Moderators: richierich, ua900, PanAm_DC10, hOMSaR
tb727 wrote:Those are the packs you can hear in that location as well as the pack cooling fans. The pack cooling fans turn off automatically after the flaps are retracted.
tb727 wrote:B system is electric and in the tailcone
fr8mech wrote:[twoid][/twoid]tb727 wrote:Those are the packs you can hear in that location as well as the pack cooling fans. The pack cooling fans turn off automatically after the flaps are retracted.
I was thinking pack fans also. The hydraulic pumps tend to whine and change pitch a little bit, even under steady load.
Though, didn’t the B727 takeoff with the packs off? Can’t remember.tb727 wrote:B system is electric and in the tailcone
The B system pumps are behind the left wheel well. The standby rudder pump is in the airstair compartment. I’m thinking aircraft left.
tb727 wrote:Those are the packs you can hear in that location as well as the pack cooling fans. The pack cooling fans turn off automatically after the flaps are retracted.
fr8mech wrote:[twoid][/twoid]tb727 wrote:Those are the packs you can hear in that location as well as the pack cooling fans. The pack cooling fans turn off automatically after the flaps are retracted.
I was thinking pack fans also. The hydraulic pumps tend to whine and change pitch a little bit, even under steady load.
Though, didn’t the B727 takeoff with the packs off? Can’t remember.tb727 wrote:B system is electric and in the tailcone
The B system pumps are behind the left wheel well. The standby rudder pump is in the airstair compartment. I’m thinking aircraft left.
tb727 wrote:
Hmm I must be misremembering the location then!
113312 wrote:I don't disagree with Aaron 747 but the sound in that video is also a result of the audio limitations of the camera used. It is not linear frequency response and enhances certain frequencies. The sound cannot be from an APU in a 727 because it is shutdown after engine start. It may not be operated in flight unlike the 737 and 747. In the 727, the APU is located inside the wheel well and would quickly overheat if running and the landing gear is retracted. You would immediately get a fire warning after takeoff. All of the sound in that video are from the engines and hydraulic pumps (B system mainly)
fr8mech wrote:tb727 wrote:
Hmm I must be misremembering the location then!
I have decided that the brain has limited capacity and once that capacity has been reached, new things bump out old things. The catch: it's not a first-in, first-out process. The brain randomly kicks out data to accommodate the new data. I completely expect that some new chunk of data from the -8 will kick out any memory of my children's names anytime now.