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By the time we'd got to the runway I
was very much enjoying the sheer size of the Caravan and I have
to admit here that I just couldn't resist flicking the switches
for 'No Smoking' and 'Seatbelts' to 'On' before lining the Caravan
up with the runway centreline and opening the power up against the
brakes. As the prop rpm settled on 1900, I released the brakes and
as the Caravan bounded forward I smoothly increased the power to
1700ft/lb on the torque gauge while also monitoring the ITT and
Ng gauges. Almost immediately the ASI came alive as the airspeed
started to build while, despite the crosswind, only small inputs
of rudder were required to track the centreline. After what seemed
to me to be a ground roll of less than 1,000 feet, the ASI swept
through 70kts and I eased the control yoke back. The Caravan rotated
cleanly into the flying attitude and leapt into the sky.
Although Vy is 107kts, this produced a dizzyingly steep deck angle
at our weight, so I retracted the flaps as the ASI passed through
90 and aimed for 120kts. This produced a flatter deck angle, which
greatly increased visibility, while the VSI continued to show in
excess of 1,000ft/min.
Now, at this point, I confess that I was ever
so slightly unsure about what to do next. As I've already implied,
the Caravan is very much a mini-airliner, and I couldn't quite shake
the feeling that such a large (well, by my standards anyway) aircraft
must have some pretty complicated systems. Yet a glance at the checklist
revealed that I'd already done everything that needed doing, while
Tann seemed perfectly happy at the way that the flight was progressing.
At 4,000ft I levelled out, retrimmed and let
the Caravan accelerate to 170kts true airspeed before reducing torque
to 1,600ft/lb and rpm to 1,750. At these settings the fuel flow
gauge was indicating around 370lbs per hour, although to be fair
the PT6 (and indeed any gas turbine engine) is far more efficient
at altitude. Indeed, when flying at a similar true airspeed, but
at 16,000ft, the fuel flow drops by more than 100pph!
Trimming around all three axes was both easy
and precise - pitch trim is accomplished through two elevator trim
tabs, controlled by a vertically-mounted trim control wheel on the
top left side of the control pedestal or via a switch on the control
yoke. Aileron trimming is via a servo tab attached to the right
aileron, which is adjusted, using a knob on the central control
pedestal, while rudder trim is through the nosewheel steering bungee,
connected to the rudder control system. It is adjusted by a trim
control wheel, that is also mounted on the central control pedestal.
During the cruise, I briefly experimented
with the autopilot but having ascertained that it functioned as
advertised, I quickly disengaged it. After all, although they generally
fly very nicely, I've never yet met an autopilot that could write!
As soon as we had reached an area of uncluttered airspace l began
to explore the Caravan's general handling characteristics.
Its flight control system is essentially the
same as any other high-wing Cessna, being entirely conventional,
with the minor exception of a pair of spoilers mounted above the
outboard ends of the flaps. These wing spoilers improve roll control
at low airspeeds by disrupting lift over the appropriate flap.
A couple of reasonably steep turns soon revealed
another area in which the Caravan is noticeably superior to its
piston-powered relatives - visibility in the turn. Not only does
the large windscreen wrap around more than other high-wing Cessnas,
but the wing is also located further back relative to the pilot's
seat. In deference to our passengers, Tann and I agreed that I wouldn't
actually stall the aircraft, but a couple of approaches to the stall
revealed absolutely exemplary handling, with plenty of warning buffet
(particularly flaps down) a good 10kts above the actual stall. A
look at the stick-free stability revealed that this is an excellent
instrument platform, while a few more steep turns indicated reasonable
control forces around all three axes.
Perhaps the most interesting discovery was
that the Caravan really is quite good fun to fly, which - bearing
in mind that it has been designed as a hard-working utility aircraft
- is quite a compliment! Indeed, I would have relished the opportunity
to chuck it about a bit more, but somehow I rather doubted that
my passengers would have agreed with me
I really do have to say that, for an aircraft
that can carry up to 14 people, this is an astonishingly easy machine
to fly. Not only does it look like a 172 on steroids, but it even
flies like a 172! In fact, I glanced over my shoulder on more than
one occasion to confirm that Ken really was sitting way back there
in seat 4B!
I must admit that I could have cheerfully
spent the rest of the day flying the Caravan, but once again work
got in the way, and all too soon it was time to return to Vandenberg.
However, Tann was keen for me to see how well the Caravan glides,
so I eased the power lever back, and then drew the propeller control
lever back to the FEATHER position. Counterweights and spring tension
then twisted the propeller blades through high pitch and into the
feathered position. I trimmed for the best glide speed of 90kts
at our weight and was astonished at how flat the glide angle seemed.
The POH claims that from our altitude of 4,000ft, the Caravan would
glide for 8 miles, and this seems perfectly plausible. Now, none
of this is intended to suggest that the aircraft would be improved
by fitting a variometer compensated for Total Energy! I just wanted
to make the point that in the unlikely event of an engine failure
at altitude, you've got time to attempt a restart and the opportunity
to glide to a landable area. Indeed, from 12,000ft the Caravan will
glide for 25 miles in zero wind, making it quite likely that, particularly
in areas of high population density, a quick press of the 'Nearest'
button on the GPS and you'd have an excellent chance of gliding
to an airport!
The unfeathering system uses engine oil pressure to force the propeller
out of feather, so I moved the prop control lever forward of the
FEATHER gate and then as the blades rotated back into position slowly
eased the power lever forward and set course back to Vandenberg.
A quick listen to the ATIS on our way back
revealed that the wind had freshened considerably and was now gusting
at up to 28 knots, with a pretty fair crosswind component across
the runway. However, during the pre-flight briefing Tann had indicated
that the Caravan was a capable crosswind performer, so rather than
ask for another runway I decided to find out exactly how good it
was in a crosswind. The pre-landing checks were as straightforward
as the rest of the aircraft's systems, and then Tann told me something
that really impressed me. "Do you know" he said, "that
the limiting speed for ten degrees of flap is the same as Vne?"
I was hugely impressed by this simple statement, as I can't think
of any other aircraft that I have flown that you can do this with.
Despite the considerable crosswind, the three circuits and landings
all pretty well followed the same pattern. I simply checked that
both fuel tank selectors were On and that the fuel condition lever
was still at HIGH IDLE, then pushed the prop control lever to MAX
and started deploying the flaps.
Regular readers may remember that I have praised Cessna's excellent
Fowler flaps on more than one occasion, and those on the Caravan
continue this tradition of excellence. As they are fitted to over
70% of the trailing edge and extend to 30° they do an excellent
job of slowing the Caravan down to our approach speed of 80kts,
while the spoilers certainly add to the low speed controllability
in roll. The first two landings worked out very well considering
the conditions, and even Tann was moved to observe that I was doing
a pretty fair job.
For the first two landings I only moved the
prop lever back into BETA but with Tann's consent I decided that
on the last landing I would attempt a real short-field landing.
Consequently on the last approach I nailed the airspeed to 75kts,
and as we crossed the fence I drew the power lever back to idle
and lowered the nose to maintain our airspeed, before a positive
flare planted the mainwheels firmly on the ground. Then, as soon
as the nosewheel was on the ground I pulled the power lever back
into reverse while holding the yoke right back. The engine bellowed
hoarsely and we decelerated at an astonishing rate. In fact we were
only in reverse for a matter of seconds before I brought the prop
out of reverse as the needle of the ASI sank off the scale. It is
actually very important that reverse is not used below 25kts in
order to avoid eroding the prop. Now, I didn't actually didn't get
a chance to measure the ground roll, but I suspect that it was certainly
less than 600ft, which for an aircraft of this size is amazing.
Once clear of the runway, it was simply a case of retracting the
flaps and moving the Fuel Condition Lever to LOW IDLE before trundling
back to the parking ramp.
So, in conclusion, what can I tell you
about the Grand Caravan? As I'm sure you've already gathered, this
is a very capable aircraft, with the ability to lift a formidable
load into and out of short, unprepared strips and turn a tidy profit
for its operator. From a purely handling perspective, I was particularly
impressed at how easy it was to fly such a large aircraft. Indeed,
most PPLs with a few hundred hours would be able to convert onto
it without any significant problems, and if that basic observation
isn't a glowing testimony in itself, then I don't know what is!
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| Statistics and Contacts |
²
DIMENSIONS |
| Length |
41ft
6in |
12.7m |
| Height |
15ft
5in |
4.7m |
| Wingspan |
52ft
|
15.9m |
| Wing
Area |
279.4ft² |
25.96m² |
Weights and Loadings
|
| Empty
weight |
4,285lb |
1,944kg |
| Max
AUW |
8,785lb |
3,985kg |
| Useful
load |
4,500lb |
2,041kg |
| Wing
loading |
31.3/ft² |
153.5kg/m² |
| Power
loading |
13lb/hp |
7.9kg/kW |
| Fuel
capacity |
279 Imp galls |
1,268
lit |
| Design G loading |
+3.8G/-1.52G |
Performance |
| Vne |
175kts |
325km/h |
| Cruise |
174kts |
322km/h |
| Stall
|
61kts |
113km/h |
| Climb
rate |
925
ft/min |
4.7m/s |
| Service
ceiling |
23,000ft |
7,000m |
Engine
Pratt & Whitney PT6A-114A turboprop, producing 675shp
(503kW)
Propeller
McCauley three-blade constant-speed reversible pitch
and fully feathering
Manufacturer
Cessna Aircraft Company
Wichita, Kansas, USA
UK Agent
Bob Crowe Aircraft Sales
Tel 01234 750442
Fax 01234 751944
Email bcrowe1234@aol.com
Web www.bobcroweaircraft.com
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September
2 0 0 2
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This article appeared in
the September 2002 issue of Today's Pilot.
Tel: +44(0)1780 480404
Fax: +44 (0)1780 757812
email: orders@keypublishing.com
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