Equipment Cooling E&E Flashcards
In flight how many fans are working?
1, Exhaust fan continues to work- temps are really cold up there!
What are the 3 non normal situations you can get?
Valve Won’t Close- Fan Fails Inflight- Smoke
On the ground after start, the VALVE light will come on if the Skin Heat Exchanger VALVE or Outboard Exhaust VALVE isn’t closed after start. Go to Checklist-Turning it to STBY on ground forces these valves closed.
Valve light goes out? Good to go!
Valve light doesn’t go out? Call mx- you’re done
OVHT light turns on in flight-we think the exhaust fan failed. Turn the selector to STBY (point it at the light). OVHT light will be inhibited for 5 minutes. Hack your clock. Hoping to energize the supply fan. If after 5 minutes OVHT light doesn’t come back on? Good to go!
If OVHT light comes back on, use QRH to select OVRD. Trying to set up reverse flow.
Air will come through cabin through 3 Way Check Valve to cool off Equipment and Instrument panels and leave system through the Smoke OVRD VALVE. All other valves are closed. Both fans are de-energized.
Selecting OVRD- NO cooling light is inhibited for 1 minute
Flying along- AUTO selected, 1 fan working, everything is normal. SMOKE light comes on. Call for non-normal checklist. Take selector from AUTO to OVRD- Point selector at light. SMOKE override valve opens. Both fans are de-energized. No Cooling light will come on. Not successful setting up reverse flow. Will tell you to go back to STBY and follow the checklist.
What is the rule of thumb for working through problems with the Equip Cooling Switch?
Point it at the light
You start the first engine, how does this change the configuration of the E&E?
No- Upon starting the first engine the config doesn’t change because you can’t fly on one engine! All the valves stay where they are.
How many fans are in the E&E System?
2
Supply Fan- On the ground
Exhaust Fan- On the ground AND In the Air
After you start the second engine, when you take airplane into flight, what does it mimic? Chicago or Miami? How?
Chicago- The overboard exhaust valve must be closed. This has to occur to pressurize.
Boeing logic.
Selecting OVRD will do what to a light?
Selecting OVRD- NO cooling light is inhibited for 1 minute
