@Geofly123 's topic “Spoiler’s on Decent” led me back to thinking about IF landing count. The connecting issue: how to slow down fast enough.
Within IF I can think of 3 highest priority situations for the need to slow down:
1)250kt speed limit below 10,000 feet
2)final approach speed (for controlled landing)
3)turn arounds for building landing count
In efficiently building landing count in my available practice time I likely want to both speed up as fast as possible followed by slowing down as fast as possible.
Of course flaps and gear add drag and spoilers add drag.
But somewhere way back I stopped using spoilers for the slow down part. That’s of course because tight turns are more effective at “dirtying” up the drag.
So I’ve come to believe the best aircraft for building landing count are those that can bank fastest into the steepest turns possible without stalling, while achieving the highest possible acceleration up until that turn around point.
The physics part I had to re-think through was: why the slow down in the turn?
Paradoxically a turn in direction itself does not directly change energy, so it doesn’t decrease speed.
But in an aircraft, the added force to change direction doesn’t come for free (as opposed to a ground vehicle).
The only force available to make the turn is lift (that’s why you bank). So lift is now doing double duty: holding up the weight of the plane plus pushing it around the turn.
And the ONLY way of making more lift at a given IAS is to increase your AoA (angle of attack).
But the key to the quick slow down: the higher range of usable AoA adds a big drag penalty compared to the added lift you are coaxing out of the wing.
So a quick aircraft (fast speed plus quick acceleration) with the best ability to roll into the highest drag penalty bank position (and not stall when maxing out the AoA) should be my best aircraft for building landing counts.
In summary I should aim for:
1)fastest race to the turn around point, followed by
2)quickest positioning into highest possible banked AoA
But which aircraft?
In less aerobatic flying, turns of course are the only effective way of managing the slow down when flight spoilers, flaps, and gear are not enough.
