Beyond Flaps

Boeings 727 has always been one of my all-time favorite airplanes. Ive never flown in one as anything other than self-loading freight, but Im old enough to remember when the 727 (and the DC-9) brought jet comfort and performance to smaller, outlying airports where the eras long-haul mainstays-707s and DC-8s-couldnt operate. These days, of course, economics-fuel burn, plus the need to pay three pilots-and noise regulations have relegated the venerable three-holer to tramp-freighter status or the scrapyard.

Joseph E. (Jeb) Burnside

Monday, August 20, 2018 at 12:00 AM ET

Verified

Key Takeaways:

The Boeing 727's ability to operate from smaller airports stemmed from its wing design, featuring slotted Fowler flaps and leading-edge slats to enhance low-speed lift and stall characteristics.
Slotted Fowler flaps increase wing area and camber, with slots re-energizing airflow to delay stall, while leading-edge slats add camber and create a blunt leading edge for improved low-speed performance.
Wing fences control spanwise airflow across the wing, maintaining roll control at lower speeds, while vortex generators create turbulent vortices to delay flow separation and enhance lift and control surface effectiveness.
These aerodynamic devices collectively allow aircraft to fly slower, maintain control at higher angles of attack, and achieve shorter takeoff/landing distances, crucial for regional operations and STOL capabilities.

See a mistake? Contact us.

Boeing’s 727 has always been one of my all-time favorite airplanes. I’ve never flown in one as anything other than self-loading freight, but I’m old enough to remember when the 727 (and the DC-9) brought jet comfort and performance to smaller, outlying airports where the era’s long-haul mainstays—707s and DC-8s—couldn’t operate. These days, of course, economics—fuel burn, plus the need to pay three pilots—and noise regulations have relegated the venerable three-holer to tramp-freighter status or the scrapyard.

I didn’t know it at the time, but one of the things that enabled the 727 to reliably operate to and from smaller, regional airports was its wing. Not having pylon-mounted engines helped simplify things a lot, but the real tricks were in the slotted Fowler flaps and leading-edge slats all 727s came with, and which are now commonplace aboard jet transports of almost any size and configuration, as well as general aviation airplanes. What’s so special about these devices, and what else might help with the low-speed handling of the personal airplanes we fly?