Litjan

If you are in VNAV you will see that our plane intially gets a bit "over" the calculated path, then dives down to re-capture it. The real plane plans a smoother initial curve - this is something we skipped to avoid the complexity - VNAV is hard enough to calculate as it is. We may add that at a (much) later stage... Jan

The initial part of the descent is "constant MACH" - and since the speed of sound gets bigger with warmer temperatures, you will see that the indicated airspeed keeps going up as you descend. So in a way you are not only descending, you are also accelerating! In addition, the "glide angle" for a constant airspeed is also constant - but you have to remember that at high altitudes the plane is moving a lot faster than indicated. (TAS > IAS). So you will also get a much higher ROD for the same angle. These effects are portrayed well in X-Plane, and it is not unusual to see 5000+ fpm rate of descent in the real 737 when descending at constant MACH at high altitudes. The passengers (and pilots) are unable to feel "high ROD" - you could descend at 20.000 feet per minute and no one would know (at least not for a minute or so...) Jan

Hi john, mmerelles is correct - we still have some issues to work out with the VNAV part of the descent - it can still be easily confused by multiple and complex descent restrictions. We plan to improve that - as a workaround I suggest going to autopilot modes that give you more control (V/S or FLCHG) so you can adhere to your desired descent path. Cheers, Jan

This approach is a "RF" (radius to fix) approach that only very advanced FMS versions can fly. The version number we model can not. Cheers, Jan

No, there is no "pipper" for runway or taxiway alignment in the 737. And it would not work in most cases, since usually during an approach there is some crosswind, and also the 737 does not taxi "straight" (it has a slight slack in the wheel castors, so it looks like it is crabbing during taxi) There is a guide on how to set up the correct seating and head position in the real manual - but there is nothing to help you judge alignment in the lateral position (just sit straight and look straight ahead) . Cheers, Jan

Whatever works for you! Happy flying, Jan

I think dr_anthony probably has the answer - the effect is called "cinema verite" and can be accidentially triggered to ON. Check the X-Plane "view" menu... Jan

Oh, the good old days of manual reversion flying in the simulator... skipped the workout in the health club on those days... Jan

Yeah, I watched the video - it is a really complicated situation for the FMC - it still thinks that you are in climb mode and wants to go to CLB speed after recalculating the route after the DIRECT TO. I don´t really know what went wrong at that point, but in that case I would suggest to simply revert to a more simple autopilot mode like MCP SPD and V/S or FL/CHG. We will look at these kind of situations (descents involving several speed and altitude restrictions) more closely in the future, there is still a lot of work to be done... Jan

Unfortunately the video is "private", so I can´t really see what is going on...

I did have a conversation on this subject with Ben Supnik, so maybe he incorporated some improvement in this regard... "Fixed max deflection of low speed nose wheel when not using a hardware tiller." Not sure, have to check if this affects us... Jan

I did have a conversation on this subject with Ben Supnik, so maybe he incorporated some improvement in this regard... "Fixed max deflection of low speed nose wheel when not using a hardware tiller." Not sure, have to check if this affects us... Jan

Thanks for letting us know, Tom - I wonder what fix affected that one... Jan

Nope, should just work like it did before. Jan

This is already fixed for the next update, thanks for reporting! Jan

Excellent - and don´t worry, the "combined modes" of A/T and AP pitch channel are probably the most complex systems in the 737. Still looking forward to clearing up that original bug - keep me posted! Cheers, Jan

mmerelles is correct, the aircraft is behaving as intended. While you are in a VNAV PTH descent, the correct behaviour for the A/T is to go to RETARD first, then to revert to ARM. While in RETARD, you can not grab control of the throttles, only while in ARM. The intention is for the plane to have idle thrust and glide down the pre-calculated path. The autothrottle is "watching" the speed, though - if you are too fast, you will eventually get the "DRAG REQUIRED" message, if you get too slow, the autothrottle will revert to FMC SPD and add thrust until you are back on speed - then the cycle will go RETARD-ARM again. Jan

No, but maybe Tom has - I am adding this to our bug-base... Thanks for the report, Jan

Hi jamarns, I would be very interested to see a short video of this happening - even if you use the AP disengage bar on the MCP, the plane should be totally controllable. The only instance that you would see trimming while the AP is off would be when the speed trimming system kicks in (only during flaps not up and high power). But it should never render the aircraft uncontrollable. Cheers, Jan

Thanks for following up on this, Jon. We are investigating and will fix this. Jan

Hi, no, sorry, it does not work - yet. Cheers, Jan

Thanks for the report! No solution for you yet, but we have seen this "turning away" before and are on track for fixing it! Cheers, Jan

Hi Maestaru and thanks for the kind words! The other guys (absolute IXEG experts!) beat me to the answer, this was something we changed between video capture and release. I do follow these threads and answer whenever I get a chance - I can´t teach how to fly an airplane in here, but if there is an advanced question I am always happy to help! Happy flying, Jan

Beautiful shots, Ricardo! I am just worried about the yellow Master Caution in picture #2, I hope you made it back to terra firma ok!? Thanks for sharing, Jan

As a general rule, after flying two single-engine departures your leg on the live engine side should shake and hurt... Jan