737 NG technical questions

[downwind]

Hello all,

What is the max start and max continuous APU EGT for the B737 NG family? I know it is not listed in the FCOM, does it exist? 9sorry i was wrong the 1st time)

Does anyone have Body attitudes/N1% settings, for the most common all engine and single engine phases of flight?

I'm new on type transiting from the B737 classics

Any other tips for the NG would be great aswell.

Thank you.

[BOAC]

Who is doing your conversion?

[iflytb20]

Start EGT limit and MCT EGT limit is given in the AFM. You can also find it in the QRH.

For the Pitch and Power setting look in the Airspeed Unreliable / Flight in turbulent air Tables. They are available in the FCOM Vol 1 PI section and in the QRH PI section as well.

PS: Max start EGT is 725 and MCT EGT is 925 deg C

[RAT 5]

Max EGT on the ground is the red line on the gauge. Does it very? Not sure, but it might. In the air QRH says 725c.

[downwind]

hi all

i meant for the apu, i did mine conversion already

[iflytb20]

I remember reading that during start the EGT indication can be as high as 1100 deg. There is no red line on the APU EGT gauge. And considering that the APU is always running at 100% RPM, I doubt if it has a MCT EGT limit.

[FlyingStone]

Originally Posted by iflytb20

And considering that the APU is always running at 100% RPM, I doubt if it has a MCT EGT limit.

APU is fuel-governed to maintain almost the exact RPM the entire time, since it acts as a constant-speed unit for the electric generator. This doesn't mean that it doesn't have a maximum continuous EGT limit (I wouldn't use the term MCT since the thrust output from APU is negligible) - EGT is not dependant only on RPM. On the APU, EGT is a good indication of the load on the APU - more load on the APU will require higher fuel flow scheduled by the fuel control unit - and if you increase fuel flow, the EGT will also increase.

I don't know specifically about the NG, but the Garret APU on Classic has a start EGT limit of 760°C and continuous limit of 710°C - so there is a maximum continous EGT limitation on some APUs.

[iflytb20]

@Flyingstone

Thanks for that info. I remember reading about the EGT limits for the classics but could not find any such limits for the NG APUs.

[myriakephalon]

I hope it helps.

The 737 APU

[sky-738]

75 and 57 is a generally used n1 set.

[de facto]

NG apu has auto shutoff....

[Yeelep]

Like defacto said, the APU has protective shutdown. When APU speed is over 95% it will shutdown if the turbine inlet temp. exceeds 2200°F. Some real general guidelines for EGT are, no load 550°C, 100 amp electrical load 585°C, two pack on with no electrics 665°C. These are upper limits of the normal operating EGT at 100°F OAT.