Pilot Report for 1978 Cessna 421C - N146TJ
By: David Freeman
Make and Model Description
Cessna's Model 421 was developed as a pressurized twin engine aircraft aimed at the business market. First flown on October 14, 1965, it was FAA certified on May 1, 1967 with deliveries beginning the same month. The Model 421B was introduced in 1970 with a lengthened nose (allowing more baggage and avionics), wider span, and strengthened undercarriage for a higher weight limit. Available in 'Golden Eagle' and 'Executive Commuter' versions, the latter was a quick change version capable of 10 passengers or cargo. These versions were discontinued in 1976 in favor of the Model 421C. This incorporated a new wing (no tip tanks), larger vertical tail, and bigger turbochargers on the engines. This was also available in 'Golden Eagle' and 'Executive Commuter' versions, and as the Model 421C II with a factory equipped avionics kit. The 'Executive Commuter' was discontinued in 1977, and the Model 421C III added with an alternate avionics package. Production of the Model 421 ceased in 1985, with a production total of 1,909 aircraft of all models.
Engine and Propeller Information
Engine Type: Continental GTSIO-520L
Propeller Type: McCauley 3 Blade
Left Engine Time: 0 Since SFREMAN
Left Prop Time: 860
Right Engine Time: 860 Since SFREMAN
Right Prop Time: 860
Engine Comments: RAM Engines - Left engine recently replaced by RAM. Previous engine was damaged due to oil starvation because of a mechanic's error in replacing the oil cooler
Propeller Comments: Both props in excellent condition, including deicing equipment
Airframe Information
Aircraft Total Time: 2800 Hours
Color Scheme and Paint Condition: White with blue trim, painted in 1995 and in excellent condition.
Interior: Gray leather, very nice. New carpet this year, new Rosen sun visors
Airframe Modifications: This is one of the lowest time Cessna 421Cs in existence. It is also one of the best equipped. The RAM conversion not only added the excellent quality and workmanship of RAM engines plus their associated instrumentation, but it included Vortex Generators and PowerPak spoilers. The Vortex Generators increase the gross takeoff weight of the airplane to 7560 pounds (a 110 pound increase), and lower the single-engine minimum control airspeed (Vmca) to 71 knots, which is well below the clean airplane stalling speed of 86 knots. The PowerPak spoilers can be deployed at any speed and configuration and allow the pilot to greatly increase the rate of descent without shock-cooling the engines. The RAM installation also provided new fuel flow and EGT gauges which take the guess work out of engine management. A propeller syncophaser is also part of the package.
N146TJ is certified for flight into known icing. The equipment required for this certification includes 100 amp alternators, deicing boots, prop deice, heated windshield and heated stall warning and pitot tubes.
Many Cessna 421Cs left the factory with one wing locker auxillary fuel tank, but very few have two. N146TJ does, therefore it has a total fuel capacity of 262 gallons and a range of over 1,000 miles. As of this report the total time on the airframe is approximately 2900 hours. The right engine is just past mid-life at 850 hours and the left engine is zero time. JB Air keeps the cabin cool in the summer and a flushing potty helps with the long flights.
Avionics and Related Equipment
Avionics: In front of the pilot a combined display includes the attitude indicator and HSI, both electrically driven and slaved to a remote stablized gyro. Navigation and communication capability is supplied by two Garmin 430 GPS units. A Garmin 340 audio panel sits on top of the stack. A nice feature of this unit is that it allows the pilot and copilot to isolate communications, each using one of the Garmins for communication without interfering with the other. The intercom system can isolate just the pilot, or just the crew from the passengers. A Garmin 337 transponder takes care of the squawking details. It automatically switches from standby to active when the airspeed reaches 30 knots and switches back to standby when the airplane is landed. A built-in timer makes keeping up with flight times a breeze. There's also a Collins ADF in the panel, should you ever need it.
The main focus of the center panel is the Avidyne E500 FlightMax Multi-Display Unit. In addition to displaying terrain data an input from the Garmin GPS units, this unit displays lightning data from the Stormscope WX-500, traffic data from the SkyWatch TCAS system, color radar from the RDR-160 and Satellite-based realtime weather including NexRad radar images, Sigmets, Airmets, and both graphical and text-based
METARS. An Insight TAS-1000 AirData computer supplies the pilot with all of the information he could ever hope to know about current windspeed and direction, TAS, IAS, groundspeed, pressure altitude, density altitude, etc. An Icarus altitude alerter provides aural altitude and GPS waypoint alerts.
Autopilot: Collins, integrated with Flight Management System and fully coupled to Garmin GPS and Glideslope. The autopilot annunicator has both orange armed and green capture indicators. A yaw damper helps keep the ride smooth and in trim.
Weather Avoidance Equipment: RDR 160 Radar, color display on FlightMax MFD, Nexrad and Metars by Satellite from Avidyne and WX-500 Stormscope with display on MFD and GPS
Flight Planning and Mission Profile
 Max Gross Weight: 7560 lbs.
Empty Weight: 5412 lbs.
Fuel Capacity: 262 gal.
Max Payload: 2148 lbs..
Full Fuel Payload: 700 lbs..
VFR Range: 1,000 NM
IFR Range: 950 NM
Minimum Runway: 3500 feet
Passenger Seating: 5
Flight Characteristics
Preflight: Four sumps to drain, check all Icing equipment if expecting flight into known icing.
Taxi: 18 foot landing gear, 46 foot wingspan, 9-inch prop clearance, so be carefull on narrow taxiways.
Runup: Check all electronics, including both alternators, and both inverters. Mag and prop checks done at 1500 rpm. Insure Gyros are up to speed and stabalilized before moving the aircraft
Flaps Setting for Normal Takeoff: 0
Flaps Setting for Short Field Takeoff: 0
Takeoff Speeds: Minimum Controllable is 71 knots, Lift nose at 88 to 90, Use 88 for best angle, 111 for best rate with one or both engines
Normal Climb Airspeed: 120 knots
Best Rate of Climb Airspeed: 111
Best Angle of Climb Airspeed: 88
Rate of Climb: 1200 fpm
Climb Power Setting: 35 inches, 1950 rpm, lean to 1450 EGT
Climb Fuel Burn: 30 gallons per hour
Typical Cruise Altitude: Flight Level 190
Max Cruise Altitude: 25,000
Best Power Setting: 35 inches 1950 rpm
TAS at Best Power: 225 knots
Fuel Burn at Best Power: 28 gph per side
Economy Cruise Power Setting: 32 inches, 1850 rpm
TAS at Economy Cruise: 207 knots
Economy Fuel Burn: 24 gph per side
Handling: Excellent. Very stable in all axis. Aileron control is fairly heavy, but rarely fly without autopilot.
Slow Flight: At 100 knots and dirty, its' a very stable airplane. At 88 to 90 knots, must keep a good bit of power to avoid high sink rate.
Stall Speed: 86 knots
Stall Behavior: Very benign, bobbles and recovers quickly. No tendancy to drop a wing if kept in trim.
Cabin Size and Comfort: Very comfortable for 2 pilots plus 3 - 4 passengers.
Descent Planning: Gradually reduce power to avoid shock cooling. Speed builds rapidly in descent. Use configuration changes to slow the airplane down for pattern, i.e., spoilers, flaps, and gear.
Approach Speed: 120
Approach Flaps: 15 degrees below 176 knots
Landing Speed: 100 knots
Landing Flaps: 45 degrees below 146 knots
Shutdown: Allow engine/turbocharge temperatures to stabilize for 3 minutes prior to shutdown.
General Comments
 When flying an airplane with this type of sophistication and capability, it is easy to take its performance for granted. But, like most airplanes, you can't just fill the
tanks, fill the seats and go. There are basic numbers that we operate with, derived from a combination of the airplane's performance charts and what it really does. We operate out of a 3500 foot strip with obstacles on both ends. That's about as short a runway as I'm comfortable with in the Cessna 421C with any kind of load at all. The RAM modifications on this airplane provide a comfortable margin of safety. On a hot day at gross weight, the airplane lifts off about three-quarters of the way down the runway. On approach, we slow to 100 knots on short final and carry a little power all the way into the flare and it gets down and stopped in plenty of time.
On short runways, 80 knots is our go-no-go decision speed. Anything over that and we are going flying in case of power failure. Anything less and we will try to get it stopped on the remaining runway. On long runways, that speed goes all the way up to the blue line of 111 knots. The gear cycles rather quickly and the airplane climbs briskly at blue line speed with both engines developing full power. Lose one and the book says 250 - 400 fpm, depending on weight and density altitude. I hope to never have to go there. I have flown and landed the airplane on one engine, however, and it handles very nicely. Those big old rudders on Cessna twins make single engine work fairly simple when there is altitude and airspeed to with which to work.
If we fill the main tanks only, we can fly 3:45 minutes with comfortable margins and carry 1100 pounds of passengers and baggage. If we elect to fill the two
auxillary tanks, we can fly an hour and fifteen minutes further, but only carrying 700 pounds. All of the RAM literature says the airplane should cruise at 223 knots
at 20,000 feet, but a more realistic figure born out over times is around 207 knots. That's the figure I use for flight planning because thats the number I get when setting the power according to RAM's recommended cruise settings. RAM makes power management very easy with their EGT gauge and the Shadin fuel flow indicators and it is best to follow their recommendations to prolong the life of the engines..
Runup is by the checklist. The attitude indicator and HSI should be allowed to stablize and the flags off before taxiing to insure the slaved gyro is aligned properly. Then, when taxing, make sure the brakes work and that the gyros turn and dip appropriately. On the runup pad, hold the brakes and run the throttles up to 1500 to check the vacuum, all the engine gauges, the mags and the props, then back to 900 rpm for the rest of the items on the checklist. In addition to setting up the navigation units, it pays to take a little extra time to set the field elevation and altimeter settings in both the altitude alerter and the TAS-1000 AirData computer. Dont forget to reset the Shadin whenever you add fuel and it will always tell you how much longer you can fly before dry tanks. You can flip a switch to turn on the fasten seat belt and no smoking signs for the passengers, but I always like to turn around and let them know were ready to go. As far as keeping the cabin comfortable goes, generally speaking when it is comfortable up front, it is comfortable in the back, but it pays to ask the passengers from time to time how they are doing.
Takeoff is with everything forward. You can maintain that power setting for up to 5 minutes, if needed. Then it's back to 35 inches and 1900 rpm with 1450 on the EGT meters for climb. This results in a fuel flow of about 30 gallons per hour per engine. Leveling off at cruise, RAM recommends setting the EGT at the top of the green arc. You can leave the power at 35 and 1900 if you want to , but the best settings for engine life are 32.5 on the manifold and 1850 on the rpm. This will burn approximately 23.9 gallons per side and net the 207 knots I mentioned earlier at most of the altitudes we fly. I typically pick flight level 190 or 210 going eastbound, but westbound we often cruise at 8,000 or 10,000 because of the winds. The fuel consumption stays the same down at the lower altitudes, but true airspeed is usually more like 185 knots.
Fuel management is simple. The fuel selectors for the mains just stay on. In case of a fuel imbalance, you can crossfeed from either tank to the other engine. If auxillary fuel is used, there are no gauges. Just wait until the main fuel quantity indcators are below 400 pounds on each side, then turn on the auxillary fuel pumps. Fuel will transfer from the auxillary tanks into the mains at about the same rate as fuel is being burned, so you won't see the gauges move much while fuel is being transferred. When the auxillary tanks are dry, a light comes on the annunciator panel to let you know its time to turn off the pumps.
Managing cabin altitude is simple, as well. There are two settings on the dial, one for cruise altitude, one for field elevation. When climbing, set the outer scale to the crusing altitude. When its time to come down, set the inner scale to the field elevation at the destination airport plus 500 feet. Thats all there is to it.
Updated Information - 2008 New owner Brian Henry has upgraded the airplane considerably. Here are some recent photos:
|
