safety factors when landing on unlicensed airfields
abridged from GASCO
Unlicensed aerodromes and private strips are often used by pilots
and private owners. They may be more convenient or cheaper than licensed
aerodromes; however they do require special consideration. Approximately
one third of GA Reportable Accidents in the UK occur during take
off or landing at unlicensed aerodromes. The proportion of flying
activity is not known.
assess the airstrip
It is important to realise that the criteria of your aviation authority
for the licensing of an aerodrome, e. g. clear approaches without power
or other cables, no trees or obstructions close to the runway and so on,
are unlikely to have been applied to the strip. Since in almost all cases
Prior Permission is Required (PPR) before landing, your phone call should
also include discussion of any difficulties, obstructions, noise
sensitive areas to be avoided and the useable length of the strip.
Find out the arrangements for grass cutting. It is no use landing only to
find the grass is so long that it prevents you taking off again. As a
rule of thumb, the grass length should not be more than 30% of the
diameter of the wheel.
Use an detailed map to
find out accurately the elevation above mean sea level of the strip
–check your map to see if it is in metres or feet!
The orientation of the
strip may have been laid out to fit in with the needs of agriculture.
Establish the direction of the prevailing winds in the area and note the
location of any windsock. Will it be affected by nearby trees or
buildings? A well located windsock will give you the ground level wind
speed and direction. Beware of strips near the coast; sea breezes can
change rapidly from onshore to offshore, morning and evening.
Tell the operator of the strip what experience you have, which strips you
have used recently, and what aeroplane you intend using. He has probably
seen pilots with similar aeroplanes flying into and out of the strip and
you can benefit from local knowledge. He does not want an accident any
more than you do! Exchange telephone numbers in case of a last minute
hitch. If possible visit it by road to see for yourself.
The length of the strip must be accurately established. If you pace it
out, remember an average pace is not one metre, but considerably less
(the British army’s marching pace is only 30 inches). This may decrease
still further after walking several hundred metres. A proper measuring
device is better; for example a rope of accurately known length.
The strip should be adequately drained or self-draining. Visit it after
heavy rain to see whether it remains waterlogged or muddy. Rain after
long dry periods may not soak away and can remain hidden by the grass.
The surface should be free from ruts and holes and should be properly and
regularly rolled. One way of assessing the surface is to drive a car
along the strip. If at about 30 mph the ride is comfortable, there should
be no problems.
If it is a disused wartime airfield, some of the runway may be unusable,
while other parts may have a surface in poor condition – including loose
gravel and stones. These can be picked up by the propeller wash and can
damage windscreens, tail and, of course, the propeller itself. Stone
damage can be very expensive.
Carefully examine from the ground, air or maps the approaches to the
strip and the go-around area, with particular reference to any runway
slope, obstructions or hills within 5 km, windshear or turbulence from
nearby woods/ buildings and other considerations.
Look closely at neighbouring properties; a climb out above the breeding
pens or stud farm next door will soon bring an end to everyone's
Aeroplane performance must be appropriate for the proposed strip. You
must be fully familiar with the performance characteristics of your
Remember, the figures
shown in the Pilots Operating Handbook are obtained using a new
aeroplane, flown by an expert pilot under near ideal conditions, i.e. the
best possible results. On the strip, the grass may be different from the
'short, dry, mown grass' of the Handbook. There may be a slight uphill
gradient, tall trees or cables at the far end, or a cross wind. Short wet
grass should be treated with utmost caution, it can increase landing
distances by 60% – it’s like an icy surface! Take account of all of these
most carefully and then add an additional margin for safety before
deciding. You should allow a 33% safety factor for take-off but 43%
Your own abilities as a pilot need critical and honest assessment. The
ability to land smoothly on a long hard runway is very different from the
skills needed for this type of operation.
Most importantly the combination of YOU and YOUR aeroplane must be
satisfactory. A weakness in either of these could show up in the accident
Some strips are located on hills where, up to a certain wind speed, take
offs are downhill and landings uphill. Re- read the above paragraphs, for
although such strips are not necessarily dangerous, they should not be
attempted unless you are totally confident about the factors described
You must check that the insurance covers operation from an unlicensed
aerodrome or a strip. It is important that you give Insurers fullest
possible written details before the visit.
Find out about the local arrangements for booking in and booking out;
usually a Movements Log is provided.
Ensure that passengers and spectators are properly briefed about where
they may go, where they may stand and what they may or may not touch.
Leave details of route,
ETA and passengers in the Movements Log AND with someone who will react
appropriately and alert the Emergency Services if you fail to arrive/
If you intend to leave the aircraft overnight at a strip, it may be
necessary for you to arrange your own tie- downs and wheel chocks. Ensure
that control locks are in place and the aircraft is properly secured. If
the wind is likely to increase, then position your aircraft so as to
minimise the possibility of it moving and be prepared to reposition it if
the wind direction changes. Covers should be used to keep insects and
water out of the pitot tube and static vents.
Next morning your pre- flight inspection should be more careful than
usual just in case birds or other wildlife have taken up residence; birds
can build a nest overnight. Check the pitot head, static and tank vents
If the strip is shared with cows, horses or sheep, then an electric or
other suitable fence to separate them from your aeroplane is essential.
Cows are very partial to the taste of aeroplane dope and their rough
tongues have been known to strip fabric from wings. Metal aeroplanes do
not escape their attentions, since they make suitable back-scratchers.
Discuss with the strip operator the security of the aeroplane. Vandalism
and fuel thefts may be a problem.
Consider having a familiarisation flight to and from the strip with a
pilot who knows the strip and is both current on your aeroplane and
operations into grass strips.
In any case you must know and fly the correct speeds for your aeroplane
and remember the importance of using appropriate techniques, keeping the
weight off the nosewheel etc.
If the strip is shorter than you are used to or has difficult approaches,
you should arrange for a flying instructor to appraise your flying skills
and revise and improve short field, soft field, general circuit and
airmanship skills. Listen and learn. If an instructor is not available,
at least practice your short landings on a long runway before attempting
to land at a short strip.
Airmanship and look- out must be of the highest order; there is unlikely
to be any form of ATC service to advise you of the presence of other
aircraft, their position or intentions, so be especially vigilant. Low
flying military aircraft may NOT avoid strips.
Circuit practice at unlicensed aerodromes could be unpopular with the
neighbours and may be in breach of part of Rule 5 of the Rules of the Air
if you are within 500 ft of persons, vessels, vehicles or structures.
However, if you find a problem with turbulence or crosswind, surface or
slope, do not hesitate to go around in accordance with normal aviation
Plan your circuit using the best available QNH, for example from a nearby
aerodrome. Failing that you could use the most recent ‘regional pressure
setting (RPS)’ but be aware your altimeter will certainly over-read if
you use RPS. You should already know the elevation of the strip, so add
this figure to the appropriate height that you would use in a normal
circuit. Thus, if the strip is 250 ft amsl, downwind will be e.g. 1250 ft
Get into the habit of flying a compact circuit using engine and propeller
handling techniques that will minimise noise disturbance. Avoid long flat
and noisy approaches, these are not conducive to good neighbourliness nor
necessarily the best short landing technique. If your approach is bad,
make an early decision to go-around. It is often useful to plan to make a
go-around from your first approach (avoiding persons, vessels vehicles
and structures by 500 feet).
Note carefully the
position and height of any obstructions on the approach especially hard-
to- see local power and phone cables. Make sure that you can clear them
(and any crop) by an adequate margin, and provided that you maintain this
clearance, always aim to touch down close to the threshold – not
halfway down the strip.
Always start your take
off run as close as possible to the beginning of the strip, unless there
are very good reasons not to do so. Work out an acceleration check point
from which you can stop if you haven’t reached sufficient speed to make a
Bear in mind when turning off the strip, Rule 17(7) of the Rules of the
Air and other arriving aircraft.
When performing power checks or engine runs try to minimise any noise
nuisance and ensure that the slipstream is not creating a problem.
Unexpected noise etc can terrify livestock; be considerate when choosing
the site for engine checks.
After take off, reduce power and propeller rpm when it is safe. Climb to
at least 500 ft agl before turning.
If you are a regular strip user, decide your weather and wind limits and
be clear about your Go/ No Go decision process.
permission from the owner/operator prior to visiting the strip. Talk to
pilots who have used the strip before and can advise you on
DO check that the combination of you and your aeroplane can safely
cope with this strip.
DO always leave details of ETA route, destination and how many are
on board in the Movements Log.
DO always nominate a ‘responsible person’ who knows how to raise
the alarm if you fail to arrive/return.
DO follow the requirements for customs, immigration and the
Terrorism Act if flying to or from overseas.
DO talk to neighbouring aerodromes or to the Flight Information
Service on the radio.
DO build up a working relationship with your nearest aerodrome.
You may need them for fuel, weather information and maintenance.
DO be ready for unexpected effects from trees, barns, windshear,
DO work hard at being a good neighbour and improving the Public’s
perception of General Aviation by minimising noise nuisance.
DO check that the strip really is long enough, with a 30% margin
DO check on the effect of power and other cables.
DO check whether any slope makes it a ‘one way’ strip.
DO NOT 'beat up' the strip or engage in other forms of reckless,
illegal and unsociable flying.
DO NOT attempt to take off or land if the grass is long, the
ground is muddy or weather is marginal. There will always be a better day
to fly or you can always divert into a neighbouring aerodrome.
DO NOT run- up an engine where the noise affects others or
slipstream can be a nuisance.
DO NOT attempt to 'scrape' in from a bad approach.