52 minutes ago, Gazzareth said:

Must be me flying bleary eyed, sure I set it manually on the last couple of flights. Although, thinking about it I would probably have set it before I even touched the tablet .. ..

 

G

PMDG called it a "tablet feature" but even that isn't entirely correct, when I first updated I spent a few minutes indignantly looking for it in the tablet only to find it was in the FMC's route loading menu as a new option. 

As others are saying, there is definitely something around your weights in the FMC. Actual weight and the FMC weight is not matching. That A in your speed window is definitely telling you something is off. I don't know about the 73, but in the DC10, the system would estimate your weight based on accelerometers from your maneuvering. If you dial the speed too low, it will give you a little alpha a in the FMA for speed. It was spot on. In a sense, approach speeds are roughly 1.3 to 1.5 of stall speed. This is on a linear curve until you start getting light enough to where VMCA becomes a factor. At this point, the speed curve will give higher numbers than 1.3 Vstall in order to maintain control ability. On the top end, that 1.3 Vstall curve will run until you hit flap speed limits. For the future and this issue, here is something that experience will buy you and I pass it on to you for free😆. 

After a few approaches, you will start to learn the body angles/pitches for the a particular aircraft on a 3 degree slope at REF plus 5. This becomes part of your cross check. Pitch on approach will change about 1 degree for each 5 knots of airspeed. So for a 737-800, you are looking at 2.5 flaps 30 and 1.5 for flaps 40 at REF+5 on a 3 degree slope. If you are on a 3 degree slope, flaps 30 and notice that the pitch is at 1.5, you are either 5 knots hot, steeper than 3 degrees or landing with flaps 40😂. If the pitch is higher, you are either on 2.5 to 2.7 slope, slow or landing flaps 25😝. It's that simple. These are good nuggets to know as it compliments your scan. Let me give you an experience I had myself.

We get to the jet in Dallas early morn and it had been raining all night long. It was foggy with heavy drizzle as we powered up the G550. 5 minutes before the passengers showed up, we started getting these weird spurious CAS messages centered around air data. As we taxied out, we had a stab/flap miss compare message. We rolled them up and back down to takeoff and the indications for flap and stab were fine. We even popped the entry door to take a look and the stab was at the mark for 20 flaps. We decided to blast on to DC. On approach, we got a flap miss compare message. We rolled them up and back down, but the message stayed. We captured the slope and the CAS went away. On short finale it came back. The PF asked if we should break off and opt for a 20 flap landing. I asked, what is the normal pitch for a 39 flap landing. He stated, about 1.5 ish. I asked, what do we have, he responded 1.5. I responded continue. At 300 feet, the message went away again. I told the mechanics that possibly something got wet. No one else experienced that issue in that tail again.

If you have this problem again in sim, check your pitch. If your pitch is fine, then you know your FMC/system is out to lunch. If you have a 737 flight manual, you can find pitch and power settings under the unreliable airspeed section. Just note that the pitch on approach will be low because it's doing REF+10 for a safety factor. In that chart, it will be 1 degree low because of the extra 5 knots.    

1 hour ago, G550flyer said:

If you dial the speed too low, it will give you a little alpha a in the FMA for speed.

That's the same in the 737. In the real one at least, no idea how PMDG actually coded it.

EDIT: To be precise - the alpha a appears in the PMDG 737, too, as seen in the video. But I don't know what values they use for that, if they actually coded gyros and accelerometers etc.

Edited December 3, 20232 yr by Fiorentoni

16 minutes ago, Fiorentoni said:

That's the same in the 737. In the real one at least, no idea how PMDG actually coded it.

It's pretty slick, will even prevent you from slowing below that speed. I did have a position sensor for the slats fail once and it gave us a slat dis agree after takeoff. It was interesting because the alpha a showed up and the throttles kept going to full power thinking we were too slow for our configuration. We did a no slat with flaps landing after adjusting weight. Costed us about four hours to get it fixed and then we blasted on to Cali. 

Thanks to all of you for that lot of precious information! Especially the body angle/pitch concept being highly interesting.

Indeed, I seem to have had a misunderstanding concerning the Pmdg EFT. It imports the correct fuel and payload/pax/gw values from Simbrief and shows them on the import screen of the FMC. However when requesting the automatic PERF INIT, it uses the values set in FS, which in my case where all at max. Hence a huge weight/fuel/payload/pax difference. So even with the automatic EFT import, you need to set the fuel/payload stuff in FS manually.

Done that, then I tentatively flew a short hop with no payload or pax, a gross weight of just 42 and 3.5 tons of fuel, 2 tons remaining on landing. Indeed, the landing went way better and left me an operational speed window. But still: My ref speed for F30 being 118, I was slowing down to 130, flaps 30. It went fine for a few seconds, then the lower amber line flickered upward, the A appeared in the speed setting window, the aural warning was triggered and I had to temporarily speed up to above 150 to make the A disappear and silence the warning. So problem still not entirely solved, but definitely getting closer 🙂

7 minutes ago, SimFx said:

Thanks to all of you for that lot of precious information! Especially the body angle/pitch concept being highly interesting.

Indeed, I seem to have had a misunderstanding concerning the Pmdg EFT. It imports the correct fuel and payload/pax/gw values from Simbrief and shows them on the import screen of the FMC. However when requesting the automatic PERF INIT, it uses the values set in FS, which in my case where all at max. Hence a huge weight/fuel/payload/pax difference. So even with the automatic EFT import, you need to set the fuel/payload stuff in FS manually.

Done that, then I tentatively flew a short hop with no payload or pax, a gross weight of just 42 and 3.5 tons of fuel, 2 tons remaining on landing. Indeed, the landing went way better and left me an operational speed window. But still: My ref speed for F30 being 118, I was slowing down to 130, flaps 30. It went fine for a few seconds, then the lower amber line flickered upward, the A appeared in the speed setting window, the aural warning was triggered and I had to temporarily speed up to above 150 to make the A disappear and silence the warning. So problem still not entirely solved, but definitely getting closer 🙂

The fuel and payload should be inserted from Simbrief, if you are following the correct procedure with the EFB, and you shouldn't have to change that at all. Sounds like you may have to do a complete uninstall and reinstall of the 737. Contact PMDG tech support and they will email you on how to do that. 

"So even with the automatic EFT import, you need to set the fuel/payload stuff in FS manually."

NEVER EVER PERIOD.  USE THE CDU import or set manually IN THE CDU.

7 minutes ago, cavaricooper said:

"So even with the automatic EFT import, you need to set the fuel/payload stuff in FS manually."

NEVER EVER PERIOD.  USE THE CDU import or set manually IN THE CDU.

Yeah, I  don't understand why he is saying that it "uses the values in FS". It should use the values  that were put into the FMC when you loaded fuel and pay load from the Simbrief data. That should never be changed after that. 

The PMDG have never liked having the route fixes not intersecting properly, and I think that (course fix 19) CF19 veering off to the left has confused the logic of the plane.  It's a bug but likely only overcome by having a direct track from the FAF to the runway.

11 hours ago, G550flyer said:

As others are saying, there is definitely something around your weights in the FMC. Actual weight and the FMC weight is not matching. That A in your speed window is definitely telling you something is off. I don't know about the 73, but in the DC10, the system would estimate your weight based on accelerometers from your maneuvering. If you dial the speed too low, it will give you a little alpha a in the FMA for speed. It was spot on. In a sense, approach speeds are roughly 1.3 to 1.5 of stall speed. This is on a linear curve until you start getting light enough to where VMCA becomes a factor. At this point, the speed curve will give higher numbers than 1.3 Vstall in order to maintain control ability. On the top end, that 1.3 Vstall curve will run until you hit flap speed limits. For the future and this issue, here is something that experience will buy you and I pass it on to you for free😆. 

After a few approaches, you will start to learn the body angles/pitches for the a particular aircraft on a 3 degree slope at REF plus 5. This becomes part of your cross check. Pitch on approach will change about 1 degree for each 5 knots of airspeed. So for a 737-800, you are looking at 2.5 flaps 30 and 1.5 for flaps 40 at REF+5 on a 3 degree slope. If you are on a 3 degree slope, flaps 30 and notice that the pitch is at 1.5, you are either 5 knots hot, steeper than 3 degrees or landing with flaps 40😂. If the pitch is higher, you are either on 2.5 to 2.7 slope, slow or landing flaps 25😝. It's that simple. These are good nuggets to know as it compliments your scan. Let me give you an experience I had myself.

We get to the jet in Dallas early morn and it had been raining all night long. It was foggy with heavy drizzle as we powered up the G550. 5 minutes before the passengers showed up, we started getting these weird spurious CAS messages centered around air data. As we taxied out, we had a stab/flap miss compare message. We rolled them up and back down to takeoff and the indications for flap and stab were fine. We even popped the entry door to take a look and the stab was at the mark for 20 flaps. We decided to blast on to DC. On approach, we got a flap miss compare message. We rolled them up and back down, but the message stayed. We captured the slope and the CAS went away. On short finale it came back. The PF asked if we should break off and opt for a 20 flap landing. I asked, what is the normal pitch for a 39 flap landing. He stated, about 1.5 ish. I asked, what do we have, he responded 1.5. I responded continue. At 300 feet, the message went away again. I told the mechanics that possibly something got wet. No one else experienced that issue in that tail again.

If you have this problem again in sim, check your pitch. If your pitch is fine, then you know your FMC/system is out to lunch. If you have a 737 flight manual, you can find pitch and power settings under the unreliable airspeed section. Just note that the pitch on approach will be low because it's doing REF+10 for a safety factor. In that chart, it will be 1 degree low because of the extra 5 knots.    

I always enjoy reading your responses/posts.  Some real world old school knowledge that goes a long way to helping the community better their skills.  Keep it up!

Even with the efb it's not fully automatic. You have to press set Fuel and aet Payload in the FMC.

I use gsx, that does the same think and i don't have ti worry about. It set's fuel and Payload according to SB

You could do all the unreliable airspeed lookup stuff... Or you could just realize that you've got an AoA gauge staring at you on the PFD and in the HUD, and put the needle in the approach band and be done with it 😁.

Airspeed on approach is really just used as a proxy indication of AoA, but is only accurate at 1g and only if you have your weight correct; if you have a direct measurement of AoA that's always going to be more reliable (obviously excepting a faulty indication) because weight confusion, data entry errors, load factor, or anything else just don't matter... Correct AoA is always correct, at any weight or load factor.

In the OP screenshot, the AoA is well above the approach band.

Edited December 4, 20232 yr by Stearmandriver

17 hours ago, Bobsk8 said:

It has been automatic since the UFT was introduced

No it was not, Bob.

The Flightplan you could set by entering XXXXYYYY for the Departure and Arrival ICAO Codel etters into the Route Field in the FMC when the UFT was introduced.

But what they changed in the last update is the realistic "Route Request" where you can then pick the latest Simbrief Route. That then brings up an Information Page including ZFW and Fuel Load and THAT'S where you can set those loads if you want to. It doesn't do that automatically though, you have to tell it to do so on that information page. If you don't you have to do it later in the old load options menus.

13 hours ago, SimFx said:

 So even with the automatic EFT import, you need to set the fuel/payload stuff in FS manually.

No you don't. On that first information page you get in the FMC after you import a Simbriefplan you have to click on the line keys next to "Set Fuel" and "Set Payload".

If you press the line key next to "Select RTE" without doing that first, it will keep your current load.

 

I have the feeling some of you are confused how that works now, so let me link you to a video that shows how it works:

Start to watch at the 2 Minute mark. At 2:28 you see the Information page with the options to set Payload and Fuel. THAT is where you set it now. Or you don't and do it where you used to do it, in order to set different numbers.

 

Edited December 4, 20232 yr by Farlis

13 hours ago, Bobsk8 said:

Sounds like you may have to do a complete uninstall and reinstall of the 737. Contact PMDG tech support and they will email you on how to do that. 

Gods NO! You guys are just doing it wrong. See above, how this works.