THERE’S only so much stretching and tweaking you can do to an aircraft design. At some stage, if you really want to make a quantum leap, you have to do something radical. And so when Cessna was faced with Brazilian rival Embraer moving into CitationJet territory with the Phenom 300, a more modern, faster, longer range, more comfortable aircraft than the existing CJ3, Cessna knew it had a fight on its hands.
The US manufacturer had some tricks up its sleeve though. The Citation range of jets comprises several different size ‘families’ and then next one up from the CJ3 is the mid-size Sovereign. A bigger aircraft with more range, the Sovereign also has a completely different wing… and so the basis for the CJ3’s successor, the CJ4, was born.
Mate the Sovereign wing to, yes, a stretched CJ3 fuselage, add several significant updates, make a thoroughly tidy job of the aircraft and there you have it. The CJ4, competitive on performance, price and equipment to the Phenom 300. Both the CJ4 and Phenom 300 are doing pretty well sales-wise, vying for top spot in terms of numbers in 2012, so both manufacturers are clearly in touch with the market.
We had a chance to fly a Citation CJ4 while on a recent visit to Cessna’s HQ in Wichita, Kansas. We flew with Brandy Althouse, who has spent the last nine years flying for Cessna’s flight ops dept… absolutely loving her job. We went through the key elements of the CJ4 which make it stand out.
1 It’s all about Performance
This isn’t just the biggest CJ ever, it’s also the best performing. The figures speak for themselves: a max cruise speed of 451kt true at a ceiling of 45,000ft. A maximum Mach speed of 0.77. A climb rate at sea level of 3,854 feet per minute. A range of 1,920nm at a cruise speed of 425kt true (that’s the brochure figure for range; some have seen fuel burn rates at cruise which would give it 2,002nm range). These are astonishing figures for a light jet.
And yet the speed, operating altitude, climb rate and range have not been at the expense of take off and landing performance. Small jets need to get in an out of small airfields sometimes, and the CJ series is noted for this ability. The CJ4 continues this tradition.
We had a perfect example of the CJ4’s liveliness on takeoff. Our first flight from Wichita’s Mid-Continent Airport (where Cessna has much of its HQ) was with two pilots up front, and four passengers, all six-footers and carrying photo and video equipment. So we weren’t particularly light.
Pilot Brand Althouse lined up on runway 19R, held the CJ4 on the brakes while the latest generation Williams FJ-44 engines spooled up to full power, then released us into a ‘Performance Takeoff’. Count to 5 and that’s how long it took us to get airborne, just as we were passing the first intersection – about 1,500ft. The acceleration to the Vr of 93kt had been a real push in the chest and even Brandy, who’s done this many times before, admitted later she was impressed by the CJ4’s response. It was a freezing cold Kansas winter’s day but even so…
We were at 17,000ft in four minutes, where we levelled off. Cessna says the CJ4 can get to 45,000ft in just 28 minutes so you can get above the weather and airliners. Again, that’s a brochure figure at standard temperatures and pressures – some have seen a considerably quicker climb to the max operating altitude.
After just over an hour’s flying, we headed back to Wichita. First to drop off the camera and video crew, then to do another takeoff, circuit, touch ‘n go and landing for the snappers. Even with our full load of pax for the first landing, it was over quickly needing less than the takeoff roll. One of the beauties of the smaller FJ-44 engines is that you land with the throttle set to idle. If you do need to go-around – or make a touch ‘n go – then they spool up to full power very quickly.
2. Size matters
Cessna has added two feet to the length of the cabin for the CJ4 over the CJ3. There’s now a more spacious galley area immediately as you come in through the door, which has also been redesigned. It’s larger, easier to lock and has a very neat set of stairs which just fall into place. The pilots also get a little more room.
Stepping into the main cabin is a surprise. This is a very roomy jet! Yes, you do have to duck your head a little if you’re a six-footer but you hardly notice it. The leg room is excellent and the seats must be among the most comfortable private jet seats in the industry. The section of the fuselage is exactly the same as the CJ3 but Cessna has worked some magic and made it appear bigger. It’s lighter, although the electronically controlled window shades can darken it quickly if you want to nap.
There’s a huge baggage area at the rear of the cabin, which can be accessed in flight. The small bathroom and lavatory actually has sufficient privacy to be usable. The demo aircraft had achieved a balance between a comfortable working environment, with individual side tables, and somewhere to relax after a busy day of meetings. In fact, you could easily hold a small meeting in the cabin… the advantage being that you could genuinely call an end to proceedings with the words, “Gotta fly!”
3. The wing makes it possible
What makes the CJ4 such a good performer at high speed and long range as well as short takeoff and landing is the new wing.
Actually, it’s not entirely new because something very similar is fitted to the next-size-up aircraft, the Citation Sovereign (itself in the process of being upgraded for launch later this year). Now, if you’re as geeky as me when it comes to technical stuff on aeroplanes, you’ll probably do what I did which was to admire the wing from every angle.
First thing you notice, particularly when the CJ4 is parked next to a CJ3, is that the wing is sweptback. On the earlier CJs it’s more or less straight out. The sweep is 12.5 degrees which is pretty modest but it also continually changes shape along the length of its leading edge. The trailing edge is dead straight which, according to Cessna engineers, is how they retain the good low speed behaviour.
Look at the wing end on and it’s a thing of beauty. Slim and clean to aid laminar flow to reduce drag but with some major changes over the CJ3.
The wingspan is less by 2ft 6in but the chord is deeper, overall increasing wing area by 36sq ft, again helpful at low and high speed. Bigger wing also means more fuel – the CJ4 can hold 5,828lb of fuel, an increase of 1,118lb over the CJ3 – and thus more range and flexibility.
Despite its clean appearance, the CJ4’s wing is more complicated but for good reason. The CJ4 not only has wing spoilers top and bottom on each side acting as a speed brake (like the CJ3) but they can be deployed at any speed and to any degree (unlike the CJ3’s which are either full on or full off). According to Brandy Althouse, our pilot, this makes it much easier to comply with ATC instructions on speed and flight levels particularly when steeping down through busy airspace.
The CJ4 has another trick up its sleeve too. The same lever which deploys the speed brakes can be pulled back another notch on landing and three ground spoilers each side pop up from the top of the wing. These immediately kill lift and press the aircraft onto the runway meaning the pilot can brake harder sooner, should he need to. The effect to reduce landing roll.
All in all, this new wing is at the heart of the CJ4.
4. Avionics are Intrinzic
‘Intrinzic’ the name Cessna is giving to its avionics installations these days. Bit confusing because I first came across the Intrinzic flightdeck in Cessna’s top-of-the-range single-engine piston aircraft, the Corvalis TTx. In that aircraft, the avionics are Garmin’s latest G2000 suite. However, in the CJ4, the avionics are Rockwell Collins Pro Line 21 with an Integrated Flight Information System but still called ‘Intrinzic’.
Whatever the name, the cockpit is bang up to date. Four 8in x 10in march across the panel. Two Primary Flight Displays and two Multi Function Displays. Even though the CJ4 is rated as single pilot, most operators will have two pilots so both need live info.
The CJ4 is a true paperless cockpit, with electronic charts, approach plates and airport diagrams appearing on the MFDs. Graphical weather can be overlaid, and MultiScan Weather Radar can be added to give actual, live awareness of bad weather.
The cockpit has been redesigned with single pilot use in mind, so things like toggle switches whose position – up or down – can be confusing at have been eliminated and replaced with simple press on or off buttons that light up when on.
Autopilot controls have been moved up to the top of the panel so you can make changes while keeping your eyes around the windscreen level rather than delving down. The autopilot also has an Emergency Descent Mode so if cabin pressure is lost above 30,000ft, the aircraft will automatically descend to 15,000ft where the level of oxygen in the atmosphere should revive a woozy pilot.
And there’s a new Engine Indicating and Crew Alerting System (EICAS) which sends plain English messages to the PFD in the event of any malfunction or unusual condition. If it’s serious, then there’s also a verbal warning.
5. Cabin and climate
Of course, all that technology up front is great for pilots and reassuring for passengers, but what the customers really appreciate is the Cabin Management System. Again, by Rockwell Collins and it’s called Venue HD. Venue manages not just the cabin climate control system (air con to you and me) with two separate zones for the pilots and passengers, but also the ‘infotainment’ system.
You’ll note in the cabin pix that there are iPad size monitors around the cabin. Each seat has inputs for mobile devices so passengers can play CDs, Blu-ray DVDs and games, listen to satellite radio channels, or even connect games consoles like PlayStation 3 and Xbox 360. Of course, you can plug in a laptop and get on with some work.
Cabin pressure is digitally managed too and Cessna says the CJ4 keeps sea level pressure up to 27,000ft. All the lights inside the CJ4 cabin are LEDs, using less power and lasting longer than bulbs.
6. Ease of use
At the heart of the Citation Jet ‘CJ’ series is ‘ease of use’, says Cessna. The CJ4 is the biggest jet Cessna makes which can be flown single pilot so the onus is on making it easy to fly.
It starts with the handling of the aircraft, with easy, docile manners at all speeds, particularly during landing and takeoff. Add in details like the speed brakes which can help you fine-tune the speed by 20-40kt easily and quickly if requested by ATC. The ground spoilers which improve landing roll and braking, particularly on a soaking wet runway. The slightly narrower landing gear spacing which helps the aircraft manouevre more nimbly when taxying.
There’s the design of the cockpit, not just from an aesthetic point of view, but having everything in a logical easy to reach place. Autopilot between the displays and the windscreen. Input pad for the Flight Management System in the centre just under the MFDs. Throttles, flaps and spoilers on the same console and operating in the same sense. Undercarriage lever bang in the centre between the MFDs so there’s no confusion.
The avionics are all about improving situational awareness and managing pilot workload. There’s no doubt that being able to call up charts and plates onto displays is much better than rooting through paper manuals.
Even the re-designed cockpit windshields with always-on heated glass reduce workload, replacing the old system of hot engine bleed air onto plastic windscreens. They look better too, sleeker and more graceful.
The latest generation FADEC-equipped Williams FJ44-4A engines are among the quietest and greenest available, and feature Cessna’s GreenTrak system. This calculates Direct Operating Costs, fuel burn and carbon emissions and thus fits right into Europe’s disputed Emissions Trading Scheme.
Perhaps the single most amazing thing about the Citation CJ4 is just how complete the upgrade is from the old CJ3. Should we expect anything less from Cessna with its vast experience in building light and mid-size jets? Maybe not but business aviation is an intensely competitive arena with much to contend with in terms of regulation, cost, customer expectation and safety. The Citation CJ4 is bang up to date on all fronts.