Archive for the ‘Uncategorized’ Category

Just ahead in the April issue

Wednesday, February 18th, 2015

2009 Senior Soaring ChampionshipsThis winter can’t last much longer…can it? We’re trying to think ahead to spring as we send the April issue to the printer. At least we’re not talking about snow and ice in the “Weather” column this month.

  • Climbing into Gliders. Soaring has a lot to offer, including the fact that it is less expensive than learning to fly a powered airplane, doesn’t require a medical, and teaches you mad stick-and-rudder skills.
  • Please Hold.” How are you going to enter that holding pattern?
  • Seeing is Believing. Why you need to get your eyeballs off the instrument panel when in VFR conditions.

Plus: Turns around a point; pilots who helped to rescue sea turtles; and more.

The April digital edition goes live on Feb. 24. Learn more about how you can get the magazine delivered to your tablet, computer, or mobile device here.

In-home delivery begins March 5, and if you’re not yet a subscriber, you’ll find it on newsstands as of March 17.

We welcome your letters to the editor; email flighttraining@aopa.org.—Jill W. Tallman

Are you interested in learning to fly? Sign up for a free student trial membership in the Aircraft Owners and Pilots Association and receive six issues of Flight Training magazine plus lots of training tools and resouces for student pilots. Click here for more information.

The first officer, the teacher

Tuesday, February 10th, 2015

 

A recent trip reminded me of something I had not seen in a long time. When I was a first officer for Comair (back when I was a young warthog), we had a lot of pilots bouncing among fleets. We had jet first officers upgrading to captains on the EMB-120 Brasilia (a turboprop), and Brasilia captains moving over to the jet. Some of these guys had never flown their new fleet type; others hadn’t flown it in years. In time, we became an all-jet company and it didn’t matter.

In my current job, I’m a junior FO who occasionally flies with people who are new to the fleet type. Some of these pilots flew the “newer” model of the 737, and some flew the “classics,” but did so years if not decades ago.

I find history repeating itself: I am often helping, in many ways, to train these folks. Let me explain.

When I was in the right seat of the RJ, I’d often fly with captains whom I knew were low-time (airlines are required to track pilots with fewer than 75 hours in both seat and type). I quickly learned to ask them if they were new to the airplane, or just new to the seat.

The ones who had flown the airplane didn’t need much help, other than asking me to go slow while they learned their new routine. The ones who were new to the airplane, however, asked a lot of questions, and expected—and needed—a lot more help. Some were better than others, and in the case of movement from a turboprop to a jet, the speed difference at times was overwhelming.

The fellow I was recently flying with had gone through several transitions in the previous few years. This one, he hoped, would be the last one. To compound the issue, he was also new to the Pacific region, and there are stark differences between trans-oceanic flying and anything else. What’s more, there are some cultural differences between our base and the “domestic” way of doing things.

I found myself offering all kinds of advice and help, and the captain was constantly asking for more, soaking up what I had to offer—which had me offering even more. At one point, he made the comment after I pointed out something that didn’t quite work the way the book said it should: “That’s what I need. Tell me what’s reality and what isn’t.”

It’s healthy to ask for help when needed. I’m relatively new myself to the company and the airplane, but I’ve accumulated a bit of know-how in a short time, and my captain was smart enough to ask questions for areas where he knew he needed help. It was a good reminder that FOs too can be effective teachers, and we really do work best when we work together.—Chip Wright

What is a good…?

Wednesday, January 28th, 2015

 

I often get asked about various aspects of my job, from what makes one company better than another to what makes a given day better than others. These are some general answers to the question, “What makes a good….”

Schedule: Generally speaking, pilots on reserve will get 11 or 12 days off each month. Line-holders will get 14 to 16, or even 17, and a rare few will get 20. Some regionals require that reserves get at least one block of three or four days off in a row each month. If you’re a commuter, a good schedule is one that allows you to commute in on the first day of the trip and commute out on the last day, so you don’t have to spend time or money on crashpads, hotels, or apartments.

Paycheck: A regional first officer will make from $19,000 to $22,000 the first year. The FO can expect to max out at around $40,000 as a base salary and might earn near $50,000 in some cases with aggressive bidding, trip trades, et cetera. A captain will usually start at around $50,000, and after 15 years or so, he or she can make $100,000. In the future, these individuals will be rare, as most pilots will be moving on well before 15 years of service. However, a $70,000 to $80,000 income is not unrealistic.

Trip: Everyone has an opinion on this, but a large number of the trips are three or four days, with as few as one leg per day, and as many as five. Before FAR 117 went into effect, seven-leg days were not uncommon. Layovers will average 12 to 14 hours, with some much longer and a few shorter. Again, FAR 117 has done much to improve this, requiring crews to have an opportunity to get at least eight hours of sleep, versus the old days in which pilots might have eight hours “free from duty,” which could mean only four to five hours of sleep.

Commute: No commute is good, but some commutes are better than others. If you feel like you just can’t live in base, the best commutes are one-leg commutes. Two- or three-leg commutes are much more time-consuming, very stressful, and no fun. A good commute has a number of options for flights, not just one or two a day. Ideally, there will be some very early flights and some very late flights, both going to work and coming home. One thing I discovered is that a commute that is short enough to leave driving as an option is both good and bad, because you know you can drive if you need to, but you find yourself doing it more than you’d like.

Work rule: The airlines are a union-heavy industry, and all but a few have union contracts. Those contracts spell out the various rules by which the company can utilize the personnel without abusing the personnel, while also giving the company the freedom it needs to move metal. From a pilot perspective, a good work rule is one that ensures you’re getting paid to be at the airport. Believe it or not, there are times when pilots are at the airport not getting paid; in fact, most of the airport time is unpaid. The more you’re paid when at the airport, the more time off you have.

There are a lot of issues that a pilot needs to consider when looking for a job, be it a first job at a regional or a move up the ladder to a major or a cargo carrier. These are but a drop in the bucket of things to consider, and as your knowledge base expands, you’ll learn to understand and ask about far more complicated subjects. This, however, is a place to start.—Chip Wright

Just ahead in the March issue

Friday, January 23rd, 2015
Best Flight School, Paragon Flight in Fort Myers, Florida.

Best Flight School, Paragon Flight in Fort Myers, Florida.

Top of the heap, cream of the crop. Our annual Flight Training Excellence Awards issue spotlights the best flight instructor and flight school, as chosen by you, our readers. If you’re not geographically close to these winners, fear not—the complete list of highly scoring instructors and flight schools may have a candidate within reach.

Also in this issue:

  • Did you forget something? 10 key tips that should be mentioned every time you fly—but frequently aren’t.
  • Technique: iPad preflight. It seems unusual to think of prepping an electronic device for flight, but these steps will keep your device working more efficiently for you.
  • Flight Lesson: Second solo spin. Practicing stalls by himself, this newly soloed student found himself in a bad spot.
  • Debrief: Bob Pittman. The man who launched the MTV Networks says he likes “anything that goes fast.”

The March digital edition goes live on Jan. 27. Learn more about how you can get the magazine delivered to your tablet, computer, or mobile device here.

In-home delivery begins Feb. 5, and if you’re not yet a subscriber, you’ll find it on newsstands as of Feb. 17. We welcome your letters to the editor; email flighttraining@aopa.org.—Jill W. Tallman

Are you interested in learning to fly? Sign up for a free student trial membership in the Aircraft Owners and Pilots Association and receive six issues of Flight Training magazine plus lots of training tools and resouces for student pilots. Click here for more information.

 

The hardest parts of the job

Wednesday, January 21st, 2015

My dad was an attorney, and I distinctly remember periods of time when he did a lot of traveling, and times when he worked a lot of weekends. Because he litigated cases, he spent a lot of time in court, and those weekend work sessions were often spent preparing for a trial that was either upcoming or ongoing.

As I got older, I asked him a lot of questions, and one of them was, “What’s the hardest part of your job?” His answer generally was getting ready for certain trials.

When I got established in my career, I was often confronted with the same question. As I suspect my dad also experienced, one answer didn’t always do the question justice. Here are three main challenges, any of which might stand on its own.

  • Training. This refers to either initial training or training on new equipment. My first training event was definitely my worst. I had no idea what I was in for, let alone what I was doing. It was overwhelming and hard. However, future events were made easier by the knowledge of how to handle it. But some pilots have never learned to relax in or enjoy training, and they get extremely stressed. Some pilots become physically ill before returning to the simulator for recurrent training. Good study habits are the best tonic for making it through training unscathed.
  • The schedules. Pilots get a lot of time off, but we’re also gone a lot. We’re away from home for two or more weeks a month. We never know our schedules more than six weeks in advance, and if your seniority is bad, you’ll be working every weekend and holiday. I prefer working weekends because it’s easier to get errands done during the week, but with kids, weekends are the best times to be off.
  • The other problem with the schedules is the constant adventure of living out of a suitcase. You can either love it or tolerate it and be OK, but if you hate it, your career as a pilot will be short. It isn’t unusual to wake up in a hotel and have no idea where you are. In fact, I’ve woken up in my own bed and found myself momentarily confused.
  • Time away from family. If I had to pick one thing, this would be it. You miss a lot as a pilot, especially when your kids are younger. Some pilots have never been home for Christmas, and that’s hard. It’s no fun missing your kids’ activities or games or big school events, but it is part of the deal, unfortunately. Spouses need to be on board with it or resentment becomes an issue. Sometimes, you just want to be home to soothe hurt feelings or to fix a broken toy.

The job has a lot of benefits, and it’s a lot of fun. But it has its challenges and pitfalls. You’re gone a lot, but you’re home a lot. The time away from your family is only equaled by the fact that when you’re home, you’re home, and not working (unlike my dad). In the end, it’s what you decide to make it.—Chip Wright

The basics of ETOPS

Monday, January 12th, 2015

Aviation is about many things, and one of those things is the pursuit of reliability. Starting with the earliest engines and airframes, the pioneers of the industry have been in constant pursuit of making everything as dependable as possible. In the modern era of flying, this has produced two things: mounds of red tape and bureaucracy, and very dependable processes, airplanes—and engines.

If you’ve ever conducted any international travel, you’ll notice that more and more international flying is done in airplanes with only two engines. After the 747, the next generation of wide-body aircraft to enter service all had either two or three engines: the DC-10, the L-1011, the 757/767, and in the last few decades the 777 and 787. The cost advantages are obvious, but what about safety concerns? After all, if two engines are good, then three or four must be better, right?

The FAA and its foreign counterparts have adapted to the world of long-range flying by creating a program called Extended (Twin) Operations, or ETOPS. ETOPS programs can be established for airplanes with any number of engines, but we’ll stick with the twin-engine derivative here. With an ETOPS program, airlines are able to establish that they can operate twin-engine aircraft for long distances over water with the equivalent safety margins as for a four engine jet.

There are rules that must be followed. One of the most important is that of maintenance. With an ETOPS program, the FARs require that certain procedures be followed if maintenance is being conducted on matching parts. For instance, if a mechanic changes the oil on the left engine, he is not allowed to perform the same task on the right engine. The theory is that if that mechanic makes a mistake or is sloppy in his work, it is best to isolate the possibility of the same negative consequence occurring twice on the same plane. This rule applies to a number of tasks in the routine maintenance of the airplane. It applies to work on the tires and landing gear, engines, and several other systems with duplication.

There are other requirements for ETOPS as well. Because participants must be able to travel great distances over water, communication needs change. There are multiple options to establish and maintain adequate communications. The most common is the high-frequency (HF) radio, which works by bouncing the signal off of the atmosphere, and as a result depends on the weather for a good signal. Another option is the satellite phone, which can also suffer from occasional signal reliability and is expensive to operate. ACARS (Aircraft Communication and Reporting System) is also common, and acts essentially as an onboard email, text, and fax system.

The most obvious need on long ETOPS flights is for extra fuel, and there are a number of FARs and exemptions that can be used to set forth a particular airline’s fuel requirements. But, when comparing the alternate fuel requirements for flight of similar distances over land and water, the water route will carry more fuel and thus will cost more.

ETOPS is generally required for twinjet airplanes when the airplane will be more than 60 minutes from an adequate airport, where the word “adequate” generally means just a runway. It doesn’t need to be new or fancy or even have a ground-based approach. It just needs to be a concrete or asphalt strip long enough to safely land an airplane in the most dire circumstances. A flight operating under an ETOPS flight plan can be dispatched for varying lengths of time. An ETOPS 120 flight is one that will be 120 minutes, or two hours, from an airport at some point in its journey.

It is not uncommon to see 737s with ETOPS approval for flights across the Gulf of Mexico or from the northeast to the Caribbean. The longest stretch of pure open-water flying in the world is between Hawaii and California, and the 737 is a common airplane for the route.

ETOPS adds several layers of safety and protection for passengers and crew, and while it’s a cumbersome process, it pays dividends. Just in the last few weeks, a Delta 757 diverted to Iwo Jima in the Pacific en route to Guam. Iwo Jima is a common alternate for Pacific flights. In this case, the system proved once again that it works as intended—red tape and all.—Chip Wright

When does the interview end?

Monday, December 29th, 2014

Several friends of mine recently interviewed at a legacy carrier. Three of them interviewed on the same day, back to back to back. I spoke to two of them afterwards, and each was lamenting the fate of the third: In their minds, it was pre-ordained what was going to happen.

In the brief period of time that all three were together in the lobby, one of them was not-so-quietly disparaging his own performance. Now, bear in mind that he wasn’t saying anything negative about the company or the process they used for the interview. Far from it.

The interview was a two-part process. The first part was the actual interview between the candidate and the interviewers, in this case a captain and a representative from human resources. There’s a break between them as people trade places. The fellow in question completed his interview first out of the three, and he was chatting with the other two before leaving to go back to the hotel.

While talking, he was second-guessing his answers to the questions he was asked and openly talking about how poorly he had flown the simulator. Here’s the catch: He really had no idea how his performance compared to anybody else’s. It’s quite possible that he was average or above. The problem with airline sim rides is that they are almost always performed on equipment that you have never flown, so the evaluation is made with that in mind. It’s almost like grading on a curve.

As for the interview itself, chances are that he went in with a lack of confidence to begin with, as though he was expecting to do poorly. While he was in the lobby, he didn’t take into account that the process was still going on, though in a more passive way. The secretary heard him, and at least one of the other folks participating in the hiring process heard him.

In the end, he didn’t get the job. The other two pilots did, and each relayed to me their belief that this individual had done himself some damage by being so self-critical, which also came across as a lack of confidence.

Years ago, at another legacy carrier, a pilot had been provided the standard round-trip transportation to the interview and had received a complimentary first class upgrade on the way to the interview. The interview itself went extremely well, to the point that the interviewer relates that this pilot was one of the few who would have made a lasting impression even without this story. His job offer was ready to go in the mail (this was pre-email) the next day.

At the airport, he was under the impression that he was entitled—entitled!—to a first class seat for the return trip simply because a gate agent in his home town was kind enough to extend one to him as a courtesy on the first flight. He apparently launched into a tirade and caused such a scene that he was denied boarding until a later flight. His reservation stipulated that he was a pilot applicant, and the agent, who was furious, couldn’t call the recruiters soon enough. His offer was rescinded, and a multi-million-dollar career was lost.

Interviews for any airline—major, regional, passenger, or cargo—do not end until you are either hired or are “regretfully informed.” Even while you are waiting for your answer, you should consider it an open process, because if anybody knows about your interview, they can always make a phone call or send an email. Be confident, be nice, and assume that “Big Brother” is watching. He (or she) just might be.—Chip Wright

Extremes

Monday, December 15th, 2014

Jean Moule last wrote for the Flight Training blog about flying in Alaska. She is an emerita faculty member of Oregon State University, and a published writer and artist. Visit her website.—Ed.

Sea cliffs of Molokai, Hawaii.

Sea cliffs of Molokai, Hawaii.

Extreme tradewinds, extreme cliffs (the highest seacliffs in the world), and extreme isolation. We travelled from Oregon, my CFI from Argentina. Jean again tests the training waters, this time in the middle of the ocean in Hawaii.

John, the owner of Maui Aviators, says his endorsement notation for a student pilot for solo flights was questioned when he added the following conditions, “able to handle winds to 25 knots gusting to 30 and a 40 degrees off the nose crosswind.”

People in the midst of training from Kahului Airport must contend with the winds every takeoff and landing. The winds reminded me of the one that blew my preflight sheet off the cowling of the airplane in Salem, Oregon, and elicited the comment from a flight instructor that student pilots would not be allowed to function solo in those winds. “Anything over 6 or 7 knots could be a challenge,” he said.

Here in Maui that is all there is.

mapproachingOf course my CFI Lucas knew how to handle such winds, and I was surprised how easy he made this flight. For the first time a CFI was honest and just put in my log, “scenic flight,” oops, I misread, it says, “basic flight maneuvers.” I have had “mountain flying, bird avoidance, scanning,” and, “climbs [duh],taxi, trim, turns.” The more experienced CFIs have led me through “stalls, steep turns, t.o. and landing.” One of my favorite simple ones: ”Intro to seaplane flying.” Another CFI, recognizing my infrequent lessons, wrote, “Discovery Flight.” Six weeks from my last training flight, I was OK with that.

Though only 29 and in his fourth year as a CFI, Lucas in Maui was wise in the ways of this area and did all he could to increase our air time, doing much of the runup himself as I was in need of review and, of course, most Cessnas are slightly different by year. Fuel injection and no carb heat in this one. And, for the first time, I helped the CFI fuel the airplane. He clearly stated each item on the checklist as he performed it or asked me to do so. I felt refreshed by his manner and the winds.

As usual, I felt the surge of energy as I pushed the throttle in and rotated for takeoff.

We crossed the channel, then we flew near the cliffs of Molokai. Lucas wisely took over the plane as I gawked.

“Wow” and “I had no idea,” I exclaimed over and over as we flew. My photos cannot begin to convey the vastness, the isolation, or the height of these falls. At one point when we flew along, I noted that the cliff tops were higher than the airplane and the altimeter read 2,000 feet. Yep. Highest drop, highest seacliffs in the world. Except some of the falls fell into pools nestled in the rocks before continuing the dizzying descent. Verdant green of many hues, inaccessible except by boat or air. And Lucas calmly communicated with the rare flights near us.

As we flew along the cliffs of Molokai and I took over the airplane again, Lucas asked if I wanted to do a touch and go on a flat spot of the island. “Sure,” I said. This isolated site is reached by mule, boat, or airplane. For many years lepers were dropped near shore to swim to their isolated treatment at this former leper colony.

The excitement of the touch and go kept me from sightseeing here. With help I land and take off and soar again near the cliffs. We edge just a bit closer when I ask Lucas to take the controls while I take photos.

The extreme isolation of the leper colony and its small, short runway reminded me of my last lesson in the Bay Area in California (flight school unnamed). There I reached an extreme I wish not to repeat. The headsets did not work properly. Although I could hear the CFI, he could only hear me if I talked loudly in the cockpit. With such a glitch I was not comfortable landing the airplane, even with detailed instruction and his handling of the radio communication.

Yet I have landed enough so I have a feel for the approach and altitude for a comfortable, non-emergency landing. We had on board my husband and a former college instructor who had been a pilot. Instead of turning in the pattern and lining up the runway, the CFI overshot the end of the runway way too high and, after the necessary correction turn, too little of the runway left in my humble and inexperienced opinion. At this point I heard my former college professor/former pilot calmly and assertively say from the backseat, “We need to go around.”

We did not. The CFI steeply banked the airplane and descended very quickly. With a bit of dryness in my throat I watched as the CFI, knowing the weight in the airplane and the long length in the runway, brought this bird down safely with a bit of runway to spare. One lesson about safe parameters learned, but not one I plan to practice on purpose (or is this a standard lesson? And what about not scaring the student?).

In Kahului, Maui, Hawaii, with help, I landed in the crosswind in between large commercial jets, the runway nicely stretched out in front of us before we taxied to Maui Aviators.

Extreme flight training at its worst and best. Adrenaline high reached on both.—Jean Moule

Are you interested in learning to fly? Sign up for a free student trial membership in the Aircraft Owners and Pilots Association and receive six issues of Flight Training magazine plus lots of training tools and resouces for student pilots. Click here for more information.

Honesty pays

Monday, December 8th, 2014
"Honesty is the best policy."---Ben Franklin

“Honesty is the best policy.”—Ben Franklin

I’m on my third airline. At each one, the chief pilot(s) have always insisted on just one thing: Never, ever lie to them. The reality, they each said, is that things happen. Sometimes those things result in damaged equipment, damaged airplanes, injuries, or just embarrassment to the pilot group or the company. But, most of the time, anything that was not done with malicious intent or wanton disregard for safety can be dealt with. There may well be punishment—even harsh punishment—but a suspension is by far better than a termination.

I’ve heard several stories about people trying to hide something. One of the worst was a crew that wanted to move an airplane on the ramp. They failed to look outside, and the movement of the airplane caused considerable damage to the cargo bin because the belt loader was still in position. They lied, got caught, and were fired. Another example is of a pilot—a former chief pilot, no less—who lied to the control tower about a non-existent mechanical problem because he wasn’t ready to go. As soon as he was, he took off. The tower wasn’t sure what to make of the situation, and called the company—which happened to have a base at that airport. An investigation ensued, and the pilot was terminated. He was also punished by the FAA.

Contrast that to this. A first officer was doing a walk-around one winter in the middle of nowhere, and it was bitterly cold and windy with blowing snow. In his haste to get back in the airplane and get warm, he did more jogging than walking, and failed to notice that somebody had placed a cover on one of the pitot tubes. This is not common at the airlines, and it was unheard of at this one. However, it happened, and he missed it. At some point during the takeoff—I’ve never been sure if they rejected the takeoff or actually flew a circuit around the pattern, because I’ve heard both versions—the cautions and chimes started, and it was obvious that something was amiss. After returning to the gate, the problem was found, and the flight departed normally.

The FO immediately went to the chief’s office and did the carpet dance, confessing his sins and placing his fate into the hands of the chief. The chief honored his word, and told the FO that he would be suspended for two weeks. However, the FO could pick the two-week period that he wanted off. He chose Christmas, and his request was honored. He missed two weeks of pay, but his honesty was respected, and his kids had Dad home for Christmas.

It doesn’t always have a happy ending. Some pilots are fired just because what they did is so egregious that they can’t be forgiven. But, more often than not, immediate honesty pays off, and the impact on a career is minimal to non-existent. I know one pilot who misunderstood the change in his trip and didn’t show up the next morning, leading to the cancellation of three flights. The chief told him that ordinarily he would have received a two-week suspension, but because of his history, he’d just get a verbal warning. The pilot knew that the real reason he wasn’t being suspended was because of a staffing shortage, which the chief acknowledged. When he asked to be suspended anyway—after all, he’d be off for two weeks—the chief denied him and sent him back to work. Sometimes, you can’t get punished even when you want to be.—Chip Wright

Pilots and diving

Monday, November 24th, 2014

scuba diverAs a private pilot-in-training, you discover that the FAA wants you to learn a modicum of information about the physiology of flight. This need-to-know training continues in instrument and commercial training, and gets more specific if you pursue training in high-altitude flight. Most of modern physiology training centers on hypoxia, night vision, and fatigue, for good reason. Early on, the FAA also talks about some basic knowledge for combining flying and scuba diving. In the interest of simplicity, the feds simply want you to say no flying after diving, and if you say no flying for 24 hours after diving during the oral portion of your checkride, the designated pilot examiner will nod in approval and move on to the next topic.

But what is the real answer? And why?

These are valid questions. Scuba diving is a popular recreational activity, and depending on which source you want to cite, anywhere from 60 to 70 percent of pilots also are certified divers. That should not be a surprise. The two activities have much in common: Each requires specific training; safety is paramount; there are some rules in each that are flexible, and some that are inviolate; pilots have flight plans and divers have dive plans; an attention to detail is key. Most important, each operates in a three-dimensional setting, so that divers often describe the sensation of being “like flying.”

In flying, we concern ourselves with effects of too little oxygen at high altitudes, where atmospheric pressure is low, thus making it difficult to consume as much oxygen as we need in each breath. Divers concern themselves with consuming air while under an increased amount of pressure. The air in the tank is under pressure, and the diver underwater is experiencing greater pressure from the surrounding water. The concern under water is not oxygen, but nitrogen.

The common answer to “Why can’t you fly after scuba diving?” is that you will get “the bends.” But what really happens, and what are the real rules?

When a diver goes underwater, the water exerts pressure on the body, as well as on the scuba tank and the air it contains. At 33 feet of sea water, the body is under twice as much pressure as it is on the surface. At 66 feet, the pressure is three times as much. At 99 feet, it’s four times as much. Divers, like pilots, feel the change in pressure in their ears. They body itself doesn’t feel any different.

As a diver inhales air from his tank, the pressure from the water causes the tissues to absorb more of the gas than is normally absorbed on land. As long as the diver stays within the acceptable limits of recreational diving, this is generally not a big deal with the oxygen. However, the body also absorbs the nitrogen that is in the tank (air is primarily a mix of oxygen and nitrogen, with about 1 percent being other inert gases). Our body needs oxygen, and so metabolizing it is no big deal. However, the body doesn’t need the nitrogen in a gaseous form. In fact, the body wants to get rid of it. But, under the increased pressure experienced underwater, the nitrogen is absorbed.

If this sounds familiar, it should: This is the exact same process that goes into making a carbonated drink. In a soda, the gas is added to the liquid under pressure, so that the saturation level of the liquid is increased. Under water, a diver’s body has an increased saturation point because of the pressure, and so the tissues absorb more of the gas that is inhaled.

As a diver ascends toward the surface, the pressure on the body decreases, and some of the gas that was absorbed into the tissues begins to come out. This is similar to slowly cracking a soda bottle to release some of the pressure before opening it all the way. Divers slow this process by ascending to the surface in a slow, controlled manner, and then perform a safety stop. That is, they ascend to 15 feet, then stay there for three minutes to “off-gas” some of the nitrogen before surfacing.

If the diver ascends too quickly, the nitrogen does not leave the tissues in a controlled fashion, and a very painful injury or even death can occur as the nitrogen bubbles—comes out of solution—in the blood stream. This is commonly called “the bends,” and is more accurately referred to as “decompression illness.”
Even after surfacing, a diver still has nitrogen in the tissues. If a diver was to go flying, the ambient pressure around the diver would continue to decrease as the airplane climbs. That would allow the nitrogen to be released from the body even faster, thus increasing the risk of injury.

So, what is the proper protocol when it comes to diving and flying? If you are flying first, you can safely dive immediately. If you are diving first, PADI (the Professional Association of Scuba Diver Instructors) and DSAT (Diving Science and Technology, Inc) recommend that a diver who has not exceeded decompression limits wait a minimum of 12 hours after a single dive before flying, and 18 hours if the diver has engaged in repetitive or multi-day dives. If the diver has participated in decompression diving (whether intentionally or unintentionally), then a preflight interval of more than 18 hours is suggested.

The blanket rule that some airlines or flight departments have about waiting 24 hours after diving before flying is more of a catch-all designed to eliminate as much risk as possible. But the guidance listed above can safely be followed, as it will allow the diver to safely expel the excess nitrogen before flying. It is very possible that a diver who does a single-tank dive in the morning can take a sightseeing flight at sunset.—Chip Wright