Tuesday, August 17, 2010

Sonic Booms over Seattle

Recently there were sonic booms over the Puget Sound region.

These sonic booms were set off by a pair of F-15 fighter jets that were scrambled to intercept a small seaplane that had violated a Temporary Flight Restriction (TFR) around the President of the United States. He was in town fund raising for our embattled Senator, Patty Murray.

There is crazy amount of disinformation around events like these. As a certified pilot with 15 years of experience with the system, I’d like to address some of these items.


  1. Sonic Booms occur when an object travels faster than the speed of sound, and is produced continuously along it the path it travels. In the article by ABC news it is reported “The sonic booms created by the fighter jet engines...” The booms are NOT caused by the engine, unless you consider the engine is what pushes the entire airframe through the air.
  2. The speed of sound varies based on the density of the media the sound waves are traveling in. Since air gets less dense at higher altitudes, the speed of sound is lower as you go up. Roughly it is around 770 mph down at sea level.
  3. There are speed limits in the sky over the continental United States. Generally an aircraft may not exceed 250 kts (287 mph) below 10,000 feet. Above 10,000 ft, an aircraft may not exceed the speed of sound – without a waiver. The military has a waiver.
  4. At high altitude, the F-15 will go about 2.5 times the speed of sound or around 1,600 mph, at low altitude it only goes 1.2 times or around 900 mph. If the plane is loaded with weapons such as external bombs or fuel tanks, the airspeed is further reduced due to drag.
  5. The F-15s came from Portland because those are the nearest armed fighters. All of the fighter wings that were based nearer have been removed. There are transport jets (C-5, C-141, and C-17) and heavy helicopters (CH-47) in Tacoma, Electronic Jammers (EA-6B, EA-18G, P-3) and on Whidbey Island, and Bombers (B-52H) in Spokane. But the nearest armed fighters are in Portland.
  6. Restricted areas

  7. How big is the TFR? The restricted space is 30 miles in radius. Imagine a circle that extends from south of Tacoma to Everett and from the east slopes of the Olympic Mountains to the west slopes of the Cascades. Aircraft may only be operated in that ring if they are working with Air Traffic Control (ATC) and entering or leaving the area.
  8. There is also an inner ring that is only ten miles in radius. Only law enforcement aircraft are allowed in there.
  9. The President ALWAYS has a 30 mile ring around him when he is on the ground. It is slightly smaller when he is in flight.
  10. Does the President need all that space? I don’t know. For a typical small airplane that only goes about 120, it is a 15 minute buffer from incursion to center of the TFR. But for a faster plane like an airliner, it could be a quarter of that.
  11. Pilots talking to Air Traffic Control and Flight Plans

  12. Since flight on Visual Flight Rules (VFR) flights require NO prior authorization from the government, there is NO ATC talking to the pilot to stop them. Quite literally, if I had enough fuel, I could take off from Copalis beach on the pacific coast in Washington state, and fly all the way to Homestead General Airport in southern Florida, and NEVER talk to ATC.
  13. The purpose of a Flight Plan on a VFR flight is to help search and rescue know where to look for the wreckage. Really. If I file a VFR flight plan, after taking off, I call a special frequency for that area, and ask them to open my flight plan. Upon arriving at the other end, I call another special frequency to close it. If I fail to close it, they assume that I did not arrive at my destination. And they will call out the search and rescue teams that will then search along my intended course looking for the plane. Remember when Steve Fossett disappeared? No flight plan. They are not required. It took a year to find the wreckage and that was by a hiker on accident.
  14. The pilot should have checked for a Notice to Airman (or NOTAM) prior to the flight. Since the President is always surrounded by a TFR, and it has been known for days that he would be in town, and the pilot is REQUIRED to check for NOTAMs prior to his flight, he should have known.

Friday, April 09, 2010

Why I Fly (Chapter 14)

I was sitting there on my way back from St Mary's, Georgia to Kissimmee, Florida, going 116 miles per hour. I was thinking, "Can't this thing go any faster?" and I was reminded of "Everything's Amazing and Nobody's Happy." I had just checked off two items from my States-I-have-Landed-an-Airplane-in list yet the plane feels agonizingly slow. Just how slow? Only 101 knots. Yawn.

No way.

The weekend before, I celebrated my birthday with my family. Each of my kids had provided very thoughtful gifts. Items better than the usual shirt, or tie, or Star Wars boxer-shorts. At the end of the gifts Sandra handed me a box. A shirt box.

"Here's the shirt," I thought.

But it didn't quite feel right. I pulled off the bow and took the lid off the box which revealed the contents carefully covered in tissue paper. I uncovered a gift certificate from Stallion 51 for an hour of flight time in a P-51 Mustang! And not just a certificate - but below that were airline tickets from Seattle to Orlando. And below that a rental car reservation. And below that a hotel. My head was trying to make sense of it all. She didn't really do this did she? What date is on the airline tickets? What date is on the gift certificate? April 2. Is that a weekend? Wait, that is really soon. WAIT, THAT'S THIS WEEK! The airline tickets are for Wednesday! Don't I have to work on Thursday?

"I called your office and I got you the time off," I heard her voice from outside my thoughts.

"No way." It was all I could come up with. "No way!" I said out loud. To appreciate the significance of the P-51, take some time and read about the development and contribution to the Allied victory in WWII. These things are legendary and widely credited for turning the momentum of the war as the top of the food chain fighter plane. Most of the remaining P-51s sit in museums now. There are about 160 of them still flying 65 years later. And I was going to fly one of them. "NO WAY!"


I took the red-eye Wednesday night and arrived in Orlando on Thursday morning. I spent the day orienting myself to the area, finding the route from my hotel to the Kissimmee airport, locating Stallion 51, and touching the airplanes. The Mustang is a visceral airplane. It just looks fast. The way it sits on its high front landing struts, the smooth flowing lines, the long nose, the bottom scoop - it all blends together creating a visual image that is sensual. The pilots of this plane have an emotional connection to these aircraft.

And Stallion 51 is immaculate. The floor is polished gray epoxy paint and free of any oil or fluids. There are no drip pans and there is not a spot or a piece of debris anywhere on the hangar floor. The same is true for the planes. No chips in the paint. No scratches in the shined aluminum panels. Not even finger prints. No signs of oil or grease anywhere on the airframes.

My first view of the hotel left me a bit concerned. It was located behind two vacant restaurants on what, at first glance, appeared to be a dirt road. Uh oh. Sandra probably didn't realize what she was getting. But I decided to give it a shot. It turned out to be a clean and comfortable place. As an added bonus, it was just below the departure end of the runway.

Also located at the airport is the Warbird Museum, which flies the advanced trainer aircraft of WWII. So on Friday morning, I awoke with a flight of AT-6 Texans going over my hotel room. Their big radial engines acting as my alarm clock. I wonder if I can get that sound on my alarm clock at home.

My turn in the Mustang is not until 1 PM. But by 10:30, I can't wait any longer. I decide to take my cup of Starbucks and drink it in the lobby of Stallion 51. Julia, an elegant lady with a charming British accent, courteously welcomes me. I wander through the merchandise and talk to the others that are arriving. Rob is there with his wife and kids. He's a veterinarian from further south in Florida. His wife got him his ride as a birthday present, too. Steve is one of Stallion 51's pilots. Prior to becoming a P-51 instructor, his call sign was "Mad Dog," but now he is called "Lucky Dog." He’ll be flying with Rob the Vet (Get it? - the vet and a guy named Dog?).

Charlie Johnson came in to meet with Lee Lauderback. Lee is the owner of Stallion-51 and has more flight time in P-51 than anyone else in the world. They will be flying together. Charlie was the head of Cessna Aircraft. I talk to Greg the Crew Chief who watches over the planes. He laughs when I ask how often they polish the floor. It is a common question.

I walk to the next hangar over and discover a couple of AT-6 Texans, and an L-39 Albatross. Rob is there with his family looking, too. By now the three Mustangs have been pulled out into the sun and our equipment and check lists are being loaded. My fence clutching has been elevated to a new level.

Now it is 12:30, still 30 minutes until I am scheduled to be there, Rob and are back in the sun standing between the three very shiny P-51's. A man comes out and calls for Rob and me. He introduces himself as John and informs us that, because we missed our briefing, we cannot fly today.

I told him the paper work says to be there at 1:00 PM and that Rob and I have both been there since 10:30 AM. And where has he been anyway?

The briefing

John smiled and took me upstairs for my briefing - he is my instructor for the flight. John Posson is small, articulate, and confident. He asks me about my ratings hours, tail-wheel time and if I have any aerobatics experience. John is an air show pilot. He flies left wing of a four-jet L-39 demonstration team.

We discuss the things that make the Mustang special with special focus on the "laminar flow wing." This is wing is different that a "normal" wing which is relatively flat across the bottom, arched across the top and the thickest part being about one fifth to one fourth of the way back from the leading edge. A laminar flow wing, on the other hand, is nearly symmetrical on the top and bottom and the thickest part is nearer the center. This creates a more slippery wing and allows the plane to go faster. But what you gain in high speed you surrender in low speed. When the airplane gets slow and the angle of attack gets too high, the once laminar flow separates quickly and the wing stops flying abruptly. And usually one wing drops aggressively. Translation, one moment you are flying straight and level and the next you are flying with one wing pointed at the ground and the other pointed at the sky – without much warning.

We discuss how the Roll-Royce Merlin engine’s one thousand four hundred and ninety horsepower will want to twist the airplane around. To compensate for that, the vertical stabilizer, or rudder, is mounted about a degree and a half out of line with the airframe. So, at high speed, the rudder will pull it one way and at low speed the engine will pull it the other. The airplane has trim on all three axis to compensate. John discusses the importance of using the trim to manage this plane.

He tells me about how noisy the cockpits are and how we will be wearing ear plugs under the helmets with earphones in them. He gives me instructions on operating the intercom and the radio.

He talks about control input. How little or hard one must work the controls to get a response. He cautions me against full control inputs, observing that the only time we will use them is when we are doing aileron rolls. He points out the airplane was built as a weapon and rather than "flying" it you "aim" it.

We discuss the flight profile. He'll taxi out, take off, do the formation flying, break us off, then I will take the plane into the practice area and do the bulk of the flying from there. I'll fly back to the rendezvous point and he will pull us into formation with the lead plane.

We talk about how there were no two-seat Mustangs made. The planes we will fly have been modified by removing the rear fuel tank and putting in the second set of controls where the fuselage is a bit narrower than the original cockpit. So he'll have a bit more room than me, and I'll be wedged in.

He sends me to the restroom for one last break before strapping in.

We meet back at the planes. Charlie and Lee with be flying lead in "The Little Witch,' John and I will be right wing in "Crazy Horse 2" and Rob and Lucky-Dog will be left wing in "Crazy Horse."

I climb into my seat while John holds up the straps to the parachute. Ha – parachute. This is the third time I’ve flown aerobatics and every time I get a nearly identical conversation. It is short, curt, and has become to me, comical. Usually somewhere in the process of strapping into the parachute harness, the instructor will ask, "Have you jumped out of a plane before?"

I give a one word answer, "Yes."

A slight head nod, "Good." End of conversation.

John talks about how, if the engine fails, we are going to fly the airplane all the way to ground. If we are over a runway, we will extend the gear and land. If we are over a field, we will leave the gear up and slide the airplane to a stop.

John discusses the protocol of emergency egress and releasing the canopy. He points out the $75,000 handle: Pull it and the canopy comes off. We will only pull it if there is no way to fly the plane. Either the plane will be on fire or we are involved in a mid-air. And I will only pull it if he is unable to pull it. Once the canopy is released, I am to release my seatbelt and dive over the right side of the plane. The discussion is all for naught, as we return safely.

Finally, I am buckled into the five-point harness that holds me to the seat. John straps in. He is meticulous with the check list. He verbally covers every item in staccato rapid fire sequence. I try to keep up.

The start

We wait for the crew chief to give the signal to start the planes.

It is finally time to hit the starter. The propeller on the Mustang is geared, so it turns at about half the speed of the engine. As the plane starts, the blades move very slowly. And then a puff of blue smoke appears from one of the six exhaust stacks on the left side, followed quickly by a second puff from the other side, and then the engine catches, the blue smoke is pushed away, the propeller blades vanish in a blur, and the big Merlin lets out that beautiful growl. It’s alive!

The whole airplane rumbles. You can feel it vibrate. Earlier in the briefing, I was told, "It is a big, nasty tail-dragger and I want to feel it talking to me." The growing engine is singing a love song. Olivia Newton John just fell to a distant rung on the ladder.

We are second of three Mustangs taxing out and, as we approach the runway, a B-25 Mitchell is landing. We have been transported back in time 65 years but I doubt any of these planes, including the Mitchell, were this well polished during WWII.

At the edge of the runway, John continues down the check list, setting the brakes and bringing up the throttle. The plane struggles against the brakes. This is going to be fun.


The tower clears us as "Mustang Flight" for take-off. Charlie and Lee roll out to the centerline; we roll to the far side of the runway on the left side; and Rob and Lucky Dog pull next to us on the right side. The first Mustang starts its take-off roll. We count five seconds and start our roll behind them. Our tail lifts off the ground as we accelerate. The plane ahead lifts off and the wheels tuck up into its wings. We lift off and tuck our wheels away too.

The P-51 accelerates quickly. Soon we are at 180 knots and accelerating in a climb. John rolls the plane to the right side of Charlie and Lee in the lead plane and they bank right towards our path. John tucks Crazy Horse 2 just behind the right wing of Little Witch. I’ve never been this close to another plane in flight.

Charlie banks Little Witch to the left and we stay just behind the wing, as Crazy Horse lines up on the left side. I’m looking down our wing, straight across at the third plane at the end our wing tip. We hold together in level flight.

John moves the plane back and tucked us up under and behind Little Witch. I can see through our propeller to the propeller of the plane ahead, the blades mix together creating synchronization moiré patterns. Rob and Lucky Dog pull up behind us. We are so close to Charlie and Lee, it seems our propeller could take the tail off Little Witch.

My Airplane

John lets our plane drift out to the right about three or four wing-span distances or so away from Charlie and turns the controls over to me. I try to keep the plane lined up. John is coaching, I’m trying to react and follow his instructions - more power, less power, move right, climb, more power. Too high, push over; move right… but I just can't do it. Formation flight is HARD – harder than I would have ever imagined. But it doesn't matter. I’m in the cockpit of a Mustang, stick in my right hand, throttle in my left hand, and my feet firmly on the rudders. I'm in command of a P-51 Mustang!

Yankin' and Bankin'!

Lee assigns each of us airspace and we all break off. I bank right to head west. The airplane is stable and solid. John's words "you aim it" come back to me. We do a couple of "S" turns as I get more comfortable with the plane. As the plane pulls around, we are greeted with some pleasing g-forces.


In the practice area, John has me slow the plane down and extend the flaps. At about 90 knots, John talks me through a couple of stalls so I can experience the buffet that precedes the stall. We stall slow, buffet – wham! Left wing drops. I push the nose back to the horizon and regain control. We accelerate and yank the stick back hard, buffet – wham! Right wing drops and I am fighting to keep the wings level while I push the nose back to the horizon. We bank to the left and pull back hard again, buffet – wham! Right wing drops and I’m turning right on a knife edge, fighting the wing back up. OK, I get it. When you feel the buffet, let off the stick or you end up going a different direction.


We accelerate and pull up vertical. When the plane is climbing up, I ease in a bit of rudder and roll the plane to near zero gravity vertical turn kicking the nose over to the right until it is pointed straight back down and pull it back out.

John coaches me a bit and demonstrates another wing-over. I do it again and we float much longer during the zero-g phase. Cool.

Aileron Rolls

I level the wings, point the nose down and accelerate. At 220 knots, I pull the nose up about 15 degrees and push the stick all the way against my left leg. The plane rolls smoothly onto its side - left wing pointing at the ground, right wing pointing at the sky. I step on the right rudder a bit to kick the nose up as we continue to roll inverted. I let off the rudder and push the stick forward and I can feel myself come out of my seat and hang against the shoulder harness as my left wing starts its arc back into the sky, and the right wing points to the ground. I step on the left rudder pedal while the plane returns to wings level. WOW!

Other airplanes I have rolled have very aggressive nose drop when they are on the knife edge. Not the Mustang. There is enough power pushing down that big flat side of the plane and enough rudder to kick the tail down that the plane just keep flying. I do it again.

Four Point Rolls

John does a four point roll. I've never done one, I try a four point roll, stopping the rotation every 90 degrees. Knife edge. Inverted. Knife edge. Wings level. This plane makes it easy.


I love the stability of the P-51 when it is on edge; I've flown nothing like it before. I want to do more four point rolls. We scream across the sky at 7000 ft in 90 degree increments. John compliments me and says, "That was pretty good. Let's see if you can do it 50 feet off the deck."

The FAA requires aerobatics be completed above 1,500 feet, unless you have a special aerobatic waiver, known as a "low level waiver." These come in increments from 1,500 feet, down to the surface. I'm confident John has one for his air show flying. And I know they are hard to get. I know John is kidding around with me.

I rolled the Mustang to 135 degrees – about 45 degrees away from completely inverted, and start to pull into a diving-arching-inverted turn headed for the ground. John says, "I was joking."

"I know," I reply. "Me too."


John suggests a loop. I line up on a road below us to use as a reference. We dive for 260 knots, and pull back hard. Four and a half times the force of gravity presses me down into my seat. I tighten my torso muscles and leg muscles and grunt in hope of not blacking out. I look left and right as we approach vertical to keep the wings about the same distance above the horizon. Tipping my head back I look out the top to the ground behind me locating the road below. Fully inverted in the loop I look left and right again to adjust the wings. At the top of the loop, the g’s are coming off. I like this point in the loop because you know you are upside-down and you should be hanging from the seat harness but the g’s are still pressing you into the seat. I stay lined up on the road as we start the inverted dive back down and I continue to hold the stick back, while waiting to feel the buffet. As our speed builds, so does the pressure on the stick. As we continue down to the vertical, I am still looking out the top of the canopy searching the ground below for the horizon. Our speed builds and the g-forces accumulate to force me back into my seat. More squeezing and grunting as the horizon and the nose of the plane converge back together. WOO HOO!!!

Barrel Rolls

From there John demonstrates a barrel roll. This is a surprisingly gentle maneuver where we accelerate up to 220 and start a gentle climb while lifting one wing and holding an arching rolling trajectory, maintaining one positive g. Then I do the same. Cool.

Cuban Eight, or um, where are we?

John says we should do it again. I ask for a Cuban-Eight instead. As we approach the top of the loop, I lose track of the road, and one of wings dropped below the other. We veered around in the sky as I came down on the 45 degree down line, but I have no idea which way I am headed and I cannot find the road. I push the stick forward to stop the loop in an inverted 45 degree dive and, with an odd twisting aileron roll, the Mustang returns to upright pointed about 90 degrees off our original heading. "What was that?" John asks with a chuckle.

No idea. "That was on purpose." I reply. Yeah, right. I line up for a second pass which is more successful.

Hanging in the straps

I ask about how long the plane can stay inverted. The problem with inverted flight is the engine. Under normal conditions, the oil is pumped from the bottom of the oil reservoir into the engine to lubricate all the moving parts. But inverted, there is no oil in the bottom of the reservoir because it all falls to the top (which is now on the bottom). The Mustang is not to be flown for more that 10 seconds inverted before returning to normal flight. I ask and get approval for four or five seconds. Over we go, and I hang in the harness. And smile. A lot. I’m still smiling.

Inverted Cuban Eights

We then move on to inverted Cuban eights. Climb at 45 degrees until the plane slows to 90 knots, half of an aileron roll to inverted, pull out the bottom of the loop, climb back up at 45 degrees to 90 knots and pull again. BIG GRIN.

Credit where credit is due

John asks if I want to say anything to my wife on the video. Sandra gets a big thumbs-up and a huge thank you.

Time to head back

I knew the time was coming but it always comes too soon. It’s time to head back. Lee's voice comes over the radio and call for a rejoin. He'll be northbound over the freeway at 6,000 just north of the southern most brush fire. We head between the columns of smoke at 7,000 searching below us. I'm struck again at how big the sky is. There is a plane out there, I know where to look and neither John nor I can spot it. How did the WWII pilots ever find each other to shoot the enemy down? Then off my left side there is a flash of light headed away and behind us. John calls "Tally-Ho" and turns the plane hard right into a diving turn. As we level out, we are closing fast on Little Witch’s right side. Charlie and Lee bank towards us and John tucks the Mustang back into formation.

It just keeps getting better

John asks how I am feeling. What? How am I feeling? You gotta be kidding me! I feel AWESOME! Apparently some folk get a bit queasy after all the yanking and banking John is making sure I can take some more.

After a brief exchange over the radio, we pull up into a climb in formation and continue to pull until we are inverted into a loop. Awesome! I am in a Mustang, inverted, in a loop, in formation. This is amazing!

At the bottom of the loop, we start a gentle roll to the left and do a formation barrel roll. This just keeps getting better!

He does this to humble me

Rob and Lucky Dog report in. Altitude assignments are exchanged and soon they are tucking Crazy Horse back into the left wing side of the formation. While cruising towards the airport we drift out wide of the formation and John turns the controls over to me again. "Stay right here," he says, "and use your rudder to move away from him." I drift back. "More power. More than that. More. He’s getting away. Nose Down. You are too high. Less power, you are getting ahead of him. My airplane."

Dang, this is hard. And John makes it seem so easy as he pulls back in.

Overhead 360 to landing

Little Witch pulls out of formation and Rob and Lucky Dog take the lead. Little Witch drops back to third position in echelon formation. We are cleared for a left overhead 360 landing. We stay in formation northbound around 200 knots. Passing to the east of the airport, we make an arching left turn back to line up with the southbound runway. As we cross the end of the runway, Rob and Lucky Dog make a left turn breaking out of formation. We start our count. One thousand one, one thousand two, one thousand three, one thousand four, one thousand five. I break left. The hard banking turn eats our airspeed and, as I cross through 150 knots, John extends the gear and starts the flaps down. I pull off power as I track Crazy Horse passing my wingtip on final. I roll left in behind them and John puts out some more flaps. There is a bit of a crosswind pushing us to the right. I try to get the wing down and step on the rudder. I trim the plane. I work to keep the left wing down. I drift a little further to the right. The main landing gear touch down and then we float back up. I put the mains back on the runway again. And again. As the tail starts to settle, John takes the airplane back, and puts the tail wheel firmly on the ground. I can feel him dancing on the pedals to keep the airplane aligned with the runway.

We exit the runway and slide the canopy open. I am sweaty and sticky. It was a great flight.

Back in reality.

The next day I took a 172 to Georgia. I checked off another state from my list. And 116 mph just seems slow. I’m still grinning. But it just feels slow.


In the comments there is a reference to a video from John Posson, shot by a high def camera. I decided to add it as a embedded here.