hi everyone
just a question about fuel pumps.
ive noticed recently when watching aviation clips on youtube (normally start ups IE:bell 206 start up) that they activate the pumps.ive also noticed that these heli's have their tubine above the fuel tanks.so it makes sense that they would need to use the pumps.Other choppers IE:R22,R44,R66 have their engines just a fraction below their tanks,and ive noticed that they dont use fuel pumps.
so what im asking is,do all helicopters that have their turbines above their tanks all need fuel pumps or is this just a coincidence?
Ive also seen planes use pumps to only PRIME their engines before start up.IE:C172.
But yet Ive also noticed that the kingair 200 or 350 (cant remember which one) used fuel pumps through-out the entire start up.The pilot only turned them off once the plane was ready to taxi.
1
Is the use of fuel pumps for technical reasons or is it simply just because the turbine is higher than the tank and it just needs to be boosted through the pipes?
2
If it is just because the turbine is higher than the fuel tanks,why would the kingair need it through-out the start up if the turbine is level with the tanks.
I know that this is not the simplist way to ask this question but i dont know what else to say.
anyway,thanks in advance
Daniele