Editing Zero-length launch (section)

{{Short description|Method of launching military aircraft}}
{{Redirect|ZELL||Zell (disambiguation){{!}}Zell}}
[[File:F-100 zero-length-launch trial.jpg|thumb|upright=1.14|A USAF F-100D Super Sabre using a zero-length-launch system]]

The '''zero-length launch system''' or '''zero-length take-off system''' (ZLL, ZLTO, ZEL, ZELL) is a [[PTOL]] method whereby [[jet aircraft|jet]] [[fighter aircraft|fighters]] and [[attack aircraft]] could be near-vertically launched using [[rocket motor]]s to rapidly gain speed and altitude, in particular for [[point-defence]] roles. Such rocket boosters were limited to a short burn duration, were typically solid-fuel and suitable for only a single use. They were intended to drop away once expended.

The majority of ZELL experiments, which including the conversion of several front-line combat aircraft for trialing the system, occurred during the 1950s amid the formative years of the [[Cold War]]. As envisioned, the operational use of ZELL would have employed mobile launch platforms to disperse and hide aircraft, reducing their vulnerability in comparison to being centralised around established airbases with well-known locations. While flight testing had proved such systems to be feasible for combat aircraft, no ZELL-configured aircraft were ever used operationally. The emergence of ever-capable [[missile]]s had greatly reduced the strategic necessity of aircraft for the [[nuclear strike]] mission, while questions over practicality had also played a role.