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KevinAu

A few aviation questions

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Hey, Vne = Never Exceed Speed, you're correct. TAS (True Airspeed) in cruise depends on several things: Pressure Altitude, Temperature above/below standard, and weight. There's probably a few minor factors, but those three are what I use when flight planning in the 172S. I really can't help you out with the Primary Trainer and Trainer. Hope this helped!http://www.kthxdone.com/images/kw_ft.jpgKen Weik [link:maam.org|MAAM-SIM][link:library.avsim.net/search.php?CatID=root&SearchTerm=kenneth+weik&Sort=Added&ScanMode=0&Go=Change+View]My AFCADs

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Hi James,Vne is never exceed speed - the red line at the high end of the airspreed indicator range.The reason cruise speed is not always stated is that true air speed varies depending on the power setting, the altitude, and the temperature aloft. The power setting can be adjusted for best power (fastest TAS) or best range (lowest fuel consumption). The Pilot Operating Handbook or Approved Flight Manual for an aircraft will contain cruise performance data for various altitudes, temperatures, and power settings.Regarding "primary trainer" versus "trainer aircraft," a primary trainer (to my mind) is one intended for training someone for a basic pilot certificate. Other aircraft may be suitable for more advanced training, such as a Piper Arrow or Beech Duchess, which are used to teach complex or multi-engine aircraft operation.My $0.02 ...John

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I agree with the primary trainer bit. The terms, and you will come across this often, is Ab-initio training. Any aircraft suitable for ab-initio pilot training is a primary trainer, like primary education if you like. The characterisitcs of a primary trainer are of a non "complex" type; fixed undercarriage and usually a fixed pitch prop. The BAe Bulldog was a primary trainer for the RAF and had a constant speed prop. Aircraft are defined as "complex" with both constant speed prop and retractable undercarriage.Cruise speed, when quoted, quotes the aircraft's highest speed in a standard ISA atmosphere. That is 15 Celcius temp, 1013.2 mb pressure and a density of at sea level 1,225 gm/M^3. With temp assumed to decrease at 1.98 celcius for every 1000' to 36,090' (then constant) and density and pressure reducing with altitude in the ISA defined non-linear way. Because, for a constant IAS TAS increases non-linearly, the maximum TAS is often determined by the critical altitude of the aircraft. The critical altitude is the height where full throttle can just about hold cruise settings/power (piston fast cruise is 75% of max power). For a turboprop, the limit is simply the capability of the props. For jets it gets quite complex. For hi-bypass engines, the N1 compressor provides 75% of thrust and acts like a poperller so it is halfway between a turborpop and low/non-bypass jet. For low/non bypass jets, the limitations are often hull pressurisation limits more than anything.Anybody still awake?

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Generally speaking a primary traiuner is used to teach pontential pilots to fly. A trainer is used as an intermediate step, particularly in military aviation, to give further training to pilots before they move onto to front line types of aircraft.

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Yes, I'm awake and do not agree with the claim that the limit of turboprop cruise performance is soley the capability of the propellers. While this may be theoretically true, the aircraft I fly (with the PT6 engines), have four limits that must be observed - max prop RPM, max %Ng, max ITT, and max torque. Max %Ng and ITT are constant. Max allowable torque will vary with the prop RPM and the altitude.Depending on the conditions and the quirks of a particular engine, you may reach the ITT limit before the torque limit is reached. Sometimes a particular engine torques out before it temps out.BTW, there are at least two ab initio training programs I know of that use the Beech Bonanza (a high performance and complex aircraft) for primary training. Go figure ...John

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The military version of the primary trainer has been a quite advanced aircraft for many years. The T-34B and now the Texan are quite exciting birds.For a primary trainer in the US these days - you'll most likely find C-172 or C-172SP's and very few C-150/52 aircraft.Most of the larger flight training outfits have at least one Piper Arrow/ Archer with fixed gear - maybe more.At the current cost of training, many places are finding the people with the money to take flight training are unwilling to fly very old aircraft (20 years +).Though there are some available for the student on a tight budget.Surprisingly there are quite a few places where a student can do all but their first 10 hours in a glass cockpit C-172 or Piper Archer III.Even programs like the University of Oklahoma are buying glass cockpits for most of their new aircraft.The rational behind this move is that time NOT in a class cockpit is wasted time for someone working on a commercial rating. Yes there are a lot of commercial aircraft without glass cockpits - but even at many companies with no glass in their fleet - you don't get an interview if your log book doesn't show a lot of glass time.I do not think that is a good plan for a new GA pilot - but ....

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For a while. Doesn't last long though, and soon after it drops again until it reaches the near absolute zero of space.

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I agrree with your last point.Military aviation is different. Pilots will eventually fly complex and/or heavy aircraft so their training needs to be aimed at that from the beginning. The military select potential pilots on the basis of their aptitude and can be ruthless in the selection process. Because of this military primary trainers are more advanced than those used for civilian training, if only because the can be! There is little point teaching a military pilot how to fly, say, a C172 with conventional instruments if only because the pilots will soon have to unlearn the techniques and learn new ones.

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>The rational behind this move is that time NOT in a class>cockpit is wasted time for someone working on a commercial>rating. Yes there are a lot of commercial aircraft without>glass cockpits - but even at many companies with no glass in>their fleet - you don't get an interview if your log book>doesn't show a lot of glass time.>>I do not think that is a good plan for a new GA pilot - but>....I do, but then I've been using aviation moving map GPS's since first available. The moving map adds greatly to situational awareness, and the glass panel does the same. After flying in two different airplanes with the Garmin 1000 and Avidyne systems, I'm now, even farther convinced.A recent test with new flight students that went through the private course and instrument rating, using glass panels & the standard instruments, shaved off an average 45 hours by using the new glass panels. Their training started immediately with navigation and IFR technique. The glass students were behind the standard instrument students in flying technique for the first few weeks, but soon jumped ahead, overall. Link to test:http://www.avweb.com/newspics/ab-initio_tr...cockpit_era.pdfI have a Sporty's Garmin 1000 DVD with Richard Collins who writes for Flying Magazine & has done many video's in the past. He's been supporting GPS for many years now, as have I. At the end, he states that many pilots will always believe the "old way" to be the better choice, but to him, it's like going back to fly old WWI aircraft. I agree! :D L.Adamsonedit: My thoughts are the way they are, because of the mountainous terrain of where I live. Every year, we have both VFR & IFR pilots flying into terrain because of situational awareness losses. These glass panels are amazing when it comes to situational awareness of terrain, other airplanes, weather, TFR's, restricted airspace, and even the planes attitude.

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This is totally irrelevant to the post - but I've found that I can fly in FS amazingly well in mountains with the FS GPS displaying the terrain features.I can definitely see that technology as a major advantage and lifesaver in the real world.

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Sorry, I didn't mean the real physical it can't do no more limit, I meant the operational limit, the point at which the whole thing just becomes and an expensive air wisk rather than a high tech means of transport :)

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As jet streams are typically found in the upper troposhpere or low stratosphere then either the temprature will continure to fall or remain constant above the jet stream. However, as a jet stream is caused by confluence of cold and warm air, within the jet stream structure, above the high speed wind, the temprature will be warmer as warm air will push over the top of the cold (or visa versa).

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In mountainout terrain, if you are vally flying on GPS (which you wouldn't be in reality), you would only be able to see satalites above you, you position resolution could be pretty bad, not what you would want in such a situation. I also imagine (because I don't know for sure) that there must be some posibility of the UHF signal bouncing of the side of a mountain or two, increasing the amount of time it takes for the received to get the signal and this increasing the error still further.I reamin very sceptical over the reliability of GPS because the very weak signal strength. This is having seen my own Skymap IIIC telling me I was 5nm north of where I knew I was too!!

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>I reamin very sceptical over the reliability of GPS because>the very weak signal strength. This is having seen my own>Skymap IIIC telling me I was 5nm north of where I knew I was>too!!>I trust them a lot, at least in the U.S.. As an example, my Garmin 296 hand-held has 12 channels, usually pics up at least eight satelittes at a time, and requires four for a good fix.A Garmin 1000 glass panel uses two independent GPS's and uses the one with the best incoming signals. Last year, a friend & I, put about 29 hours of cross country on an airplane with a dual axis auto-pilot that relied on the panel mounted GPS for heading information. No problems at all, except when a thick "flight guide" was sitting on the antenna which is located under the windscreen on top of the glareshield. edit: these small solid state gyro auto-pilots are widely used in experimental aircraft. Reading as many experimental/kitplane forums as I do, I always read how well the A/P works for cross-country's & seldom any problems; keeping in mind, that the A/P depends solely on the GPS for guidence. When I say small, the gyro itself, will fit in a 1/4" cube. Quite different from the spinning motorized gyros of yesteryear. L.Adamson

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The Grobs are not used in the role of primary trainer. They're used as pre-selection trainers. Aspiring pilots get a few hours of Grob time to determine whether they "have what it takes", "are naturals", etc. etc.In other words, to weed out those who want to but likely will fail in the actual training process.Those who succeed in this first step then go on to Tucano.

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>be some posibility of the UHF signal bouncing of the side of a>mountain or two, No, signals don't bounce of a mountain or two.>I reamin very sceptical over the reliability of GPS because>the very weak signal strength. With your understanding of physics you should be.Michael J.

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Hey, I think I'm in the right place.. my previous experience has been hanging around the MSFS forum and the screenshot forum so I'm not too sure :) I've been an on-and-off simmer for around 4 or 5 or 6 years (I can't remember). Recently, I have began an undergraduate degree in Aerospace Engineering and have been pleasantly surprised, how much flightsim, with all its quirks, helped as background knowledge for this course (at least the flight mechanics bit anyway). I do have a few questions however, if anyone is willing to answer. I have been looking at aircraft performance mainly, and am wondering what VNE speed stands for, I think its the absolute maximum never exceed speed, but I'm not sure. Also, while looking up aircraft data, I have found that sometimes I cannot locate a cruise speed, maybe just a speed such as trimming speed range or a manoeuvering speed. Is there a reason for this? This may sound like a silly question, but is there a difference between a primary trainer, and a trainer aircraft? When looked up on the internet, they give different things. I would have assumed primary trainer would be your Cessna 150 or Piper Arrow type of aircraft. I would very much appreciate someone shedding some light on these questions! I'd also be interested to hear from anyone who is also studying this course (or similar) or has studied it! Many thanks, James:-wave

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What the Garmin high end kit introduces is RAIM. The kit can't improve on the fundemental weakness of GPS signals, but the RAIM system ensure sufficient satelites are tracked and compared to each for errors with additional available for redundancy. If that is not the case then you get a warning, and those warnings are no infrequent. With stuff like the Skymap, there is no such system.

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>This is totally irrelevant to the post - but I've found that>I can fly in FS amazingly well in mountains with the FS GPS>displaying the terrain features.>>I can definitely see that technology as a major advantage and>lifesaver in the real world.We actually do. EGPWS is replacing GPWS on aircraft now. Enhanced Ground Proximity Warning System uses the GPS/FMS derived position of an aircraft in relation to a stored database of terrain in order to generate terrain warnings. The radar altimeter is out of the picture in many of the modes.

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>The Grobs are not used in the role of primary trainer.>They're used as pre-selection trainers. Aspiring pilots get a>few hours of Grob time to determine whether they "have what it>takes", "are naturals", etc. etc.Not entirely true. The Royal Navy use the Tutor/Heron for "Grading" (preselection) before entrance to Dartmouth than Elementary Flying Training on the Firefly, but all RAF pilots now do just over 60hrs on the Tutor as their elementary flying training. At this point they are then streamed to Linton (Tucano), Shawbury (Squirrel/Griffon) or Cranwell (King Air) for the next stage of their training.

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