Cirrus How-To
January 2005
Out of all my adventures, people keep asking for more CIRRUS adventures, and I admit that I have not been as good about journaling them as I could be… so let’s break that rule now and do a good Cirrus adventure. On this flight, Randy Witt (the new X-Plane customer service guy, info@X-plane.com) will be accompanying me from Columbia, SC, to Washington DC to test-drive and purchase my new Ferrari (well.. new to ME.. it’s a 2001 Modena). This flight is a perfect example of how to run the Cirrus SR-22 properly. (note: the pictures are from various flights… not all from the CAE->Washington flight… all my other adventures have accurate per-adventure photos, but I have included pics from many different flights here for illustrative purposes).
So, it’s Friday at high noon on a cool South Carolina winter day as we head out to the airport in my C-5 50th Anniversary Vette, the engine purring perfectly in 4th gear at 100 mph on the gently curving ramp from I-77 to I-20… wait, you want the AIRPLANE, not the car.. sorry… we’ll skip the drive and go to the AIRPLANE. Arriving at the hangar and walking up to the Cirrus SR-22 the first thing you are struck by is the lack of any rivets, seems, aluminum dust, wrinkled aluminum, or any other imperfection… the plane is just a perfectly smooth, clean, curved piece of plastic, with no hint of it’s building materials visible from its perfect, curved, form. With its round nose and tapered, skinny, tail, it looks like a plastic space-sperm from Mars… a big smooth rounded projectile with long sharp skinny wings. Here’s what it looks like on the ground:
So, for the pre-flight, you run around the plane checking in every tiny control surface gap to be sure the little cotter pins are in place and the various bolts and hinges are secure, and that the pitot, static, stall warn, and fuel vents are all clear. Make sure the prop blades and spinner are firmly attached with zero play, and ditto that the exhaust stacks. Check the fuel (up to 84 gallons) oil (up to 8 quarts for the huge flat-6) de-ice (full gives you 45 minutes of sweat on the plane to keep ice off) oxygen (tank can give me air for about 10 hours at 17,000 feet) and tire air (I pull the plane out of it’s hangar myself for each flight, and at 2355 pounds empty, 2900 pounds with fuel (84 gallons, or about 500+ pounds when full), I would instantly realize if the tires were flat)! This complete the check of fuel/oil/de-ice/air… now to check the electrons: The plane has 3 separate complete databases on board (2 GPS’s, one moving map) and every now and again you drop a little data card into the Garmin 430 GPS’s, or plug a zip drive into a USB port in the big Avidyne moving map to update it’s database. The zip-drive thing is a pretty poor joke… zip drives are slow, break all the time, and the zip disks are easily corrupted… with Apple’s tiny new solid-state I-Pod holding MORE stuff than a zip disk, and jacking right into a USB port with no clumsy drive, this is an area that needs updating in the Cirrus/Avidyne package.
Once the pre-fright is done (kidding.. while my car-drives are frightening, my Cirrus flights are not) you hop in and buckle into the plush Corinthian leather seats with 4-point restraint belts, available for all 4 people. The doors are notoriously finicky on these birds (difficult to close and latch), and you have to sort of HOLD them closed as you latch them or they WON’T latch… but once they ARE latched, they are LATCHED… you can feel the door tighten snugly up against the frame as you pull the handle through it’s high-pressure, long-stroke travel to the locked position… once done, that door is a frigging PART of the frame, like it’s WELDED there, with ZERO slop. Now, to start, you hit the primer pump for 10 seconds and then the starter… the engine on this plane is very carefully tuned to purr perfectly at 2700 rpm, and it sure does, but you pay the price at starting and idle… the prop turns through a few blades and the engine barks and grumbles unhappily to life, barely running at idle, only half the cylinders firing, and then half the time dies out after about 5 seconds… no problem.. another few seconds of primer and starter again and it barks to life again, the second time for keeps.. the engine does this when new, and when old… it makes no difference.. the engine is like me: it does NOT want to get out of bed in the morning, but once appropriately stimulated it runs awesome all day long. Anyway, after the second start, the engine grumbles and growls like a stock car engine that is barely running at idle… if you give it any more throttle right now, the engine WILL QUIT AGAIN, so you have to just let it grumble and kick for a few moments until it gets firing on all cylinders, THEN advance the throttle a little up to 800 rpm and THEN it purrs gently at idle like a content cat, obviously happy and ready to fly. Bottom line, when the throttle is at idle and the engine is cold, the engine is BARELY able to run, it is going so slow. Lest anyone email me and tell me there is something wrong with the engine, I will tell you that ALL the Cirrus SR-22’s are like this.
Now that you have managed to shut the doors and start the engine and the engine has been running for about 60 seconds and the throttle is advanced a hair, you have a tightly-sealed, tight-feeling, responsive machine with the engine humming smoothly and lightly like a sewing machine or something up front.. the plane is now PRIMED AND READY, a much tighter and smoother package than any other plane I have ever flown short of the Lancair Columbia, which matches the Cirrus. Bring on both alternators (2 alternators, 2 electrical systems, 2 GPS’s, 2 magnetos, 2 artificial horizons, 2 airspeed indicators, 2 altimeters, 3 nav databases, 4 moving maps) and wait for about 90 seconds the primary EFIS to align itself with the Earth to figure out which was is up and which was is north, and the secondary EFIS to grab some satellites and figure out where it is, and the plane is primed and ready to go. (Rewind: FOUR moving maps? Yes. 2 Garmin 430’s, each with a built-in map, the secondary Avidyne EFIS which is a huge moving map, and a little map overlay of the HSI on the primary Avidyne EFIS, for a total of four moving maps… and two of all the primary instruments? Yes… the primary Avidyne EFIS shows everything you need, and there are old-school mechanical back-ups right in your lap below the EFIS.. I routinely turn random stuff off in flight, often at night, or in instrument conditions, and practice getting around the sky with half the stuff on the plane shut down… it’s no problem).
ANYWAY, getting back to our flight today, Randy and I catch ATIS at Columbia Metro and make the long taxi out to runway 29.. the plane has a free-castoring nose-wheel, allowing it to pivot around in it’s own radius, but this means you sometimes have to ride a brake a little when taxiing if the wind is not cooperative with your taxi direction. As you taxi, you are checking to be sure the art horizons stay level, the turn coordinator indicates you turns, the heading indicators actually indicate correctly, the oil pressure is good, and the fuel is good both tanks. If you are good, you will even check voltages and charge-rates, and the EGT and CHT of each cylinder on the engine page of the secondary EFIS to make sure all cylinders are firing equally and heating equally. Once at the end of the runway, run it up to 1700 rpm and check each electrical system (each alternator working? each battery charged?) and each magneto (each spark plug in each cylinder firing?) and you are ready to go! Advance the throttle slowly and smoothly and you are typically airborne BEFORE you even get to full throttle… I often catch air while advancing thru 2500 rpm… and am coming through 50 feet or so by the time the throttle is up to the full 2700 rpm. (note: the throttle handle in the Cirrus controls both the throttle AND the prop pitch… it’s sort of like 2 handles in one.. handle all the way forwards is 2700 rpm, throttle back a way is still wide-open throttle, but only at 2500 rpm, and then everything is reduced as you go back farther from there). After take-off, I STUPIDLY turned on course BEFORE being told to do so by the tower… my take-off instructions were to maintain runway heading.. DUH-OH! A quick course correction recovered from that dumb error, and away we went!
The plane is more crisp in roll than you can imagine… the wings are SO LONG AND THIN, and the ailerons so effective, and the mass so concentrated near the center of the plane, that the roll acceleration does NOT feel like it follows the laws of physics.. there is simply NO DELAY! You simply deflect the little sidestick and the plane POPS it’s wings left and right like a cheap video game. She climbs at over 2,000 feet per minute, putting out 110% power on a cold day with a moderate load.. at this point, you can hand-fly or smack the autopilot on and let it fly either heading or your GPS flight-plan, either holding VVI or going to selected altitude. On this trip to Washington, we were IFR at 17,000 feet. Why 17,000 feet? Look at these numbers:
2,000 feet: 72% power, 167 knots 17 gallons per hour
8,000 feet: 62% power, 168 knots 15 gallons per hour
17,000 feet: 50% power, 167 knots 10 gallons per hour
The BOOK says we burn 12 gallons per hour at 17,000 feet, but the book is INCREDIBLY STUPID BECAUSE THAT IS NOT RUNNING LEAN OF PEAK! At a mere 50% power, there is absolutely NO PROBLEM AT ALL running lean of peak, thus cutting your fuel flow by 20% with no loss in speed. You can NOT run lean of peak at 72% power so easily… this would be hard on the engine, but at a mere 50% power? NO PROBLEM! So, cruising at 2,000 feet rather than 17,000 feet burns 70% MORE FUEL FOR THE SAME SPEED! This being the case, flying this airplane low is just plain stupid. People that are slow with math will say “WHAT IF THERE IS A HEADWIND UP HIGH?”… well, with a 60% decrease in fuel flow when you go up high, you would need about a 60% reduction in speed due to headwind to make it not worth it to climb… now what is 60% of 167 knots? 100 knots. How often do you see that much headwind? Basically NEVER. So you should almost ALWAYS fly Cirruses HIGH. And, UNLIKE what the (dumb, in this case) book says, you CAN run the engine lean of peak when at lower power settings, even though they never bother to specify this in the performance tables.
So how do you handle yourself and the plane to get this high-altitude efficiency?
Well, as you climb through 12,000 feet you put on your O2 Canula (you know, what they always put on people in hospitals and stuff… the little plastic hoses that go under your nose). With the seatbelts welding you into the airplane’s structure, the headset jacks wiring you into the airplane’s comm systems, and the O2 canulas jacking you into the airplane’s O2 system, you are really jacked into the machine at this point… since the Cirrus has a sidestick controller, you do not have a yoke in your lap to tangle with the cables… you just have a map in your lap to back up the 4 moving maps, and all the cables hooking you into the plane. Once at 17,000 feet, you keep an eye on your oxygen flow to be sure you are getting oxygen, and your pulse oximeter that you keep on your finger to keep tabs on your blood-oxygen saturation. You can’t run your brain right at this altitude without oxygen, so watching the oxygen flow from the tank to your cannula and the blood-oxygen saturation on the little pulse-counter on your finger are critical steps to survival up here. In the thin air up here, the engine is spinning at it’s 2,700 rpm redline, making only 50% power with the rarefied dose of air it gets each rotation. Now time to lean it out: Put the secondary EFIS on the ENGINE page to see the exhaust gas temp per cylinder, and the cylinder head temp per cylinder. (as well as fuel flow, fuel remaining, percent power, and a bunch of other things). Hit the “LEAN ASSIST” button on the EFIS and start pulling back the mixture. As you pull back the mixture, the fuel flow falls off a lot and the exhaust gas temperature climbs up to 1,450 degrees… this is the highest temperature you can get out of the engine, and very close to the perfect fuel-air ratio, and the point where you get the most power… it is also the point where you will fry your engine if you leave the mixture here: you need to cool it down a bit. How? LESS FUEL. Keep pulling the mixture back and when the exhaust gas has gotten 50 degrees cooler than peak the EFIS will advise you “PEAK ECONOMY REACHED!” Leave the mixture there, and you will be zipping through thin air, at 17,000 feet, the engine purring fast-n-smooth at 2,700 rpm, only 50% power, sipping only 10 gallons per hour (same as a Cessna 172) loping across the sky at 167 knots, or 192 miles per hour. This is 19 miles per gallon at 190 miles per hour. This is better gas mileage than some cars, but at a speed of 190 miles per hour, straight-line, no detours, no stop-lights, all day long. THIS is where the Cirrus truly struts it’s efficiency, BUT YOU HAVE TO KNOW HOW TO RUN IT. You have to know to go high, low power, lean of peak exhaust gas temperature. So you are travelling about as efficiently as possible.. fast in the thin air, in a reciprocating (not jet) engine (reciprocating engines get 100% more efficiency than jet engines, 50% more efficiency than turboprop engines) in a NON-pressurized airplane (saves weight) but stil high (as high as you can go and still get half power) normally aspirated (turbo engines tun so hot and hard it is rare to take them lean of peak), so this is the most efficient flight mode you are going to find, really. You can run for 6 hours, over 1,100 miles this way, without touching a single control, except to switch fuel tanks once… you have to move your right hand about 2 inches.
As you fly, in addation to watching the exhaust gas and cylinder head temperatures, you are watching (aslo on the Secondary EFIS in Engine mode) the fuel on board, fuel flow, time to go to destination, and (my favorite) THE FUEL THAT WILL BE ON BOARD WHEN YOU LAND, based on current conditions. Finally, you can see in one number just what your reserve really is.
Below, approaching clouds with the secondary EFIS in engine mode… only pulling 2500 rpm down low at 8,000 feet here, waiting for ATC to let me to 17,000 (they usually do it very quickly)
Then, in the clouds and rain:
And then clear of clouds:
Entering night mode, I command and Randy as co-pilot:
Or, alone.. totally alone…
dark thoughts enter your mind at times like above: What if the engine dies? What if I enter icing conditions? What if I get lost? I can’t even see the ground.. I can’t even tell this is planet Earth! Never fear! You can’t easily get lost with 3 databases, 2 GPS’s, 4 moving maps, 2 nav radios, and 2 comm radios, and at 17,000 feet the plane can glide for 33 miles… always to any of several airports. The plane has a switch in the cockpit that pumps anti-ice fluid out through thousands of tiny laser-drilled holes in the metal cuffs along the leading edge of the wing and tail (most clearly visible in first picture on this page) keeping ice from forming on the plane… as well, this anti-ice fluid is slung out along the propeller blades to coat the airplane in flight and the little pitot tube heats up to keep ice from forming on it. The plane has a little sensor that seeks out other airplane’s transponders, and plots those other airplanes on the big moving map as little purple diamonds so you can avoid them as well. There is a little antenna on the plane that feels disturbances in the force that are caused by lightning strikes, plotting those on the map as little yellow jaggies to be avoided. (the plane has a metal foil enmeshed inside the composite skin to direct lightning strikes harmlessly around the outside of the plane if it is still struck, though, so a direct lightning strike is still not a show-stopper).
If, despite your redundant, dual-redundant, or triple-redundant everything, and seeing of other airplanes and weather, and ability to slip through ice and direct lightning strikes un-molested, you STILL manage to lose control of the situation, just pull the big red handle, and a parachute ROCKETS out of the back of the plane on a solid-fuel rocket engine, deploys, and floats you safely down to Earth. Four people have pulled this so far (although, arguably, perhaps none of them actually needed to.. 1 guy had an improperly-installed aileron come loose, though of course he had another working properly, another guy had a confusing EFIS indication, though of course he had his mechanical back-ups, and two other guys were in sever turbulence at night and said they “lost control”… I have been in turbulence so string the wings were visibly flexing up and down Arnold Schwarzeneggers biceps and my head was hitting the ceiling no matter how tight the belt… and was nowhere near “losing control” though)… SO, regardless of how many of the deployments have been needed, it has been demonstrated 4 times now that you can pull the chute and float gently to Earth without a scratch… every Cirrus that has done that so far has taken only light damage from it’s ungraceful return to Earth.
The Garmins soon tell us that we will have to descend at about 750 feet per minute to get down to Washington (KHEF, Manassis field) so I reduce power even below the miserly 50% we have been loping across the sky at, enter -750 in to the autopilot VVI and 2,000 (or whatever ATC says) into the altitude and down we go, maintaining a lean mixture at 40% power as we descend (we have to richen the mixture a bit every 1000 feet or so, always watching that EGT to make sure the engine is still burning fuel and not starved for gas!) At such a low power setting, there is no mixture setting we could possibly choose that would hurt the engine, so I just richen the mixture to hold around 1400 EGT or so… a nice HOT temp to help compensate for all the cold air racing thru the engine as we descend (we are always well over 200 mph here.. the plane is sleek and heavy, and the air thin, so even a slight descent builds significant speed). Remember, at HIGH power, you must run a nice RICH mixture to cool the engine… all my lean-of-peak and any-mixture-is-ok preaching ONLY APPLIES TO LOW POWER SETTINGS.
Manuevering into the pattern is so easy it is ridiculous… pull the power all the way back after nursing it back for the long descent and the prop just turns into an airbrake for you and drags you down to 100 knots or so where you deploy the huge flaps and the plane comes right down to 77 knots where you glide down final with the smallest little hint of power, and I basically have YET to make a hard landing in the plane.. the wing is so long and thin and low that it gets GOOD ground effect, the plane cushioning ITSELF in that ground affect to arrest the final descent rate without any intelligence at all needed from the pilot. The gear is nice and springy, so silky-smooth landings are the absolute norm. The engine is normally aspirated… and I have been cooling it down gradually for the whole descent, landing, and taxi in, so no cool-down period is needed.