Boeing 747 brakes, autobrake and anti-skid
Early 747s stopped with heavy steel disks and an anti-skid system that prevented wheel lockup. The 747-400 introduced carbon brakes on all 16 main-gear wheels, saving about 1,800 lb, plus an autobrake that holds a selected deceleration rate on landing.
A 747 landing at weight stops using brakes on all four main-gear bogies — sixteen wheels under the -400. Anti-skid cycles the brakes to prevent locked wheels, and on the -400 an autobrake holds a precise deceleration rate automatically.
| Key facts | |
|---|---|
| Main-gear wheels | 16 on the 747-400 |
| Brake material | Structural carbon on the -400 vs steel on earlier 747s |
| Weight saving | About 1,800 lb (820 kg) of unsprung weight vs steel |
| Autobrake | Holds a selected deceleration rate; introduced with the -400 |
Carbon brakes on the 747-400 saved almost a tonne versus the steel brakes of classics while absorbing far more kinetic energy — carbon actually grows stronger into the temperature range where steel begins to fade.
The -400’s autobrake and anti-skid system combines hydraulic brake power with digital monitoring and automatic pressure control to hold consistent deceleration across varying runway conditions, including reduced braking on wet or icy surfaces.
Sources
- Boeing 747-400 guide — Aircraft Commerce
- 747-400 Airplane Characteristics for Airport Planning — Boeing
- Autobrake/antiskid system on the 747-400 — Transglobal
Sources
Facts on this page are checked against the primary and institutional references below.
- Boeing 747-400 guide — Aircraft Commerce
- 747-400 Airplane Characteristics for Airport Planning — Boeing
- Autobrake/antiskid system on the 747-400 — Transglobal
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