PDA

View Full Version : Engine power and hydraulic pressure



XyZspineZyX
09-12-2003, 10:54 AM
Somebody enlighten me. I work on jets, so I only know how things work on modern fighters. Aren't the hydraulic pumps on the majority of planes in FB run off of the motor? And don't those pumps operate the flight controls and landing gear? If I'm right about this, then shouldn't the flaps and landing gear (the ailerons, rudder and elevators are cable operated, I think) fail to move when the engine has failed? I'm asking this because I chased down a 109K4 forever and FINALLY nailed his engine. His prop seized and he was seemingly out of power. He was still able to lower his gear and flaps (I can understand the gear with the manual gear control) to land; I didn't get credit for the kill. Thanks in advance!


SSgt Tim Schuster
8MXS Inspection Section
Kunsan AB, Korea

-Defend the Forums!
-Accept Follow-on Patches and stuff!
-Take the Fight Online!

XyZspineZyX
09-12-2003, 10:54 AM
Somebody enlighten me. I work on jets, so I only know how things work on modern fighters. Aren't the hydraulic pumps on the majority of planes in FB run off of the motor? And don't those pumps operate the flight controls and landing gear? If I'm right about this, then shouldn't the flaps and landing gear (the ailerons, rudder and elevators are cable operated, I think) fail to move when the engine has failed? I'm asking this because I chased down a 109K4 forever and FINALLY nailed his engine. His prop seized and he was seemingly out of power. He was still able to lower his gear and flaps (I can understand the gear with the manual gear control) to land; I didn't get credit for the kill. Thanks in advance!


SSgt Tim Schuster
8MXS Inspection Section
Kunsan AB, Korea

-Defend the Forums!
-Accept Follow-on Patches and stuff!
-Take the Fight Online!

XyZspineZyX
09-12-2003, 11:27 AM
I too have worked on modern jets most of my life and in every case, the hydraulic system is powered by electric pumps for use on the ground and this also acts as a back up system in flight after engine failure. This could also be the primary systems drive too. Some a/c at that time had pneumatic retraction systems which do not fail so completely when damaged.



Message Edited on 09/12/0311:52AM by ELEM

XyZspineZyX
09-12-2003, 01:04 PM
On most if not all aircraft of WWII vintage, primary flight controls were cable or rod operated.
Hydraulic systems were not used very often because they are not very battle damage resistant (penumatic systems have the same problem). Puncture a line and you loose several systems. Hydraulic power was really only used for brakes (pneumatic too) and some power turrets.
Electric/mechanical systems for flaps, trim and gear were more in favor because more resilient.
e.g. the FW190 is an all electric aircraft (exept for primary flight controls of course)
B-17 as well.
Of course they may be few exceptions but not much...