DYNASTY HVY

I was too busy watching him miss the fence !

Cubdriver

The run rate is accelerated in this video clip which distorts it somewhat. However, no-flap landings are fairly common in light aircraft of this type when crosswinds are stiff. It serves to stabilize the aircraft and make up for the low mass of the airplane.

Thedude

I though the 228 had to watch for bird strikes from behind.

Twin Wasp

I had to do a no flap landing for my 727 type. Ref +60. You start banging into tire speeds at normal weights. Feds finally figured out the chance of not being able get any flaps out with 2.5 hydraulic systems was miniscule and dropped the requirement.

NoBeta

Ohh..... no worries. Must have been TM....

bcaviator

no flap or partial flap landings seem to get assigned often in training, and at FSI they used to give me a hard time about knowing landing distances. My solution has been to find the longest possible landing distance for flaps up, that the chart gives numbers for. Write that number on the flaps up approach and landing checklist, and there you go. As long as the runway is longer than that number you are good! (ex. 4300 in a KA 350)

Singlecoil

You lost me there. The answer I would give a student would be that for a given crosswind, a higher speed will result in a lower wind correction angle to maintain a straight ground track. Increasing speed also gives you more rudder effectiveness. An excellent way to fly an approach at a higher speed is to use less or in some cases, no flaps.
Flying at a faster speed allows you to transition from crab to side slip with less of a crab to kick out, and a more effective rudder to kick it with.

Cubdriver

For flight training those would be good answers and they are correct. But I often think from an engineering perspective as opposed to an airplane drivers perspective. You can think either way, one gives better piloting skills while the other gives better scientific understanding. Reynold's number is lower for smaller aircraft because of the smaller mass- Reynold's number is the ratio of viscous forces to inertial forces for air moving over the aircraft. You can alter the equation by flying faster. More significant is the greater ratio of dynamic pressure (air speed) to control surface effectiveness by flying faster. This is the same thing you are talking about- better rudder effectiveness. Your other points are also good.

Cubdriver

I was thinking about this and felt bad that we did not explore it more. It is such an important topic.

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No one explicitly mentioned the most important thing about this, which is the fact that for no-flap landings your aileron authority is better because the airplane is simply going faster. Control in the roll axis is better at high speeds. Increased rudder authority is the other advantage, as SC already pointed out.

But a few, inexperienced pilots will say oh, you want those flaps in high winds because as the airplane settles there may be a sudden wind change and you risk dropping the airplane to the runway. True, but I would much rather retain my aileron authority than give it up for a slightly lower stall speed.

Another thought. With flaps you have a boosted lift curve slope for the wing, and if there is a sudden gust the airplane is prone to ballooning. Another way of looking at this is through the lift-to-weight ratio. Airplane A weighs the same as airplane B but A (flaps down) has a higher lift curve slope due to the flaps. Since weight is one of the forces acting on an airplane and weight is opposed by lift, you want to reduce the lift factor so the airplane may be stabilized by its own weight. Sort of like two balloons with two equal rocks hanging off. The smaller balloon is more stable against gusts.

My argument above concerning Reynolds number (Re) may be technically correct but it is pretty weak. Sorry about that. Lighter airplanes have lower Re numbers and the idea was their flight control surfaces are somewhat compromised by the lower Re. Creative argument, but the problem is it has nothing to do with gusting winds so scratch that.

Someone might ask if no flap (slat) landings are so useful in gusting winds, why don't transport aircraft seem to perform them. I think the answer would be those aircraft will stall before getting to the airport due to the nature of the wing. High-speed wings must use high-lift devices to make up for their weak low speed lift characteristics. My guess is that heavy jets still use less flaps on windy approaches, but I am not a transport driver.

jungle

Transports usually stay with normal flap/slat setting regardless of wind, not because of stall but because your Vref can end up near 200 knots and that takes a lot of concrete, nears the tire limits and tends to get the brakes excited. They also have two sets of ailerons on some heavies that only activate the outboard set below a certain speed/flap/slat setting.