| Short
field operations - preparation.
Quite often the skills we need in flying are the ones that
we don't practice all that much. For most people the shortfield
takeoff and landing (STOL) fall into this category. Keep in
mind that a short field is not necessarily a grass strip or
an unsealed landing area. Depending on the type of aircraft
you fly - you might find that your home base with its sealed
runway becomes a short field at times.
This discussion is more about the preparation for STOL operations
rather than the actual flying of the takeoff or landing - they're
skills you need to go out and practice.
Importantly, there is more to short field operations than just
the takeoff and landing - but we'll come to that later.
If you're going to fly into a short field then there are some
really important questions to ask yourself first.
1. Are you current? Have you been flying enough recently
to be able to handle the additional skills required for this
operation?
2. What are the weather conditions like? Will they make
the short field operation much more difficult? More on this
later.
3. How much do you know about the field? Is it really
suitable - do you know enough about the surrounding terrain,
obstacles etc. Be wary of farmer's fields - they're always "long
enough" according to the farmer - but don't take anything
for granted!
4. Will you be up to the landing when you arrive? Are
you doing a really long flight and therefore be tired when you
arrive? Not the ideal conditions to be requiring extra skills.
5. What alternatives are there? Is there a better field
not far away that you could use instead? What if you decide
that you can't make the landing - what alternate airfield will
you be using? Do you have sufficient fuel?
Once you've gone through the above questions the next thing
to do is to run through a performance chart (P-chart) for both
takeoff and landing. Check both operations as there's not much
point landing somewhere that you can't take off from! Consider
hotter temperatures and lower QNH's than you currently have
- increase the density altitude and see whether you can still
use the strip.
Remember that the P-charts have the configuration you'll need
to use listed on them. If you need flap for takeoff it'll be
listed on the charts. The charts will also list the speed you
need to use for the takeoff or landing.
Don't forget to check the length of field you actually have
available. You can drive a vehicle along the strip and use the
odometer to get a fairly accurate strip length. Remember also
to time the strip when you arrive and use that to calculate
the length. A rough figure is: Groundspeed divided by 2 is roughly
metres per second (erring on the safe side!).
Check the CAAPs for recommended field dimensions, and obstacle
free gradients. This is important - you mustn't have obstacles
protruding into the area in which you'll be climbing.
If you find that the strip is too short under some conditions
then you may need to consider the following:
1. Wait for favourable winds to arrive (sea breezes on the coast
in summer?)
2. Depart early in the morning while temperatures are cool.
3. Only fly one or two passengers out to a nearby field with
a long runway, and then come back and pick up the rest.
Weather conditions
This is one of the considerations I find most people on flight
tests do not think enough about.
High winds and turbulence will make a short field landing (in
particular) a lot more difficult. The fluctuations in your airspeed
from the turbulence will be a significant problem to you if
you need to maintain a precise approach speed. Remember - you
can't add a few extra knots on if you're doing a short field
landing!
There are many other factors you need to take into consideration
when preparing for a STOL operation. The most important consideration
is your own abilities, and whether you are prepared or not.
If you aren't happy about any of these factors - go somewhere
else - and enjoy your flight!
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