Ok i set the N1 knobs near the upper DU's set them at lets say 84.4 thats what topcat spewed out for me i was doing a circuit, i set them manually pressed toga and the N1 exceeded my limits upto 101? Have i missed something?

You don't typically use the manual bug day-to-day. Were you just experimenting? Just use the FMC and to set the N1 for takeoff.

Have i missed something?

 

Yep.

 

FCOMv2 7.10.4 and 7.10.5.  In AUTO, the bugs are displayed at the A/T limits.  In BOTH, N1, or N2 the function "has no effect on A/T operation."

Yep.

 

FCOMv2 7.10.4 and 7.10.5.  In AUTO, the bugs are displayed at the A/T limits.  In BOTH, N1, or N2 the function "has no effect on A/T operation."

So in manual its for reference purpose only then?

 

And when at cruise is it normal for the N1 displayed to be different to that of the N1 cruise in the FMC ?

You don't typically use the manual bug day-to-day. Were you just experimenting? Just use the FMC and to set the N1 for takeoff.

Yeh messing about doing circuits and tried to put the N1 TO setting from TopCat

I've used the bugs only with the FMC INOP and for the departures out of John Wayne.

 

 

And when at cruise is it normal for the N1 displayed to be different to that of the N1 cruise in the FMC ?

The actual N1 shouldn't be more than the N1 limit, but it usually is less. eg. Say you're cruising at FL350 and have planned 456KTAS, well that'll be somewhere around 88% N1. You don't need whatever the limit is, just like you (probably) don't drive down the freeway with you accelerator pushed to the floor.

 

Of note: Mountain wave. If I get in to mountain wave activity, I'll select CONT in the N1 rather than CRZ in the N1 page so I have better acceleration if I get slow.

Hi spin think you missed what i'm trying to explain. Right, the fmc calculated N1 is different to that of the N1 displayed?

 

What is mountain wave?

Hi spin think you missed what i'm trying to explain. Right, the fmc calculated N1 is different to that of the N1 displayed?

 

What is mountain wave?

So there's the FMC N1 limit and the actual N1 that the engine is giving you right now.

 

Mountain wave is a form of turbulence. If you could see it, it'd look like rolling waves. It can cause large airspeed deviations. Your engine works hard to get you back on speed if you get slow. I don't think the NGX needs to worry about it.

Spin i'm using topcat and pfpx when i come to the takeoff page for the vspeeds will i press each one in the fmc and let that calculate it or will i manually enter them from topcat?

 

Thanks

 

 

Spin i'm using topcat and pfpx when i come to the takeoff page for the vspeeds will i press each one in the fmc and let that calculate it or will i manually enter them from topcat?

 

You're going at this a little backwards.  Use TOPCAT to get you your TO derate and/or assumed temp.  TOPCAT should then spit out numbers (V speeds, distances, and N1s).  Use those values to evaluate against what the FMC is giving you.  Use the V1 speed (because it's field-specific, and not the FMC's balanced field - or generic - calculation of V1), confirm the other V speeds are at least similar, and do the same with the N1.

 

The FMC is part of the aircraft.  It knows best what it can handle.  It's best at determining all values.  TOPCAT should be used to confirm that its values are in the right ball park.  TOPCAT is saying "your N1 should be around this much," but the plane is going to be a better calculator for that value because it's getting real-time data.  TOPCAT is not.

Am i calculating it through pfpx or openup topcat itself? I'm finding my vspeeds on the fmc don't match that of topcat calc? i'm finding the N1s % is the same.

 

am i going by the FMC or topcat?

 

scan, i'm watching your 737 supp tutorial 2 when landing you set speed 220 kias but why? i thought you set it straight to the up marker?

 

 

Am i calculating it through pfpx or openup topcat itself? I'm finding my vspeeds on the fmc don't match that of topcat calc? i'm finding the N1s % is the same.

 

Again:

v1 displayed is balanced field v1, not field specific - this will likely be different (use TOPCAT's v1)

v2 and vr should be very close (if they're not, did you enter the correct information on TAKEOFF PG 2?)

 

 

 

scan, i'm watching your 737 supp tutorial 2 when landing you set speed 220 kias but why? i thought you set it straight to the up marker?

 

I set it to 220 when inbound, not when landing.  Note that at about 1:26:00, the "controller" issues a speed restriction of 220 knots of less.

 

Don't blindly follow.  Sure, ideally, you'd follow the flap schedule, but - ideally - you'd be the only aircraft in the sky and could get direct, and fly whatever speed you'd like.  The NAS is a group game, though, and keeping your speed up helps to avoid a ripple effect backwards for all aircraft behind you.  Slow an aircraft at the front: everyone behind it has to slow (or accommodate that speed drop, somehow).

Again:

v1 displayed is balanced field v1, not field specific - this will likely be different (use TOPCAT's v1)

v2 and vr should be very close (if they're not, did you enter the correct information on TAKEOFF PG 2?)

 

I'm doing a flight now i'll take the V1 SPEED and enter it into the FMC will look out for VR - V2 differences and let you know yeh everything was entered correctly!

 

 

The N1 and V-speed setting knobs are one of the least touched controls in our airplanes.  We can't be dispatched with both FMC's inoperative so the only time you would be called upon to set the N1s or speeds manually would be if both FMCs failed in flight or you were dispatched with one FMC inop and the other failed enroute.

Changed V1 speed in the FMC and the FMC's VR and V2 plus N1 was the same as topcat!

 

Got a question on VNAV from the FCTM -

 

I just done a VNAV app in vnav / lnav

 

As soon as the airplane is at least 300 feet below the missed approach altitude and stabilized on final approach in VNAV PTH, set the MCP altitude to the missed approach altitude.

 

I done this but the A/C started climbing to the missed app alt. Have i done something wrong? Because at that point your still in Auto and how do you stop it from climbing. I followed the procedure but that part has confused me?

 

Thanks!!

You don't set the missed approached altitude on the MCP until after you've captured the glide slope. That way,  the a/c won't start climbing as you are experiencing.