Wednesday, September 14, 2011

A Touch of Class

My Flight Evaluation was carried out on N208FD, sister ship to N208ED pictured above
Photo credit: Cessna

A Touch of Class

Flight Evaluation of the Cessna Grand Caravan

Originally built as a utility aircraft, the Cessna Caravan has evolved into a useful addition to the turboprop market for the personal owner. With an impressive load capability, and stretched to become the Grand Caravan, it has a huge cabin. Equipped with fully integrated avionics, and powered by the reliable single PT-6A turboprop, it is an easy aircraft to fly. Over two thousand of the single-pilot Caravans are now in service and it is flying in over a hundred countries. A recent avionics upgrade has added Garmin 1000 displays to the instrument panel.

Caravans now feature a 3-screen Garmin 1000 instrument panel, with two LCD Primary Flight Displays flanking a central MFD with moving map. Photo credit Cessna

After an increasing number of Caravan owners opted for customized interiors, Cessna introduced an STC for the luxurious Oasis interior, installed by Yingling Aviation of Wichita. Oasis options are available with 10, 9 or 8 seats including the crew. Sumptuous leather seats are standard. In each case two forward-facing seats are positioned behind the crew, together with four-place club seating with executive side tables.

The leather upholstery is an option from Yingling Aviation and adds a further touch of class to the Caravan. Photo credit Cessna

The Oasis cabin blends large scenic windows for each passenger with sumptuous leather seats and stylish cabinetry.

The typical Caravan purchaser these days increasingly is an owner-pilot, rather than the traditional fleet manager, purchasing multiple aircraft for commuter and cargo operations.

(Having said that, Caravans are finding use in many Air Forces, not forgetting Federal Express.)Many Caravan owners are trading up from piston twins. Insurance experience requirements are typically less stringent, because of the single engine, simple systems, and lack of the complexity of pressurization or retractable gear. Another selling feature is the size and convenience of the cabin, coupled with load-carrying ability. The option to have the Oasis interior is the icing on the cake.

Price of a typically equipped Grand Caravan is around $2M. Operationally the Grand Caravan can be very flexible on approach and at Mid-Continent the Cessna pilots regularly fly approaches between 160 and 75 knots to merge in with other jet and piston traffic.

My Grand Caravan flight was with Greg Pavlish, Manager of Flight Operations at the Cessna Wichita facility. During our preflight walkaround Pavlish pointed out the easy access to the engine, with the inertial separator (a movable vane for protection against foreign object ingestion from contaminated runways), oil filter and standby generator all accessible. There were two crew doors, which open 180 degrees, each with a fold-away ladder, so that the pilots could board without disturbing the passengers in the cabin. Two rear doors supplemented the crew doors, with a large two-piece door for cargo on the left side, and a regular passenger airstair door on the right.

N208FD was destined for eventual delivery to Australia. As befitted an aircraft living in warmer climes it had no “flight into known icing” systems but instead had anti-abrasion boots on the leading edges of the horizontals. All Caravans were plumbed for the icing system option that included boots for wings and tail surfaces, windscreen and propeller de-icing. For the bush-flying role at its ultimate destination, this Caravan was fitted with the optional larger 29 inch diameter tires and extended nose gear fork to increase the propeller clearance. The rugged steel-tube gear was designed to handle rough runways.

The wings were fitted with Fowler flaps, with slot-lip spoilers supplementing the ailerons to give excellent low speed roll control. Outboard flaps had Wheeler vortex generators and trailing edge Gurney angles to keep the airflow attached at low airspeeds. This was to keep the stall speed with flaps down below the 61 knot limit for FAR 23.

An underfuselage pod had 112 cubic feet capacity. It has little effect on cruise. Our Grand Caravan with the pod would cruise around 170 knots TAS at medium altitudes. The pod will carry 1,090 pounds with a maximum floor loading of 30 pounds per square foot and typically all baggage is carried in the pod, leaving the cabin free for the passengers. The four cargo pod compartment doors were all on the left hand side, easy to latch and with lockable doors. With our preflight completed it was the work of a minute to close all the doors and cowlings.

Into the Air

I climbed the short ladder, slid into the left seat, folded the ladder into its stowed position next to the seat, and closed the door. Pavlish did the same in the right seat. I adjusted my seat, which had ample vertical and horizontal movement, then clicked into the 5-point harness.
Before start our fuel was 900/960 pounds and our takeoff weight was 6,800 pounds

I appreciated the spacious cockpit. I’m over six feet tall and found that I was not cramped at all, and all the controls and displays were conveniently placed. The overhead panel contained fuel tank select handles and the standby flap motor controls. Starter and electrical switches were on a panel conveniently located on the left hand cockpit wall. The circuit breakers were arrayed vertically below this panel.

Engine start was simple. I just switched the battery and boost pump ON and hit the start switch. At twelve percent Ng I moved the Condition lever from cutoff to low idle. I heard the engine light up and the engine ITT wound up to a cool 750 degrees. I brought up the avionics displays. We switched on the air conditioning. ATIS informed us that the wind was blowing from 220 degrees and was 20 knots gusting 35. Temperature was 80 Fahrenheit. A typical hot,windy day in Wichita.

Releasing the brakes I taxied out for Runway 17L. The mechanical nosewheel steering was light and effective. We held for a moment while a Citation taxied across in front of us also heading for 17L. Our large windows provided excellent all-round visibility from the Caravan cockpit. I taxied after the Citation. With the strong following wind we tended to accelerate even at idle and to avoid having to use the brakes I twice pulled the propeller back into Beta (Reverse) to slow down.

Pretakeoff checks were quickly accomplished while we were holding short of 19L. We checked the overspeed governor and standby alternator. I checked the Inertial Separator operation by pulling the T-handle and observing a drop in torque and rise in ITT, then ensured that we had full and free control movement, and trims were set for takeoff. Fuel was selected to feed from both tanks. We were ready to go.

Cleared into position and hold, I lined up on the centerline. The tower cleared us for takeoff. I advanced the power lever, watched the torque increase through 1,000 foot/pounds and released the brakes. I needed only moderate right rudder to keep on the centerline. (The engine is canted three degrees to the right, to reduce the torque effects) With the strong headwind, after a short run we reached 70 knots and I rotated into a positive climb. Switching to Wichita Departure frequency we were given a turn to 230 degrees and cleared to climb to 6,500 feet. I stabilized at 120 knots, the recommended climb speed. Rate of climb was a solid 1100 fpm on this ISA +10 day. I trimmed out on the electric switch on the yoke. The Caravan was stable in the climb, despite the rough air at low level. At four thousand feet I selected the autopilot ON, with heading, altitude and yaw damper selected. We were flying this mission without headsets. Noise level was acceptable and we could converse across the cockpit without having to raise our voices.
As we reached 6,500 feet, the autopilot smoothly leveled the aircraft. Stabilized in cruise at 6,500 feet, we had 1,750 foot pounds of torque, the prop was turning at 1,900 rpm and at an OAT of +10C our TAS was 167 knots. The PT 6 was burning 370 pounds per hour of Jet A.

To assess the roll performance I hit the autopilot disconnect button on the yoke and rolled into a turn. Roll performance from a bank angle of thirty degrees left to thirty right was sprightly, with the spoilers supplementing the ailerons to give a good roll rate. There was no adverse yaw. I realized that, despite its size, the Caravan maneuvered like a Cessna 182. It was quite fun.

We turned south, and into the wind, for some low speed flight and I extended the flaps. Quickly decelerating we stabilized at 70 knots IAS. We were heading into the wind and almost in the hover relative to the ground. Southbound highway traffic far below was pulling away from us. I continued slowing into a stall. We had a forward center of gravity and the yoke was almost to the back stop when the nose finally dropped straight ahead. The stall was well-mannered, there was no wing drop and I simply relaxed backpressure and advanced the power to recover from the stall.

The reliability of the PT-6A turboprop is legendary, but Pavlish pointed out that in the unlikely event of the engine quitting, all was not lost. First he had me retract the flaps and accelerate to 95 knots, our best glide speed, then pull the power lever back to flight idle. I lowered the nose to maintain 95 knots. Rate of descent stabilized at 1,500 feet per minute. At his bidding I then pulled the prop lever round the gate, and back into the feather position. The propeller rpm wound down to around 200 rpm and the individual blades came into view. With the decrease in propeller drag, the rate of descent reduced until we were whispering along, losing height at a mere 500 feet per minute. The Caravan was a good glider.

To get back to cruise I switched the boost pump and ignition on, and brought the prop out of feather. The prop spun up, I reset the power lever for 1,000 feet per pounds of torque and we regained level flight. With autopilot engaged I rotated the heading bug on the EHSI to north, the Caravan banked to the new heading, and we adjusted the autopilot altitude selection for a gentle descent down to 3,500 feet. Pavlish turned the radar on as we headed towards the ICT VOR, west of Mid-Continent airport. On this sparkling Kansas day, we had no thunderstorms, and no mountains appeared on the display, but ahead of us we could see an antenna farm on the ground. The radar picked up the antennas, and the TAWS also warned of obstacles ahead and below. I appreciated the reduction in workload given by the autopilot while I experimented with the avionics.

We selected the ILS for 19L on the Garmin 530 and set up for a coupled approach. A Learjet was preceding us on the ILS and crossed left to right across our bows. We needed to keep up with him. Here was a chance to use that flexibility of raising the approach speed mentioned in our pre-flight brief. I initially set Torque to 1,500 foot pounds , which gave us 160 knots IAS rather than the usual Caravan approach at 120 knots. Cleared for the ILS approach we were directed initially to fly 090 degrees and to descend to 3,000 feet. The controller then vectored us onto 160 degrees two miles from KECHI, the outer marker.

I simply hit APRCH mode on the autopilot to arm the system and as the localizer came alive the Caravan banked right and intercepted the localizer. Still at 160 knots we were matching speed with the Learjet. To avoid catching up as the Learjet landed I simply reduced torque to 1,000 feet pounds and stabilized at 120kts. As we crossed the outer marker, the glideslope came alive and we started descending. The wind was still in excess of twenty knots, from the right of track, and the tower was reporting wind shear as well. Despite this our autopilot was tracking us easily down the final approach, with the nose angled off to the right against the strong crosswind. I eased the power back and we slowed to the recommended 85 knots final approach speed as I progressively lowered the flaps.
TAWS gave a “500 feet “ audio warning as we descended on the glideslope. I disconnected the autopilot and continued the approach for a touch and go.

The Caravan had ample control effectiveness to cope with the gusting crosswind, and once we were on the runway, Pavlish retracted the flaps. I advanced the power, and took off for a left hand pattern on 19L. Leveling at 2,800 feet downwind I brought the power back and extended the flaps. As we turned from base leg to finals, the tower asked us to go around for traffic on the ILS approach. No problem. We did a go-around, completed an abbreviated pattern, and this time as we turned base were given a change of runway to land on 19R. Still no problem. The Caravan’s maneuverability enabled me to offset to the other runway with no problem. I completed a touch and go on 19R with full flaps, and came round onto 19L again for a final landing, this time with zero flap, before taxiing back to the Caravan hangar. Surrounded by jets on the ramp, Greg Pavlish demonstrated the ease of parking the Grand Caravan in a confined space. Using differential brake increased nosewheel deflection from 15 degrees to 56 degrees, enabling the Caravan to be swung round in a surprisingly small area.

With this version of the Grand Caravan, Cessna has found a niche market. There are other single-engine turboprops around, such as the TBM 700/850, the PC-12 or the Meridian, designs geared for the high-flying, longer-range mission. All three come with increased complexity, pressurization and retractable gear, stringent insurance requirements …and around a million-dollar increase in the price.

I found the Grand Caravan easy to fly and it offers a lot for a person wanting a capable aircraft combining rugged simplicity with load-carrying capability and full IFR capability, with the option of a luxurious interior.

Specifications and Performance Cessna 208B Grand Caravan

Engine PT6A-114A turboprop of 675 SHP
Propeller MacCauley 3-blade Constant Speed, fully feathering and reversing.

Span 52 ft 1 in
Length 41 ft 7 in ft
Height 14 ft 10in

Cabin dimensions

Length of passenger cabin 12 ft 4 in
Height 4 ft 3 in
Width 5 ft 2 in


Ramp Weight 8785 lb
Takeoff Weight 8750lb
Landing Weight 8500lb
Empty Weight 4364lb
Useful Load 4548 pounds
Fuel Capacity 2224pounds

Wing Loading 31.3 lb/sq, ft
Power Loading 13.0 lb/HP


Cruise 10,000 ft 175 kts TAS

Range 10,000 ft 870NM
(includes takeoff, climb, cruise, descent and 45 min reserve at max cruise power)

Sea level rate of climb 925 feet per minute

Service Ceiling 23,700 ft

Certified ceiling 25,000 ft

Takeoff ground run ISA 1405 ft
Distance over 50 ft 2500ft

Landing run ISA 950 ft (no reverse)
Distance from 50 ft 1740 ft

Stall speed,
landing configuration, 61 kts.

1 comment:

PT6 Nation said...

"Class" is the right word to describe this beautiful aircraft.

I suggest you to visit the and share this well written blog post with our community of PT6 fans, operators and pilots. They will love it.

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