Cessna
Hawk XP pilot report
by
Budd Davisson
Just as surely as the swallows dead reckon
their way back to Capistrano and as
unerringly as the IRS computer spits out
your name as being overdue in your tax
return, the season for 172 pilot reports is
sure to return. It is a yearly thing, a
ritual, a known happening without which it
would be felt that the entire world, even
Wichita, was about to succumb to some sort
of Andromeda Strain ending. For over a
quarter of a century, if you include the
170s, the annual debut of Cessna's newly
refined models has been ac-companied by
company press releases proclaiming ". . . an
all new Skyhawk more horsepower, more speed,
greater climb, higher ceiling. . . . " And
the beat goes on . . . and on, and on. 1977
continues the cycle.
The lowly (or lofty,
depending on your point of view) 172 Skyhawk
is now such a cultural artefact that a model
year without a 172 would be unthinkable
Aviation's philosophy seems to be "They
wouldn't dare not produce the Skyhawk."
(Editor's note from the year 2000: Boy, are
you in for a surprise!). It is simply the
most popular four-place airplane in
production today, and Cessna isn't about to
bury the aluminium goose that annually lays
a 14 carat egg
1977 may not be the year
that the 172 is transmogrified into an
entirely different breed, but this is the
year that the changes are far more
substantial than a different paint scheme
and unborn tortilla upholstering. 1977 is
the year of the "XP" and to a lesser extent,
of the Skyhawk/100. The Cess-na press
releases call them ''. . . all new
single-engine airplane . . and all new
Skyhawk . . .", which may be stretching the
facts a bit, but they are airplanes that
step far enough ahead of their ancestors to
warrant being called new generation Skyhawks.
The Skyhawk XP (marketingese for Xtra-Performance,
get it?) is by far the most significant of
the two new airplanes, as It introduces
higher horsepower and the constant speed
propeller to the American 172 market for the
second time in twenty years. The first time
around in the '50s it was called the 175,
the designation, which, according to some
owners was almost exactly the number of
hours they got between overhauls on the
geared Continental. The Skyhawk XP, however,
has a leg up on the older hot-rodding
attempt. The USAF has been flying 172s with
big motors and constant speed props for
quite a number of years and the French
Rheims Rocket, a licensed conversion on
locally assembled air-frames, has been
around for at least as long. The XP took
some tips from both of those airframes and
went on from there. Its 195 hp Continental
10-360-K fuel injected engine is actually
the well-known 210 hp Continental, but all
the muffling required to meet FAA/EPA
standards sucked up 15 horses.
The Skyhawk/100---so-called
be-cause it drinks 100 octane fuel-is a
Skyhawk with an extra 10 horses (160 hp
Lycoming 0-320-H2AD) and some minor
cockpit/airframe changes that it shares with
the XP. These include a rudder trim
(optional on Sky-hawk/lOOs, standard on XPs),
a flap switch with pre-selected detents for
10, 20 and 40 degrees deflection, an
instrument panel rehash that does away with
some of the flimsy appearance of early
airplanes, and a vernier mixture control.
The throttles on both airplanes are still of
the push-pull, non-vernier variety. In
addition, the Skyhawk/100 had a slight .nose
job, especially around the air intake to
eliminate the need for running carb heat
during heavy rain to prevent water ingestion
The XP is going to be the
airplane everybody wants to know about. 10
extra ponies in a 172 isn't going to boggle
anybody's mind, but a jump of 45 horsepower
with a constant speed prop is something to
sit down and think about. The empty weight
is up by only 170 pounds so the power
loading is down from about 14.5 lb/hp to
13.1 lb/hp, a significant decrease and
something which should point to like-wise
increases in performance.
The XP Hawk looks good on
paper, but the only way to really find out
is to go strap it on and have a go at it. As
it happens, you can't just go out to your
local dealer and grab an XP and go flying.
First of all, the airplane is so new, that
at the time of our flight evaluation they
had actually finished only one production
airplane. There were several prototype
machines around, but only one airplane was
available that was typical of what you would
be likely to be buying. The other reason
there was only one XP to be had was that
Cessna was hit by a labour strike the same
time the XPs were about to start flowing off
the production line. By now, that problem
should be long since solved. Anyway, the
airplane we cornered at the Cessna
transportation centre in Wichita was the
very first of the new breed. There were no
engineering gimmick's, no fine tuning, no
nothing. Just an airplane that would
eventually go into the distribution pipeline
to be gobbled up by a lucky consumer.
Unless you are a real
Skyhawk freak, you could waddle right past
an XP and never know it (assuming you can't
read "Skyhawk XP" emblazoned on the cowl).
The cowl changes are very subtle. The
downward flowing line of the Skyhawk cowl is
replaced by a slightly curving one that runs
more parallel to the longitudinal axis. The
cowl flap needed to cool the big Continental
is a single-door that mounts in the middle
of the cowl's belly. It's easy to miss. The
constant speed crop is nestled in a slightly
larger version of a Skyhawk spinner and is
painted flat black like the Skyhawk's. All
in all, the XP is a sleeper, a muscle
machine in sheep's clothing that won't draw
any excited glances at your local aerodrome.
After climbing
in the cockpit, I had the feeling there
should be a placard about a foot square that
says "This is not a Skyhawk." It looks like
a Sky-hawk, it feels like a Skyhawk,
everything around tells you you're in a
regular 172 - so you behave accordingly.
Unfortunately, 172 habits won't even get the
XP started. Starting procedure calls for
pushing everything, throttle included, clear
to the firewall and building up fuel
pressure with the momentary boost pump
switch prior to cranking. When cranking the
engine over, the throttle is brought back
slowly until the proper air/fuel ratio is
hit and the engine starts. Then, in a very
un-172 move, you have to double check to
make certain the cowl flap is open.
Although it's not
noticeable from the inside, when the engine
lights off, it has a very throaty exhaust
tone that sounds as if it is equipped with
augmentor tubes. It must have been a real
bear before they were forced to throw all
that muffling junk on it
Cessna's airports are not
exactly the places to try out an airplane's
new performance; their pattern altitude is
300 ft. because it lies directly under
McConnell AFB's pattern. So after a gentle
172-style takeoff, we struck out in search
of greener pastures to play in.
In general, what we did
with the XP that day was snoop around
looking for places to shoot touch and goes,
checking cruise performance between periods
of pogo-stick activity. We banged around on
grass, gravel, pavement, asphalt and some
stuff we couldn't identify. We cruised at
300 ft. and 8000 ft., stalled and slow-flighted,
timed speeds and gauged gallons and did
everything else we could to find out what it
was that made the XP different and exciting
The first takeoff will
convince you that this is no ordinary
Skyhawk. As a matter of fact, you'd be far
better off if you'd get your brain into
Skylane gear because that's how it feels.
Al-though we were fairly light, full tanks
and two guys, the increase in acceleration
over the 172 should stay relatively constant
regardless of load. We were working in pools
of our own sweat with an OAT of nearly 100°
and the XP still showed the Xtra Performance
Cessna was hoping it would. When you drop
the hammer, the XP leaps forward and you
have to gather your wits about you to make a
smooth, lift -the- nose -wheel - off -first,
takeoff. Most 172 drivers will have a
tendency to run along nosewheel down and
jerk it off from a three point position.
The XP is much
more a trim airplane than the 172 ever
thought about being. On takeoff, if we left
the trim indicator in the green, it took a
determined amount of effort on the wheel to
rotate and keep the nose up. Trimming out
the elevator loads with two guys on board
proved to be a bit tricky because the
increased weight of the engine combined with
our own weights to put the cg somewhere out
in front of the spinner. If I trimmed far
enough aft to lighten the stick loads on
takeoff, I immediately had to push forward
fairly hard after rotation to keep the nose
down until I retrimmed it. With-out a doubt,
the XP would probably handle much better
with several screaming passengers (they
always do that with me) strapped in the
back.
Climbout in the
XP certainly showed why they put the rudder
trim in it. Without it, your right leg
develops a bad torque-cramp pronto. The trim
mechanism is a lever at the bottom of the
console near the floor that moves left and
right and right out of a centred position.
It has a peg on the bottom that engages
holes, so you lift it up and move it a hole
at a time. In climb, you need it as far
right as possible. They need to structurally
modify the engaging mechanism slightly
because I noticed ours popped out of the
hole once and it would be a simple thing to
change.
At the normal climb speed
of 78 kts the nose is at a thoroughly
uncomfortable angle and covers a healthy
amount of sky. It gets about 850 fpm, or
about 100-150 fpm more than a stock Hawk. I
prefer to give away a little climb and go up
at a flatter angle, so I usually climbed the
XP about 100 mph, which still showed about
550 on the VSI.
When pushing over for cruise, I found it was
best to close the cowl flap before doing
anything else be-cause when that door is out
in the wind it acts like a ramp and lifts
the nose a bit, changing trim. At almost all
power settings I found the cruise numbers to
be slightly better than Cessna showed on
their charts. This was probably because we
were at least 500 pounds under gross. The
best number we got was a timed, two-way
average of 133 kt true at 8,000 feet, as
opposed to Cessna's claims of 131 TAS.
That's about 152 mph, which is a pretty
substantial number for a foot dragging,
dirty old airplane. That's 10 mph faster
than at least one retractable we know of.
The flight characteristics, including
stalls, are traditional 172. Docile with a
smallish amount of buffet, the stalls give a
little nod and sluff-off straight ahead or
back into level flight, if banked. The rate
of sink goes up a little, but that's about
it. And of course, the stall warning horn is
strictly Cessna; when it goes off, you jump
a couple inches off the seat.
The XP is
trim-critical in all flight regimes, but it
gets especially important in making
approaches. When slowing to approach speed,
a sizable amount of trim is needed because
the nose becomes extremely heavy. However,
if you trim it up, you wind up having to
trim it back down again when you run the
flaps out. The 1.3 Vso approach speed is 60
knots, so to keep from screwing around with
the trim quite so much, I flew most of the
pattern at 80 KIAS right through base leg.
Then I'd start the flaps out, using them to
both change my rate of descent and kill
speed at the same time. The trim difference
between cruise and full-flap approach speed
is very little and it's only in transition
that the trim becomes important.
Again, because of our
forward load-ing situation, if I flew the
last portion of final with it trimmed
neutral or slightly aft, the elevator
pressures be-came extremely heavy during the
flair. I flew the standard Skyhawk/100
directly after flying the XP to verify this
pressure build-up during flair and found
none of this characteristic with the
Hawk/100. It's undoubtedly a cg related
characteristic and which can also be seen in
flying a Cherokee 140, then a 180 and then a
Cherokee 235, where there is a decided
pressure build-up during flair in the bigger
engine models. With full flaps in the XP, I
found it difficult to land on the main gear
and hold the nosewheel off during the
roll-out. Possibly because of the heavier
elevator pressures, the XP has a larger,
more anatomically shaped control wheel then
the Hawk/100.
Both the XP and Hawk/100
have airspeed indicators calibrated strictly
in knots. There isn't a mph to be seen
anywhere. This certainly causes no problems,
except most of us aren't used to approaching
at such low numbers; 60 KIAS looks awful
low.
While flying approaches,
it seemed to me that the XP was much less
speed stable at low airspeeds than the Hawk!
100. I had to work to hold 60k, and with
full flaps adding so much drag it was
certainly easy to set up a deceleration
that, if left unchecked, could cause severe
problems. I personally feel the XP could
almost be considered dangerous in this one
tiny area. The airplane will be flown mostly
by low-time 172 pilots, and if they are not
precise in their attitude control, they
could easily find themselves decelerating
into a stall. However, with all that extra
power, if a guy sees himself slow and nails
the nose down, a short poke with the
throttle will put everything back in fine
shape. Also, the wing has a slight cuff on
the leading edge which will go a long way
towards keeping a guy out of trouble.
Basically, the Hawk XP is
available with the same variation of options
as a standard Skyhawk/100. This includes a
stripped airplane, (and we mean "stripped")
called the XP, an XP "II" version with VFR/IFR
capabilities, or a II with Nay Pac. The
prices for the three different versions were
announced as: Hawk XP, $29,950; XP II at
$32,650; and XP II with Nav Pac, $36,500.
It's a nice flying
airplane in the tried and true 172 tradition
. . . a machine for the short haul
businessman or a Sunday pilot with his wife
and kids. However, it is going to be up to
the individual pilot to evaluate its
advantages over the Skyhawk 100, which are
slight, and decide whether it is worth the
extra cost, both in acquisition and
operating. It's faster and more powerful but
whatever its nameplate, it's still a 172,
through and through.
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