Glom
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What Would Be The Point Of This?

Sat Nov 11, 2006 6:21 am

This comes from the comments left on Randy's blog.

Quote:

I'm a long time Boeing stockholder. Regarding the 737 replacement, I have a suggestion that is outside the box, if you will. Design the new 737 with 1 larger engine but keep 2 small engines inside the main frame of the aircraft, that would be deployed in event of main engine trouble, that could fly the plane in a slow flight condition for say 500 miles. I don't know if this feasible or not but I like to think outside the box.

Why on Earth, Mars or any other terrestrial planet or moon would anyone want to do that?

The 737 (as well as 757, 767, 777, 787, A320, A330, A350) propulsion concept is straightforward and simple. Two identical engines, one hanging off each week. Only two to be maintained, both with absolute commonality, both sitting in a comfortable and easily accessible position for maintenance, both in an intuitive position aerodynamically.

But this new idea. Now there are two different types of engine, the main big one and the two smaller backup ones. Commonality is lost. There are also three of course, which complicates things. As for position, where do you put the big one? It would be awkward. Hiding the backup ones in the fuselage would just take up space and it would also requiring moving parts - yes that's right moving parts - to deploy them.

It's madness. Sheer madness.
 
B6JFKH81
Posts: 2005
Joined: Thu Mar 16, 2006 6:35 am

RE: What Would Be The Point Of This?

Sat Nov 11, 2006 6:42 am

1) Where are you going to store a "pop out" engine inside the fuselage of a B737 and NOT lose cargo space?  banghead 

2) Does this person even understand how heavy an engine is??? Even an APU is very heavy. Nothing like carrying dead weight on an a/c just for the heck of it. In a day and age where everyone is trying to conserve fuel, lets just add thousands of extra pounds of dead weight just in case and burn more fuel carrying that weight around.  banghead 

Quoting Glom (Thread starter):
Hiding the backup ones in the fuselage would just take up space and it would also requiring moving parts - yes that's right moving parts - to deploy them.

3) ...and lets add some MORE weight to have a hinge-type pylon! Not to forget that this would also probably need hydraulic power which typically is generated from the running engines. So if you lose the ONLY engine you have on an a/c, what backup system do you have to deploy the backup engines?  banghead 

My list could go on for pages.  box 

Now, don't get me wrong here. I like thinking outside the box, and lets face it...a lot of the advances in aviation are because someone did think outside the box. However, one must remember that there is a tit for tat type thing when it comes to aviation. When you think outside the box, you have to think of what negative things come with the positives that you thought up. This industry is still bound by the laws of physics and aerodynamics just to start things.

Glom, I applaud you for showing that there are some folks out there that have great ideas, but don't think it through completely before opening their mouth...and completely agree with you when you say:

Quoting Glom (Thread starter):
Why on Earth, Mars or any other terrestrial planet or moon would anyone want to do that?

 praise   praise   praise 
"If you do not learn from history, you are doomed to repeat it"
 
LHRSpotter
Posts: 57
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RE: What Would Be The Point Of This?

Sat Nov 11, 2006 7:01 am

Quoting Glom (Thread starter):
The 737 (as well as 757, 767, 777, 787, A320, A330, A350) propulsion concept is straightforward and simple. Two identical engines, one hanging off each week

Hanging off each WING rather.

The guy just likes to think "outside" the box that's all. He's probably not a propulsion engineer, probably not an engineer at all. He just has some Boeing stock.

He probably sees the single big engine at the rear or under the tail and the two backup ones under the wings (like the missiles on fighter aircraft). Since both additional engines are almost never in use they require a lot less maintenance and because they are small they save on weight and don't eat up cargo space. Hell, because they are small they save on weight and reduce drag and fuel burn...

I am sure that 50 years ago a lot of people have laughed at the idea for two jet engines under the wings but time has proven them wrong.
 
bringiton
Posts: 763
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RE: What Would Be The Point Of This?

Sat Nov 11, 2006 7:06 am

There are many things that pop up in the COMMENTS SECTION which are very ridiculous and funny . It just goes to show that there is a wide diaspora that reads that blog for various reasons ( be it share-holders , Reporters , pilots , or enthusiast - some smarter then others) .
 
beech19
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RE: What Would Be The Point Of This?

Sat Nov 11, 2006 7:17 am

All for the thinking outside the bun... wait thats not right.
BOX... yes thinking outside the box but this just a bad idea. Lugging around dead weight for the sake of dead weight in the case of an emergency doesn't sound very intelligent or efficient.

Quoting B6JFKH81 (Reply 1):
Not to forget that this would also probably need hydraulic power which typically is generated from the running engines. So if you lose the ONLY engine you have on an a/c, what backup system do you have to deploy the backup engines?

The same way any other aircraft maintains power to its systems and control services. The RAT.
Also... lets take for example the 787. It will not be using hydraulic power for brakes, gear, flaps ect... it will be all electric motors. The RAT would supply the power for these systems along with the Fly By Wire and radios in the case they lost both motors.
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Tango-Bravo
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RE: What Would Be The Point Of This?

Sat Nov 11, 2006 7:20 am

The "long time Boeing stockholder" reminds me of pax who fly 2-3 times a year who therefore assume they know much more about the job functions of airline employees than the employees who have been performing their job functions 40 hours a week, 49-50 weeks a year, for many years. Why they ever ask airline employees for help is beyond my understanding inasmuch as they know much more than any of us (airline employees) know, perhaps because their booking experiences on the internet have turned them into instant experts who know it all.
 
B6JFKH81
Posts: 2005
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RE: What Would Be The Point Of This?

Sat Nov 11, 2006 7:26 am

Quoting Beech19 (Reply 4):
The same way any other aircraft maintains power to its systems and control services. The RAT.

This is true, but deploying the RAT to deploy the engines doesn't make much sense either considering it is designed to give electric to the primary systems in the flight deck and hydraulics to the primary flight controls LOL! This entire outside the box idea is just not a good one.  no 

Thanks for catching me on that one though Beech19. I did.. footinmouth 
"If you do not learn from history, you are doomed to repeat it"
 
beech19
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Joined: Fri Jul 21, 2006 11:30 am

RE: What Would Be The Point Of This?

Sat Nov 11, 2006 7:30 am

Quoting B6JFKH81 (Reply 6):
This entire outside the box idea is just not a good one.

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Francoflier
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RE: What Would Be The Point Of This?

Sat Nov 11, 2006 7:33 am

Well, you certainly can't blame anyone, no matter how much they know or don't know, for trying to throw ideas out.

However, I wouldn't want to be the one calculating the takeoff performance of this thing, especially the main engine failure scenario...
I'll do my own airline. With Blackjack. And hookers. In fact, forget the airline.

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