a thing, better to have crew damage a perfectly fine aircraft. Still impressive feat of loading, almost on par with the Russians, they use the cargo door to squeeze the cargo properly in, like avergae Joe slaming his trunk.

Re: Qantas ferried an engine on the wing of a 747 (2016)

#83

Post by rzzzt »

embedded_hiker wrote: post #79
rzzzt wrote: post #29

I have never heard or read the word "cowling" before, but just finished watching a video saying that Apple's repair guide refers to the tiny metal covers within the phone this way. Cowling cowling cowling.

One of the early accomplishments of "NASA", long before it became NASA, was the development of an improved cowling for airplanes: https://en.wikipedia.org/wiki/NACA_cowling

Thanks! I was just excited about experiencing the frequency illusion in real life -- fifteen-ish years of English without cowling, then two cowlings in a day from two different sources.

Re: Qantas ferried an engine on the wing of a 747 (2016)

#85

Post by inferiorhuman »

jsjohnst wrote: post #51
StillBored wrote: post #7

Ok, given its flying just the core, and not the fan, why doesn't it fit in the cargo hold? I mean they wouldn't have to worry about the extra drag/etc in the hold. It also seems odd that they would do this on a plane carrying commercial passengers since it seems more of an "experimental" modification even if the manufacture has approved it.

The issue is the dimensions of the cargo doors. A 747 engine is approximately 2.25m in diameter and 5.5m long. Of the 4-5 different sized doors on a 747, there’s only two that it would fit through: - Front nose cone door - Main deck cargo door I believe neither would be used on a passenger airline configured 747 (could be wrong though!) and hence why the wing based fifth pod configuration was likely used.

Wikipedia puts the CF6 from a 747-400 at 4.27m long, 2.69m diameter. An RB-211 looks to be a little narrower and longer. Cargolux puts the biggest rectangle that can fit through the main cargo door at 3.05m x 3.10m. So yeah you could probably fit an engine in a nacelle and fixture through the main deck door on a freighter.

However your big limitation will be height at either 2.44m or 3.00m depending on where on the main deck you're checking. The lower deck (which is all you'd have available on a passenger 747) has a much lower height limit (an LD-1 has a height limit of 1.62 m).

An engine's just not going to fit inside unless you're talking about something designed for oversize cargo like the Dreamlifter (747) or Beluga (A300) or Beluga XL (A330). Oversized cargo is also the main use case for the An-124/225.

https://www.cargolux.com/fleet-equipment/aircraft/747-400f-s...

Re: Qantas ferried an engine on the wing of a 747 (2016)

#86

Post by belter »

This capability was into the original design of 747, but historically it's not the only model capable of transporting the spare engine.

Here is an Air Lanka L-1011-500 TriStar doing the same: https://en.wikipedia.org/wiki/Lockheed_L-1011_TriStar#/media...

And an even older DC8: https://nitter.net/PilotJamesB/status/1262751026408378369

Other models like the 707-300 or the VC-10 and Super VC-10 also did it: https://www.airliners.net/forum/viewtopic.php?t=775179

Aparently doing this makes the fuel consumption increase a lot.

"What are the consequences of attaching an unused extra engine under Boeing 747 wing?': https://aviation.stackexchange.com/questions/53755/what-are-...

Re: Qantas ferried an engine on the wing of a 747 (2016)

#87

Post by jsjohnst »

hef19898 wrote: post #82
jsjohnst wrote: post #54

Earlier quoted context omitted.

> Back the day we did it with a ten foot sea container, never thought it would fit How’d you end up doing it? Roll it on its side? Usually the height of a sea going container is ~2.6m and per the specs I’m seeing online the allowed height through the nose is only ~2.49m. Because they are just taller than they are wide, spec wise it would fit laying on its side, but still curious when doing it for real if that was nec…

They maneuvered it through the side door, with four people, inch by inch, millimeter by millimeter. Working for the airport at the time I didn't touch a thing, better to have crew damage a perfectly fine aircraft. Still impressive feat of loading, almost on par with the Russians, they use the cargo door to squeeze the cargo properly in, like avergae Joe slaming his trunk.

Ah, side door. That should’ve been easy then, no?

Re: Qantas ferried an engine on the wing of a 747 (2016)

#88

Post by sreevisakh »

Rebelgecko wrote: post #84

Does this "5th pod" exist solely for transporting spare engines, or does it have other uses?

It's known to be used for testing new engines and launching rockets [1]. But I don't understand what they mean by 'pod'. Can't figure out if they are referring to the hard point, pylon or the engine nacelle.

[1] https://simpleflying.com/boeing-747-5-engines/

Re: Qantas ferried an engine on the wing of a 747 (2016)

#89

Post by sitkack »

can16358p wrote: post #25
Animats wrote: post #2

No big deal. External payloads seem strange, but 747s have carried much larger ones, such as the Space Shuttle. Worse things have been carried under wings.[1] [1] https://en.wikipedia.org/wiki/2007_United_States_Air_Force_n...

> W80-1 variable yield nuclear warhead, were mistakenly loaded onto a... Imagine mistakenly loading a nuclear warhead on the wrong plane.

So now we consider Human Factors when designing weapons designed to kill millions. They need to be operated by the forgetful, the stressed, the young the drunk or anyone not experiencing their full faculties. Lets internalize this.

Re: Qantas ferried an engine on the wing of a 747 (2016)

#90

Post by somat »

bobthepanda wrote: post #75
dorfsmay wrote: post #65

Earlier quoted context omitted.

Isn't the main reason the amount of fuel required to fly supersonic?

The designs did burn a lot of fuel, but sonic booms were also extremely unpopular. The FAA picked Oklahoma City (without asking them first) for an experiment to subject a city to regular sonic booms. It, uh, didn’t go well. https://en.m.wikipedia.org/wiki/Oklahoma_City_sonic_boom_tes...

If curious what a sonic boom sounds like. I found this video.

https://www.youtube.com/watch?v=M_KbZON5sW0

The normal caveat about how microphones are really unable to capture sounds of this magnitude probably apply here.

For example, I once went to vandenburg to see a rocket launch and that was the biggest sound I have ever heard, not the loudest, we were five miles away, but the way the sound shook you impressed the hell out of me.

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