Wirraway
26th Nov 2002, 20:04
Source: Ozflight.com.au and the Syd airport message board:
Fuel capacity on Qantas 747-400 aircraft cut
Boeing and the FAA released an Airworthiness Directive on Monday relating to the use of fuel tanks on Boeing 747-400 aircraft. This was further supplemented by a second release only late this evening which more strictly restricts the use of fuel tanks on the large jets.
A brief summary of the documentation released indicates that an optional fuel tank fitting to some 747-400 aircraft, situated in the horizontal stabilizer, is now prohibited from being used. Furthermore the center wing tank on these aircraft can no longer be run dry and the aircraft must always operate with a specified amount of fuel in this tank.
The reason for the release of the AD was prompted by “reports indicating that two fuel pumps from different Model 747 series airplanes shows evidence of extreme overheating of parts in the priming and vapor pump section of the fuel pump. Such overheating provides an ignition source in the tank during dry running of the pump, which could result in fire/explosion of the fuel tank”.
The AD aims directly remove the possibility of the “dry running of the pump” by ensuring that fuel remains inside the center wing tank at all times and by prohibiting the use of the horizontal stabilizer fuel tank. The operational requirements addressed by this release are specific to all Boeing Model 747-400, -400D and -400F aircraft.
Australia’s largest and only international airline Qantas operates 28 Boeing 747 aircraft including their newest edition of 747-400ER aircraft. It is believed that these new aircraft will not be affected by the release.
The primary issue facing Qantas and other operators of the 747-400 series is the loss of fuel load on long haul flights. The horizontal stabiliser fuel tank has a capacity of 12.5 tones of Jet A1 fuel and with a requirement for the center fuel tank to possibly hold 3.2 tones of fuel, direct flights between Australia and the United States may be in jeopardy.
The loss of 15.7 tones in fuel capacity will result in two operational options available to the airlines. They can either continue to operate the aircraft with existing payloads but with a greatly reduced range, or fly the same range but with greatly reduced payloads. Either option provides an economic loss for the airlines and may put in jeopardy direct flights between Los Angeles and Sydney and Melbourne, as well as the direct flights between Sydney and Johannesburg.
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News Fuel capacity on Qantas 747-400 aircraft cut
Date November 27th, 2002
Source OzFlight.com.au
-------------------------
More specific overview...
HSFT capacity is 3300 gallons - 12.54 tones
CWT capacity unknown, however if the CWT has less than 22.7 tones of fuel in it at aircraft at start up then fuel in the tank must not go below 3.2 tones. However if the fuel in the CWT is greater than 22.7 tones at start up then the fuel in the tank must not go below 1.4 tonnes.
Hence depending on the fuel loading the capacity lost could be either 13.94 tones or 15.74 tones.
--------------------------------------------------------------------------------
Skip Fulton
OzFlight.com.au - The Australian Aviation Directory
-------------------------------------------------------------------------------
Impact so far on Air NZ SYD/LAX flights.
Cannot accept more than 370 pax for SYD/LAX sector when aircraft can hold around 400 pax.... Applicable to all registrations except SUI and SUH which are better performers.... hehe...
LAX/SYD sector will operate via AKL effective Thurs with STA SYD now 0850am. Regards to SYD/LAX sector will see how things go as shorter sector than LAX/SYD but if pax loads go through the roof will have to operate via AKL also...
Major implications for trans pacific carriers and any sector over 10 hours which will impact SYD/JNB services definately as well as most Asia-Europe long hauls... including Korea, Japan services to Europe....
MAJOR STUFF FOR LONG HAUL CARRIERS!!!!!
==========================================
Well this is big news. All SIN - LHR services(QF 31/9) will now require a tech stop in Dubai. Useable fuel in the Horizontal Stabiliser Tank (HST) is 10 000kg and the Centre Wing Tank (CWT) is 53 000kg. All longhaul flights would require more than 22 700kg in the CWT, thus the minimum fuel allowed in this tank would be 1 400kg and so, the total useable fuel load lost is 11 400kg. Typically, cruise fuel burn is around 11 000kg/hr so the lost endurance equalls just over an hour or about 1000km. Hopefully this issue will be rectified ASAP, but in the mean time I'm looking forward to checking out Dubai!
John.
Fuel capacity on Qantas 747-400 aircraft cut
Boeing and the FAA released an Airworthiness Directive on Monday relating to the use of fuel tanks on Boeing 747-400 aircraft. This was further supplemented by a second release only late this evening which more strictly restricts the use of fuel tanks on the large jets.
A brief summary of the documentation released indicates that an optional fuel tank fitting to some 747-400 aircraft, situated in the horizontal stabilizer, is now prohibited from being used. Furthermore the center wing tank on these aircraft can no longer be run dry and the aircraft must always operate with a specified amount of fuel in this tank.
The reason for the release of the AD was prompted by “reports indicating that two fuel pumps from different Model 747 series airplanes shows evidence of extreme overheating of parts in the priming and vapor pump section of the fuel pump. Such overheating provides an ignition source in the tank during dry running of the pump, which could result in fire/explosion of the fuel tank”.
The AD aims directly remove the possibility of the “dry running of the pump” by ensuring that fuel remains inside the center wing tank at all times and by prohibiting the use of the horizontal stabilizer fuel tank. The operational requirements addressed by this release are specific to all Boeing Model 747-400, -400D and -400F aircraft.
Australia’s largest and only international airline Qantas operates 28 Boeing 747 aircraft including their newest edition of 747-400ER aircraft. It is believed that these new aircraft will not be affected by the release.
The primary issue facing Qantas and other operators of the 747-400 series is the loss of fuel load on long haul flights. The horizontal stabiliser fuel tank has a capacity of 12.5 tones of Jet A1 fuel and with a requirement for the center fuel tank to possibly hold 3.2 tones of fuel, direct flights between Australia and the United States may be in jeopardy.
The loss of 15.7 tones in fuel capacity will result in two operational options available to the airlines. They can either continue to operate the aircraft with existing payloads but with a greatly reduced range, or fly the same range but with greatly reduced payloads. Either option provides an economic loss for the airlines and may put in jeopardy direct flights between Los Angeles and Sydney and Melbourne, as well as the direct flights between Sydney and Johannesburg.
--------------------------------------------------------------------------------
News Fuel capacity on Qantas 747-400 aircraft cut
Date November 27th, 2002
Source OzFlight.com.au
-------------------------
More specific overview...
HSFT capacity is 3300 gallons - 12.54 tones
CWT capacity unknown, however if the CWT has less than 22.7 tones of fuel in it at aircraft at start up then fuel in the tank must not go below 3.2 tones. However if the fuel in the CWT is greater than 22.7 tones at start up then the fuel in the tank must not go below 1.4 tonnes.
Hence depending on the fuel loading the capacity lost could be either 13.94 tones or 15.74 tones.
--------------------------------------------------------------------------------
Skip Fulton
OzFlight.com.au - The Australian Aviation Directory
-------------------------------------------------------------------------------
Impact so far on Air NZ SYD/LAX flights.
Cannot accept more than 370 pax for SYD/LAX sector when aircraft can hold around 400 pax.... Applicable to all registrations except SUI and SUH which are better performers.... hehe...
LAX/SYD sector will operate via AKL effective Thurs with STA SYD now 0850am. Regards to SYD/LAX sector will see how things go as shorter sector than LAX/SYD but if pax loads go through the roof will have to operate via AKL also...
Major implications for trans pacific carriers and any sector over 10 hours which will impact SYD/JNB services definately as well as most Asia-Europe long hauls... including Korea, Japan services to Europe....
MAJOR STUFF FOR LONG HAUL CARRIERS!!!!!
==========================================
Well this is big news. All SIN - LHR services(QF 31/9) will now require a tech stop in Dubai. Useable fuel in the Horizontal Stabiliser Tank (HST) is 10 000kg and the Centre Wing Tank (CWT) is 53 000kg. All longhaul flights would require more than 22 700kg in the CWT, thus the minimum fuel allowed in this tank would be 1 400kg and so, the total useable fuel load lost is 11 400kg. Typically, cruise fuel burn is around 11 000kg/hr so the lost endurance equalls just over an hour or about 1000km. Hopefully this issue will be rectified ASAP, but in the mean time I'm looking forward to checking out Dubai!
John.