Welcome back to our Word of the Week!
We all know the feeling of having a power blackout at home. It’s never fun when you need to work, but in some cases, it can provide for a relaxed candlelit atmosphere (careful! fire safety!). And then after a while, we get the powerback. Oh, wait, no. Not what we meant…
UK /paʊəbæk/ US /paʊərbæk/
Powerback is used by aircraft to move backwards on the ground using the power of their engines along with the aircraft’s thrust reversal, rather than by relying on external power (vehicle, powered towbar…)
During the 1980s, many aircraft with aft-mounted engines, such as DC-9s, Boeing 727s, and MD-80s used powerbacks to reduce the number of ground personnel required. For example, Northwest Airlines’ fleet of DC-9 aircraft used powerback operations at certain airports, but discontinued the practice in 2005 citing the need to conserve fuel. KLM also avoids using the procedure for the same reasons, noting that powerbacks cause extra wear on the engines.
While many aircraft are physically capable of performing powerbacks, many companies impose restrictions on the practice, mainly due to the risk of FOD (foreign object damage) from debris propelled into the air. This problem is magnified even more with planes having wing-mounted engines, as their proximity to the ground can exacerbate debris ingestion if powerbacks are used. Small metal objects are particularly dangerous as they can be propelled into terminal windows, employees on the ground or even the aircraft itself. Applying the brakes when backing up also has the potential to cause a tailstrike.
In Europe only propeller aircraft tend to use powerbacks as a means of reversing, while in the United States some larger jet aircraft also perform powerbacks.
In addition, in the United States, restrictions on powerbacks are enforced by the FAA, and the local aviation officials. Only certain gates at certain airports are approved for powerbacks, and are usually placarded as such. Many airlines impose stricter safety procedures for powerbacks, which often include disallowing a powerback under certain environmental conditions, such as rain or snow.
It is sometimes mandatory to powerback for take-off. In Grand Case Airport (official name L’Espérance Airport, French part of Saint-Martin island) the runway can be used only by ATR-42 and ATR-72 after a powerback to get its full length available.