Posted on

Simplify Flying: it’s attitude plus power equals performance

I’ve had the pleasure of flying with a retired airline pilot who really made me think about flying in an entirely different way. His view demystifies flying into it’s basic, component parts to understand a complex task and achieve a certain goal. Attitude plus power equals performance.

He maintains that after over 20 years of airline flying, he found there are two very important concepts in flying airplanes. Once these concepts are understood, will help you understand aviation and flying at it’s core. The most important concepts in aviation are ones we have all heard before, and it’s impossible not to overstate their importance. They are:

  1. Aviate, Navigate Communicate; and
  2. Attitude plus Power equals Performance.

Think about what flight training is trying to achieve. Yes, you are trying to pass your flight test, at a minimum, but you can certainly do better than that. You can be a great pilot. Why practice stalls and spins? To avoid entry, to recognize if one should occour, and how to recover. 

Let’s relate it to a few examples. 

Once our wheels are off the ground, we are in a ‘risky environment’ where it’s important to keep vigilant.  When we are airborne, our one and only task is no minimize the risk, using all of our knowledge and resources. So break it down into what you have to achieve once you’re wheels up.

Remember clearing turns? We do them so we can be safe and check for conflicting traffic, and not just because they are a flight test item. Risk mitigation is also why we have standardized procedures for uncontrolled aerodromes.

On takeoff, after rotation, the airplane is just passing through a very slow speed at a low altitude. On the 172 we rotate at 55 knots, so after we rotate it’s close enough to stall speed to warrant extreme attention, particularly given our proximity to the ground. When you rotate, will you pull the nose up excessively? No, of course not, you can easily enter a stall that way, a departure stall, and you won’t have the leisure of altitude to recover.

So when we depart, we use the combination of attitude and power to produce the desired performance that we want: a climb. When we recover from a stall is it necessary to push the nose down excessively? Not really, and if you think about what stall practice is meant to achieve, we really should avoid pushing the nose down too much.  If it works on a take-off, it should work on stall recovery. If we push the nose down too much, we’ll loose altitude, and if we stall close to the ground that can be dangerous.

The purpose of stall practice

Stalls are a great case in point. Stall recovery has no practical application in everyday flight like short field, soft field landings, navigation, circuits and so on. We only learn them so we can avoid them, learn to recognize when we are in one, and know how to get out of them. Licensed pilots who don’t fly professionally will find stall recovery skills atrophy after awhile, because unless flight training, stalls are something we want to avoid. 

What produces a stall? A high nose attitude where the angle of attack of our airplane can no longer sustain flight. Your attitude is nose high, the airplane will automatically drop the nose because it wants to fly.  A nose down attitude will break the stall, and the application of power will allow you to return to a normal flight attitude. Attitude plus power equals performance. Aviate: break the stall, return to normal flight, navigate: establish where you are; communicate: this includes communicate with your airplane. Why did it stall?  

How about the forced approach?

The forced approach is a good example. With an engine failure, we’ve got to: (1) aviate: establish the best glide speed, establish a controlled approach and landing; (2) navigate by deciding which is the best field to land our airplane at; and (3) communicate, make a mayday call on 121.5 and give our passengers, if any, a full off-airport emergency safety landing briefing.  For the forced approach, we use best glide speed, a combination of attitude and power (in this case, lack of power), that produces a level of performance: the descending glide.

cessna 172 lake view
cessna 172 lake view

A heap of metal

Remember the airplane is just a “thing.”

The airplane is not alive. Many things on the flight test and flying itself can cause confusion, and above all, anxiety, which can take the fun out of flying. When learning to calm anxieties, it’s helpful to think about the airplane having no feelings or malicious intent. It’s just a heap of metal that you control and has no goal or agenda of it’s own. It’s simply a tool, a tool that you, the pilot, control.  You are flying the airplane and the airplane is not flying you.

A blend of two important factors, attitude and power, will produce the environment that we can control. Like a car, the airplane is a predictable thing. When given certain parameters it will always do the same thing. Nose up? Airspeed will decrease. Nose down? Airspeed will increase. No power? It will enter a descent. Full power? It will climb. Winds will push the airplane in known directions, crosswinds will have a known effect on approach paths, and so on. 

It’s all well within our control.

Posted on

How to master the power-on stall

The departure stall

Throughout my training, I have done a lot of stalls, and eventually got the point where I was quite comfortable with them. Power off, power on, including the more advanced high power stalls.  I was rather surprised when doing my full review of everything before my flight test, when my instructor asked me to demonstrate high power stalls I became rather nervous and was unable to perform one without throwing in the aileron on recovery.

I had let my training lapse and it had been quite awhile since I’ve done these more advanced stalls.  A few power-off stalls allowed me to feel comfortable with them again but I continued to struggle with stalls using higher power settings, which cause sometimes a very pronounced wing drop due to asymmetric thrust, slipstream and other factors.

Why do we learn power-on stalls?

The power-on stall is basically a departure stall. We practice this stall to simulate a stall on departure, when we have a nose high attitude and high power settings (full power for take off).  How could we stall on departure? If we fly into IMC on climb-out, hence loose the horizon and become disoriented, possibly succumb to an illusion that we are level and not nose-high enough (not reference or trust our instruments which tell us that we are in fact in a climb) and we pull back too much.

The airspeed bleeds off, and without knowing it we are nose high. As the aircraft reaches stall speed one of the wing drops off and when uncorrected, can enter a spin. At low altitudes, we have  no time to recover. Before long we can be nose down in a spin with no altitude to spare.

Cessna 172 about to stall. Image from
Cessna 172 about to stall. Image from

Stall/spin accidents

There are a number of these stall-spin accidents every year, and most of them occour at low altitudes.  According to an AOPA study, from 1993 to 2001 stall-spin accidents accounted for 10% of all accidents and 13% of all fatal accidents for fixed wing aircraft weighing less than 12,500 pounds.   An earlier study by the FAA Small Aircraft Directorate analyzed a sample of 1700 stall-spin accidents as far back as 1973 and found that 93% of them began at or below pattern altitude, which was 800 feet back in the 1970’s.

So the reason we learn a high power stall is to avoid a dreaded departure stall and to recover quickly, with minimal loss of altitude, and in coordinated flight (avoid a wing drop).

More rudder coordination is required

The reason why a power-on stall can be more challenging and more scary, is because it will require more use of rudder than a power-off stall.  We must remember not to use aileron, ONLY rudder, because not is only aileron ineffective in a stall – the wing is stalled – it can also exacerbate or aggravate the  wing drop in a stall, making it even more banked.

Anticipate a wing drop

Generally with a power-on stall, we will get a wing drop. Because of asymmetric thrust and slipstream, we generally see the left wing drop. Recall the left turning tendency of the aircraft at high power settings, for example while on the takeoff roll. On the takeoff roll with full power we always apply plenty of right rudder to keep the aircraft on centreline.

However we will not always get a left wing drop, it can, in fact be the right wing that drops, requiring the use of left rudder instead of right to correct.   There are many reasons for this: one wing could have more fuel than the other and be heavier, it can also vary with the prevailing winds. So it is important not to anticipate one wing dropping but to watch which one does and react appropriately.

So one wing drops, so there is a tendency for us to use aileron to correct.  This is very natural. In a stall, we have to fight the urge to use aileron and instead, “step on the rising wing.” (thanks to my instructor Steve for the tip – it works!)  This means to use rudder instead of aileron, in the same direction if the rising wing:

Left wing drops (right wing rises): instinct will tell you to use right aileron – use right rudder instead

Right wing drops (left wing rises): instinct will tell you to use left aileron – use left rudder instead.

Check out this video as a power on stall develops into a spin. Looks like the student puts it into a spin (on purpose, note how he uses aileron) and the person in the right seat, likely the instructor, recovers.

How can I become more comfortable with these types of stalls?

In a word, practice will make them easier, as you do them over and over again and you are able to control them, you will regain confidence. Another great tip is to visualize the manoeuvre and talk yourself through it, when you are not flying. I used visualization and imagined one of the wings dropping, and what I would do. Eventually lost my fear as I learned I could control the airplane with rudder.  It is important to use rudder opposite to the turn to correct the wing dip as fast as possible, and to leave the aileron in neutral position.

Like anything with flying, repetition will help you learn and feel more comfortable over time. Practice means everything!



Posted on

Power-off Stalls

How to enter into a stall in Cessna 172.  Why do we learn stalls?

We need to be able to recognize when we are in a stall, to know how to recover. When trained, recovery becomes automatic when trained to react.  Also, we stall the aircraft whenever we land.

I first learned stalls in Edmonton, at CYBW after about 10 hours of flying.

For a power-off stall:

1)  Do your checks. These are a series of checks to do before we are allowed to enter into a stall.

At Centennial flight school in Edmonton we did the “HALT” check, which consisted of:

  • H for Height: make sure we are recovered 2000 feet above ground.
  • A for Area: we are not over a built up area, such as a residential community or over buildings.
  • L for Landing checks: I memorized mine, but they can also be retrieved from your checklist. They consist of: fuel selector valve on both, mixture full rich, carb heat cold, circuit breakers all in, primer in and locked, engine gauges in the green, seat belts on, doors latched, everything tied down in the back and positive pressure on the brakes.
  • T for Turn checks: we do clearing turns to check if the area around us is free of traffic.  We turn at a 30 degree angle of bank 90 degrees to our right, and 90 degrees to our left.

We are ready to enter into a stall.

2) Maintain altitude and heading – keep pulling back on control column to maintain altitude; this will cause the aircraft to loose speed. Use rudder to maintain heading.

3) Confirm approaching stall: buffeting and stall horn – say “approaching the stall”

4) Continue full aft on the control column to stall the aircraft. Do not use ailerons in the stall – they are not effective, and only exacerbate a wing’s tendency to drop.

To recover, immediately:

1) Control column forward: nose down attitude

2) Full Power – carb heat cold

3) Maintain heading and regain altitude

4) Level off into cruise

My instructor told me that we have stalled if we loose over 500 feet of altitude with a lose nose high attitude.