Why did British Aerospace build the BAe-146 with 4 engines?

The manufacturer built this model with a unique design.
FlightGlobal

First flying BAe 146 faces uncertain future after airborne laboratory funding axed

British Aerospace's first flying 146 prototype faces an uncertain future after funding for its atmospheric laboratory work ...
Flightglobal

Dassault Falcon trijets to replace RAF’s VIP-roled BAe 146s

The UK Ministry of Defence (MoD) is acquiring two Dassault Falcon 900LX business jets as replacements for its retiring British Aerospace BAe 146 VIP transports. Announcing the procurement on 8 ...
WBAL

A look at the BAE 146, the plane that crashed near Medellin

LONDON (AP) — The plane type that crashed near Medellin, Colombia, is a short-haul aircraft that has been used to land in hard-to-access airports and is increasingly used in firefighting duties.
Hackaday

british airways

[Adrian Smith] recently scored an avionics module taken from a British Aerospace 146 airliner and ripped it open for our viewing pleasure. This particular aircraft was designed in the early 1980s when ...