![]() |
If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
|
#1
|
|||
|
|||
![]()
I'm quite sure the device will be powered by the APU, which will
produce electricity and air conditioning for all the equipment, and the pressurized air needed to start the engines later. An idling jet engine uses a TON of fuel and makes quite a bit of thrust; aside from initially getting the plane moving, taxiing is normally done at idle thrust anyway. But it's that high idle fuel consumption that this will eliminate for the taxi-out, and I think it's a terrific idea. Just to throw some numbers out, an older 737's engine (I don't have specs in front of me for the newer ones) burns about 1200 pounds of fuel per hour, per engine, at idle.. The APU burns about 300 pounds per hour. A savings of 900 pounds, or about 135 gallons of fuel per hour over a single-engine taxi. (315 gallons less than a more-common two-engine taxi!) Jet fuel's costing the airlines upwards of $1.75 a gallon. For every minute the airplane could taxi using only the APU instead of one engine, an airline would save about $4. A typical 15-minute taxi-out at a semi-busy airport would save $60. An hour-long taxi on a bad weather day? $240. Obviously the economics will be different for each airplane type, and for some airlines like Southwest that don't normally fly into delay-prone airports, it might not make financial sense to install this device. But an airline that flies to LaGuardia, Chicago O'Hare, Atlanta, etc., all day long? It could save a ton of money if they can make it work. -- Garner R. Miller ATP/CFII/MEI Clifton Park, NY =USA= |
Thread Tools | |
Display Modes | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Is a Turn Coordinator an electric motor or powered by fan? | kickinwing | Piloting | 5 | June 11th 05 12:25 PM |
Cherokee Electric Pitch Trim | Jonathan Goodish | Owning | 4 | November 18th 04 02:43 AM |
Piper Arrow electric fuel-pump | MC | General Aviation | 7 | June 3rd 04 02:50 AM |
taxi in reverse? | Malcolm Teas | Home Built | 10 | February 21st 04 12:26 AM |
More on the electric verses turbojet | cdubya | Soaring | 8 | September 25th 03 09:16 AM |