V Australia's long-haul burden

[john roe]

V Australia's long-haul burden

 

V Australia's new air link to Johannesburg comes with 'baggage', writes Clive Dorman. Virgin Blue's long-haul international carrier, V Australia, launched services last week on what is believed to be the most remote air route ever flown by a twin-engine aircraft between Australia and South Africa.

 

The Melbourne-Johannesburg route is only 10,339 kilometres - about the same as Auckland to Los Angeles - but rules governing the operation of twin-engine planes require V Australia to add more than two hours to the flight in each direction.

 

This is to ensure that the 361-seat Boeing 777-300ER can stay within about 1500 kilometres of the nearest airport if anything goes wrong - a maximum of three hours flying on one engine if the other engine has to be shut down.

 

Unlike the northern hemisphere, the extreme latitudes of the southern hemisphere are full of "no-go areas" for twin-engine aircraft and the V Australia 777s are required to stay out of them.

 

If the Melbourne-Johannesburg route was operated by one of Qantas's four-engine Boeing 747-400s, which fly the 11,044 kilometres between Sydney and Johannesburg six days a week (via the so-called "great circle" route - the shortest distance), the flight would be scheduled to take about 13 hours. That's because Johannesburg-bound Qantas Boeing 747s often fly almost due south after they leave Sydney, flying over Melbourne and western Tasmania, in search of the most favourable winds.

 

In latitudes near the South Pole, the prevailing winds, often called the "Roaring Forties" because of the latitude and the wind strength, generally come from the west at a minimum of 40 knots (74 kilometres an hour) but can be 100 knots-plus.

 

The 747 is considered so reliable it faces few restrictions on where it is allowed to fly.

 

The Sydney-Johannesburg "great circle" route almost touches the Antarctic Circle, passing close to the Australian territory of Heard Island.

 

To comply with regulations for twin-engine aircraft, V Australia has to add more than two hours to the scheduled flight in each direction to keep within range of the two main airports on the way: Perth and Mauritius.

 

At 15 hours and 15 minutes, the new V Australia service - the first between Melbourne and South Africa - will be quicker for Melbourne passengers than connecting with the Qantas service from Sydney to Johannesburg, which takes 13 hours 55 minutes, but only just.

 

The Boeing 777-300ER, a hugely popular version of the earlier Boeing 777-300, was the first twin-engine aircraft in history to be certified with a 180-minute ETOPS (extended range twin-engine operations) allowance when it went on the market in 2005. It was certified with that allowance by the US Federal Aviation Administration, whose rules are generally followed by the Australian Civil Aviation Safety Authority (CASA).

 

CASA says it's unlikely an Australian airline would ever be allowed to fly beyond the 180-minute diversion limit, even though the US authority occasionally authorises 777s flying across the North Pacific between the US and Japan to operate up to 210 minutes from the nearest airport to save fuel by avoiding strong headwinds.

 

At the launch of the Melbourne-Johannesburg route last week, Virgin founder Sir Richard Branson announced that demand for the service was so strong that V Australia would add a third weekly service from December, when it takes delivery of its fifth 777-300. Aviation industry sources say the UN's International Civil Aviation Organisation, which is responsible for global policy governing airlines, might introduce tighter rules for twin-engine planes in the next few years because of concern that remote operating limits on both four-engine and twin-engine aircraft have already been stretched too far.

 

Airlines love the Boeing 777 because it is about 20 per cent cheaper to operate than the four-engine 747, which it was designed to replace.

 

In its certification program, Boeing flew the 777-300ER as far as 5½ hours from the nearest airport and it performed flawlessly.

 

Qantas, with partner South African Airways, which flies from Johannesburg six days a week, until now has been the only carrier directly linking Australia and South Africa.

 

Many thanks..

 

Article supplied by Scott Fletcher.

 

http://www.watoday.com.au/travel/travel-news/v-australias-longhaul-burden-20100324-qwd9.html