- Nearly 80 percent of arrivals into MSP perform continuous descents.
- Airlines saved 2.9 million gallons of fuel-per-year after the implementation of OPDs at MSP compared to traditional step descents.
- Arriving aircraft emitted 28,465 fewer metric tons of carbon dioxide into the atmosphere annually after the implementation of OPDs, the equivalent of removing more than 12,000 cars from the road.
Airports referenced in this story
- Performance Based Navigation (PBN)
- Addresses ways to leverage emerging technologies, such as satellite-based Area Navigation and Required Navigation Performance, to improve access and flexibility for point-to-point operations.
Millions of passengers are benefiting from smoother NextGen arrivals each year at Minneapolis International Airport (MSP), and the benefits don't stop there. Airlines are using procedures called Optimized Profile Descents, or OPDs, to descend from cruising altitude to the airport in a continuous arc rather than traditional step descents. New analysis shows OPDs are having a major impact at the airport.
Aircraft engines are set at near idle during continuous descents. The lower thrust settings reduce fuel usage and carbon dioxide emissions, and provide a more comfortable experience for passengers. A traditional descent — which requires aircraft to repeatedly reduce altitude and then rev the engines to level off in the shape of a staircase — burns more fuel at each step. By reducing the likelihood of step descents, OPDs also allow aircraft to stay higher, longer at more fuel-efficient altitudes.
The Metropolitan Airports Commission (MAC), a public corporation that owns and operates MSP and five other airports in the Twin Cities region, committed to evaluate the real-world benefits of OPD procedures at MSP. In close coordination with the FAA, the MAC created an analysis capability using data from the agency and from airlines that are using OPD procedures at MSP. These include: Delta Air Lines, Endeavor Air and Sun Country Airlines. The FAA has verified the fuel and emissions savings associated with OPD arrivals into MSP.
Here is what MAC analysis found:
- 79 percent of aircraft equipped to fly OPDs are performing continuous descents into MSP.
- Aircraft saved more than 15 gallons of fuel-per-flight on average after implementation of OPDs.
- Airlines saved 2.9 million gallons of fuel-per-year after implementation of OPDs.
- As a result of the reduced fuel burn, arriving aircraft emit 28,465 fewer metric tons of carbon dioxide into the atmosphere annually. This is equivalent to removing more than 12,000 cars from the road.
- It also equates to more than 42 percent of the total emissions attributed to electricity use on the MSP airport campus.
- The implementation of OPDs represents the biggest single action to reduce greenhouse gas emissions at MSP in documented history.
- Since airlines started flying OPDs in March 2015, they have saved more than 5.8 million gallons of fuel, 9.5 million dollars, and prevented more than 57,000 metric tons of carbon dioxide from entering the atmosphere.
In addition to reduced fuel burn, cost, and emissions, voice communications between air traffic controllers and pilots are greatly reduced with OPDs since clearances required during each part of a step descent are eliminated. MSP air traffic controller Jeff St. Germain says this means more time to convey other key information to pilots. "It frees up the radio frequency for other important messages whether it's calling weather or calling traffic," he said.
The decreased communications with flight crews during continuous descents, however, takes some getting used to on the part of air traffic controllers who are accustomed to offering speed and distance instructions through the entire decent with traditional procedures. Controllers and pilots also need to learn a whole new vocabulary to communicate and receive OPD instructions. "It took a little while to get used to but our controllers have worked hard to embrace it, understand it, and make it work," said St. Germain.
MSP is Delta Air Lines' second largest hub, so the changes have greatly impacted the airline. Steve Dickson, Delta's senior vice president of flight operations, notes the airline encountered some challenges at first but is now feeling the benefits of OPDs. When first implemented, Delta experienced difficulty in trying to get aircraft — within 300 miles of the airport — into the overhead stream in order to begin the OPD procedures.
"We've been working with the FAA over the last year or so to implement some pre-departure coordination which has been very beneficial. It's actually improved our arrival performance on the order of about 20 points," said Dickson. "This initiative with the FAA shows a lot of promise, particularly with modern decision support systems that are beginning to come online and scaled across the system," he added.
OPDs are currently in place and providing benefits at airports across the country.