I feel like I'm doing something wrong here, but I'm not sure.
We'll use 1 version for reference, but it's happening with all of them I've tried.
The 727-200F Advanced with the -9 Engines.
When I follow the procedures as outlined in Section 5 of the Handling thread, I'm not even close to what it's telling me. Climbing out at 94% N2 and at 2500 FPM, I'm overspeeding like crazy. In fact I've climbed out at 5000FPM at 70% N2 and it's blasting through 300KIAS like it's going to the moon. Granted I'm not "Fully Loaded" as laid out in the procedures, but when I've tried it like that I'm getting the same result. Yes, I'm using the correct panels(I learned that lesson a long time ago).
Have the planes been updated and the Handling notes just haven't caught up?
Post by aerofoto - HJG Admin on Oct 8, 2021 21:02:03 GMT
Are you FS2004 or FSX ?
FSX is known to be more "slippery" in regard to performance/s.
The guides I compile are based on FS2004 performance indications and are still current .... and do work well (if applied correctly) under normal circumstances.
Granted I'm not "Fully Loaded" as laid out in the procedures,
"THAT" .... under normal circumstances would a likely reason.
The prescribed procedure was are all based on MTOW only.
Reduce weight and performance/s will only increase proportionately, but, I wouldn't have thought the like of what you're reporting is the least bit practical let alone possible .... unless you're "virtually empty".
A little while back someone reported something very similar in regard to an L-1011 simulation .... and it was determined his over-performance was for reason of similar significant weight reduction.
"NO CHANGES WHATSOEVER" have been applied to any of the B727 FDE's .... at least "NONE" that I'm aware of or have been sanctioned by me
At the very top of your AIRCRAFT.CFG file is a paragraph of information/a header .... prior to the FLTSIM.XX entries. Within that data there is a date .... according to Month and year only.
I want you to quote me that data .... not the last modified date of you CFG.
In fact I'd you to copy & paste (here) that entire paragraph of intro/header header information in order to be able to properly analyse what you've actually got.
From there I'll get back to you "as I can" due to other R/W priorities at the moment, but, get back to me as quickly as you can regardless.
Post by aerofoto - HJG Admin on Oct 9, 2021 1:56:36 GMT
There's times I wish I could produce videos .... and right now's one of them
I've had a look at our current B727-200F ADV JT8D-9 base pack files (only) .... both NTL/VHF and TL versions. No time to check "the lot" though.
Both of these contain correct data by virtue of content and Last Modified dates for their supporting FDE files, so, no problem's there.
I took the TL version for a spin. It doesn't perform any differently from the NTL/VHF version. Both use the very same weight and power assignments. The only difference is their CFG stated Lighting configurations and 3D models .... which is why they're separate base pack files.
I loaded the simulation as per the current guide and applied the same recommended power settings to fly more-or-less the same climb profile all the way up to cruising altitude.
I didn't experience any problem/s at all
I need to say the current guide was compiled almost 10 years ago. If I were recompiling it now (and I may), then, apart from fixing a few minor typo's I'd likely make a few "very minor adjustments" to what's currently recommended based on experience since gained with these B727 simulations .... to the extent I'd probably now recommend a slightly shallower ROC all the way up to cruising altitude, but, for around the same recommended power settings.
In order to be able to reply to this query (since it's been a while since I'd properly flown any of our B727's) I performed 4X MGW departure T/O's .... climbing to cruising altitude (31,000 FT) during each test.
The first 2 tests followed the present guide whilst the last 2 tests were flown in accordance with a shallower climb profile all the way up to cruising altitude .... and each using the same recommended power settings. I never hit 300 KTS at any stage. My climb speed remained at a steady 270 through 290 KIAS with the simulation eventually settling into a 31,000 FT cruise at around 295 KIAS or MACH 0.78 .... and which is about right.
I simply can't replicate the issue you've described .... at least not in accordance with the way I fly our B727 simulations.
Just a few advisory details ....
In the case of our JT8D-9 powered B727 simulations, when correctly paired with our corresponding JT8D-9 panels, the maximum power setting used for TO should not exceed N2 94.2% .... and which equates to the indicated pre-bugged EPR value of 2.04 (that for the JT8D-7 it's lower .... and the -D-15 and -17 each correspondingly higher) if you're using the panels we market. If you're not using our panels .... then .... all of my words will be about as useless as tits on a bull.
"IF" .... you're using greater than the recommended maximum power setting and/or are too slow to reduce power after clean up .... and/or are flying a shallower ROC .... and/or are much lighter than MGW also .... THEN (all of these factors combined) .... you're likely going to get into trouble with airspeed and very quickly if you don't manage the power.
"IF" you've set a much lighter than MGW loading .... THEN .... you can/should probably be using a reduced TO power setting (just as we advised in the case of a similar L-1011 report) .... provided you've also got a good RWY length of course, or in cases of shorter RWY's, use the recommended maximum power setting, but, once cleaned up after T/O opt to use a less power throughout the climb and whatever ROC might be appropriate in order to keep airspeed under control. I read your evidence that you've apparently done this, but, I've never known power indications to be "THAT LOW".
Flying these B727 simulations .... at no stage should the AI pitch attitude ever be allowed to exceed +10 (+11 at the very most) degrees.
Again .... I can't replicate your problem in accordance with the way I/we recommend these simulations be flown
I suspect your difficulties may simply come down to "technique".
Dare I ask though .... Have you, by any chance, applied any FDE editing yourself ?
PLEASE NOTE: I'm not suggesting you've edited your FDE's, but rather, are merely inquiring as to whether, or not, you may have.
Other than the above advice ....
I also note you say you've checked your panel/base pack assignments .... BUT .... suggest you re-check these once again. The FDE supporting these simulations represent different weight and power statements for each aircraft version and if mismatched "WILL MOST CERTAINLY" throw performance/s right out of whack.
Try reinstalling everything also .... just in case what you currently have was corrupted during downloading processes. Such "CAN" (albeit rarely) happen.
Post by aerofoto - HJG Admin on Oct 9, 2021 7:42:44 GMT
No problem "FITCH".
Just remember .... a 50% reduction in fuel load is "A BIG REDUCTION" weight-wise.
So any time you contemplate light weight operations consider using reduced TO and climb power settings also to curb over-performance .... and bear in mind also such a markedly reduced weight factor is also going to alter the entire climb profile too.
Post by Mike Monce - HJG on Oct 9, 2021 12:35:19 GMT
Mark has pretty much answered the question. I would just add that the reason for the flight guides and our FDE development set for MGTOW is that if the sim won't perform properly at that weight, it won't in lighter load regimes. FS does fairly well as the plane's weight is reduced from MGTOW.
I will also say, the only time I ever have a plane at MGTOW is when testing. For 99% of my flying I set the fuel load as close as possible to real world expectations based on length of the flight, altitude, and since I use Active Sky, winds aloft. Much of the time that results in 50% or even less fuel load. Most modern airliners with their FMS have derated takeoff settings which guide the pilot for thrust settings based on weight etc. The 727, being a much older plane, it's up to the pilot to do the "derating". For me, a general guideline is never exceed 92% N1, or the equivalent in an EPR rated engine at lower weights on takeoff. And you will have to decrease thrust on the initial climb especially as the gear and flaps come up and the drag decreases. Experience and practice; which is the funpart of flying these "classic" type planes.
Pilot reports Number 3 engine missing. Mechanic replies: Engine found under right wing after brief search.
Post by aerofoto - HJG Admin on Oct 10, 2021 3:51:30 GMT
Well presented/explained Mike
Mike and I spend more time (than we can or should justify before our wives and families) fine-tuning/tweaking FDE's than we often have available to use FS for our own personal enjoyment.
Unlike almost everyone else we (at least I) seldom get the chance to fly FS outside the impositions of development and testing work
I want to elaborate on a particular detail Mike mentioned (above) in regard to weight assignment/s in FS.
The situation "IS" precisely as he relates/explains in regard to the lighter most simulations become the less authentic they're inclined to feel and perform.
Some developers use overstated weight assignment/s to assist FS performance .... to generate "a feel" for a simulation.
At HJG we "DO NOT" do that.
The weights we assign to each simulation generally come straight from straight the manufacturers book .... depending upon which material one references as as even among official information it's not uncommon to find contradictory data, so, what we compile is correct "in accordance with the best technical data we can source".
We find plus or minus 500 LBS to 1,000 LBS of weight. or engine thrust, variation is sufficient to make a difference (that we notice at least) "in FS".
The overloads one sees among our flight line .... prior to fuel and/or payload adjustment/s .... are quite accurate too. This "IS NOT" not done to add "weight for feel". We always compile full (100%) payload and fuel load capacities into each of our simulations. The end user is then expected to manually adjust either, or both, within the FS Payload & Fuel schematic for the purposes of their intended virtual flights .... to the extent that if range is one's priority then one needs to sacrifice payload to promote more fuel for greater range .... and if payload is one's priority (usually my own) then one needs to sacrifice fuel load accordingly but at the expense of range. This's all "BASIC FLIGHT PLANNING" .... but again .... we offer the ability to do this "by default" for the benefit of those whom like doing so.
So long as our simulations are flown "relatively full" .... then .... they usually perform, and feel, feel "about right", but, if subjected to drastically reduced loading's one then has to "accept whatever performance/s" infidelities that may result .... and which is simply "an FS thing".
The MS FS platforms may be "As Real As It Gets" .... but .... whilst good/enjoyable they're certainly "NOT" entirely realistic .... and which is something that needs to be understand/accepted
Therefore enjoy it for what, and the way, it "IS" .... is our "VERY BEST ADVICE"