Boeing tests electric motor for airliners

[Bmused55]

Article found here (http://yahoo.reuters.com/financeQuoteCompanyNewsArticle.jhtml?duid=mtfh17462_2005-08-01_15-44-44_n01537548_newsml)

An interesting idea. Could potentialy save an airline millions in annual fuel bills. Thats a good 10 to 20 mins average taxi time cut off the fuel bill for each flight. Could be as much as an hour if you factor in the taxi to gate on arrival at some busy airports. Then you also have savings by not needing a tug either.

I think this has lots of potential if they get it to work.

Opinions?

[GotTheTshirt]

Lockheed looked at a similar idea in the 60/70's for the Tristar.
They also looked at a ground railway system for airports like the SF trams.
At the time the fuel saving did not justify it but now ?
;) ;) ;)

[Bmused55]

Well the fuel savings are probably what would make this the best thing since sliced bread.

Think about it, hook it up to a generator feeding off of the APU and you have an unlimited electrical powersource which uses a fraction of the jet A that 2, 3 or 4 full size jet engines use.

If trials are successfull, I'd bet the 787 will come with these babies installed as standard.

[TheOddOne]

Environmental issues: this is an excellent idea, for reducing the amount of atmospheric and noise pollution on the ground. Admittedly, there'd still be the pollution caused by the APU, which tend to make rather more noise nuisance due to their higher position and 'pink' noise signature.

You'd probably still want a headset person to monitor pushback and engine start, unless you went for a more sophisticated camera system. This has long been advocated for monitoring the exterior - the Royal Aircraft Establishment at Bedford, England had a setup fitted to a BAC 1-11 twenty-odd years ago. It could now find that its time has arrived.

This could change the face of aircraft ground handling. No more 'sorry, Ground, we'll have to cancel our pushback, our tug hasn't arrived!'

Cheers,
The Odd One

[Bmused55]

TheOddOne

I thought it was implied this electric motor could be used to taxi, not just puchback.

Therefore at a busy airport where you could be looking at 30 mins taxi time, you need not turn the engine on untill you were number 3 or 4 for take off.

The fuel saved with this method would be a very strong selling point for this.

[Agaricus bisporus]

Speaking strictly as Devils's Advocate I'd have thought this idea a non-starter. It clearly takes several hundred horse=power to shift a big jet on the ramp, and the size of the electric motors, their oversized generators (APU) and not least the huge power transmission system would weight tons and tons, cost many millions to fit, more to maintain and probably billions to develop, and do no more than a hundred grand of tug does every day using bus technology and a pint or two of Dieso. So why not just tow the things to the runway?

Well, partly because you need all the systems - ie engines - everything - running for several minutes to get thru the checks etc, and that just happens to be the length of the average taxi - more or less. Tug to the end of the runway and you'll sit there burning fuel for 15 minutes doing checks and going nowhere...

Anyway, what Reuters reported isn't quite what the headline said...

[insert only slightly tongue-in-cheek icon here]

"...had used the nose-wheel motor, built by Gibraltar-based Chorus Motors Plc, to move around an Air Canada Boeing 767 jet in tests simulating..."

Note, they said, and I quote; "used the nose-wheel motor" ... "to move around an Air Canada Boeing 767...".

Apparently he motor was used to move around a 767, not to move a 767 around - which is a totally different proposition. Any half competent electric wheelchair (or pair of roller skates/sneakers) can do that... And any half competent student of basic English knows the difference... mangle the grammar equals mangle the meaning...Poor practice in Aerospace!

As in, " Wanted. Commode, by old lady on castors".

duh!

[747FOCAL]

This one is a dud right out the door. looks real good on paper, but when you look at actual airline operations it stinks to high heaven.

It will weigh several hundred pounds and be one more complex problem to break and then you need to find a tug and there is NEVER an extra one around.

The cost in fuel to carry that several hundred pounds around will negate an economic benefit from not running the engines for taxi. the environmental benefit will also lose because of the extra fuel needed to carry it being dumped in the high altitude where it does most damage and not on the ground.

The noise will still be there because the APU is louder than the engines until about 50-60 percent full takeoff thrust.

Just think of the horsepower required to get a 765K 777 moving again after stopping on a 1 degree incline. the motor might get it going again but it will be several minutes before it will be moving faster than a few MPH and if there happens to be a 20 knot headwind forget it.

It would be easier to put some kind of in ground tram that hooked to the nose gear and pulled it around kind of like a steam catapult, but even then you will have to start the engines and wait for warmup and then start pre flight check.

Nope, 3 million spent on this already and its never going to see the light of day. :ok:

[TheOddOne]

747FOCAL

A most comprehensive post - idea suitably de-bunked!

Wonder why Boeing wasted 3 million on it?

Cheers,
TheOddOne

[Hotel Charlie]

If an APU can provide significant thrust to increase take off performance, then it would sure as hell be able to provide the thrust to taxi a heavy a/c on the ground, and retain all the benefits of a standard apu, without increasing the aircrafts weight. Would this not be a more logical solution?
Not correct! Getting a little bit of increase in MTOW due a few lb extra forward thrust does not at all mean that there is enough thrust from an APU to bring 250 tons from a standstill to movement!!
When it comes to eletrical motors on the nosegear- well most likely not usable on wet or slippary taxi ways (which it is half the time in northern Europe at least)!
Sounds like a waist of $ to me!

[Bmused55]

Clearly 747Focal is not aware of the developments in electrical motors ;)

There are some pretty heavy duty machines going about, shifting hundreds of tonnes of intact buildings and even scrapped aircraft, all using a flatbed type vehicle with electric motors. Heck I think even such a vehicle is being used to shift parts of the A380 about.
Thus I think we can dispell the thought that an electric motor cannot shift a 777 or even a 747. With the correct gearing, even I could shift one.

I have no idea how much all this would weigh though, so I can't argue with you on that.

I think the potential benefits to the environment and the fuel bill will make this a top notch idea if Boeing can make it work, efficiently and with managable weight. I think we shouldn't de bunk it so easily.

[patdavies]

Whilst not arguing about size etc. just remember that the space shuttle vehicle used for moving it to and from the launch pad has drive from electric motors

[ETOPS]

A more sensible solution would be to use the aircraft hydraulic system (typically pressurised to 3000 psi) to run hydraulic traction motors built into the main wheel hubs.

As an example have a look at these units (http://www.whitehydraulics.com/)

There are plenty of road vehicles that carry heavy loads that use this sort of propulsion..........

[Konkordski]

Wasn't this system mentioned in Flight International back in May?

[Jerricho]

Well the fuel savings are probably what would make this the best thing since sliced bread.

And you think this saving would be passed onto passengers? Forgive my cynicism.

[ZQA297/30]

Hey, if you could make those hydraulic wheel-motors big enough, and with big hyd. pumps on engines, think of what they could do to the takeoff roll!
Move over fuel dragsters, the the cloud of smoke on the runway is a hvy 747 "burning out" his tyres in preparation for T/O!
To add the icing, if motor/pumps were used, the wheel-pumps could feed power back into the engines, providing wheel braking, augmenting reverse thrust, and reducing fuel cons. during the reverse cycle simultaneously.
Ha! which way to the patent shop?

Seriously, in respect of a low power taxi system, the proof of the pudding would be the economics of the extra weight and complication versus the fuel savings.

[747FOCAL]

SASKATOON9999,

The thrust generated by the APU on any aircraft is in the tenths of a percent of thrust increase vs. the engines. The extra thrust would not even add one passenger worth of capable MTOW.

Bmused55,

You have no idea what your talking about. Ron Woodard (EX-Boeing BAS President) has a company that makes electric motors that generate 500 horsepower and weigh only 75 pounds. Tugs have big tires for a reason. The skinny small tires on the nose gear of aircraft are not ideal for pulling that much weight. You need a lot of torque to even get the thing moving.

One of the bigger challenges is how to transfer the power to the ground. Imagine the complex gearing system required that would need to be built into the front gear. Gear are already draggy enough. Imagine the cost of a failure of the system where it locks the front gear from rotating. I am sure you can remember the pictures of that Air Canada 767 that ran out of fuel and busted the front gear on landing.

Technological advances are always tough in this industry. But, like I said above..... This one looks good in theory, but once you get down to the nitty gritty of airline operations it all falls apart.

:ok:

[alexmcfire]

Why not unmanned tugs, that attach themselves to the front-wheel at the taxi-way?

[Seat1APlease]

Why not have an electric tractor that tows you out to the holding point, then the handler brings it back and recharges it, that way you get the benefit without the weight penalty.

[Bmused55]

Jericho:
And you think this saving would be passed onto passengers? Forgive my cynicism.

Did I even imply such?


747FOCAL who says this technology will be limited to the nose gear?
Sure the tests are being conducted on such, but that doesn't mean its limited to nose gears. ;) Have an open mind.

[UNCTUOUS]

When they put folding wings on fighters that flew off aircraft carriers, it was only a matter of time before one (and then another) took off with its wings folded.

Surely the hazard here is the odd aircraft getting airborne after forgetting to start engines. Once the bean counters get onto that it will be made compulsory for maximum fuel savings.

[Bmused55]

Now thats grasping at straws.

These electrics motors would be for taxi speeds max, not to propel aircraft to take of speed.

And only a total idiot would not notice that an engine or two had not been turned on when they advance the throttles slightly before applpying take off power in order to check engine sync and functionality.

Next excuse for not using this technology...

[egbt]

I was flying as a pax with a work colleague a couple of weeks ago and he was relating a problem on a previous flight where they had had to get a tug because the a/c could not get over a bump. When I suggested this could have been a potential jet blast problem I was astonished to hear that he thought that the wheels were powered for taxi and take off. :confused:

He is the head bean counter but reading this thread perhaps he had insider information and was playing dumb.

[er340790]

Yeah right - hold short of runway while the engines are fired up from cold, then move onto runway for immediate application of take-off power - have they factored the reduced engine life into their projected fuel savings!

[Loose rivets]

Electric powered cars have been a pipe dream for me for 25 years. One of the things that I have become ‘certain’ about, is that the windings or stators will have to be in the periphery of the wheels. i.e. no drive train and high torque.

An aircraft might have the non wound part of the motors in the main-wheel rims and devices that travel with the aircraft, perhaps owned by the airport, that then peel off at the appropriate time. This way there is no need for the aircraft to power the units and most of the added weight gets left behind.

As for operational suitability. Well, not to make use of the energy for takeoff would be a blatant waste of potential, but most crew have a high enough work-load at commencement of roll anyway…monitoring the departure of any device still in the equation at this late stage, is perhaps more than should be undertaken. We certainly couldn’t just trust the system to leave the aircraft cleanly.

One thing is certain, we cannot keep wasting fuel the way we do now, and computer controlled devices will be taking us to the holding point, liberating the crew to start an monitor the engines at an appropriated time. It’s just a matter of deciding on a system.

[Bmused55]

Yeah right - hold short of runway while the engines are fired up from cold, then move onto runway for immediate application of take-off power - have they factored the reduced engine life into their projected fuel savings!

Have you thought about the possibility of starting the engines when number 2 or 3 for take off?

It is, or was common pratice for 3 or 4 holers to shut 1 or 2 engines down when in an extended queue, then re light when number 2 or 3 for take off.

So, out the window goes that excuse.

[Buster Hyman]

Lets see that smug little barstard, the Energiser Bunny pull a 747!!!:hmm:

They should be researching the Nuclear powered airliner. That'd make the FO's gonads glow in the dark!:ok:

[Blacksheep]

Nowhere in that article does it say that this is meant to be a system that gets airborne - the article doesn't give enough information to work out exactly what it does.

All it suggests to me is an electric motor for moving B767s around that attaches to the nose gear and gets its power from the APU. In the Air Force we used "Yellow Perils" for one man to move a helicopter about on his own. From what the article says it could easily be such a ground handling device for large jet transports that eliminates tugs. As to doing away with the use of main engines, though British LAEs seldom do it, US A&Ps and plenty of others generally move aircraft about by taxi-ing them.

[guclu]

Well I do not understand why Boeing is spending millions of $ for this. Instead they could buy and place tow vehicles on airpots where the taxi time is exceeding 15mins. And Boeing A/Cs will be towed until they will start the engines.

:E

OK I accept that the driver of the vehicle will have to make some maneuvering around !

:ok:

[khaosanroad]

alexmcfire, seat1aplease:

Unmanned tugs, that attach themselves to the front-wheel do exist. I saw them at Marseille Provence Airport. They were used by Air France to push back their B737s and A320 away from the ramp, then the aircraft taxied under their own power. I don't know if they were electrical but they were surprisingly very small: less than half the size of a car.

[chipsbrand]

Does anyone remember the little machines they used for pushback on aircraft at BRU about 15 years ago? They were hand steered and battery powered. They used very little power and could be recharged using ground power. They were approved for use on aircraft up to 757 size.

[Seat1APlease]

"Does anyone remember the little machines they used for pushback on aircraft at BRU about 15 years ago? They were hand steered and battery powered. They used very little power and could be recharged using ground power. They were approved for use on aircraft up to 757 size."


Yes, I used to use them too on the 737 but there were problems.

Firstly they just drove one main wheel and the aircraft had to be steered by the captain moving the tiller the wrong way whilst pushing back, not ideal, and you had to keep your feet firmly off the brakes to avoid banging the tail. Then the ground man had to walk alongside giving steering instructions because you can see nothing.

The aircraft had to have its own brake and steering circuit powered so no lock out pin fitted. I think overall it was a triumph of accountancy over safety, as it was a completely different SOP procedure and one you might only do every other month.

[PAXboy]

A tug that does the push and then tows out to a suitable holding point is only a matter of time. The problem is trying to make it unmanned - they will want to save the manpower. Since this process could be initiated now, I wonder what is holding the airports back.

Oh, silly me. The airports say that the carriers benefit more than they do, so they should take all the costs. The carriers say that the airports will be able to meet their noise regulations more easily and so they should pay more ... :rolleyes:

If there WERE tug assist to the hold, it would certainly fix the problem, recently discussed, of not having anough tugs to go around to carry out all the pushes on time.:ok:

--------------------
"I tell you, we are here on Earth to fart around, and don't let anybody tell you any different." Kurt Vonnegut, Jr.

[barit1]

There's a write-up in the 8 Aug. AW&ST.

[Flightmech]

Well if its going to be used for self-pushbacks then are we going to need reversing lights on our tails?;)

[Charles Darwin]

How about some realistic solution. Buy more diesel tugs, hire more drivers (low cost labor) and the existing tugs tow us towards the runway. The diesel engine is far more effective than the RB-211 when idling. On the grand scale, wouldn´t this be a realistic fuel saving solution?