737 Questions

[Olendirk]

Jockeys,

some questions i have:

1.Why do the engines go to high idle when all generators drop offline?


2.What are your hints and tips when we have to fly a normal go around and the level alt is 1500ft AGL and the airport is in sea level. pretty fast and tricky situation


thanks


OD

[barit1]

1) I can't say absolutely, but I'm 95% sure it's loss of DC that would cause high (flight or approach) idle. Engines I'm familiar with need 28vdc on the solenoid to select ground idle.

[Rainboe]

Bulfer says it is not less than 59%N2 to allow for IDG operation. This would either mean to ensure adequate inflight IDG operation of generator or to allow disconnect to take place if needed.

Regard it as a circuit. I believe when you have difficulty in operating the automatics adequately when a lot is going on, simply say 'I have control, my throttles', disconnect everything and pull throttles back to a sensible power early. Fly it as you would a normal circuit. you can re-engage automatics at your leisure, but the important thing is not to blast through 1500' with GA power and too much flap while you are wrestling with MCP modes!

[bhoju75]

about engines going to approach idle if both the genies drop off line .. its a guess but ( in a NG ) below 15000ft if the flap position feedback fails the engs got to appch idle...and with both genies off line the flap position indicator does not work.....


The go around question depend on how fast you work the MCP panel cause you go into ALT ACQ really early depending on the ROC... best option as the FCTM also recommends is to take over manually and level her off ..

[frontlefthamster]

I strongly object to your use of 'jockeys'...

However,

1. Without checking the books, I assume that a generator parameter is used in the idle logic;

2. You're a pilot (not a 'jockey'). Fly the aircraft. Autopilot out, autothrottle out, 70-75% N1, sensible pitch (aim for about 1000 fpm), and level off as you learnt to in a little aeroplane. DO NOT try to use the automatics for this. The all engines go-around is the most frequently screwed up exercise in the sim and on the line, largely because it's never trained (other than following a coupled approach in LVO).

[Cough]

1/ I remember an eng doing ground runs one day trying to sort an EGT gauge fault. When both the EGT gauge CB's were pulled together both engines went to flt idle.(on ground). Don't know whether that may give a clue!

2/ At AA, pull back a whole heap of thrust to make the level off and accel manageable.

[luddite]

If you do a battery start then the engine will stabilise at high idle until such time as a gen comes on line... not that that explains why...

[electricdeathjet]

luddite.....
you giving advice about wiggly amps, who would have thought ;)

[Centaurus]

Interesting thread. I wonder why the God Almighty rush to engage the autopilot at 400 feet following an engine failure at lift off. Is it because pilots have forgotten the ancient art of hand flying? One operator said it was because F/O's in their company are not trained to monitor to hand flying - only trained to monitor automatics. Other operators policy is to only engage the autopilot following engine failure at lift off when the aircraft has been cleaned up.