Originally Posted by
CONF iture
OK, great ... so, without talking of WHEEL WELL FIRE warning, is it fair to say that an EICAS caution or warning, or a QRH procedure requesting to lower the gears, would not come up as long as one brake temp did not reach that 500C equivalent value ?
SMOC, do you agree with that value, or is it somewhat different on 747 Classic or any Boeing product ?
I was also surprised to learn that wheel well fire detection was available on option for 330/340, thank you Zeke.
Would you know which percentage of 330/340 fleet is equipped with that option ?
I cannot say much about QRH procedures here, since I am the guy in the cockpit with grease on his hands
. A 757 driver can give better answers.
As for 757 wheel well fire, fairly simple. That same manual says there are two loops (one each wheel well) with sensors that trigger when temperatures reach 200°C. There is an EICAS message "Wheel Well Fire" and a "fire" light just underneath the light "brake temp" and next to the three greens. At the same time the master warning signal and lights go on. There is also a test button at the lower right pedestal corner.
Surprises me that brakes can go to 500° without warnings, and well temps can go to 200°. So there must be something requesting the wheels to stay lowered. In real, I've never seen a 757 brake going above figure "2" on EICAS.
I looked up some cockpit pictures on the net, and almost every airline has the brake temp option installed.