Stalls at “Any Attitude, Any Airspeed”

Every pilot learns that a wing can stall “in any attitude and at any airspeed.”

But it’s difficult to demonstrate that principle in a typical training aircraft. This video of an exercise that I do with my stall/spin/upset recovery students shows the value of training in an aerobatic aircraft.

I fly a basic loop, but at several points during the maneuver, I intentionally increase the angle of attack by pulling back abruptly on the stick. Each time I pull, the angle of attack quickly reaches the critical angle of attack, and the airplane shudders in an accelerated stall, regardless of the airplane’s airspeed or pitch attitude relative to the horizon.

In other words, you can change the airplane’s attitude (and its angle of attack) almost instantly, but changing its flight path requires more time. That difference between the attitude and the flight path is angle of attack, and when that angle exceeds the wing’s critical angle of attack, the wing stalls.

It’s also helpful to remember that a loop is just a vertical turn. The same principle applies when you bank the wings and turn an airplane in the horizontal plane. If you pull back on the yoke or stick during a turn, you increase the angle of attack. Pull back too aggressively, and the wing will reach its critical angle of attack and stall, regardless of the indicated airspeed.

Advertisements

Simulated Wake-Turbulence Encounter

I do the exercise below with my stall/spin/upset students to simulate the disorienting effect of a wake-turbulence encounter. We perform 1-1/2 aileron rolls to inverted and then push and roll to recover to normal upright flight. The exercise is confusing at first, and the nose always drops well below the horizon during the “upset.” It’s a great way to help pilots understand what could happen if they were caught in a wintip vortex.

Wake turbulence caused by wingtip vortices is major hazard to small aircraft.

WakeTurbulence

The wingtip vortices are a by-product of lift. You can find detailed information about wake turbulence in FAA Advisory Circular AC 90-23 and in the Aeronautical Information Manual (Chapter 7, Safety of Flight; Section 3, Wake Turbulence).

 

 

 

Short Aerobatic Videos

I have collected short excerpts from a recent aerobatic flight near Seattle, WA to demonstrate a few basic aerobatic maneuvers. Each video shows the maneuver first from the left wingtip and then from my perspective in the rear cockpit of the Extra 300L.

You can find many more videos at my YouTube channel, BruceAirFlying.

Early Summer Aerobatic Ride

Here are highlights from an early summer aerobatic ride in the Extra 300L east of Seattle.

The passenger from Switzerland enjoyed the view of the “Cascade Alps” east of Seattle as we flew through a series of aileron rolls; loops, half-Cuban 8s; big, lazy barrel rolls; slow rolls; hammerheads, and a little inverted flight.

 

 

Taking the Extra 300L for a Spin

Here’s a basic intentional spin in the Extra 300L. The camera shows the instruments in the front cockpit. Note the airspeed during the spin.

A Dose of Vitamin G

I practiced a series of basic aerobatic maneuvers on this flight out of Boulder City, NV (KBVU). I’d been busy working with instrument students in Seattle, so I needed to refresh my G tolerance and get ready for summer aerobatic flights. Keen observers will note lots of bobbles and other flaws. But it was fun to be back in the Extra 300L, which is a thoroughbred.

I mounted one camera so that you can see the control stick in the front cockpit. Note how little the stick has to move during basic maneuvers–only a slight deflection of the ailerons and elevator is required to achieve large effects.

 

Scenes from a Morning Aerobatic Training Flight

Excerpts from a training flight one lovely summer morning out of Boeing Field (KBFI) in Seattle. My student practices incipient spins that result from stalls during skidding turns, barrel rolls, stalls and spins from the top of barrel rolls, and aileron rolls and loops. This video has a music track, not the usual chatter and airplane noise.