Adjective
(chemistry, aeronautics, of a reactant, fuel, or propellant) Igniting spontaneously upon contact with an oxidiser.
(chemistry, aeronautics, of a reaction) Involving such a hypergolic agent.
Source: en.wiktionary.orgBeyond Brown's unauthorised flight, the British never tested the Me 163 under power themselves; due to the danger of its hypergolic propellants it was only flown unpowered. Source: Internet
Both fuel and oxidizer were toxic and required extreme care when loading in the aircraft, yet there were occasions when Komets exploded on the tarmac from the propellants' hypergolic nature. Source: Internet
E: Article containing a secondary detonating explosive substance without means of initiation, with a propelling charge (other than one containing flammable liquid, gel or hypergolic liquid) (1.1E, 1.2E, 1.4E). Source: Internet
F containing a secondary detonating explosive substance with its means of initiation, with a propelling charge (other than one containing flammable liquid, gel or hypergolic liquid) or without a propelling charge (1.1F, 1.2F, 1.3F, 1.4F). Source: Internet
It took two minutes to fuel before launch, which could be a long time in high-speed intercepts, and its hypergolic propellants (hydrazine and nitric acid) were very dangerous to handle, leading to several serious accidents. Source: Internet