This pilot report brought to by Barry Hancock, a supplier for the camps airplane.
CJ-6 Pilot Report
Walking up to a Nanchang CJ-6A it doesn’t take long to feel as if you’re stepping back into the Golden Age of aviation, because you are. The radial engine, tandem seats, rear sliding canopies, and a dihedral “gull shaped” wing all suggest an experience reminiscent of what it must have been like to fly 50 years ago – which just so happens to be when the plane was first designed. The actual flying experience in a “CJ” only confirms those romantic notions. So, for anyone looking to step back in time to enjoy round engine nostalgia, the CJ is sure to please. There are many reasons that the endears itself to so many pilots – good looks, comfortable cockpits, great visibility, delightful control harmony, and gentle yet sporty flying characteristics. Not only is the Nanchang CJ-6A a great looking and capable airplane, but it is arguably the best bang for the buck warbird flying. When the sweet sounding 9 cylinder radial comes to life, first coughing big puffs of white smoke, and then quickly spinning to a smooth but rumbling idle, it’s like Scotty has just beamed you back to the days of Earhart, Boyington, and Doolittle…of aerodromes and aviators… of goggles and leather skull caps, soda fountains and the girl next door……..OK, enough talking, let’s go flying!
PREFLIGHT
The preflight of the CJ is pretty standard for any complex aircraft, with a few nuancesdue to round engine care – you will get oil on your hands. Airframe and panel integrity, strut and tire pressures, free controls, and FOD free cockpits are the main tasks of the preflight…and then there’s the caged beast under the cowl. Whether it is the stock Housai H6A (285 h.p.) or the M14P (360 h.p.), the principals are the same as any round engine. First, peak through the rear of the cowling on both sides and the gill shutters in the front to look for excess leaks or anything that might have shaken loose during the previous flight and was not caught on post flight inspection. Then it’s time to check for hydraulic lock by manually pulling the propeller through a dozen times. By pulling the prop through in this manner it allows any oil that has drained into the bottom cylinders to drain out through the exhaust valves. This is one of the vital (read life and death) pre-flight items that must be done religiously - one bent rod in flight could ruin your whole day –and must be done right (mags off, hands no more than half way down the blade, no reverse rotation, etc.). A few teaspoons to as much as a cup of oil draining out the exhaust is normal. Remember, round engines don’t make a mess, they are simply marking their territory…
Once the engine is pulled though to clear the cylinders of oil, and cockpit preflight
complete, it’s ready for priming. Most aircraft are equipped with a plunger type primer in the cockpit – if you’re really cool, you have an electric boost pump/primer like this #47 does. ;) Typically six shots of prime and then six blades pulled through will do the trick. Done right, the engine will fire on the first blade without fail - this engine wants to run! At the top of the rest of the list is ensuring that the gear lever in front cockpit is down, and in neutral in the ground. There is no squat switch on the CJ and no one needs to experience an inadvertent gear retraction on the ground - it’s expensive and down right embarrassing. Your only protection is the little slide lock that prevents the handle from moving into the up position, so it’s a good idea to double check this prior to opening the
main air valve. Yep, I said air. The CJ uses pneumatics instead of hydraulics to run the landing gear, flaps, and brakes. It is a great system that is easily serviced and
repaired…and air is cheap.
START UP and TAXI
Once your back-seater is briefed and strapped in (you are sharing the experience, right?), it’s time to climb in the front cockpit. Helmet or headset on, harness secured, air open, appropriate switches on, a bit more primer, and you’re ready to breathe life into 9 cylinders of the sexiest sound in aviation outside of a Merlin at full tilt. With the emergency parking brake mod, all you need is a flip of the switch and you’re ready to go, if not a Velcro strap around the brake handle will do. Next comes the “clear prop!” call (this is where an uncontrollable smile comes to my face every time). There’s just something about knowing you are about to light off one of the coolest sounding engines ever made and puking smoke everywhere that is just hard to explain…but once felt, you’ll always remember. A check of the surrounding area and it’s time to engage the air starter. A “POP!” and a hiss of the air starter pushing the cylinders is followed quickly buy the first cylinder firing – this baby was born to run. Keep your finger on the start button and flip the mag switch as the engine catches, adjust the throttle to help the engine settle in, and set about 37% on the RPM gauge…which will turn to 40% as the engine warms (these settings are for the M14P, which uses percent RPM instead of raw numbers as with the stock H6A engine). Once the engine is at taxi temps, the most difficult part of operating the CJ is next….taxiing! It is often said that “if you can taxi this plane, you can fly it,” and that’s not a grand exaggeration. Time to find out what this handle on the stick is all about – the CJ uses a brake handle on the stick, similar to a bike brake handle. With differential braking on the mains controlled by the rudder, brake pressure actuated through the brake handle, and a free castering nose wheel it does take a bit of time to learn how to deftly maneuver the CJ on the ground, especially at low speeds. That being said, a half hour of figure 8’s on the ramp we’ll have you pretty squared away with taxi technique…and the center of attention at the airport.
RUNUP, TAKEOFF, AND CLIMB
Once you’ve successfully negotiated the taxi ways to the run-up area and once again
congratulated yourself for your superior skill it’s time to for the run-up. Engine checks are standard for a piston engine…prop cycle, mag check, temps and pressures normal, everything in it’s place, a sweep of the controls and your ready to go.
One of the biggest differences in flying a CJ or any other round motor airplane is that it does require a slightly more deft touch on the throttle. Rolling in the power from idle to full tilt should be a 3 second affair, minimum. The standard CJ accelerates smoothly and is airborne in about 1200 feet. The M14P powered version will be off in a little or a lot less than 1000 feet, depending on whether you have the 2 or 3 bladed prop…and if you have the 3 blader, keep pullin’ back on that stick. I’ll never forget the first time I took a friend and fellow stock CJ owner up for his first ride in an M14P powered CJ. As we sucked the gear in the wells and established about a 30 degree nose high attitude, this veteran pilot’s only comment was an appreciative “WHOA!” At best rate climb (90knots) the stock powered CJ will give you about 1200 fpm through 4000’ AGL, the M14P provides about double that rate. There are more exaggerated claims out there, but in 800 hours of flying both, this is what we typically see. As far as engine management goes, both engines have small blowers. This means that while providing a bit of extra power, over boosting the engine is not a concern. Climb rate and aerobatics are where the M14P really shines through, more on that later. Engine temperature management is especially critical in this phase of flight because you can easily cook the cylinders in a full power climb with the gill shutters closed. On that note, we call the gill shutter knob in the cockpit the $30,000 dollar knob because that’s about what it can cost you if you don’t use it to manage engine temperature correctly.
CRUISE FLIGHT
Once leveled out at altitude and throttled back to a cruise setting that nets from 13-15 gph, typical cruise speed is about 150 KTAS, which will vary slightly depending on rigging, trim, and weight. Adjusting the gill shutters for cruise CHT of approx. 170-180C and the oil cooler outlet for an oil temp of about 70C are the major concerns of managing your engine in cruise. With the stock fuel system of 40 gallons, 300 nm flights are a comfortable VFR range. Extended range tanks offer anywhere from an extra hour to three extra hours of flight time. Having sat in a CJ for a 4:22 flight, I can tell you speaking for my behind, that 2 extra hours of fuel is plenty! With a stock trim system, you can only control elevator trim from the cockpit. Roll and yaw trim are accomplished with bendable trim tabs on the control surfaces. This means that you can only accurately trim the aircraft for straight and level flight at one airspeed. While perfectly manageable the vast majority of the time, it does create a fuel feed imbalance with the gravity feed fuel system. There are several things that can be done to mitigate the problem…the best one we have found is installing a 3 axis electric trim system that allows you to trim the plane for hands off for any cruise speed. It’s also a nice feature in the climb, particularly with the M14P which requires a boot full of rudder whilst ascending from the surly bonds of earth. The CJ provides a very comfortable ride for a warbird. The cockpits are roomy enough for even larger people to comfortably sit for a couple of hours. The visibility is very good and the tandem seating puts you right on the center line of the aircraft behind the spinning propeller. On warm days, it is fun to put the canopy back and fly open cockpit style.
MANEUVERING, AEROBATICS AND FORMATION
Being light and responsive on the controls, the CJ does a very good job of telling you when you’re flying the plane correctly, and gently nudging you when you are not. The center control stick gives maneuvering a much more natural and innate feel than a yolk. There’s also something about having the stick in your right hand and the throttle in your left that just feels right. The tandem seating and bubble type canopies allow for fantastic visibility. All these things combine to make you naturally feel as though you are truly a part of the airplane. In the slow speed regime slow flight, stalls, and spins are all quite benign, and not to be
confused with it’s cousin, the Yak-52 which has more aggressive but still completely
manageable departure characteristics. The CJ does not exhibit any bad habits, and is
perfectly predictable throughout the entire flight envelope. It truly is a joy to fly and is one of the many reasons that the CJ is the choice of many former fighter pilots.
Stalls:
The CJ stalls dirty at 62 knots and clean stall is about 67. Power on stalls require a significant nose high pitch angle and a lot of rudder to keep the ball centered. With the M14P, full power on stalls require about a 60 degree nose high attitude! Flight controls start to go mushy around 75 knots and the buffet begins roughly 5 knots slower. Any competent pilot can easily recognize the onset of the buffet and avoid a stall at this point, so going deeper into the stall regime is a conscious decision. With full aft stick, power off, and the ball centered, the nose of the CJ will just gently fall through at the break and quickly recover with the release of back pressure. Secondary stalls are possible, but require the same conscious effort as a primary stall. Accelerated stalls are also easily recovered from and not likely to result in spins.
Spins:
Just as with the stall, the spin does require a concerted effort to achieve. Without getting into the details of basic spin entry techniques, the CJ does take urging and a bit of power just before the break to cleanly enter the spin. Despite proper inputs held in place, the CJ will start to come out of the spin on its own after approximately 2 turns. At this point a very nose low spiral will ensue and measures need to be taken quickly to avoid over speeding the aircraft (Vne = 201 KIAS) and subsequent rapid build up of G’s.
Aerobatics:
Being built as a military trainer, the CJ is no stranger to aerobatics and other more
exhilarating forms of flying. The airframe is rated +6/-3 and will handle all basic
aerobatic maneuvers with ease. With a little practice, even a loop can be comfortably
accomplished at 3 G’s. Gentleman’s aerobatics are a sheer delight in the CJ and are as gracefully and easily accomplished in the CJ as any plane I’ve flown. Roll rate is a modest 120 degrees per second, and a loop takes about 800’ of vertical. With the stock engine, the CJ requires you to exchange altitude for energy, so after a sequence of a couple of vertical maneuvers, you will have to climb back up to reset. Acro is where the Venyendev M-14P powerplant makes a very noticeable difference. With this engine, you can fly all the vertical maneuvers you want without loosing altitude…it really is a different airplane in this regime. It should be noted here that, just like any other airplane, the CJ is no stranger to design limitations. Having a dihedral wing, it does not do negative G maneuvers particularly well and does not like sustained inverted flight. Then again, most of us don’t like sustained inverted flight much either!
Formation:
The CJ is also a great formation platform. Because of that afore mentioned dihedral, the plane is quite stable. Combine that with responsive controls and great visibility, the CJ is a delight in formation. If you’ve not experienced formation before, don’t be quick to dismiss it. Even the most reluctant pilots often come to really enjoy the challenge of flying formation well, and the camaraderie and social aspects of flying with others. And the CJ community is, in fact, the most active formation community in warbirds. The Red Star Pilot’s Association (www.flyredstar.org), of which most CJ pilots are registered members, has the most comprehensive and active formation training program in the country.
DESCENT, PATTERN WORK, AND LANDING
The main concern in the CJ during descent is no different than most other piston engine aircraft – maintaining proper CHT. Once in the pattern the main thing to remember is that if a radial engine is going to quit, it’s most likely going to be during a power change. The CJ does not glide particularly well, so keeping your pattern tight is best for safety
concerns. Gear speed (Vfe) is 120 knots and flap speed is 90 knots. The flap is a single split flap design that we affectionately refer to as the barn door. Speed in the standard pattern is 80 knots. RPM goes to climb power on downwind. Properly flown the approach angle in the CJ is much steeper than a standard GA aircraft. If you need to get down quicker, the aircraft side slips beautifully with full rudder and you can create some pretty exciting yet perfectly controllable decent rates if desired. Also, with the bigger propellers used on the M14P your power off descent is comparable to a set of keys. Hold 80 knots until final is pretty standard and 70 knots over the fence works well. The CJ’s robust trailing link gear readily absorbs even less than average touchdowns. Holding the nose off reduces wear on the brakes, but will decrease your visibility (you have nearly 6 feet of nose out in front of you, which is something to remember when you are taxiing in as things disappear under the nose at about 20 feet in front of the aircraft). Go-arounds are easily accomplished. Since you’ve already moved the RPM to climb power, simply advancing the throttle full forward will quickly arrest your sink rate and send you climbing, even with the flap still down. It is a good practice, however, to grab
both the throttle and prop with your left hand and take the engine to full power.
POSTFLIGHT:
(One note on shutdown before climbing out to examine your bird: 20-30 seconds of 60%
power prior to shutdown cleans the plugs and puts most of the oil in the sump back in the tank, which is good practice with the oil shutoff valve installed)
The post flight is simple: a quick walk around that includes draining the moisture catch, or “snot” valve and wiping down the belly with an oil rag is all that is left. Oh, and don’t forget to turn off the air, lest you come out to an empty air bottle the next time you go flying! Pushing the plane back into the hangar is simple and can be accomplished with a hand tow bar by one person. My favorite part of the post-flight is wiping the plane down with an oil rag and reminiscing about the flight. Just like in the days of Boyington, goggles, soda fountains, and the girl next door….
