Ask Captain Lim ~ All about Aviation

Dear Captain Lim,

I have been a 'flying doctor' for a good part of the last eight years as well as a frequent long-haul flyer. I have flown many hours in all manner of aircraft.

Never have I experienced turbulence like I encountered while flying in a small Westwind jet over the South Pacific towards American Samoa. It was without warning, like a rollercoaster, went on for close to 3 or 4 mins and I was out of my seat at the time.

Now I have panic attacks even thinking about flying and obviously it affects my job. I have read widely on the facts about turbulence and your site has been very helpful.

Recently, I flew internationally on the 777. I knew there was turbulence suppression technology on the aircraft and for the first time in some months, I began to have some confidence again.

I have three questions please...

Firstly, were the effects of the clear air turbulence we encountered made worse in the smaller jet?

Secondly, do older generation 767s, have a worse ride in turbulent conditions than newer Airbus aircraft?

Thirdly, I have read the 787 will have very advanced lateral and vertical gust suppression, vastly improving the effects of turbulence. Are there similar technologies in the A380? Do you know from the industry how it handles turbulence? I live in NZ and unfortunately you have to fly a long way to go anywhere.

Thank you so much for your response.

Kind regards,

John

Hi John,

I have written a few times regarding your first two questions in my Air Turbulence topic but now, I will answer your third question.

Yes, the Boeing 787 has similar gust suppression system as the Boeing 777 and will definitely provide a more comfortable ride in air turbulence. In fact, Boeing has engineered its new Boeing 787 Dreamliner to reduce light to moderate turbulence by up to two-thirds while the plane climbs to high altitudes. Hence the ride quality should certainly improve with this new active gust alleviation system. Airbus uses almost similar kind of system in its digitally controlled aircraft such as the A380 - including the A320 family as well. In addition, because of the shear size, it does help to make the Airbus A380 more resistant to effects of severe turbulence.

That said, turbulence cannot be completely removed as long as one is flying in the air. But the good news is that a new turbulence detection system is being tested whereby this device can alert pilots to patches of rough air as they fly through clouds. This system is designed by the National Center for Atmospheric Research (NCAR) and tested by United Airlines on commercial flights.

This new system uses a method known as NTDA (NEXRAD Turbulence Detection Algorithm) to analyze data obtained from the National Weather Service's modern weather radars. The resulting real-time snapshot of turbulence can be transmitted to pilots in the cockpit and made available to airline meteorologists and dispatchers via a Web-based display.

In the past, pilots have lacked accurate measurements of turbulence that develops in clouds and thunderstorms partly because turbulent areas may be small, evolve quickly and occur outside the most intense parts of the storm. As a result, FAA guidelines suggest that planes avoid thunderstorms by at least 20 miles when possible even though large sections of that area may contain relatively calm air.

The NTDA captures turbulence in storms by peering into clouds to analyze the distribution of winds. It reprocesses radar data to remove factors that can contaminate measurements, such as sunlight, nearby storms, or even swarms of insects flying near the radar dish.

The NTDA does not measure clear-air turbulence such as that caused by the jet stream or by wind flowing over mountainous terrain. But about two out of every three turbulence encounters are associated with clouds and storms. For more, go here.

The United Airline's pilots who tested the system found it gave them an accurate depiction of the intensity of turbulence.

NCAR scientist, Bob Sharman says the system will provide a safer air travel in the United States by 2011.

Well, John, you may have to wait for at least three more years for the system to be enjoyed worldwide! Meanwhile, the Dreamliner and the Airbus A380 (SIA flies them from Sydney to London but not from NZ yet ) should be your choice for a more comfortable flight in future!