Review and analysis of a January 16, 2014, major turbulence event Author:John Thivierge

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Major turbulence event analysis

Review and analysis of a January 16, 2014, major turbulence event

On January 16, 2014, United Airlines flight 89 from

Newark to Beijing departed at 12:55 p.m. Eastern,

carrying 189 passengers and 16 crew members.

Forty-five minutes into the flight, food and beverage

service had just begun when the plane began

to experience severe turbulence. Pilots were not

expecting turbulence of that nature; it was so severe

that it injured five flight attendants and the plane had

to return to the Newark Liberty International Airport.

Traditionally, air turbulence forecasts provide a

meteorologist’s interpretation of weather model data,

as well as real-time reporting from pilots, covering

broad areas and spans of time. In addition, relying

on reports from pilots means that flights still have

to experience turbulence in order for subsequent

flights to avoid those areas. Today’s forecasts are

divided into generic categories, with basic details

for light, moderate, or severe hazards. Additionally,

these forecasts cover large geographical areas

and altitude ranges. For example, a forecast could

read: moderate turbulence from FL250-400. With

information available over such widespread areas,

it forces flight planners, dispatchers, and pilots

to make assumptions and chance the severity of

turbulence they’ll encounter, or to route around large

areas, adding both time and fuel costs to the flight.

Pilots and flight planners need early, proactive

information in order to make routing decisions

before a plane is en route. With generic, unspecified

turbulence forecasts, pilots are unable to discern

genuine threats from manageable conditions, leading

to issues in the air. What if flight planners, operations

managers, and pilots had access to accurate, up-to-

date hazard forecasts — complete with aircraft and

altitude-specific information?

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Event analysis

At Schneider Electric, our flight hazard forecast solutions provide hourly high resolution turbulence, icing, and thunderstorm forecasts based on multiple global weather models. This approach is opposed to traditional forecasts offered today that are only issued a few times daily and cover large generically-defined areas. Our solution offers continuously-updated, detailed geographic alerts that allow flight planners and pilots to proactively preplan and avoid flight hazards while airborne.

At the time of the incident, radar images were clear (as shown here), and although other pilots had reported turbulence in the area, they were at different altitudes and flight paths. As a result, the crew of United Airlines flight 89 did not have specific information to show the severity of the turbulence they would encounter.

This image shows the SIGMETs for turbulence at the time of the event. Notice the large area of potential turbulence over the East Coast issued for FL130-330. This requires interpretation by both pilots and flight planners due to the large geographical area, as well as the large vertical component.

(Image provided by NOAA, ADDS)

Review and analysis of a January 16, 2014, major turbulence event

The aviation industry is in need of flight weather

hazards forecasts that are timely, targeted, and not

dependent on operations and planning managers to

interpret potentially dangerous and costly situations.

Our newest, patented model delivers better-defined

turbulence, icing, and thunderstorm forecasts more

frequently, based on global weather data models and

a high definition U.S. model, which help to reduce

the need for interpretation.

Available both in graphical and digital formats, it can

be used in flight following, planning, and decision

support systems to automatically optimize routes

based on user-defined variables. Airlines and aircraft

operators can plan less-circuitous routes, reducing

overall operating costs, fuel consumption, and CO2

emissions with digital integration of flight hazards

with numerous flight systems.

Our flight hazards forecast offers an industry-first

Eddy Dissipation Rate (EDR) based global turbulence

forecast that integrates mountain wave, boundary

layer, convective, and upper level clear air turbulence

into a single forecast product — the higher the EDR

number, the more violent the turbulence.

EDR is the universal measure of turbulence,

based on the rate at which energy dissipates in

the atmosphere. It is based on quantitative — not

qualitative — forecasts that are related to thresholds

set by aircraft manufacturers and define the specific

aircraft types at risk for certain types of turbulence.

The scale is from zero to one. An EDR of less than

0.10 is equivalent to no turbulence for most aircraft;

0.15 to 0.34 is light; 0.35 to 0.55 is moderate; and

greater than 0.55 is severe turbulence. Forecasts

can be identified for multiple flight levels, and are

displayed in a layered view to optimize flight levels.

We also include aircraft-specific icing forecasts

based on NASA research on ice accretion specific to

individual air foils. Models are updated frequently with

location-specific information and in a high-resolution

presentation. Additionally, the product contains a

global, radar-like thunderstorm forecast that helps

identify precise areas of convective activity, letting

pilots and planners know which areas to avoid.

The system is rooted in scientific calculations, not

interpretations of weather conditions.

Alerts are generated worldwide while the aircraft is

in the air, based on the aircraft operator’s specific

parameters along the planned route. This allows

a flight’s aircraft dispatcher and captain to decide

on the best, minimum-cost reroute during a flight

if forecast conditions suddenly change. Location-

specific alerts are exclusive to our organization.

Information can be integrated into existing flight

planning solutions, allowing flight planners to better

plan ahead — specifically for long-duration flights,

with forecasts that extend for more hours and are

updated more frequently.

Along with our weather forecasts deemed the most

accurate in the industry for the last seven years,

our single-source aviation weather solution vastly

improves awareness of adverse weather for flight

operations managers, flight planners, and pilots.

As a result, the interpretation traditionally needed

to determine hazards in the air can be minimized,

allowing aviation operations to optimize fuel and

operations costs, reduce the risk of aircraft damage,

and improve passenger comfort and safety.

The Schneider Electric solution

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Review and analysis of a January 16, 2014, major turbulence event

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Our team reviewed its forecasts for January 16,

2014, and found that our system’s flight hazards

forecast was able to predict the turbulence

experienced by United Airlines flight 89 up to

four hours in advance — more than enough

time to reroute the plane and save on the costs

and inconvenience of turning the plane back to

the airport. In addition, our forecasts show that

the turbulence decreased significantly at higher

altitudes, as opposed to the traditional turbulence

forecast for that day, which called for severe

turbulence from FL130-330.

A closer look

According to our forecast, United Airlines flight 89’s flight path to get to cruising altitude at FL270 (shown above) took the plane directly through a band of severe turbulence, rated at 0.6 to 0.7 on the EDR scale.

The turbulence that day became less severe at higher altitudes. Shown at right, at FL300, the turbulence values on the flight path ranged from 0.4 to 0.5.

Review and analysis of a January 16, 2014, major turbulence event

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There is another significant drop in turbulence severity at FL 320; now the forecast shows an EDR of 0.3.

Turbulence was forecasted to diminish almost entirely above FL340.

Ultimately, our forecast shows that United Airlines flight 89 most likely could have avoided severe turbulence entirely with a slight flight plan modification, flying more east of the forecasted severe turbulence. A sample route change, shown here, could have cut costs and ensured safety.

Schneider Electric USA, Inc.

9110 West Dodge RoadOmaha, NE 68114Phone: 800-610-0777Fax: 402-255-8125www.schneider-electric.com/us

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February 2014