properly executed fixed gear design does not give up any significant perfomance to a RG design
Isn’t that a bit simplistic? Surely the inherent cost (in weight and complexity and reduced reliability) is more and more justified as the speed goes up? I mean, there are neither combat planes nor airliners with fixed gear, today, there must be a reason for that. Oh and don’t come and tell me of the Twin Otter and the Islander and the An-2, those types do get used in both roles, I know, I know. But as performance goes up, so does complexity.
complex-pilot wrote:
Give me a fast new retract anyday!
And I’ll race you for pink slips !
I’ll race (and beat !) any 4 seat, normal certified production aircraft ever built.
What don’t you guys get ???
The thread subject was sturdiness, not speed.
The 182 is available as FG and RG, too. As is the 210/205. There are many experimentals offering both.
But you could do the math, as well. You have to balance drag from the FG (assuming it doesn’t create any lift. If it does, it get’s worse for the FG) against the drag created by additional weight of the RG. That is, if you wanted to see who is more efficient at a given speed. You will hit a velocity, where the reduced parasitic drag outweighs the added aerodynamic drag by that added weight. My guess is that this speed is well below the max cont. cruising speed of the Acclaim.
If you gain for better speed per installed power, you will definitely want to tug away that gear, because added mass (wing loading) is shifting your best glide speed towards higher velocities and the drag has an adverse effect on aerodynamic efficiency (= glide angle at a given speed).
Furthermore, the Acclaim gets her 242KTAS out of 280HP, whereas the Cessna 400 uses 310 HP for a top speed of 235KTAS and the SR22TG5 gets 213KTAS out of the same 310 HP. I think I can easily justify the assumption that the Acclaim is the most efficient of these three aircraft.
That said, I have no intention to diminish the other two planes or the engineers achievements. After all, there is more to a plane than aerodynamic efficiency.
Peter wrote:
There are very very few such examples.
Doesn’t anyone fly the C172RG? I have flown it but cannot remember the performance numbers.
Jan_Olieslagers wrote:
The thread subject was sturdiness, not speed.
No problem.
The Cirrus actually has a very poor nose whel design :
Michael wrote:
The Cirrus actually has a very poor nose whel design :
So does a PA28 
“
For all intensive purposes isnt drag proportional to the square of the velocity?
If you’re looking for direct retractable versus fixed gear comparisons, this one provides some unusual data:
The speed difference is about 5 knots. Some argue that this or a tailwheel is the optimum compromise between drag and weight/complexity for a medium speed plane. Burt Rutan’s Long Eze uses the same solution, with the same reasoning.
