Poor 'Standard Atmosphere' Found in FS9

[tgibson 11]

Hi,Something that might be the problem - The gauges for the default minipanels must be in the main FS2004 GAUGES folder (or in the Minipanel's PANEL folder?). I had all my gauges in my plane's PANEL folder and they wouldn't show up in the default minipanel (duh!).I do love the new ability to put the panel's gauges in the panel's PANEL folder, though - keeps the gauges much better organized.Hope this helps,

[Guest Ron Freimuth]

>I made some tests of Mach number today with the Learjet using>my air data package to which I added Mach number to 3>decimals. At several points from 30,000 ft to 41,000 ft I>compared the observed Mach number with the value calculated>from true airspeed and temperature. They matched exactly in>all cases. Mach Number and 'TAS' are essentially perfect in FS. I also calculate 'Mach 1' at the current Temperature and TAS=Mach1*Mach. Though, I noted a 0.5 ft/s error a couple of days ago. I can live with that. I was going to show an image of my XML test gauge, but when I tried to add an attachement I got 'error on page'. >Thus, if you fly using Mach number as a guide, you will get>the proper true airspeed. This is indeed what you should do>from 30,000 ft up. But, one should also get the appropruate 'IAS' reading on the panel. It depends on the AC, but more than one jet FM shows IAS for some cruise conditions. I know Mach 0.742 at FL 350, ISA, should result in IAS = 250 kts. B727 info also says there is no calibration error around 250 or 280 kts IAS. Only the standard 'compressability error'. I have graphs of CAS vs Mach and FL. They include compressability effects (which start appearing around 200 kts IAS). I was able to adjust the REC 1101 'Airspeed Weighting Factor' to get a close fit to those tables. "+32200" gives a good fit. The default makes IAS read about 5 kts high at FL 350, Mach 0.74. The 'base offset' should be 0.0. But, MS, in its infinite wisdom, has now killed that adjustement. Flying the same AC in FS9, the IAS error is back. I put that [airspeed indicator] block from the C208 in my 727 aircraft.cfg file but have not yet experimented to see the effect. I have also adjusted that AIR file parameter against PoH CAS vs IAS tables to get within 0.2 kts at two speeds, and probably about as close at others. The -10 kts was still a good offset setting. Of course, the gauge needs to be appropriate for these AC. >True airspeed in a sim is the direct result of the>integrations of the accelerations. That gives it as good a>level of accuracy as the sim can deliver. Indicated airspeed,>which must be used by pilots below 30,000 ft for proper>control of the aircraft, is a calculated quantity from the>true airspeed given the density ratio. But I am beginning to>think that MS is corretly using mach number to introduce a>deviation into the IAS value which could occur in the pitot>system due to Mach effects. Maybe this was explained in one>of the Learjet documents I failed to read. 'IAS' is important only for the pilot. q, TAS, and Mach number are what count in the aerodynamics. 'IAS' only appears in a few places in the AIR file, those REC 1101 adjustment parameters are one place. I need to find the formula for EAS. I have come to realise it is the value 'that counts' when compressability comes in. I calculated it backwards in my test gauges, but the display field is blank. At least in FS2K2, XML is very fragile and readings often disappear when I edit the code. I just added 'p', Roll Rate, to my test gauges. I can now see Roll Rate very nicely. To 0.001 deg/sec/sec. I'll add other useful rates as time goes on. Ron