Ratty's Ramblings - Remember Me?

By Ian Radcliffe

2021 was a strange year for just about everybody. For me it was made additionally interesting by our move from a house in California to a condo in Florida, with the associated sorting, downsizing, packing and shipping, and a six-day drive across the continent with our two cats. And then, after we moved in and were beginning to impose order, we found ourselves the owners of a second, larger, condo that also needed a fair amount of TLC.

All of which is really just a long-winded way of saying: I've been busy, I'm sorry I haven't written sooner. Here's some stuff.

Test Pilot

There she stands, gleaming on the ramp. Your newest aircraft. Time to read the READMEs and the manual, and then venture inside and begin your cockpit familiarization. Or, alternatively, time to jump in, fire this baby up, and take to the skies!

Wherever one is on the spectrum, we're all test pilots. Although the latest addition to your hangar may already have been flown by thousands of others, this is your first time, and you don't have a check pilot sitting beside you. Regular readers will probably not be surprised when I admit that I lean towards the "Get up there NOW" school of thought, but there is benefit in approaching the early flights with deliberation, and taking time to note some of the unique characteristics of your new mount.

Before you fly, set up your plane. Load fuel to half tanks or less, and load the airplane to the middle of the CG envelope or slightly forward. Set the weather to something benign. Choose a long runway; a bit of extra width might help, too.

Start up, run up, and check the controls visually. As you taxi, check the brakes, the direction indicator, and the turn coordinator. Before you start your first takeoff roll, check that everything in the plane is set the way you want it. WW2 ace Douglas Bader's brief first flight in a Spitfire ended in a prang off the end of the runway when he tried to take off with coarse propeller pitch selected. Check your mindset and put aside your expectations. There is a recording of Bader describing his first experience with a jet, the Gloster Meteor. He talked about how sleek and fast it looked and how, when he pushed the throttles forward for takeoff, it "rumbled off down the runway like an old lorry".

Approach your first takeoff with caution. My favorite plane of all time, of which more anon, is A2A's Civilian P-51. The flight model has been endorsed by several real-world Mustang pilots, but posts will appear from time to time on the A2A forum that each say, essentially, "I just bought the P-51 Mustang and there's something wrong with it: every time I try to take off it flips upside down".

Line up your plane and open the throttle, not too slowly but not too quickly either, managing the torque with steering, brakes, and rudder. Watch the airspeed and very slowly lift the airplane off when you think you are fast enough. It may be nose heavy or light. Climb straight ahead to at least 3,000 feet and make sure there are no significant controllability issues.

Find the stall speed. Apply carb heat, if you've got it, and throttle back gently, noticing the tendency of the nose to rise or fall. Apply back pressure to stay level and reduce your speed. Don't use the ailerons, keep the wings level with rudder. Watch the airspeed and the horizon. Notice the stick back pressure, any buffeting, and oil-canning or other noises. In the A2A fleet, both the Comanche and T-6 make very distinctive noises close to stall that have saved me more than a few times.

Most well-designed aircraft will have a gentle stall, though one wing may drop before the other. At the stall, note the indicated airspeed then release the stick pressure to increase the airspeed and get the wing flying again. Smoothly apply full power and climb at 130 percent of the stall speed. Trim, and note the setting. You now have your takeoff trim for this configuration, at this weight and CG.

Now that you're up here, check out how your plane flies. How does it roll, pitch, and yaw? How are stalls with power on? How much power does it take to maintain altitude with gear and flaps hanging? What happens when you raise and lower the gear and flaps? Experiment and explore.

If you're really daring, on subsequent flights you can go into extreme test pilot mode and try some "out of the envelope" stuff. Is it possible to get into an unrecoverable attitude? How much can you actually load on board and still take off? How does she fly loaded outside the CG envelope, both forward and aft?

And be ready for the unexpected. Flight Simulator 4.0 allowed users to "build" an airplane by tweaking the parameters of a basic airframe. Inevitably, at one point I tried a canard arrangement, moving the wing to the back and the "tail" to the front. Although the runway at Meigs was a bit less than 4,000 feet I was pretty sure my little jet would take off easily in that space. But, racing down the runway on the first flight, I discovered that pulling back on the stick produced no result at all. Just before the far end, on a hunch, I tried PUSHING, and the plane leaped into the air. It was tricky but, mumbling "The stick is backwards, the stick is backwards . . . ", I actually managed to lurch around the pattern and land again. Apparently I was not the only one thus endangered; the next edition of the program included a "canard switch".

B and D

I was prepping the Comanche for a flight and, as I do, I tapped the B and D keys prior to taxiing. In FSX and P3D, the B key sets the altimeter to the local barometric pressure setting, and the D key sets the directional gyro to the magnetic compass heading. But this time I paused a moment, and pondered what I had just done. It has become my habit to tap the two keys from time to time during a flight: when making a heading change, for example, or when approaching an airfield, or just whenever I happen to think of it. But I realized I've become a bit casual with my use of these shortcuts because in real flying conditions it isn't always easy - or, sometimes, even possible - to reset these instruments in real life.

The altimeter works by comparing the atmospheric pressure where you are with the atmospheric pressure at a reference surface - sea level or the airport of departure - or with the flight level standard of 29.92 inches/1013.25 millibars. But as you fly you will almost certainly be moving into areas of differing atmospheric pressure, and that affects the accuracy of your altimeter. For example, if you fly into a region of lowering pressure without adjusting your altimeter while maintaining a constant indicated altitude, you will be descending. How much? I took a quick look at weather systems and found an extreme example that in 300 nautical miles had a pressure change of 28 millibars or 0.8 inches. That represents an 800-foot altitude difference, which could obviously be an error of some significance if flying, say, on instruments at night. So if you're looking for verisimilitude (and a little more excitement), you should only reset your altimeter when you receive a setting from ATC, or when you can be sure of your altitude, as when you're sitting on the ground at the airport.

Our primary instrument for telling which way we're going, the magnetic compass, is a quirky little beast. In anything but smooth air and unaccelerated flight it swims in its little tank subject to a number of forces. Of course, it doesn't point North (well, rarely), but we map the variation between True North and Magnetic North and pretty much have that handled, though a close look at a US sectional map, for example, will often reveal small areas of localized magnetic disturbance.

Besides variation, we have declination and deviation. For many, "declination" has become synonymous with variation; it is, actually, the tendency of the compass to follow the curve of the magnetic field, which is most noticeable the closer you get to the poles, and so is also called "angle of dip error". Deviation is the phenomenon noted on the little card next to the compass, and indicates the effects that electronics and structure have on its accuracy in that location. Note that in the real world other things will affect it: a few tons of steel pipe in the back, or a headset on top of the panel.

Acceleration/deceleration errors cause the compass to turn on easterly or westerly headings (and to dip on northern or southerly headings). In the northern hemisphere, acceleration gives a turn to the north and deceleration a turn to the south. In the southern hemisphere it's opposite: acceleration gives a turn to the south, and deceleration a turn to the north.

In a coordinated turn, the compass dips to the low side of the turn, an error most noticeable when turning through headings close to north and south. Turning from a northerly heading, the compass will briefly indicate a turn in the opposite direction; from a southerly heading, it goes the right way but faster than the plane is actually turning.

And then there's turbulence. Not really an error, but it makes the compass unstable, and therefore an unreliable reference.

And so we have: the directional gyro. It's usually powered by suction. An engine-driven pump draws air out of the instrument's case, and a jet of incoming air strikes little buckets on the rotor to make it spin. Neat, huh? So after you set it on the ground to match the compass heading it is, for the most part, unaffected by the eccentricities that plague the compass. However, because the Earth is rotating at about 15 degrees per hour, the DG will, over time, drift and must periodically be reset, using the magnetic compass - with all its quirks.

More sophisticated installations incorporate a solution for gyro drift. The directional indicator on the HSI in my A2A Civilian Mustang, for example, is slaved to a fluxgate, a magnetic sensor that continuously senses the Earth's magnetic field and causes a servo to constantly correct the indicator. I still press D.

Travels with Miss Sheila

The question came up on a Misfit Squadron flight a few months ago: If you could only fly one aircraft from your collection, which one would it be? My choice was the A2A civilian version of the North American Aviation P-51D Mustang. It is, for me, the ultimate personal flying machine. At 30,000 feet I can buzz along at light jet speeds for a thousand nautical miles, and stretch the range to 1,300 if I slow down a little. And when I'm done I can get into (and out of) a grass strip less than 2,000 feet in length.

Like its equine namesake, this Mustang can be challenging; after around 2,000 hours I still find takeoffs and landings exciting. You can't master this one, only strive to master it, and that's a huge part of its appeal. With the A2A version I get the additional treat of having to be responsible for my aircraft. That means checking it in the hangar before flight, maintaining fluids, managing power, watching temperatures, and not exceeding the structural limitations. If I don't treat the engine properly, parts will need to be replaced more often, and it's more likely to fail.

Of all the aircraft I've owned and flown in almost forty years of flightsimming, this is the first one I've been moved to name. I'm creating a series of videos, "Travels with Miss Sheila", to share this magnificent aeroplane and our experiences together exploring both the world and the world of flight. The first episode, featuring an initial look at the plane and some unusual geography, will be up on YouTube soon. Details to follow. I hope you'll check it out!

Ratty's Ramble

One of the flights I planned for the Misfit Squadron last year turned out to be more challenging than I expected. It was designed as a scenic tour of the Canadian Rockies, from Fort St John to Prince Rupert, a distance of 426 nautical miles through some spectacular mountain scenery.

What made this particular trip so exciting was the weather on that particular day: there was just the right amount of low cloud to make it challenging combined with enough clear skies to take in the stunning terrain. Fly in any weather you like, but if you want to duplicate the conditions we encountered, set your weather to 0800 local, June 13, 2021 - and fly low.

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