In addition to it's use as a monopropellant, hydrazine has been used as a fuel in bipropellant combinations, for example in a 30% by weight mix with 57% methanol and 13% water, with concentrated hydrogen peroxide as the oxidiser in the Messerschmitt Me163 rocket propelled interceptor. This suggests that it's use as a fuel in a scramjet engine might be technically possible although it's toxicity and instability in pure form make it dangerous to handle.

In addition to it's use as a monopropellant, hydrazine has been used as a fuel in bipropellant combinations, for example in a 30% by weight mix with 57% methanol and 13% water, with concentrated hydrogen peroxide as the oxidiser in the Messerschmitt Me163 rocket propelled interceptor. This suggests that it's use as a fuel in a scramjet engine might be technically possible, although it is chemically unstable and toxic in pure form.