New composites-based drag reduction kit for Boeing 737 NG receives FAA STC, cuts fuel burn

As airlines face what is said to be the highest jet fuel prices in two decades, aerospace engineering startup, Aero Design Labs (ADL, Fort Worth, Texas, U.S.), has revealed an extensive, composites-based drag-reduction system (ADRS-1) kit for the Boeing 737 Next Generation family for 2022 entry into service, according to Aviation Week’s Guy Norris. 

“Our next steps are to build out the customer base for the 737-700 and the introduction of the 737-800 and 737-900 kits,” Jeff Martin, ADL president and CEO, says. “Our first customer on the 737-700 is WestJet [Calgary, Canada], who partnered with us and was instrumental in the testing and the proving of our STC [FAA supplemental type certificate]. They stood by our side during flight test and shared our conviction toward carbon reduction further supporting our industry’s [environment, social and governance] goals.”

In addition to WestJet, which will require Transport Canada’s approval based on the FAA STC before entry into service, other major 737 Next Generation (737NG) family operators such as Delta Air Lines (Atlanta, Ga., U.S.) are said to be set to adopt the upgrade, Martin says. “Each kit will provide a different benefit based on the carrier’s fleet composition and how they fly the aircraft,” he adds. “Based on our computational fluid dynamics results, we are targeting a 1.5% carbon reduction with the 737-700, and we expect additional gains on the 737-800 and 737-900.”

Made predominantly from composite structures, the kit weighs 180 pounds but results in a net gain of only 110 pounds.

Based on an average of $3 a gallon, Aviation Week notes that reduced drag equates to around $12,000 per month in fuel cost savings and “over 40 tons of CO₂ reduction per aircraft per month,” Martin says. “So that puts them right in line with the Corsia and 2050 carbon neutrality targets that many of the airlines are adopting,” referring to the International Civil Aviation Organization’s Carbon Offsetting and Reduction Scheme for International Aviation (Corsia).

The fuel burn benefits are expected to improve with the larger 737-800 and 737-900 models because of the longer stage length usually flown by these versions as well as the “design of the ADL kits and the length of the fuselage and how that ties into the airflow,” Martin says.

Designed by a team led by ADL’s chief technology officer (CTO) and airframe drag-reduction specialist, Eric Ahlstrom, the modification kit was refined using proprietary computational fluid dynamic (CFD) algorithms that were tested on supercomputers in the U.K. and U.S. “Our proprietary software has embedded artificial intelligence that will significantly shorten future run times,” founder of ADL, Lee Sanders, says. “What used to take us five months to develop a product we can now get done in a matter of a few weeks.”

The ADRS-1 kit consists of a revised wing-to-body aft fairing, modified flap track fairing tips, updated wheel-well fairings, revised aerodynamics around the environmental control system (ECS) pack ram air exit duct and several strategically placed vortex generators. The modifications are particularly tailored to address areas of interference and parasitic drag around the fuselage that have never previously been tackled or only partially treated over the life of the aircraft.

Made predominantly from composite structures, the kit weighs 180 pounds but results in a net gain of only 110 pounds. after replacement of the original structure. ADL says future weight reductions are being studied but adds that the current material set is designed to “far exceed FAA standards and airline rigor.” The kit is expected to require around 150 work-hours to install. “We feel that the kit is minimally impactful from an out-of-service time perspective,” Martin says.

To industrialize the kit and meet a demand curve that ADL expects will rival that of the 737 winglet retrofit programs, the company has brought together a team of manufacturing and distribution heavyweights. Nordam (Tulsa, Okla., U.S.) will produce the bulk of production kits — ramping up to produce 92 kits per month initially — and will be supplemented by LA Composite (Prague, Czech Republic), a manufacturer that made the initial parts for the flight-test program with WestJet. Distribution will be handled by another strategic partner, aviation services company AAR (Wood Dale, Ill., U.S.), as “AAR ensures that we’ll have timely distribution and support for our service for our airline partners,” Martin adds.

ADL is optimistic about placing the ADRS-1 kit with a large percentage of the 737NG in-service fleet, which currently includes more than 5,200 aircraft, according to the Aviation Week Network’s Commercial Aviation Fleet Discovery database. Not including some subvariants, 923 of these are 737-700s, 3,665 are baseline 737-800s, and the 737-900/-900ER model accounts for almost 460 more.

Looking further ahead, the company is also seeing additional projects. “There’s a lot of opportunity to reduce drag across all airframes, and we’ve proven that we can solve it for the 737 Next Generation series,” Martin says. “And we’ll demonstrate that and move that across other fleet types.”

Read the full, original article from Aviation Week here.