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Volume 25, Number 25c
June 22, 2018
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ATC Privatization Comes Around Again
Kate O'Connor

Six general aviation associations have issued a statement strongly opposing the inclusion of provisions to privatize air traffic control services in the government reorganization proposal unveiled by the White House on Thursday. “We are disappointed that the Administration continues to reintroduce a failed proposal,” the groups said. “Instead, it should put its weight behind FAA legislation pending in Congress that will advance the aviation industry, including general aviation, which contributes $219 billion to the U.S. economy and creates over one million jobs in the U.S.”

According to the statement, opposition to privatizing ATC includes congressional leaders from both political parties, more than 100 aviation organizations, over 100 business leaders, 100 U.S. mayors, consumer and agricultural groups, conservative think tanks and the majority of Americans. It also points out that the idea has already been considered and rejected by Congress. The last attempt to introduce ATC privatization legislation came in the form of a last-minute amendment to the FAA reauthorization bill being voted on by the U.S. House of Representatives. The amendment prompted immediate opposition from the GA community and was removed from the bill.

Overall, approximately 300 aviation organizations, businesses, and officials have stated their opposition to ATC privatization. The groups issuing the statement are the Aircraft Owners and Pilots Association, Experimental Aircraft Association, General Aviation Manufacturers Association, Helicopter Association International, National Air Transportation Association and National Business Aviation Association.

Airlines Refuse To Transport Immigrant Children
Kate O'Connor

American Airlines has issued a statement asking the U.S. government to “refrain from using American for the purpose of transporting children who have been separated from their families due to the current immigration policy” on Wednesday. United and Frontier have taken similar positions. Whether they can legally prevent the government from using their services in such a way is uncertain.

All three airlines stated that they are not aware that their aircraft have been used to transport immigrant children separated from their families, but that the new immigration policy conflicts with their companies’ values. “We have no desire to be associated with separating families, or worse, to profit from it,” the statement from American said. “We have every expectation the government will comply with our request and we thank them for doing so.”

Tyler Houlton, a spokesperson for the Department of Homeland Security (DHS), said via Twitter that the airlines’ decision not to partner with DHS was “unfortunate.” He added that “Despite being provided facts on this issue, these airlines clearly do not understand our immigration laws and the long-standing devastating loopholes that have caused the crisis at our southern border.”

The immigration policy in question, which was announced in April, emphasizes “zero tolerance” for illegal immigration, resulting in the referral of 100 percent of illegal border crossing cases to the Department of Justice for prosecution. It has been estimated that more than 2,000 children have been separated from their families under the policy. The President signed an Executive Order on Wednesday that he says is aimed at curtailing the separation of families while still maintaining a “very strong border.” 

Healthy Pilot #12 – Sleep Problems And Solutions
Tim Cole

Healthy Pilot has been covering the BasicMed checklist in the past few installments, but we will be departing from that protocol in coming issues to cover health problems that impact the population in general and pilots in particular. Sleep disorders are up first, a condition that seems ubiquitous. For pilots, fatigue caused by sleep problems can have profound consequences. After all, it’s hard to pull off at a rest area when you’re shooting an ILS.

It's more than just fatigue. Chronic lack of sleep can actually make you ill.  According to recent posts at our sister site University Health News, Vitamin D levels needed for optimum health can be compromised with insufficient sleep. Lack of sleep is also associated with weight gain and the host of health complications that result, including joint pain. Studies also show that sleep problems can even affect cholesterol and triglyceride levels. 

Could it be Sleep Apnea?

Obstructive sleep apnea occurs when throat muscles relax and collapse the airway, leading to what’s known as “fractured sleep.” Central sleep apnea is a signaling problem in the brain, which fails to trigger breathing. There is a strong association between sleep apnea and diabetes, obesity, and cardiovascular disease. Sleep apnea directly increases your risk for having high blood pressure, cardiac arrhythmias, and stroke. Untreated sleep apnea is also associated with increases in insulin resistance, gastrointestinal reflux disease, and cognitive impairment.


An overnight sleep apnea test, called polysomnography, is required to diagnose obstructive sleep apnea. This recording of sleep and breathing usually involves in-laboratory measurement of brain waves and arousals, eye movements, chin movements, airflow, respiratory effort, oxygen levels, electrocardiographic (ECG) tracings, body position, snoring, and leg movements. In-home testing is also widely available.

The most common and effective conventional treatment for obstructive sleep apnea symptoms is continuous positive airway pressure (CPAP), which provides a steady stream of air through a mask that is worn during sleep. This airflow keeps the airway open to prevent pauses in breathing and restore normal oxygen levels. Patients will often report feeling dramatically better after beginning treatment.


Studies show that treatment with CPAP reduces excessive daytime fatigue and increases energy. A randomized controlled trial in 2011 specifically looked at fatigue and found that three weeks of CPAP therapy significantly reduced fatigue scores to the point that participants were no longer suffering from clinically significant levels of fatigue after the three-week intervention period. Self-reported energy levels also increased significantly.

However, some individuals simply cannot tolerate CPAP as a sleep apnea treatment option because of nasal congestion, and the pressure felt because of the high flow of air created by the device. Other conventional sleep apnea solutions include surgery or a sleep apnea mouth guard, known as “mandibular advancement devices” or splints.

Oral appliances, which hold the mandible in a protruded position during sleep, are increasingly used for mild to moderate sleep apnea symptoms, as well as in more severe patients who are unable to tolerate or refuse CPAP. Although oral devices generally do not work as well as CPAP in reducing the actual number of episodes and increasing oxygen, they do help with sleep apnea symptoms and increase energy in sleep apnea patients. Studies have found that overall improvements and outcomes seem comparable with both types of treatment.

Mind over Sleeplessness

One of the key strategies that sleep specialists employ to help patients overcome behaviors that contribute to chronic insomnia is stimulus control therapy. This approach includes tactics such as removing yourself from the bedroom if you can’t fall asleep, and not watching television or surfing the internet while you’re in bed. Instead of staring at the clock, get up and do a boring task. Only return to bed when you’re sleepy.

Similarly, if you’re having sleep troubles, limit your cell phone use around bedtime. One study found that people who spent more time on smartphones, especially close to bedtime, were more likely to have shorter sleep duration, poorer sleep quality and take longer to fall asleep. So, turn off your cell phone, computer and television at least an hour before bedtime.

One approach that helps in many cases is cognitive behavioral therapy for insominia (CBT-I). While CBT-I is not a quick fix, it can be a long-term solution that doesn’t involve medications. Among the strategies called for by CBT-I are the following:

1. Stop clock-watching. People with insomnia can become chronic clock-watchers, obsessing over how long they’ve been trying to fall asleep, how many more hours they have before morning. Chronic clock watching leads to obsessive thinking. Turning the clock away from your bed or putting it out of site and out of reach are two ways to reduce the temptation to check the time.


2. Sleep less. It may seem illogical to suggest that you sleep less, but sleep reduction therapy is based on the idea that some people may actually spend too much time in bed. Taking too many naps or staying in bed for too many hours may actually disrupt normal sleep patterns. For example, if you barely get six hours during the night and then take a nap in early evening, the recommended therapy might be to go to bed at 1 a.m. and wake up at 7 a.m. During the next several weeks, you gradually go to bed a little earlier, eventually forgoing the evening nap. This approach can help reset your sleep/wake schedule.

3. Control your environment. The bedroom should be designated for sleep and sex—not working, reading, watching TV, eating, or surfing the internet. In addition, a cool, dark room that is quiet can help you sleep better. Avoid alcohol and caffeine close to bedtime. And although daily exercise is helpful, give yourself several hours between exercise and sleep time.

Pills and Potions

While prescription sleep aids may keep you from counting sheep, like many prescription drugs, they are not always safe to use. First and foremost, most of these medications are addictive so many people who use them become dependent upon them.

In reality, some of these prescriptions are actually habit-forming narcotics and are not intended for long-term use. This means that even when a person’s sleep disorder is resolved, trying to get off the medications poses a whole other set of challenges. Prescription sleep aids also come with a host of side effects.

Besides the potential dangers associated with sleep aids, these drugs aren’t always needed. In fact, many doctors believe most people don’t actually need a prescription sleep aid, and the vast majority of people with sleep disorders can find relief in other ways.

These natural remedies for insomnia are non-habit forming. There is little downside to trying one of these approaches and it might be just the thing you need to get a good night’s rest.

  • Melatonin: Melatonin is a hormone secreted by the pineal gland in the brain that helps regulate circadian rhythm. As we age, the amount of melatonin produced in our body decreases; so the older we get, we are naturally inclined to sleep less. The use of melatonin supplements enables a person to fall asleep without feeling “drugged” and to remain awake and alert during the daytime hours, decreasing those excessive fatigue feelings. Melatonin is also helpful for people with jet lag or for those who work night shifts, as it helps readjust the body’s sleep cycle. The dosage for melatonin is one 3 mg tablet one hour before bedtime.
  • 5-HTP: A serotonin deficiency (neurotransmitter deficiency in the brain) can be an underlying root cause of both insomnia and depression. If your lack of sleep is accompanied by persistent feelings of sadness, hopelessness, or negativity, taking 5-HTP may help you. A serotonin precursor naturally produced by the body, 5-HTP is also prepared in a supplement form from the seed pods of a West African plant called Griffonia simplicifolia. This 5-HTP has the ability to be converted into the mood-regulating neurotransmitter serotonin as well as the sleep-inducing hormone melatonin. It is a close relative of tryptophan—an essential amino acid found in certain foods that is also a precursor to serotonin. (Have you ever felt sleepy after eating that Thanksgiving turkey? Tryptophan is the reason why!) 


  • Valerian root tea: If, in addition to insomnia, you experience feelings of anxiety, stress and worry, Valerian root tea can help ease your tensions and rest your mind. Valerian root (Valeriana officinalis) contains a number of active chemical compounds including different alkaloids; however, the most important ingredient in Valerian root is gamma-aminobutyric acid, or GABA. GABA has often been referred to as “the brain’s own anti-anxiety medication.” It is the same active chemical that is triggered by taking the anti-anxiety prescription drugs, Valium and Xanax.
  • Antioxidant Supplements: Aside from diet and exercise, natural remedies for sleep apnea should focus on increasing antioxidant capacity. Why? Sleep apnea is associated with oxidative stress, the excessive build-up of free radicals. It is also associated with decreased antioxidant capacity (ability of the body to counter oxidative stress) and decreased blood levels of various antioxidants, such as vitamin E and carotenoids (such as beta-carotene). The excessive oxidative stress associated with sleep apnea then leads to what is known as “endothelial dysfunction,” in which the blood vessels do not properly relax and contract. Endothelial dysfunction is the primary mechanism causing atherosclerosis, heart disease, heart attacks, and strokes. Various types of antioxidant supplements have been researched as treatments and found to be beneficial as natural remedies for sleep apnea.
  • DHA: Another supplement that may be helpful for those with sleep apnea symptoms is an omega-3, such as fish oil, especially one which is concentrated in the omega-3 fatty acid DHA. Low omega-three levels, especially DHA levels, are related to more severe sleep apnea. Omega-3 fats are one of the top natural remedies for sleep apnea because they protect cells against stress; sleep apnea causes long-term oxidative stress and puts severe demands on the body which is thought to deplete the omega-three levels. Taking an omega-3 fish oil with concentrated levels of DHA may improve sleep apnea symptoms while improving your cardiovascular health.
  • Vitamin D: One last vitamin is worth mentioning when it comes to natural remedies for sleep apnea symptoms: Vitamin D levels have been found to be lower in patients with sleep apnea compared to those without the disorder. Vitamin D deficiency has been found to be particularly prevalent in those sleep apnea patients who also have issues with blood sugar and insulin regulation, including those with diabetes, prediabetes, metabolic syndrome and insulin resistance. The more severe the sleep apnea symptoms and blood sugar dysregulation, the lower the vitamin D levels.
    Treatment with vitamin D may help ameliorate the blood sugar disturbances and inflammation associated with insulin resistance in sleep apnea patients. Even if you do not have poor blood sugar metabolism, it is strongly recommended that you make sure your vitamin D levels are optimal by taking at least 2000 IU of vitamin D daily and having your blood levels checked yearly. This is because vitamin D deficiency is so common and linked to many fatigue symptoms, including mood disturbances and muscle pain. Many patients report relief from feeling so tired all the time when their vitamin D levels are optimally treated.
Fatigue Crack Causes British Airways Engine Fire
Kate O'Connor

The 2015 engine fire on a British Airways 777 was caused by a fatigue crack and the resultant uncontained engine fire, according to the NTSB final report issued on Wednesday. The crack was found in an area of one of the aircraft’s GE GE90-85BG11 engines that was not required to be inspected at the time. The cause of the crack couldn’t be determined and GE implemented new inspection procedures after the accident.

The engine failure occurred on the takeoff roll as the aircraft was departing from McCarran International Airport (LAS) for London. The captain aborted the takeoff and the 157 passengers and 13 crew members used the emergency slides to evacuate. One serious and nineteen minor injuries were reported.

The NTSB investigation uncovered some issues with the flight crew's checklist use during the evacuation, noting that the unaffected right engine was allowed to run for 43 seconds after the order was given to evacuate on that side of the airplane. According to the report, “Because the captain did not follow standard procedures, his call for the evacuation checklist and the shutdown of the right engine were delayed.”

As related safety recommendations, the NSTB referenced two previously issued recommendations stemming from an American Airlines engine failure and fire in 2016. Safety Recommendations A-18-6 and A-18-10 call for separate checklists for engine fires on the ground and in the air and the development of “procedures for an engine fire on the ground to expeditiously address the fire hazard without unnecessarily delaying an evacuation.”

Diamond's Christian Dries: One Of A Kind
Paul Bertorelli

I have a handful of vivid memories of Christian Dries, founder of Diamond Aircraft, but none are more searing than watching him storm across a windswept ramp in Austria all but foaming at the mouth. He wanted me to commit to my notebook his solemn pledge that the airplane I was looking at would absolutely, positively be the last he would ever certify. It was the prototype of what became the Diamond DA62, the latest innovation in a modesty long line of innovative airplanes.

As he usually was, Dries was steamed at “the authorities,” specifically EASA, for making his life as an airplane builder a living hell through a construct of impossible-to-satisfy but ruinously expensive certification hoops. I knew Dries well enough to understand that it was just his characteristic bluster, but I thought of it earlier this year when the press release announcing the final terms of Diamond’s sale to Chinese interests trickled into my inbox. The presser described Dries' future role as an advisory consultant.

Frankly, Diamond will never be the same. The entire company was an embodiment of Dries’ creative energy and mile-a-minute thought stream directed at the future of aviation. It was cooked into his DNA and he infused it throughout the company through sheer force of will. As is so typical of entrepreneurs, Dries had more ideas than the company could possibly bring to fruition and I suspect many of the ones that never made it off the sketch pad deserved to remain there.

Even those that ultimately succeeded struck me as nutty at the time, not the least of which was the DA42 twin. It appeared in 2002 as a surprise entry at the Berlin Airshow. Here was a new airframe with entirely new and untested engines that were diesels, for Pete’s sake. It’s an article of faith that untried engines in a new airframe court developmental disaster and although the DA42 did stumble, its teething pains were sorted and it stands as a highly successful model. When the Mercedes-based Thielert engines proved tentatively problematic, Dries responded with typical bravado by starting his own engine company, Austro. Although heavier, Diamond engineered around that and the Austros became the most refined engines in aviation, albeit on low volume.

Diamond distinguished itself by building airframes with essentially no bad habits. All of them are mild mannered and pleasant to fly. That and Diamond’s attention to things like putting the fuel tanks between heavy spars with armored fuel lines and providing generous flail space in the cabins yielded a low accident rate unique in piston GA. The first time I researched the fatal accident rate of the DA40, I found it to be effectively zero. I couldn’t find any fatal accidents.

Diamond had—and has—an unusually active Skunk Works, again driven by Dries’ tireless devotion to things that fly. Will the new management duplicate that? I suspect for a while, yes, just by dint of momentum. But a few years in, I’ll be surprised if there’s much of Dries’ residual passion remaining. Rare is the company handed off from an entrepreneur that retains that same fire in the belly that caused it to be started in the first place. And the grim business cases that govern new aircraft model launches encourage reticence at the expense of boldness.

I wish Wanfeng Aviation Industry the best with their new purchase. My observation has been that Chinese companies have tended to be hands off in managing their acquired aviation assets and that’s probably a good thing. Still, Christian Dries strikes me as the definition of sui generis. He’ll be a hard act to follow.

Government Issues Directive To Keep Space Clean
Kate O'Connor

The U.S. government issued a policy directive aimed at managing growing space traffic more safely and effectively, including tackling increasing orbital debris, on Monday. Space Policy Directive-3 (SPD-3) calls for “a new approach to space traffic management (STM) that addresses current and future operational risks.” SPD-3’s goals also include encouraging commercial space travel, developing STM best practices and improving the space object registry.

According to SPD-3, the Department of Defense already tracks over 20,000 objects in space and publishes a catalog of those objects and potential object collisions. That number is expected to rise substantially as sensor technology improves and there is concern that debris will cause safety issues, especially as space travel becomes more common. “Reducing the growing threat of orbital debris is in the interest of all nations, and NASA looks forward to working with the National Space Council, the Department of Commerce and other partners on a path forward,” said NASA Administrator Jim Bridenstine. “SPD-3 provides guidelines and initiatives to ensure that America is a leader in providing a safe and secure environment as space traffic increases.”

“This new legislation also commits the U.S. to exploring active space debris removal [which] has so far only been explored theoretically in paper studies,” said Carolin Frueh, an assistant professor of aeronautics and astronautics at Purdue University. She also believes that there are some technological hurdles to overcome, especially when it comes to object tracking. “For air traffic,” Frueh said, “there are multiple radars tracking several airplanes per hour, but for space traffic, only a few sensors on earth are tracking … known objects.”

Hall Of Fame To Honor Four Aviators
Mary Grady

The National Aviation Hall of Fame will induct four new members Sept. 28, at its 56th annual ceremony, in Washington, D.C., organizers have announced. This year’s enshrinees are Col. Walter Cunningham, who flew the Apollo 7 lunar module and served as chief of Skylab; Gen. John Dailey, former director of the National Air and Space Museum; William Dana, who served as project pilot for the X-15; and Gen. Ronald Fogleman, who served in the U.S. Air Force and wrote the Air Force Core Values. The four will be honored with a ceremony and dinner to take place at the National Building Museum. The event is open to the public, and seats are available at the NAHF website, starting at $400.

The enshrinement ceremony will be hosted by David Hartman, former host of ABC’s “Good Morning America,” and nearly 1,000 people are expected to attend. Among those in the audience will be former enshrinees, including astronauts Eileen Collins and Hoot Gibson, general aviation leaders Dale Klapmeier, of Cirrus, and Tom Poberezny, of EAA, as well as former Tuskegee Airmen and other ace pilots from World War II, according to the NAHF.

FAPA Holding Job Fair and Future Pilot Forum
Kate O'Connor

Future and Active Pilot Advisors (FAPA) is holding a free pilot job fair and future pilot forum on Saturday, June 23, in Chicago. Topics to be covered in the forum include financing flight training, pathways for professional pilots and the outlook of the global pilot job market. Although open to everyone, the company says the forum is particularly aimed at people looking to change careers, students of all ages, parents, teachers and school counselors. The forum will run from 1 p.m. to 6 p.m. and presentations will also be available on video after the event.

The job fair, which is scheduled from 9 a.m. to 12 p.m. the same day, is designed for pilots with a commercial certificate and more than 250 hours' flight time in either rotor or fixed wing aircraft. Airline recruiters will be present to speak with interested pilots at the event. Along with several others, confirmed job fair participants include ExpressJet, SkyWest and Republic Airline.

The company has additional forums and job fairs planned throughout the year at multiple locations around the country. Although there is no cost to attendees, registration is required for both events. FAPA is a career and financial advisory service for pilots.

Picture of the Week, June 21, 2018
A Blue Angles F-18 at KAFW. Photo by Ben Taylor.

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Significance of V-Speeds
Rich Lanning

I am not a big proponent of memorizing airspeeds. It can be a risky practice if you fly many different types of aircraft. Most of the important airspeeds can be determined from the airspeed indicator (ASI), though there are a few you probably should commit to memory, or at least keep on a placard.

Eight speeds not found on the ASI are listed in the associated illustration. These are not annotated because they vary with weight and other factors. Yet we are often asked to memorize these. This is an interesting anomaly given they are based on maximum gross weight (MGW)—a condition you should never experience legally once airborne. Let’s take a closer look.

Rotation Speed — VR

This is one V-speed I wish pilots would never be exposed to. The non-thinking pilot seems to reason that at VR the airplane will magically fly and many inappropriately try to force it into doing so by yanking back on the stick at the designated airspeed. A smooth transition from takeoff into the climb portion of fight is essential on an instrument departure.

Forcing an airplane into the air before it’s ready to fly is anything but smooth— VR is determined by the airplane. All the pilot needs to do is apply a little backpressure on the yoke to set the appropriate pitch and the plane will fly on its own when sufficient lift is available based on prevailing conditions. In general, VR equals 1.15 times VS1 (the bottom of the green arc). The only reason to know VR is if you find yourself significantly above this number and still on the tarmac—then it might be time to abort the takeoff. Leaving snow or frost on the wings is an example.

Knowing the general performance numbers for your aircraft and the length of the runway, you should be able to visually determine if the aircraft is not performing as it should.

Approach Speed — VRef

Use this speed for a stabilized short final instrument approach. It assumes all maneuvering has been completed. While not indicated on the ASI, it can be calculated as 1.3 times VS0 (bottom of the white arc). The catch being it is based on MGW, which we will typically never be anywhere near during the landing phase. A general rule of thumb is to reduce VRef by half the percentage you are below your MGW.

From the weight and balance completed before departure you know the current relationship to MGW and should be able to estimate the weight reduction from fuel burn. Thus, a reasonable VRef can be calculated even before departure. How important is VRef? If you fly just 10 percent over VRef you can expect your ground roll to be over 20 percent longer. Another common rule of thumb used is each knot above VRef adds another 100 feet to the ground roll. We tend to become complacent about the landing roll flying light general aviation aircraft from runways that are three or four times longer than we need. This can bite us when popping out of the overcast with too much speed and a tailwind.

Maneuvering Speed — VA

Calculated by the manufacturer, VA is the speed at which the aircraft will stall before exceeding design maximum G loading. This is a good speed to know when flying in turbulence, something quite common in IMC, since it will help prevent damaging the airframe. Just like VRef you can calculate VA. It is typically determined by multiplying the flaps-up, power-off stall speed (VS1—typically the bottom of the green arc) by 1.95 which is the square root of the normal category load limit of 3.8 Gs.

A more conservative thumb rule uses 1.7 times VS1, which is generally associated with turbulence penetration airspeed, VB, not normally specified for general aviation aircraft. VA can then be reduced in the same manner as VRef is based on weight. If you anticipate turbulence, then create a timeline of what VA (or VB) should be over the course of the flight as fuel is consumed.

Climb Speeds — VX, VY

These can be calculated but would require knowing a host of factors related to your aircraft and some complicated math. Best angle of climb (VX) is useful for takeoff over an obstacle, an ODP with a challenging climb gradient, flying a delayed missed approach, or need to perform a short field landing.

Best rate of climb (VY) is an airspeed to get you efficiently to the enroute altitude. Further complicating things a bit is the fact that VX increases slightly with altitude while VY decreases about a half to one knot per thousand feet until they are equal at an airplane’s absolute ceiling. Fortunately, both of these values are normally needed at low altitude so the published figures are good to use if corrected for weight.

Best Glide — VG

This is one of the most important airspeeds you should know. For most airplanes, it’s about halfway between VX and VY. Once again, most manufacturers establish the best glide speed at MGW. This means your best glide speed will always be lower than the book value should the need arise to use it. VY, VX and VG should all decrease about a half-knot for each 100 pounds under MGW.

Recall that weight itself has no effect on the glide range or ratio, only the proper airspeed to attain the max glide range. However, a tailwind allows you to decrease VG further by about one-third of the tailwind component while a headwind requires an increase in glide speed—typically by one-half the headwind component—to maximize your range. VG can also be approximated by keeping the wing cord parallel with the horizon—provided you can see the horizon—not typical on an IFR flight. Another trick using VX and VY is to use them to calculate cruise climb (VCC) by taking the difference between the two and add it to VY.

Knowing VX and VY and using the ASI color coding can allow you to determine all the important airspeeds for instrument flight. Naturally, consult the POH for more specific guidance for your aircraft.

Did you ever wonder why they are called V speeds? The “V” is from the French word ‘Vitesse’ which means ‘speed’ or ‘rate.’

Some Caveats

A word of caution when using airspeeds based on the color coding of the ASI. Airplanes manufactured before the mid-1970s had their color coding based on calibrated airspeeds (CAS), and were primarily in mph (some may show knots as a secondary indication). However, airplanes built after this period primarily had their ASIs marked in indicated airspeed (I AS).

For most of us, the differences between CAS and IAS will be small but you need to be cognizant of this difference. CAS is important when calculating True Airspeed (TAS) and Equivalent Airspeed (EAS). As always, follow the guidelines specified in your POH for your particular airplane.

Richard Lanning Ph.D. is a graduate of the U.S. Naval Academy and a pilot for more than 30 years. He is an ATP, CAP Check Pilot Examiner, and CFII.

This article originally appeared in the January 2018 issue of IFR Refresher magazine.

For more great content like this, subscribe to IFR Refresher!


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Do You Have An Aviation Dream Job?
AVweb Staff

Do you have an aviation dream job? AVweb wants to hear from you. From flying to fixing, we’re looking for stories about fascinating and unusual GA jobs. Surprise us with the rare aircraft you instruct in, specialized maintenance you do, or anything else beyond the average aviation industry workday. Please submit up 500 words about what you do and a photo of you in your work environment to Selected stories will be edited—with author approval—and run on our website. Authors of chosen stories will receive an AVweb baseball cap.

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