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Old 05-20-2019 | 09:38 AM
  #23  
Hydro Junkie's Avatar
Hydro Junkie
 
Joined: Nov 2004
Posts: 10,629
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From: Marysville, WA
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So you're telling me that I know nothing about aircraft EVEN THOUGH I HAVE DECADES OF AIRCRAFT EXPERIENCE????
Seems to me that having had full sized flight instruction as well as decades of aircraft maintenance and repair should count for something. BTW, I never claimed that I flew any of those aerobatic planes, didn't have to either since it's not needed to understand the basics of aircraft design and operation.
Now, to quote your last post "Remember that a model airplane is a bunch of compromises, what can be benificial in one area can be detrimental in another" doesn't just apply to models. The wing designs used on Boeing jetliners are a compromise of high and low speed efficiency. This meant the wings had to be optimized for flight with speeds into the trans-sonic range yet they needed a high lift design for slow speed operation during take off and landing. To get the required flight characteristics, an airfoil with a fairly thin height was used to keep drag at a minimum yet with enough lift to support an airliner weighing in at over 200,000 lbs. To get the needed slow speed performance, hydraulic retractable slats are used on the leading edge of the wing to increase the wing thickness while hydraulic fowler flaps are used at the rear of the wing to increase wing chord. The use of flaps and slats provide the lift and low speed performance needed for take off and landing, the most dangerous part of any flight. They are also part of a series of trade offs:
  • Slats add a weight penalty due to actuators, hydraulic lines and fluid, as well as operating linkages, tracks and switches
  • Flaps add a weight penalty due to drive motors, hydraulic lines and fluid, tracks, linkage and switches
  • The added weight of the flap and slat mechanisms are something that has to be overcome by the lift generated by them at low speeds or the wing itself at high speeds
  • The added weight of these "lift enhancing systems" lowers the amount of weight the plane can actually carry, making the use of larger wings a requirement or, conversely, removing seats or limiting the amount of cargo that can be carried to keep the plane within its weight and balance limits
BTW, I built my first R/C model in 1982 and my first R/C aircraft in 1986. I've learned, over the years that, since an R/C doesn't have the same weight and mass as a full sized aircraft, it won't perform the same as the full sized aircraft. In some ways, the full sized plane is actually harder to set up since you won't have the same weight and balance on every flight like you will with an R/C

Last edited by Hydro Junkie; 05-20-2019 at 09:47 AM.