Density Altitude and Winds Aloft in Flying

Density Altitude

Density altitude is pressure altitude corrected for temperature. Increasing temperature makes the air less dense. Remember how a plane flies. You create a downward force that is equal to the weight of the plane. When that downward force is greater than the  weight of the plane you are flying. Your takeoff run will increase, when the temperature is higher, later in the afternoon than a takeoff in the coolness of the morning when the air is more dense. You increase the speed of the airplane to reach a downward force of air that is equal to the weight of the plane. If everything is equal at takeoff you need more runway to achieve that downward force. 

If you think of a container at one temperature contains 20 molecules of air. If you could weigh the container it would weigh more than a container that contains just 15 molecules of air.  You weighed the first at 60 degrees and the second at 75 degrees. The density altitude is less at higher temperatures. 

High altitude has fewer molecules in the container just like the container at 75 degrees.

Flatlander pilots sometimes forget the altitude effect when taking off from mountain airports that are significantly higher than sea level flying.  Expect longer takeoff runs in the mountains.

Winds Aloft

Winds Aloft are important to fuel management on long cross country flights. Pick an altitude with the least resistance as possible that provides comfort and structure avoidance altitude. 

You can use winds aloft to pick a tail-wind for a quicker flight to a destination or return to your home base.

Winds are critical in both low and high altitude locations where turbulence could occur.

Altitude Brightness in mountains! Proper googles may be a choice. You know what you need.

At high altitudes  forecasts pay close attention to ridge and mountainous wind aloft reports. Density altitude and turbulence can affect your planes performance in critical situations. In mountains the 9,000 to 12,000 foot forecasts are important both from plane performance  and oxygen availability and use.

In eastern regions the wind velocities are lower. Turbulence can occur and thunderstorms are more frequent and just as dangerous as mountain flying.

Flight Planning is very important to a safe flight and winds aloft can make a difference.

Alkalosis and Flying Safety

Alkalosis and Flying Safety

Acute respiratory alkalosis occurs rapidly. Panic, in a crisis precipitated in flying, causes a rapid increase in your breathing rate. This is called hyperventilation.

Causes that relate to flying include:

• Anxiety, hysteria and stress from flying or a crisis event in flying.
• Aspirin, caffeine and coffee abuse.
• High altitude flying where the decreased atmospheric pressure of oxygen stimulates breathing rate.
• Lung disease where a hypoxic drive controls breathing more than carbon dioxide levels that normally control breathing.
• Flying with a fever that stimulates the breathing center in the brain stem.
• State of pregnancy.
• Kidney disease that precipitates neural problems from brain swelling.

Sometimes just a "Don't Panic" cup produces "comic relief" just at the right moment!

Symptoms of Alkalosis

Decreased blood carbon dioxide causes symptoms of respiratory alkalosis. You may experience a tingling or numbness in your skin. The alkalosis may disrupt the electrolytic balance of calcium ions which may cause your skeletal muscles to remain extremely tense, for a brief time ( tetanus ) and cause fainting. If the alkalosis is caused by an underlying chronic condition pain and disorientation may occur.

The physiology of alkalosis is complex. The acute (short term) respiratory alkalosis has many causes. You must understand some habits, even enjoying several cups of coffee, may trigger alkalosis.

Distraction from your pilot in command duties is not in your best interests. Knowledge of the possible causes is safety for you and your passengers.

Anger Control in Flying

Anger Control Tips

Is losing your "Cool" worth the consequences?

The tips below may help in controlling anger.

• Take an Anger Management Course.

• Know what makes you angry and recognize situations that lead you to express your anger.

• Don't become angry when you don't receive attention you think you deserve.

• If you feel anger arising during a conversation find a way to assert your feeling and reconcile it peacefully.

• Anger is normal but calmly tell other people what your needs are.

• Hey, no one wins  in a power struggle. Back off from the situation if you can.

• Obnoxious folks are out there. Control how you act. You  control your emotions and responses.

• Avoid things that get you mad. Think of strategies to avoid irritating people.
• When confronted, think if getting angry is really worth all the trouble.

Sleep Apnea

Flying and Sleep Apnea

Memory lapses and lack of concentration while flying a plane are serious safety concerns. Sleep Apnea is a preventable factor in aviation accidents.

The United States population is changing with respect to weight. Its' putting on weight.

With weight gain you compromise an important gas exchange system. The Respiratory System can't exchange gases efficiently.

The respiratory system inhales oxygen and exhales carbon dioxide. Thats breathing and sleep apnea interferes with that function.

There are many accessories that help folks with sleep apnea. For me the CPAC was effective. I don't know the effectiveness of the devices offered.

The body and its cells restore their normal function from sleep. When physical obstructions prevent that restoration physiological changes occur. 

Sleep apnea's association with hypertension, heart attacks, stroke, obesity and diabetes are documented. These  serious conditions and flying is dangerous.

Symptoms include snoring, unusual daytime sleepiness, prolonged breathing pauses while sleeping, loss of concentration on activities and memory loss.

Weight gain, and the distribution of fat around folds surrounding the entrance to the trachea, can prevent the entrance of air entering the lungs. Structurally, the epiglottis covers the entrance to the trachea when you swallow and slides back to let air once again enter the lungs. When a person gains weight the folds increase in size which impairs the retraction of the folds. Net effect is impairment of gas exchange in the lungs.

If the lungs can't replenish oxygen to the cells during restorative sleep, a state of hypoxia begins. If carbon dioxide is retained rather than blown off, a state of acidosis begins.

If the physiological replenishing doesn't occur when you sleep,  the net effects mentioned above happen.

If you suspect you may suffer from sleep apnea because of the symptoms above and, if you're a man, have a shirt size of 17 inches or better or a body mass index greater than 30 you need evaluation.

There are treatments available for sleep apnea. It begins with an evaluation for sleep apnea by a sleep apnea specialist. It includes a detailed history and a stay overnight to evaluate.

With treatment you can avoid or delay the onset of these chronic illnesses and prolong a quality life.

Hypertension and Medical Certification

Hypertension

Elevated blood pressure. Unrecognized it is strongly associated with strokes, heart attacks, kidney failure and damage to your heart and blood vessels.

It  is called "The Silent Killer" because symptoms are not visible to you. A good physical shows whether you have high blood pressure. It is important for you to establish a "baseline" for the physician to make a decision. Why?

Blood pressure is affected by things like fear, anger, anxiety, and what you eat or drink. This is a short list. You need to establish an "average" value for your blood pressure to show your physician. One way I did this was visit my local fire department. I told the personnel attending what I wanted to do. They welcome the additional training and will suggest times to come by for testing. Keep a record and take this in for a second visit or on the first visit to your physician. It works. Remember one other factor that may give you high readings - the "white coat syndrome" and just visiting the physician can spike a reading or two.

The FAA acceptable blood pressure reading of  155 mm Hg (systolic) / 95mm Hg (diastolic) works only if it is controllable to levels much lower. Today Cardiologists would like folks to consistently be in the 115 mm Hg (systolic) / 70 mm Hg (diastolic) range.

Blood pressure medications are fine for control but there are other things you can do to help out.

• Weight loss
• Exercise
• Low Salt Diets
• A diet low in fats and rich in fruits and veggies
• No smoking

A rule of thumb is a loss of ten percent of body weight will decrease your blood pressure by ten percent. If your blood pressure before weight loss is 160/95 a ten percent body weight loss would lower your blood pressure to 144/85.5.

Keep losing and you could reach cardiologist correct levels.

I swim everyday. South Carolina has mild winters and a wet suit will allow you to swim year round. Hey, I am 75. You can do it! I don't like pools but a lake or river (slow moving) is fine. Physical exercise lowers blood pressure. ( Get a check up before selecting a routine of physical exercise. Dying is not an acceptable method of lowering your blood pressure.

Natural foods (no unnatural foods allowed) contain only small amounts of sodium chloride (salt). Salt makes food taste better just like fat does. Processed food "soups up" their products to make them taste better. 

This is a model very similar to a wrist model I use. Be sure to check your readings with the physicians or fire department readings.

You only need 200 mg (milligrams) of salt per day. We consume large amounts above that value on the average.

Depending on the severity of your hypertension, if you follow the above changes in lifestyle you may not need medication.

The FAA has found most medications for hypertension safe and acceptable. Please, if on medications, consult your aviation medical examiner for the correct procedure for continued medical certification.

Pulse. 70 beats/minute for men; 75 for women. Keep in mind the pulse will lower with physical activity. Medication, stress, coffee, smoking and obesity will affect pulse rate the other way.

Here are ranges for Hypertension Categories:

Systolic / Diastolic Levels

Mild Stage I                  140-159 / 90-99

Moderate Stage II         160-179 / 100-109

Severe Stage III            180-209 / 110-119

Very Severe Stage IV    210+     / 120+