Hard to trim the 737NG for level flight

[Guest james320]

In the full-motion 737NG simulator it's very easy to trim the aircraft for level flight (or a certain constant vertical speed). When flying the PMDG 737NG I find it almost impossible.Is the because of a limitation of MSFS? When you disconnect the PMDG autopilot you see that the autopilot has managed to trim the aircraft accurately. I have experimented by editing the aircraft.cfg file for the -600 and changing elevator trim effectiveness from 0.8 to 0.3. Doesn't seem to completely solve the problem.Any suggestions?

[crvm 0]

I believe the TRIM in flight simulator 9 is awful and not related strictly to the PMDG sim but most every aircraft. I can trim it ok but maybe not as easy as in rl or the full motion sim. On another note how many 737NG pilots do you know who trim for manual level flight without the A/P involved? I'm sure they do not do this as often as ALT HOLD...Best Wishes,[h4]Randy J. Smith[/h4]http://www.rawbw.com/~bdoolin/shinault/southparkcartmad.gif[h3]PMDG 747![/h3]Caution! Not a real pilot, but do play one on TV ;-)ASUS KV8 DLX | AMD 3200 64 | 1 GIG PC 3200 DDR | GIGABYTE 5700 ULTRA | ViewSonic VP192b 19" |

[Guest nattydread]

Its certainly do able, but it requires much more input then I originally thought it would. It also helps that my CH Flight Yoke has a mechanical trim wheel, that way I get more precise trim after I get it in the ball park with the in-game trim.

[Orlaam 306]

This is perhaps my only real complaint about the NG. I've had some planes that were hard to trim, but this one is way too touchy. I can't imagine a real 737 not being able to trim perfectly. It's not like it can't be done in FS, I have several add-ons that I can trim level without a whole lot of work.

[mburkhard 23]

Might this be related on the acutal hardware used with the product?With my PFC Jetliner Yoke I am able to trim the 737NG just fine. I can't compare it with the real airplane as I've never flown a 737 (Sim), I can only compare with the MD-11 which I know well, and as such find trim nicely done. But as I said, that might be only because I use the Jetliner Yoke, don't know...Now I remember a collegue of mine who is using the CH Yoke has also major trim difficulties. So it really seems to be a hardware problem.Regards,Markus

[Orlaam 306]

Maybe, I really can't say for sure. I only have the CH Yoke and Pedals, but I know I can trim the other planes I have just fine. They are all payware as well. I have the trim settings in the MSFS set at half, and if I lowered the slider to the least amount I'd never be able to trim fast enough to make good use of it in other planes.

[Guest gordonrd45]

It is certainly easier to trim a 737 Level D simulator than anything in Flight Simulator, but with good hardware the task is much less daunting. With my PFC yoke and the GoFlight LGT module I find it reasonably easy to trim the PMDG either for steady climb or cruise.Regarding separate comment in this thread -- who would trim without using the AP? -- the answer is real ATP pilots -- that's who. I asked the chief pilot at United, who was my co-pilot in the 767 Level D sim in Denver at AVSIM, how often they fly without the autopilot and if they trim for level flight manually and he replied "more often than you might think -- just to keep skills sharp. " He also told me that he often will fly the plane completely manually from takeoff up to 20,000 feet or so before activating the AP as much as 50% of the time, weather and traffic conditions permitting, to maintain skills. And then he had me do the same in the sim.I also found it much easier to trim either the PIC 767 in FS2K or the PMDG in FS9 after some nice lessons on pitch management from my pilot instructor at United. It really helps to know what pitch to aim for for each aircraft at various stages of flight.Rob G

[crvm 0]

">Regarding separate comment in this thread -- who would trim>without using the AP? -- the answer is real ATP pilots -->that's who. " Hey Rob, Maybe you missread my question so here it is again"how many 737NG pilots do you know who trim for manual level flight without the A/P involved? I'm sure they do not do this as often as ALT HOLD..." Notice that I said it is not as often as using ALT HOLD. Why? Well1. Economy for one 2. Workload and at times saftey but this last bit depends on many things so won't get into that. Pilots already fly DEAPARTURES and APPROACHES most of the time manually but not all of them. A captain can do what he wishes but just because one pilot likes to "hand fly" and another likes to use all the tools availble to him does not mean either one is better or even more desired than the other. I tend to believe the true hands on pilots are the old timers who come from the day when the A/P was not something one could put much trust in. Even with the NG series aircraft VNAV DESCents were not all that great until later U10X software so pilots fly them manually or used other modes like LVL CH. This information is only from reading various accounts over the years. Some pilots just don't like the idea of a "computer machine" in control. I think a good pilot becomes master at both hand flying with or without the F/D and the AFDS. Whatever makes the job safer and easier (less workload) I believe is the goal of the modern FMS. Anyways, how one sim trims in FS2002 means nothing here since they aren fact very different in the trim department. This simulator was never meant to teach a rl pilot in training how to master trimming or anything else related to rl flight. At best it provides a user an introduction to the various aircraft systems on a home computer. Even FAA approved PC ATDs like this http://www.flyelite.com/hardware.php?product_id=59 lack in many areas related to it's platform. I have read pilots who only trained with these and were amazed at how much they did not provide how the real one would be like. PMDG have more than a few real life 737 NG pilots who tested and still test on the team who failed to mention anything related to this subject for whatever reasons and one can come to their own conclusions as to why they would not make mention of "they" felt there was any trim related problems in the sim directly. Back to PMDG - There are ways to minmize the trim's sensitiveness within FS. Each user's setup is different so one much go trial and error to find a happy medium. As some who have posted already they seem to be able to trim it fine in level flight. Best Wishes,[h4]Randy J. Smith[/h4]http://www.rawbw.com/~bdoolin/shinault/southparkcartmad.gif[h3]PMDG 747![/h3]Caution! Not a real pilot, but do play one on TV ;-)ASUS KV8 DLX | AMD 3200 64 | 1 GIG PC 3200 DDR | GIGABYTE 5700 ULTRA | ViewSonic VP192b 19" |

[Guest nattydread]

Those with CH Yokes should also keep in mind that it tends to stick. Make sure you lube the shaft with plenty of Silicone spray. Doing this made me go from wanting to throw it out and not fly FS to absolutly loving the Yoke overnight. My biggest gripe before lubing it was my inability to trim and maintian precise control.

[Guest bobsk8]

Best thing to use on the CH yoke for for lube is Gunk's Liquid Wrench Dry-Lube with PTFE. You can spray it on the shaft or carefully open up the yoke and spray it around the sliding parts and it will last for a long time and won't ruin the plastic parts like a petroleum based lube will. You can find it at most good auto parts stores. Just make sure it is the Dry-Lube version with PTFE. Of course, this yoke stickiness has nothing to do with trim. I flew a real 767-400 motion sim a few years ago at an airline training facility, and the instructor pilot had me hand fly the plane around the airport with everything on manual except the autothrottle. I found that the trim worked OK, but needed alot of attention to set it correctly as you changed speeds. Not too much different than the trim in PMDG.

[Guest gordonrd45]

Randy -I guess we really don't disagree here. Obviously a professional ATP will need to maintain proficiency in both the automated capabilities of his aircraft and his ability to handle the airplane manually -- but my point was that the pros do a lot more manual flying than many believe, conditions (and company procedures) permitting. Many sim pilots simply fly their virtual heavy planes on automatic most of the time and seem to assume that real pilots do too. That had once been my impression until my pilot instructor clarified things.Of course, MSFS does not trim quite like a real plane or a level D sim -- another point we agree on. We would have to have much more sophisticated yokes with dynamic feedback to come close to what it is like trimming a big commercial jet, or even smaller craft. But from my experience flying heavy iron Level D sims, it is actually much easier to trim the real thing than to trim a plane in MSFS. I did not find it difficult to translate what I learned in MSFS to the level D sim, especially after a lot of practice in FS9 with a good yoke and a functioning trim wheel (made much better by the recent changes to the GoFlight configuration utility which allows for adjustment of trim wheel sensitivity on the LGT module).The Level D 767 I flew at United was a dream to handle and to trim --incredibly responsive airplane -- and I was impressed to find when I got back home that the pitch managment that I learned in the Level D sim transferred quite well to the PIC767 and the PMDG737 in MSFS (generally use slightly lower pitch targets for the 737 than for the 767), despite the differences in how the Level D sim and MSFS handle trim. This is a tribute to the skill of the PIC and PMDG programmers who did the flight modelling. Happy New Year.Rob G

[teropa 4]

Bob,Do you know where I could order that lubricant in the internet ?Or would you care to send me some over to Finland ;)Tero

[Guest gremel]

Rob quoted:"-- and I was impressed to find when I got back home that the pitch managment that I learned in the Level D sim transferred quite well to the PIC767 and the PMDG737 in MSFS"Could you enlightened me and possibly others what it was exactly that you learned about pitch managment from your level D experience with the real simulator. Regards,jack

[Guest rcritz]

>Could you enlightened me and possibly others what it was>exactly that you learned about pitch managment from your level>D experience with the real simulator. One thing he may have learned and something I have to hammer into my students (particularly those learning to fly a twin for the first time -- it has a wider range of airspeeds than they are used to seeing) on a regular basis is that pitch trim doesn't set altitude, it sets airspeed. A lot of times, pilots who haven't grasped this will be fighting the trim up and down through speed transitions and not have any idea why they are having so much trouble.So, for example, if you're going to fly a constant pitch climb (e.g. 10* nose up -- this is our SOP in the Challenger up through 10000', all things being equal), you're going to have to keep running nose-down trim as the aircraft accelerates. Through 10000, we transition to 5* nose up and it's the same deal. Lots of bumping the trim switch for nose-down trim as the a/c accelerates from 250 to 300+ KIAS.

[Guest gordonrd45]

I'll do what I can -- it's easier to show than to explain, at least for me.First, I have not had formal flight training and do not have a pilots license so what I knew about pitch before my experience at United in the 767 level D sim (LDS) was based upon reading and lots of time playing with MSFS. Unfortuately, pitch and trim are easier to manage in a real plane and in an LDS than in MSFS, so it really helped to have the time with an instructor in a more responsive setting. I knew that pitch was an important factor in controlling airspeed, but did not appreciate how really important it is as a major focus of attention in flying until I got to play with the 767 in Denver with a excellent pilot instructor (PI).When I got ready for takeoff, my PI told me to aim for 8 degress of pitch on initial rotation (what I would expect), but once up and climbing, to target for 15 degrees (more than I would have expected) for most of the way to 20,000 feet, making only minor adjustments of thrust to sustain climb and increasing or decreasing pitch slightly if speed got too high or too low. First thing I noticed in the LDS, was that it took very little back pressure on the yoke to get the 767 rotated and off the ground -- much less pullback than I need on my home sim. Fortunately, I was aware of how responsive the real planes are and did pull back gently (no tail strike!). Once up and climbing I did exactly what he told me and, while maintaining an instrument scan, I kept my primary focus on the pitch and targeted on 15 degrees. The plane settled right in at a steady climb of 2000-2500 fpm and an airspeed of about 240 knots. As we got higher, I found I could relax a little on the pitch as the airspeed would tend to drop so by the time we got to 20,000 feet I was closer to 10-12 degrees of pitch.On a visual approach into 28L at SFO, he told me to target 5 degress of pitch. Sure enough, keeping that as my primary focus and using throttle for fine tuning descent rate, and making fine adjustments in pitch for airspeed control, the plane settled nicely into a steady approach with a descent rate of about 500-800 fpm. Obviously some adjustments were needed in thrust as the flaps came out.I had always, as I think many novices do, focused more on throttle control and vertical speed in controlling the aircraft than keeping a primary focus on pitch. Obviously, everything is important, but I have become much more sensitive since my experience in the LDS to the importance of using pitch as a primary focus in controlling the airplane and on always keeping your eye on it. I now fly by targeting pitch and adjusting around it, rather than using thrust and vertical speed and adjusting pitch around them. It just seems to work much better and give me smoother control of the plane.The 737 needs slightly less pitch than the 767. For example, 2.5 degrees on approach rather than 5. I got that tip from a Delta 737 captain I sat next to as he was deadheading home and we discussed my experience in the 767 LDS. He told me to try the lower pitch targets in the PMDG and he turned out to be right. In flying the PMDG 737-800, I set the elevator trim at about 7 before takeoff, but once climing out, I gradually reduce the elevator trim to less than 5 as I gain altitude and find that a pitch of 10-12 degrees is all I need to keep airspeed under control. I drop down to about 2.5 degrees pitch to pick up speed over 10000 feet and then up the pitch to about 8-10 once I am at my new targeted airspeed (usually 315 knots). Again, it is usually necessary to drop the pitch further as you get up towards the higher altitudes.These are just targets -- obviously what pitch you need depends on other things too, including weather conditions and load factors.Hope that helps. I am sure this is not news at all to real world pilots. For those of us who live in the sim world, trim in MSFS is not the easiest thing to manage so its harder to get a handle on it unless you have had some experience in real planes or LDS equipment. Pitch was a lot easier to handle in the LDS, but what I was able to learn there could be translanted back to MSFS and has really enhanced my enjoyment of our hobby. Good hardware like the PFC yokes and the GoFlight LGT module do help make pitch control easier in MSFS. Cheers,Rob G