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JSACKS

Flight1 Cessna 172 vs Default FS9 Cessna - Performance Q

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I love my Flight1 Cessna 172 but she seems to lack power on takeoff as compared with the default Cessna 172 model. I just took off in each from St. Bart's, that scary but very pretty little 2100' long field in the Caribbean. The fully tanked Flight1 Cessna achieved 60 knots after eating up about 80%-85% of the runway and after rotating at that speed (with flaps 10), clipped a hedge low down, lost speed on climbout and crashed over the hill. The fully tanked default Cessna in comparison achieved 60 knots at 50-60% of the runway (and in a further test was at 70 knots at the point where the Flight1 Cessna was just scraping 60). So the default Cessna easily made it out (rotating at just over 60 knots) and over the hill and we all survived.Is the Flight1 Cessna in fact underpowered and if so, how do I tweak the cfg file to get a tad more power out of her?Appreciate any observations, info, or advice from others. Thanks!JS

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I should think it's 'tother way round. - the default model is no doubt overpowered.

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Aha, that is interesting. Well, if that is the case, then so be it! I am far from expert on this aircraft, or on props in general, that is why I posted here. JS

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Every payware aircraft i've used has always had more realsitic (read less power) power curves than the FS counterparts.

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The Flight1 Cessna is a 172R model (1996), which was derated to 160 H.P.The later SP model (1998), which I believe the default is, is rated at 180 HP. Same engine, but different prop & higher r.pm. redline.L.Adamson

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Ah, further enlightening. So now I know: no more St. Bart's takeoffs for the Flight1 Cessna!JS

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Hi JS,I don't have the Flight 1 Cessna 172, but out of curiousity, try this. No flaps, hold a bit of back pressure on the yoke/stick and as soon as your bird breaks ground, lower the nose to pick up airspeed. Hold it until the "last moment" then firmly, but gently, pull back on the yoke/stick (not yank it) and over the hedges you go. Hopefully. :-zhelp Let us know? :-hmmmRoger

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Some other points to mention would be if the Flight1 Model was overloaded? Full fuel adds a lot of weight. Also you have to worry about Pressure and Density Altitudes, these have a huge effect on engine performance. The higher the field, the lower the performance.

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I don't think that applies in this case. All was at sea-level and the a/c was slightly below max gross weight. I also did a takeoff test at 50% fuel only and was thus comfortably below MGTOW and I had fairly similar results. I am just surprised that the Flight1 Cessna can eat up around 1900 feet of runway getting to 60 knots at close to MGTOW with flaps 10 set and use up not much less concrete with only 50% fuel too. But I shall keep testing for a bit and try a takeoff with no flaps and see how that goes.The climb out over the St. Bart's airport hill is just a killer for the Flight1 Cessna because it requires a climb angle of 1000-1200 fpm for a few moments to clear the terrain and during such a maneuver, the airspeed drops heavily to stall speed. In the default Cessna, I can just maintain 60 knots and clear the hill by 20 vertical feet and then accelerate with no problem. No such luck with the Flight1 Cessna but now I understand from this forum thread that the Flight1 Cessna is in fact less powerful.JS

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>The Flight1 Cessna is a 172R model (1996), which was derated>to 160 H.P.>>The later SP model (1998), which I believe the default is, is>rated >at 180 HP. Same engine, but different prop & higher r.pm.>redline.>>L.AdamsonYup..L.Adamson got it right!Manny

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>The climb out over the St. Bart's airport hill is just a>killer for the Flight1 Cessna because it requires a climb>angle of 1000-1200 fpm for a few moments to clear the terrain>and during such a maneuver, the airspeed drops heavily to>stall speed. Looking up the 172R's spec sheet; I see that it's only rated for 720 fpm at sea-level/ gross weight. In other words, don't even try a straight out climb that requires 1000-1200 fpm; at least in real life. These planes just are not performance demons, and you really need to pay attention to payload & density altitude, with these machines.L.Adamson

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The first place I every heard of density altitude was at a near sea level tropical airport.At certain temperatures, dewpoint and pressue settings - our A-3 Skywarrior jets could not takeoff NAS Agana Guam (PGUM) with a fuel load sufficient to reach the Philippines or Japan. 298 ft ASL - 10,000 ft runway.Remember the aircraft spec charts are for 56 degrees F - and it's never that cold on St Barts.On that short runway - temperatures in the high 80's / low 90's can result in a density altitude issue which basically takes away 10-15% of the runway.

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I would like to try the St,Bart's t/o using the default C 172, but at reduced power. :-lol Would anyone care to suggest an rpm for this that would duplicate the Flight 1 Cessna 172's 160 h.p. engine? Roger

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Not a bad stratagy, but it's not really STOL precedure is it?

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Hi Jon,You got that right! I've been messing around this morning trying 2OO0 rpm from RW 10 at St. Bart's. I've "killed myself" about 7+ time so far. One thing that makes it harder is that FS 9 default does not place you at the exact end of the RW. I've taxied back a few times, but it's hard to get exactly at the very end and spot on looking straight down the center line. I've made it off a few times from the default placement, though. No flaps > hold the brakes > throttle at 2000 rpm > leave the trim at 1-notch above the T/O stetting > pop the brakes > as she rolls, hold firm forward pressure on the yoke ( I have a CH yoke ) to hold it on the RW for gaining speed > at the last moment when you see the other RW number ( you should be a tad over 70 mph and your knuckles white ) haul back on the yoke and, here's the tough part, try to maintain between 50 and 55 mph...closer to 50 better.(1) DON'T TRY THIS IN A REAL AIRPLANE (2 ) if you have passengers on board, tell them to close their eyes (3) have a pot of tea or coffee for a cup in between mishaps. :-)Roger

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