Testing a shorter flight path

PHNOM PENH Cambodia’s government says a proposal presented by Vietnam that asked Cambodia to open airspace to allow planes to fly direct between Hanoi and Ho Chi Minh City is under consideration.
The State Secretariat of Civil Aviation air navigation director, Chhun Sivorn, told local media that the proposal gained provisional approval followed a meeting between deputy prime minister Sok An and Vietnam’s transport minister, Dinh La Thang, in August.
The “golden air route,” as it has being referred to in Vietnamese media, will also pass through Laos and cut travel time between Hanoi and Ho Chi Minh by about 20 minutes, the director said. This was later disputed by simulated test flights carried out by Vietnam Airlines and Vietjet.
The proposed route would initially be open to only Vietnam Airlines and low-cost VietJet Air, but would eventually be available to all international carriers.
The two airlines would have to pay about USD400 in air-navigation fees to Cambodia, but the more-direct route would also save fuel costs, he argued.
Cambodian aviation officials are currently conducting a feasibility study on the route.
“We have to examine existing routes that pass through Cambodian airspace to consider the possibilities of providing airlines with different separation levels,” he added.
But a check by Vietnam Airlines, using a simulated flight between Hanoi and Ho Chi Minh City, crossing the airspace of Laos and Cambodia, was not significantly shorter in flight time for an airline travelling at 800 to 900 kmph.
Vietnam Airlines tested an Airbus A321 on the proposed straight flight path, using a flight simulator, last Wednesday. It showed the route was only 85 km shorter than the current one and saved just five minutes of flying time, or 190 kg of fuel, according to the national flag carrier.
It took the simulated flight 103 minutes to complete the 1,191 km theoretical journey from the Vietnamese capital city to the southern hub through Lao and Lao and Cambodian airspace consuming 4,140 kg of fuel.
But this was only possible if the plane was allowed to pass over current no-fly zones and restricted airspace, the airline said.
The simulated flight was carried out under the assumption that the plane would be able to cross prohibited airspace in Hanoi and over military zones at Tho Xuan and Bien Hoa airports, as well as several restricted areas in Lao and Cambodian airspace.
Low-cost carrier VietJet Air tested the route last Tuesday, but a company spokesperson said the results from the Airbus A320 simulator showed that it cost the plane an additional 1 ton in fuel consumption and cut the flying time by only one minute compared to the current path.
Civil Aviation Authority of Vietnam then will conduct their own flight simulation to verify the results of Vietnam Airlines and VietJet Air.
The ‘golden air route’ remains a controversial topic since it was first proposed by a retired pilot in Ho Chi Minh City in 2009, and again by an aviation expert in 2012.

sourced:ttrweekly.com