Author: Sahil Page 2 of 16

Winter mornings in New England are not a fun time to walk a half mile without knowing exactly where the hangar is. Walking past the fuel pump and over the wind swept snow piles of the airport apron, we paid careful attention to the numbers on the hangar doors. The blistering cold wind swept through the gaps of our jackets, sapping away what heat we had in our ears and fingers. We breathed a sigh of relief once we got to the right row and quickly rushed in to get shelter from the wind. That walk was brutal.

Pushing the little door open, we were greeted by the sight of the plane resting cozily inside. A small blue blanket covered the engine to keep it extra toasty. (It just looked so cute, 🙂 and now I really wish I took a picture! [Update: I finally got around to taking a picture of it!) The best part of it? The whole hangar was heated too! What a luxury to have a heated hangar to do our preflight in! While checking the oil, I could feel the heat emanating from the engine block and the smell of hot oil filled the air.

After doing the preflight and passenger briefing, we got ready to tow the plane out of the hangar and into the cold air. It took a few minutes to get the block heater and battery tender unplugged, the main hangar door open, attach the tow bar, and push the plane out. Then we had to get the hangar door closed again and get ourselves seated inside. All in, it was probably around 10 minutes or so from the door first opening.

I say all of this because, when it was time to start the engine, it wouldn’t start. The engine cranked and the prop spun for a few seconds, but nothing. I waited and tried again. And again. And again. This time, I waited a good 30 seconds before trying to let the starter cool down. I fiddled with the mixture and primer. Honestly, I thought we might have to scrub the flight and walk back to the terminal in the cold again! I told my passengers that this might happen, but that we should try a few more times.

Finally, I primed it one more time and leaned the mixture. Turning the key once again, and after a second or two of cranking, the engine finally came to life. Relief flooded the cockpit, and especially myself. I thought back to the first time I flew in this particular plane and we had a similar issue. That time, it took us quite a few tries to get the engine started and it made me nervous. I can only imagine what was going through the minds of my passengers today.

In hindsight, I probably should have familiarized myself with cold start procedures before the flight. I really thought that it would be a breeze with the engine block heater, but no — cold starting really is an art form.

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It was only a day after 6 inches of snow fell in central Massachusetts. The whole landscape was covered in a layer of fresh, pure white snow. The timeline here may be confusing, as I flew again later in the day. I will intersperse elements from both flights in the story. But we pick up here at the beginning of the next flight.

For the second flight of the day, we needed to fuel up. I’m used to taxiing up to the self serve fuel, but at this airport, the fuel is full service. We called up the FBO and requested fuel at the hangar. By the time they got there, we had towed the plane out — this time leaving the cute little blanket on the engine to keep it warm and toasty! (I smile every time I think about this. . . 🙂)

Quite a bit easier than having to top up the tanks ourselves! I didn’t think to discuss the leaded fuel with my passengers. After fueling and closing the hangar door, we all hopped on board and got ready to fly. I reviewed the preflight check and realized, whoops, I forgot to sump the fuel. After all the difficulty I had with starting the engine on the earlier flight and the brisk weather, I was seriously tempted to forgo sumping the tanks.

A few seconds later, I snapped out of it. I got out of the plane and checked the fuel tanks for water or other contaminants. It took less than a minute to do that. I scold myself now for even thinking about skipping the fuel check.

We eventually got the engine started. A bit quicker than the morning flight, I might add. Now feeling much more confident, it was easy going towards the city for some sight seeing. Worcester is a Class D airport, meaning that in order to enter, we need to establish two way radio communication. While we don’t need permission to do a city tour, per se, it is good to let the tower know what you’re planning to do. We radioed up Tower and let them know our intentions and were approved.

Overflying the city was beautiful, only intensified by the effusive sunset glow.

During the flight, I made sure to ask my passengers how they were doing several times throughout the flight. Key to this was asking them to rate their feeling on a scale of 1 to 10. This helps bring some objectivity into it. Many people, myself included, report that they’re doing fine even if they’re feeling slightly motion sick or tired. It’s not so bad that they feel the need to change the status from “okay.” As pilots, this is not a good situation. It means that passengers are not comfortable. This is a tip I learned from Flight Chops.

Funny story, I forgot to switch on the heat! I didn’t realize until half way when it got quite cold in the cockpit. At least we were all wearing jackets 😛

Flying at night is incredibly beautiful. To see the lights of the city off in the distance and the moonlight glinting off of the small lakes and ponds scattered throughout the eastern half of Massachusetts was an amazing opportunity. For practical reasons — night illusions, navigation, terrain avoidance — it’s a completely different ballgame than flying during the day.

I vividly remember looking out to my right over Boston. Flying further north, I saw the ocean beyond and the immense inky blackness that loomed over the right wing, occasionally interrupted by the glimmers of aircraft landing at Logan. From that first captivating night flight from Mansfield, MA to Portsmouth, NH and back, I’ve continued to look up at the night sky scanning for the red and green navigation lights, yearning to again experience the still night air and glimmering lights.

Because I haven’t flown at night since my training, I wanted to do a night currency flight. So I booked the plane on a Saturday evening and read up on night illusions. After reading about the “black hole,” and the ensuing spatial disorientation, that killed JFK Jr. off the coast of Martha’s Vineyard, it’s no wonder that night flying is a part of our training as pilots.

Later that week, I arrived at the airport. One of the instructors at the local flight school checked me in and kindly showed me how to operate the hangar lights and door. What a luxury to have a hangar to do the preflight in on a frigid December evening!

I unplugged the engine block heater and the battery tender. After putting my bag on the back seat, I pulled out my checklist. Running through the flow, I noticed that the position / navigation lights didn’t switch on, only the strobes.

FAR Part 91.205 defines the minimum required equipment to fly during the day and at night. There’s an acronym pilots use to to remember this: ATOMATOFLAMES, FLAPS. The first, ATOMATOFLAMES is the minimum required equipment for the day. In the night, we also add FLAPS, which stands for Fuses, Landing lights (if flying for hire), Anti-collision lights, Position lights, and Source of electricity (i.e. alternator/generator).

The position lights help other pilots determine which direction an aircraft is heading. For example, if only the green and white light are visible, we can deduce that the aircraft is traveling from left to right. If both are visible, the aircraft is heading towards us.

This particular aircraft is equipped with strobes. I held my hand in front of them so I could better see the bulbs of the adjacent position lights. Perhaps the filaments were broken, I thought to myself. I messed with the brightness wheel and tried a bunch of combinations of switches, but I couldn’t figure it out. Resorting to the only solution that I had, I called up the instructor I spoke to earlier. Luckily he had just gotten in his car and hadn’t left the airport premises yet.

He spent the next 25 minutes trouble shooting the issue. All to no avail. Neither of us could figure it out. He called up one of the other instructors with more knowledge, and on the phone I heard him saying, “I’ve got a pilot here who’s trying to do his night currency, but the nav light is inop.”

Wow! It was really strange to be called a pilot now rather than a student!

He suggested to start the engine and see if that solved the problem. Perhaps it was a power issue and the battery wasn’t able to supply enough current to get the incandescent bulbs going. As he was leaving, however, he tacitly explained that the strobe lights would quite easily make up for the inoperative position lights in terms of visibility to other aircraft.

While he’s not technically wrong, it’s certainly not something that I would be comfortable doing! I ended up canceling the flight and listed the issue as a squawk so it could hopefully get resolved by the mechanic in the near future.

I fly for fun, so there’s no point in even coming close to crossing that line. Once you cross it for something so trivial as this, the whole line becomes blurred. When it matters, it becomes easy to trot into dangerous territory. I’m only flying as a hobby, so there’s no reason to add any unnecessary risk, even for something as minor as this. As Steve from Flight Chops explains, a rule is meant to alleviate the burden of making difficult decisions. You make the decision in advance and stick to it.

Now, with the benefit of hindsight, it turns out that the position lights are wired to the avionics bus, which means that in order to get them to switch on, the avionics master switch must also be on. I found it kind of strange that the position lights are wired differently than the strobe lights, but it might have something to do with the ADSB-out beacon that needed to be retrofitted to meet the 2020 requirements.

Ultimately, it was a great learning experience.

Dossier

“The Drama of Flight: One Radio Call at a Time,” by David Mamet, February 1, 2019. https://www.flyingmag.com/drama-flight-one-radio-call-at-time/

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As an aside, let me know if you would be interested in more posts like this. If it provides a unique or valuable perspective, it would be fun to write more about each flight and the lessons contained within.

I want to avoid the “purple prose” of aviation writing, as David Mamet put it in Flying. To him — and I’m inclined to agree — “the drama of flight does not take place between the pilot and the environment, but between the airplane and the pilot, and between the pilot and himself.”

One interesting concept would be to create an online companion to the digital debriefs that I designed to distribute to my passengers after a flight. It could be akin to the idea of the expedition journal that I’m so enamored by. I’m inspired by the National Geographic Field Notes expedition blog and the Medical School 2020 book.

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Edit: I later was able to night flying and have included the video here.

Almost everyone in tune with the general aviation scene has at least heard of Steve Thorne from the YouTube channel Flight Chops. In particular, he is well known for flying a variety of different airplanes as part of his videos and his involvement in the Canadian Historical Aircraft Association (now the Canadian Aviation Museum). Ranging from standard 172s to warbirds like the T6, to hand built experimental like his new RV-14, Steve has likely flown it — and made a video about it!

Suffice to say, he flies a lot of different planes and often finds himself navigating an unfamiliar cockpit. Listening to this seminar, I found myself comparing his experience to my own recent transition from a Hershey-bar Piper Cherokee 140 to a larger, taper-wing Piper Cherokee 151. While largely very similar, there are so many subtle differences in the flight characteristics, panel layout, and equipment, not to mention transitioning to an entirely different airport.

Steve explains that he uses ForeFlight as a “touchstone” of familiarity. No matter what cockpit he’s in or what plane he’s flying, he has an iPad running ForeFlight right in view. I certainly can relate to that, although for me, it was my checklists that served as the touchstone.

The ideas presented in this seminar were intriguing. And because it was right on the heels of performing our final ovarian hysterotomy as part of our lab animal surgery course, it got me to think about the parallels in aviation and surgery. Now, having experienced both fields first-hand, I see the value of the cross-disciplinary thinking that leads to innovation.

What I noticed was that there is so much shared innovation in aviation because of how standardized it is. There is an easy opportunity to continue to learn. It is easy to measure our improvement, even if it’s only a qualitative pat on the back for a good landing. Ultimately, many people seem to think that pilots do the same basic things again and again, day in and day out. In contrast, or so the argument goes, people say that medicine is not standardized. Each patient is unique; during each surgery, the surgeon must deal with the unique anatomy and circumstances of the patient.

But I think that this argument is flawed. Each flight is unique. Just like the anatomical differences in individuals, each flight is slightly different. It’s a different airport, it’s a different plane, a different time of day, different traffic volumes, among others. I could go on about each field ad nauseum. But, therein lies the key takeaway: using checklists and familiarity helps in both aviation and in surgery.

I’ve always said that the biggest part of innovation is cross-disciplinary work. Through that type of collaboration, you get a chance to look at a problem from a fresh perspective. That shift may hold the key to thinking outside of the box and coming up with a new solution without having to force-fit it within the confines of the aggregation of discourses or common knowledge in a field.

Dossier

“Pilot in Command: The Power of Familiarity in Unfamiliar Cockpits,” by ForeFlight, December 14, 2021. https://www.youtube.com/watch?v=gRxgwwf7NV0

“Ovarian Hysterectomy | Lab Animal Surgery,” by Sahil Nawab, December 12, 2021. https://www.youtube.com/watch?v=5DTgylNFQf8

“Piper PA-28 Year Model Changes,” by Skywagon University, December 8, 2021. https://www.youtube.com/watch?v=-W-A4L4tE70

Most of my training was in a Piper Cherokee 140 with an upgraded 160 hp engine. I used to wonder when entering the designations in my logbook — PA 28 140? P28A 140? What do these numbers and letters even mean?

Even after taking immunology, this video gave me a better, more visceral, understanding of the immune system!

https://www.youtube.com/watch?v=KS1HdnKG0YY

Dossier

“Generating the Dots vs. Connecting the Dots,” by Sahil Nawab, July 28, 2020. http://www.sahilnawab.com/blog/generating-the-dots-vs-connecting-the-dots/

“The Business Case for Electric Aviation,” by Sahil Nawab, June 18, 2021. http://www.sahilnawab.com/blog/the-business-case-for-electric-aviation/

“The Dilemma of Electric Aviation,” by Sahil Nawab, January 10, 2020. http://www.sahilnawab.com/blog/the-dilemma-of-electric-aviation/

“Electrification of Last Mile Delivery,” by Sahil Nawab, April 24, 2020. http://www.sahilnawab.com/blog/electrification-of-last-mile-delivery/

Beyond the locked gate of the airport, the plane waits patiently out on the tarmac. It’s thirsty for fuel. I punch in the code and push open the chain-link door as it squeals on its tired hinges.

Filling up fuel in your car is typically not a fun activity. But, somehow, it’s different with a plane. Perhaps it’s the fact that the tank is just the inside of the wing — you can see (and hear) quite clearly as the fuel laps up against the edges. I watch the blue tinged fuel slowly creep its way up to the top. As it nears, I slowly let up on the pressure of the filler handle and let the fuel slow to trickle. As the vapors vent, I smell the distinct odor of AvGas.

Climbing under the wing and bracing myself against the wheel, I drain the fuel sump to check for contaminants. I lift up the fuel inspector to the sunlight to check for the characteristic blue tint of the fuel. In the old days, some would simply dump the 50-odd mL of fuel on the ground, but today, conscious of the environment and the rising cost of fuel, most pour it back into their tank, including myself.

During this whole process, a few might even don protective rubber gloves as to avoid touching the fuel. After all, unlike automative gasoline, AvGas — or more appropriately 100 Low Lead (100LL) — is still contains trace amounts of tetraethyl-lead. The additive serves several purposes, including preventing engine knock and detonation as well as for lubrication of valves.

This situation plays out every day at nearly all airports in the United States and the rest of the world. Yet, according to the United Nations Environment Programme in their August 30 press release, “the era of leaded petrol is over.”

As others have pointed out, that’s not exactly the case. The UN EP announced that leaded fuel was finally phased out in Algeria, one of the last holdouts for automotive gasoline. However, leaded fuel in the form of 100LL AvGas is ever-present, exhausted by the light planes flying in the skies directly overhead.

Unfortunately, there currently exist no viable alternatives to leaded AvGas, which has a higher octane rating of 100 compared with the 87 of regular automative gasoline or 93 of premium automative gasoline. Consider also that most planes were designed in the 1950s and remain essentially unchanged in their powerplant designs since then, and the market is ripe for disruption. I think this highlights the need for significant research into developing alternatives that could be a drop-in replacement for traditional 100LL.

Dossier

“Scrap the proposed $1,000 landing fee. Keep general aviation alive.” by Sahil Nawab, June 6, 2021. http://www.sahilnawab.com/blog/scrap-the-proposed-1000-landing-fee-keep-general-aviation-alive/

“Here’s Why Planes Still Fly With Leaded Fuel,” by Mercedes Streeter, September 6, 2021. https://jalopnik.com/heres-why-planes-still-fly-with-leaded-fuel-1847615621

“Era of leaded petrol over, eliminating a major threat to human and planetary health,” August 30, 2021. https://www.unep.org/news-and-stories/press-release/era-leaded-petrol-over-eliminating-major-threat-human-and-planetary

When we think of surgery, the image that most often pops into our heads is the darkened operating room, with a huddle of attendants surrounding the surgeon, all eyes glued to the surgical field. This is what Nikolai Begg, then an engineering student and now engineering director at Medtronic, thought when he first observed a surgery. While this heightened drama certainly is better for the camera and focuses our attention, the real operating room is quite a different scene.

The room is kept cool and bright, with staff bustling around setting up sterile equipment and readying the patient. The anesthesia team wheels the patient in through the double doors, gently talking the patient through what will happen as they get the anesthetic. As the patient goes under, the ventilator is connected, and a heater is switched on around the patient to keep them warm against the cool air of the OR. Eventually things settle down, but the lights do not dim just yet. Instead, the lights above the operating table are switched on and provide a focused beam on the surgical site. A time out is performed, inspired by the pre-takeoff briefing by pilots, to verify the patient and procedure.

THE PHYSICS OF PUNCTURE

Now as the first incision is about to be made, this is a critical moment in laparoscopic surgery. As Begg describes, the whole room quiets down and the surgeon is handed a trocar, essentially a modern version of a bayonet, to make several punctures through the abdomen for the camera and instruments. Begg suggests that we are all familiar with the physics of this — remember trying to stab a straw through a CapriSun juice pouch? Put too much pressure, and the instant it goes through, bam! You get a nice splash of juice all over your hand. Do it very wrong, and you might have a hole on both sides or a hurt hand as well. So imagine the stakes if the puncture is happening right above the abdomen?

Underneath the skin of the abdomen is a thin layer of fat. Beyond this is the peritoneum, similar to a balloon that encloses the abdominal organs. The challenge for the surgeon is to puncture through the peritoneum without going too far and entering the abdominal cavity and unintentionally damaging the anatomy below. In his TED talk, Begg compares this to drilling through a thin wall.

The physics are the same after all, right? When you apply a force towards the wall, there will be an equal and opposite force back towards your hand. Right at the moment when the drill first goes through the wall, however, there’s suddenly an imbalance. The wall cannot apply any force back, which results in the drill accelerating towards the wall until you can react. Begg wanted to solve this problem, and he had an idea.

POPSICLE STICKS AND RUBBER BANDS

Nearly eight years later, I too observed a laparoscopic colectomy. At the moment of puncture, I remembered this talk. The scene was the same, but this time, the surgeon was using a modern trocar which automatically retracts just as the puncture occurs. The journey from a simple metal awl to a complicated mechanism started out as a simple model using popsicle sticks and rubber bands.

It goes to show that coming up with a solution for a complex problem can sometimes be as simple as putting together a bunch of popsicle sticks in an interesting and thoughtful way. And by thinking through the physics of puncture, Begg decided to use a spring to retract the tip as soon as it went through. As pressure is put on the tip, it pushes the popsicle sticks outwards, which interferes with the wall and “sticks” through friction. However, as soon as the pressure is removed, i.e. as soon as it punctures, nothing is holding the popsicle sticks in place. The spring is then able to pull back on the tip and retract it before it can damage any structures underneath.

LOOKING FOR THE OBVIOUS

As Begg explained, this had been a serious problem for over 25 years with little change in the trocar device itself. Solving this required looking at it in a different way. Rather than attributing it to the skill of the surgeon, a mechanism could take the guesswork out and react to changes much faster than a human. The genius in this particular device is that it requires no active components and accomplishes the retraction purely mechanically.

Often, it is the most obvious problems that are the most challenging to see. We’re not always aware of them or we take things for granted. By seeing the physics of puncture, Begg was able to find a new solution that seems obvious now in hindsight. Perhaps this will inspire us to look deeper at the world around us, searching for things that we otherwise would have overlooked.

Dossier

“A tool to fix one of the most dangerous moments in surgery,” by Niklai Begg, November, 2013. https://www.ted.com/talks/nikolai_begg_a_tool_to_fix_one_of_the_most_dangerous_moments_in_surgery/transcript?language=en