Pilot September 2017

http://www.pilotweb.aero Pilot September 2017 | 61

airmanship. Quite obviously, this is not an

aircraft that you should ever taxi faster

than walking speed and, as it is not

exactly over-endowed with power, should

the ground be soft it is advisable to try to

keep moving at all times−just not too

fast! Furthermore, the big wingspan,

monowheel (no differential braking) and

barely steerable tailwheel combine to

create a machine that is quite unwieldy,

and great care must be taken whenever

you’re moving near another aircraft,

person or object. The turning circle is vast

and turning out of wind can be a

challenge, particularly on narrow runways.

This is an aircraft that has to be flown

all the time and I use aileron to put the

into-turn outrigger on the ground to add a

little drag, particularly on grass. It’s

debatable whether this actually does

anything but at least it shows that you’re

doing everything you can! However,

sometimes you must either signal for a

wingwalker or shut down, get out and

turn it by hand. One thing you must never

do is allow anyone to pick the tail up

when the engine is running−there really

isn’t a lot of propeller clearance and a prop

strike is very likely. The bottom line with

the T61 is that if you can manoeuvre it

to the runway you can probably fly it

(although not necessarily land it

gracefully, of which more anon).

The pre-takeoff checks are very simple;

you cannot even check the magneto! One

thing you must do is double-check that the

carb heat is working well. It is such an

efficient ice maker that the engine really

should be called a refrigerator, not a

Rollason, so be particularly wary if you’ve

had the engine ticking over for any time in

either humid conditions or while standing

on wet grass.

Before lining up take a long hard look at

the windsock. That monowheel means

there is not much control authority at the

start of the takeoff roll, so if there’s a lot of

crosswind (and particularly from the right)

be ready for it to swing. Do not raise the

tail at slow indicated airspeeds, as even a

small crosswind will cause a Venture to

weathercock most alarmingly. This is

because that large fin has a pretty long

arm to work through, while the low-power

engine and small prop aren’t putting much

airflow over the rudder. It’s at times like

these that you curse the monowheel and

ruefully wish you had two main wheels

and differential braking.

Final checks complete, roll slowly out

onto the runway, line the aircraft up with

the centreline and push the throttle open

smoothly. Maximum static rpm is 2,800

and a quick glance at the tachometer is

prudent. As mentioned earlier, the engine

is claimed to produce up to 45hp but only

at 3,500rpm (so you don’t have anywhere

near 45hp on takeoff). In fact, when taking

off close to the MAUW the power-to-

weight ratio is more likely a pretty bleak

20kg/kW, if not worse. If it’s down on

revs take it straight back to the shed, for

even if the engine is working well the

acceleration will not produce exhilaration.

In fact acceleration is probably too strong

a word to describe the start of the takeoff

run, a more apt description would be that

it gathers speed. It certainly won’t leap

into the air−Ventures never do, and its

best to expect a protracted ground roll. On

the plus side, the ailerons come alive quite

quickly, enabling you to keep the aircraft

balanced on the main wheel with neither

outrigger touching the ground. As the

needle of the ASI starts to move, the

elevator becomes effective, but don’t pick

up the tailwheel too quickly.

Eventually it will lumber into the air but

another potential ‘gotcha’ here is that,

although it will fly in ground effect at very

low speeds, it is imperative that you do

not initiate a climb until you have

achieved 55 knots. This is the magic

number so fly level in ground effect until

you’ve attained 55 (which can take a

surprisingly long time), then allow a gentle

climb to develop while maintaining 55.

However, if you decide to take off with

wet wings (and I’d advise against it) add

another five knots. That thick wing may

look unsophisticated, and the aerofoil is

far from laminar, yet for some reason it is

remarkably intolerant of being wet.

If you’re heavy on a hot, windless day the

rate of climb can be quite depressing, and

care must be taken to keep the oil

temperature within limits because it will get

hot. As mentioned earlier there isn’t a CHT

gauge, which initially I found rather odd.

However, its omission is probably

deliberate, as I suspect the cylinder heads

Flight Test | Slingsby T61F

The view over the nose isn’t brilliant, nor is

there much prop clearance, tail-up

The Venture in its element — not a great glider, but an aircraft designed to teach gliding technique independent of launch winches or tow planes