# @stem_antics on Instagram

- **Type:** Video
- **Original URL:** https://www.instagram.com/p/DbMRc8EvKtd
- **Gondola URL:** https://gondola.cc/posts/68267162-stem-antics-instagram
- **Thumbnail:** https://img.gondola.cc/tr:w-,h-,fo-auto/postThumbnails/15c43b5f1d.jpg
- **Posted:** 2026-07-24T22:06:58.000+00:00
- **Account Owner:** Stem Antics (@stem_antics) — https://gondola.cc/stem_antics

## Caption

Every wing flying today is a compromise frozen in aluminium. The shape that makes lift at 140 knots on approach is the wrong shape for Mach 0.85 at 38,000 feet, so designers settle on a geometry that is mediocre everywhere and bolt on flaps to paper over the gap. Aircraft now in flight test are starting to refuse that bargain.

Induced drag scales with lift squared over span squared. Stretch the wing and cruise efficiency climbs, but root bending moment climbs faster, structure gets heavier, and eventually you simply cannot fit the aeroplane into a 65 m gate box. That one constraint has shaped commercial aviation for decades.

In-flight adjustable geometry attacks it from several directions:

- Folding tips. The 777X hinges its outboard sections upward so 235 ft of span parks inside a 213 ft box. NASA’s Spanwise Adaptive Wing went further, using nickel-titanium shape memory alloy torque tubes that twist when heated, folding tips in flight to trade lateral control authority for directional stability, with no hydraulics at all.

- Compliant trailing edges. The NASA and FlexSys ACTE flap replaced hinged surfaces and their gaps with one seamless flexing structure, sweeping roughly minus 2 to plus 30 degrees on a Gulfstream III testbed and cutting airframe noise sharply.

- Semi-aeroelastic hinges. Airbus’s AlbatrossONE unlocks its tips so they float through gusts, shedding load spikes rather than resisting them, which lets the spar be lighter for the same span.

The hard part is never the aerodynamics. It is fatigue life across tens of thousands of cycles, actuator redundancy, ice creeping into moving joints, and persuading a certification authority that a wing which changes shape will still be the right shape in twenty years.

Birds settled this question in the Cretaceous. Engineering is only now catching up with the paperwork.

#stemantics #aerospaceengineering #aerodynamics #aviation #materialsscience

## Stats

- **Views:** 54,550
- **Likes:** 1,005
- **Shares:** 0
- **Comments:** 36

## Tags

materialsscience, aerodynamics, aviation, aerospaceengineering, stemantics

---
Copyright (c) Gondola