Introduction
While the subject of air law may seem a bit daunting at first glance, it
needn’t be. Nearly all air law is about being sensible. Any right minded
person would agree that flying an aircraft while incapacitated through
drugs or alcohol is not a good idea: perhaps it is not a great surprise to
find that it is also illegal. Any good pilot would agree that an aircraft
should be inspected before flight: it is also a legal requirement. Ninety-
nine percent of air law falls into this ‘be sensible’ category.
Scope
All of the following information applies to gliders (including hang gliders and
paragliders). Not all of this information will apply to foot-launched powered
aircraft (FLPA): pilots of these craft should consult the special terms of the
CPA Exemption that details their legal operation. (The current version of this
Exemption is available from the BHPA office.)
The sources
The Air Navigation Order (ANO) forms the basis of the UK’s air law and airspace
legislation. This document contains more than 120 Articles of law covering
airworthiness, operation of aircraft, documentation, licensing and so on. It
also includes a number of Schedules (appendices) which provide supplementary
detail. Supporting the ANO are the Rules of the Air Regulations (looked at next)
and the Civil Aviation (Investigation of Accidents) Regulations. There is one
further important document: the UK Aeronautical Information Publication (AlP).
This details airspace regulations, hazards and so on (these are explored in
Chapter 24).
The AIr Navigation Order
Many of the Articles contained in the ANO do not apply to gliders. Summarised
below are those that clearly do, and are most relevant to normal paragliding,
hang-gliding and parascending operations. (Where appropriate, additional
information is included.)
Pre-flight actions
The pilot must satisfy himself that the aircraft is fit for flight and checked,
that any passengers have been briefed and that the flight can be safely made.
(This includes checking weather conditions and forecasts, and accessing
up-to-date airspace information.)
Radios
For a pilot legally to operate a radio from a hang glider or paraglider, he must
comply with the law in three areas:
• The radio transmitter must be of a type approved by the CAA.
• The glider operator or owner must have a station licence for that radio. These
can be obtained by writing to: WT Radio licensing, Directorate of Airspace
Policy, K6 Gate 6, CAA House, 45 -
Kingsway, London WC2B 6TE, by telephoning: 0207453 6555, by e-mailing:
radio.licensing@dap.caa.co.uk, or from their web site at www.caa.co.uk (search
for ‘hang glider’).
• The pilot must either possess a Flight Radio telephony Operator’s (BiT)
licence or must only use the following frequencies: — 118.675 MHz. This is a
dedicated paragliding and hang- gliding frequency which can be used anywhere in
the UK FIR, up to and including 5000 ft AMSL. — 129.9 MHz, 129.95 MHz, 130.1
MHz, 130.125 MHz and 130.4 MHz. These are sport aviation frequencies, and their
users include parachutists, balloon pilots and sailplane pilots.— The
International Distress Frequency, 121.5 MHz. This frequency can be used to
alert the emergency services. Among the station licence conditions is the
requirement that operato’
must exercise strict radio discipline and that the procedures must I based on
those set out in the CAA publication CAP 413.
Dropping persons or articles
Articles shall not be dropped or be permitted to drop from an aircraft in
flight, except for the purpose of saving life, ballast in the form of fine sit’
I or water, or (at an aerodrome) tow ropes.
Imperilling safety
Persons must not endanger the safety of an aircraft or cause an aircraft to
endanger any persons or property
Drunkenness
Persons must not fly while under the influence of drugs or alcohol.
Exhibitions of flying
Display flying is tightly regulated: pilots must have a Display
Authorisation, and each display and item must be vetted.
Inadvertent entering of a Restricted or Prohibited Area
If a pilot inadvertently enters such an area then he must, unless otherwise
instructed, leave the area as quickly as possible and not descend over the area.
Winch/tow-launching
It is illegal to winch or tow to an altitude greater than 60 metres above ground
level (AGL) — or at all within an aerodrome traffic zone (ATZ) — unless
permitted by a current specific CAA Tow Site Permission.
Public transport and aerial work
The law attempts to draw a clear distinction between private (recreational)
flying and commercial (moneymaking) flying. In order to fly commercially (public
transport or aerial work), very closely defined levels of pilot qualification,
operator organisation and aircraft airworthiness must be met. These are not
available for hang-glider and paraglider operators!
To help deal with ‘grey areas’ which emerged as people tried to find ways around
the law, the CAA introduced the term ‘valuable consideration’. The CAAs short
definition of valuable consideration is ‘a consideration which is of more than a
nominal nature’. If valuable consideration is accepted as part of a flight, then
that flight is commercial, and therefore subject to all the rules and
regulations applicable to commercial flying. However, in order to allow some
normal aspects of recreational flying to continue, the CAA have defined a few
special cases where valuable consideration may be exchanged in connection with a
flight, without the need for special licences and paperwork:
• Receiving reimbursement of costs directly related to a competition flight is
allowed, as is receiving a prize of less than £500 per contest.
• If a pilot is taking part in a display, then receiving reimbursement of the
costs directly related to the flight is permitted but remember that there are a
whole host of other regulations relating to display flying.
• The direct costs of a flight may be paid for by or on behalf of the pilot’s
employer, provided neither the pilot nor any passenger are legally,
contractually or otherwise obliged to fly.
• When dual-flying, only qualified instructors may be paid, and only then to
instruct fellow-members of their club when flying aircraft owned or operated by
the club.
In addition to the above conditions, payment to anyone other than the aircraft’s
pilot or owner is only acceptable if the only beneficiary of the’ valuable
consideration is a registered charity and the flight is completed in accordance
with a specific CAA written permission.
The holder of a PPL (Aeroplanes) may tow a glider using an aircraft owned or
operated by a club of which the tug pilot and all those carried in the glider
are members. The tug pilot may not receive payment for these services (but the
club may charge the glider pilot for the launch).
You will be flying illegally if you accept any ‘valuable consideration’ for any
flight other than under these conditions shown above.
Other Articles
Other Articles that may be relevant in certain circumstances cover tb. law
relating to ‘Aircraft Towing Gliders’ (covered in the BHPA Technicil Manual),
‘Dropping People’ (CAA permissions required except in an emergency) and the
‘Method of Carriage of Persons’ (only in purpose designed seating etc).
5
Rules of the Air Regulations
The Rules of the Air Regulations concentrate on the practicalities of safely
operating an aircraft. These are summarised below with specific regard to
gliders (encompassing sailplanes, hang gliders and paragliders).
Low flying
Gliders must not fly over congested areas below a height that would allow them
to land clear of the area and without danger to people or property, or less than
1500 ft above the highest fixed object within 600 metres, whichever is the
higher.
A congested area means any area that is substantially used for residential,
industrial, commercial or recreational purposes.
An aircraft may not fly over or within 1000 metres of an open-air gathering more
than a thousand people, nor below a height that would enable it to land clear.
An aircraft must not fly closer than 500 ft to any person, vessel, vehicle or
structure. This provision does not apply to an aircraft taking off or landing,
flying low for the purpose of dropping tow ropes, or to gliders that are in
ridge soaring.
Right-hand traffic
Au aircraft flying within sight of the ground and following a road, railway,
coast or other line feature must keep that feature on its left (except where
otherwise instructed by ATC).
(II hang gliders and paragliders rarely follow line features, but pilots should
remain aware when crossing line features that other aerial traffic may be doing
so.)
Choice of VFR or IFR
I here are two sets of rules under which an aircraft may fly: the Visual Flight
Rules (VFR) or the Instrument Flight Rules (IFR). Which set of rules you must
fly under depends on the Meteorological ( conditions and the class of airspace
you are flying in. If you are in one of few classes of controlled airspace that
gliders may enter, then you must Fly in Visual Meteorological Conditions.
Visual Meteorological Conditions means that you are no closer than the
set distance clear of cloud (horizontally and vertically) and can see for at
least the minimum set distance forward (flight visibility).
Outside controlled airspace, by day, you may fly in Visual Meteorological
Conditions (VMC) or in Instrument Meteorological Conditions (IMC) as you choose.
If you do not maintain the minimum distances for VMC (because the weather is
deteriorating or you are flying rather closer to a cloud) then you are
automatically in Instrument Meteorological Conditions.
If your flight (outside controlled airspace, by day) is in VMC, then you may
choose to conduct your flight in accordance with either the Instrument Flight
Rules or the Visual Flight Rules. If on the other hand you fly in IMC, then
there is no choice: you must operate in accordance with the Instrument Flight
Rules.
Rules 29 and 30 are the Instrument Flight Rules that apply to aircraft flying
under IFR outside controlled airspace. Rule 29 is a minimum- height rule, and
forbids flying at less than 1000 ft above the highest obstacle within 5 nautical
miles except as necessary for taking off or landing, and except when flying at
or below 3000 ft AMSL, clear of cloud and in sight of the surface. Rule 30 is
only applicable to aircraft above 3000 ft AMSL cruising in level flight. (Rule
30 prescribes set altitudes for given headings; gliders are constantly ascending
and descending, so this does not apply.) (The foregoing is the legal position.
While it is clear that in many situations hang gliders and paragliders could
legally fly in cloud, the fact remains that this would be extremely foolhardy.
Maintaining control without visual reference to the horizon is virtually
impossible, as is avoiding other traffic and keeping track of your position.
Exploit the freedom to fly right up to just below cloudbase if you wish — but
leave it at that.)
Night flying
An aircraft flying at night shall be flown in accordance with Instrument Flight
Rules. ‘Night’ means the time from half an hour after sunset to half an hour
before sunrise (both times inclusive), sunrise and sunset being determined at
surface level. At night, lights must be carried in accordance with the Air
Navigation Order.
7
Rules for avoiding aerial collisions
The prime rule is the first one!
• It is the pilot’s responsibility to take all possible measures to avoid a
collision with any other aircraft.
• An aircraft shall not be flown so close to another aircraft as to create a
danger of collision.
• No formation flying is permitted unless all the pilots have agreed.
• When required by these Rules to give way, an aircraft shall avoid passing
over, under or ahead of another unless well clear.
• An aircraft that has right of way under these Rules shall maintain its course
and speed.
Converging
Other than in the cases of approaching head-on and overtaking:
• A powered aircraft shall give way to airships, gliders and balloons.
An airship shall give way to gliders and balloons.
A glider shall give way to balloons.
• When two aircraft of the same classification converge at approximately the
same altitude, the one with the other on its right shall give way.
Converging courses (gliders and distances not to scale)
When approaching head-on
When approaching approximately head-on with a risk of collision, both aircraft
shall alter course to the right.
Approaching head-on (gliders and distances not to scale)
(This rule is modified slightly by UK ridge-soaring conventions: when ridge
soaring, if two gliders are flying towards each other at similar height, the
pilot with the ridge on the left should move out so that the other has room to
maintain course without having to turn into or over the ridge.)
Approaching head-on when ridge-soaring (gliders and distances not
to scale)
Overtaking
When overtaking another aircraft, you must give way to it and alter course to
the right to overtake. In the UK a glider may overtake another glider to either
the left or the right.
Overtaking
(gliders and distances not to scale)
(This rule is modified slightly by UK ridge-soaring conventions: when
ridge-soaring, overtaking should be done on the hill side, so that the overtaken
glider remains free to make a normal turn, away from the hill. Beware — in other
countries different rules or protocols apply.)
Flight near aerodromes
Part of the official definition of an aerodrome is: ‘Any area of land or water
designed, equipped, set apart or commonly used for affording facilities for the
landing and departure of aircraft... ‘Therefore it can be claimed that all our
sites are aerodromes, just as Heathrow is!
When flying in the vicinity of any aircraft’s take-off or landing sites you must
keep clear or conform to any established pattern, making all turns to the left
unless ground signals indicate otherwise.
(Although this is how the Rule is written, it is rare for ground signals to be
used at our sites, and because of the constraints of location and weather any
turn pattern may not be to the left. However, there may be an established
pattern which you need to be clear about before you launch. If in doubt, ask.)
Landings
• An aircraft landing or on final approach has right of way over all other
aircraft in the air or on the ground.
• The lowest aircraft of any on an approach to land has right of way, provided
it does not cut in front of or overtake any aircraft on final approach.
• When landing, you should leave clear on the left any glider that is landing,
has landed or is about to take off. (This Rule may have to be modified to suit
the site.)
• After landing, you must clear the landing area as soon as possible.
Airspace
Introduction
Every cubic inch of sky above the UK is within a block of airspace that has a
formal designation, and for which there are rules governing who or what can fly
in it and under what circumstances. Thankfully, a sizeable chunk of this
airspace is Class G, where we can fly more or less unimpeded, but an awful lot
of UK airspace is no-go territory for hang gliders and paragliders. You need to
know which is which
Types of airspace
ICAO airspace classification
The UK uses the system of international airspace classification developed by the
International Civil Aviation Organisation (ICAO) whereby the status of a piece
of airspace is denoted by a letter that is shown on all aeronautical charts. It
is this letter that determines the rules applying to it. Airspace Classes A, B,
C, D and E are all forms of controlled airspace, while airspace Classes F and G
are uncontrolled.
Controlled airspace comes in various shapes and sizes: aeronautical charts
depict the horizontal boundaries accurately and state the vertical dimensions.
Class A Controlled Airspace
This airspace is effectively closed to gliders. (Exceptionally, gliders may
cross sections of Class A airspace by virtue of a Letter of Agreement which will
have very detailed procedures which must be followed.)
Class B Controlled Airspace
The entire airspace over the UK above FL 245 is Class B airspace, and gliders
are not allowed to enter it. (A few specified areas can be temporarily activated
for glider flights using a special procedure.)
Class C Controlled Airspace
No UK airspace currently falls into this category.
Class D Controlled Airspace
For gliders to enter and transit Class D Controlled Airspace, an ATC clearance
is required. This involves using radio to:
• Contact the ATC unit and pass details of the aircraft’s position, level and
proposed track.
• Obtain entry clearance.
• Listen out on the relevant frequency while in that airspace.
• Comply with ATC instructions.
Class E Controlled Airspace
Gliders may fly in Class E airspace without ATC clearance, subject to
maintaining VMC. In this situation VMC is defined as:
• Below 3000 ft AMSL: minimum flight visibility of 5 km, clear of cloud, in
sight of the surface.
• Above 3000 ft AMSL: minimum flight visibility of 5 km, 1500 m horizontally
clear of cloud and 1000 ft vertically clear of cloud.
You must still comply with the rules governing other airspace with specific
restrictions (e.g. ATZs) that may exist within the Class E airspace.
Local agreements
Letters of agreement between local clubs and the nearby airport can make
airspace more or less restrictive than previously described. The local club will
have details of any such agreements.
Class F Airspace (Advisory Airspace)
An advisory route (ADR) is a route used by airline-type traffic, but without the
full protection of an airway. Although depicted only as a centreline on UK
aeronautical charts, it is nominally 10 nautical miles wide. Gliders may cross
Class F airspace without restriction, but caution should be exercised. In this
class of airspace, VMC for aircraft flying at hang_glider and paraglider speeds
is defined as:
• below 3000 ft AMSL: in sight of the surface, clear of cloud, minimum flight
visibility of 1500 m
• 3000 ft AMSL to FL1 00: 1500 m horizontally clear of cloud,
1000 ft vertically clear of cloud, minimum flight visibility of 5 km
• above FL 100: 1500 m horizontally clear of cloud, 1000 ft vertically clear of
cloud, minimum flight visibility of 8 km
But bear in mind the fact that you may choose to fly in IMC (see Chapter 23).
Class G Airspace
This term is given to the ‘open’ FIR (Flight Information Region), the
uncontrolled airspace not subject to any of the above classifications.
The VMC criteria in this class of airspace are identical to those for Class F
above, as is the freedom to choose to fly in IMC.
Other types of airspace
Even within ‘uncontrolled’ Class G airspace there are various non-ICAO types of
airspace that have entry restrictions or requirements, some of which are
described below.
Aerodrome Traffic Zone (ATZ)
Aerodromes with an ATZ have it shown on the charts, except where they are
already inside controlled airspace (in which case they still have one but it is
not shown). An ATZ consists of the airspace from the surface to a height of 2000
ft above the level of the aerodrome, bounded by a circle of either 2 nautical
miles or 2.5 nautical miles radius, depending on the length of the main runway.
(The horizontal dimensions are drawn accurately on the aeronautical chart.) The
aerodrome’s altitude is printed alongside the symbol. Gliders, including hang
gliders and paragliders, are not allowed in active ATZs without having been
given permission by the ATC unit.
At airfields without an ATZ, pilots should conform to the traffic pattern or
keep clear of the circuit airspace, and should observe the normal rules of good
airmanship.
Figure 24.1 Aerodrome Traffic Zone
2 or 2.5 nm
Military Aerodrome Traffic Zone (MATZ)
These typically consist of the airspace from the surface to a height of 3000 ft
above the aerodrome’s altitude (which is printed alongside the symbol, as with
ATZs), bounded by a circle of radius 5 nautical miles from the aerodrome’s
reference point — plus a projecting stub aligned with the principal runway 5
nautical miles long and 4 nautical miles wide — between 1000 ft and 3000 ft
above the aerodrome’s altitude. They look like a pan with a very oversized
handle; indeed, the stub is sometimes called the pan-handle. Some MATZs have no
stub, or have two or more stubs, or form part of a combined MATZ (CAAATZ).
Again, the aeronautical charts clearly show their horizontal dimensions.
The rules applicable to entering an MATZ are not compulsory for civil aircraft,
but there are two very important things to consider: every MATZ contains an ATZ
(which you cannot enter without permission), and an MATZ is usually a very busy
bit of sky especially during the week. 3000 ft high
Military Aerodrome Traffic Zone (ATZ not shown)
Danger Areas
A Danger Area is exactly that: an area where there is an activity that is
dangerous to aircraft. Not all of them have by-laws prohibiting entry — but they
are all best left well alone unless you are certain that they are inactive. They
usually extend from the surface upwards. On the charts they are identified with
a ‘D’ number, e.g. D306/5. The first part is the serial number of the Danger
Area, and the final figure (or figures) is the altitude in thousands of feet
that it goes up to. The charts also differentiate between those Danger Areas
that have published hours of activity (which may be varied by NOTAM) and those
that are only activated by NOTAM.
Prohibited and Restricted Areas
As with Danger Areas, the number on the chart after the ‘P’ or ‘R’ number
indicates the altitude to which the area extends, usually from the surface. The
names Prohibited and Restricted are self-explanatory, referring to areas that
are established to protect places or activities that are potentially very
hazardous or have security implications. Prohibited areas are exactly that:
details of the rules governing specific Restricted Areas can be found in
En-Route 5. 1, a section of the AlP (which is a very expensive publication). In
the absence of accurate information to the contrary, all Restricted Areas should
be avoided. Some Temporary Restricted Areas are set up from time to time, and
these are notified on Freefone 0500 354802 and on the Web at www.ais.org.uk
daily.
Areas of Intense Aerial Activity (AIAAs)
These areas contain a large amount of civil and/or military aircraft activity
Paragliders and hang gliders are allowed to enter these areas, but should keep
an even better lookout than normal (if that’s possible!).
High Intensity Radio Transmission Areas (HIRTAs)
Again this is self_explanatory: the transmissions may cook either you or your
instruments — or both — from the inside out!
Other warnings
These include a variety of things, including areas where free-fall parachuting
takes place. Collecting a parachutist wouldn’t do you or him any good!
Other symbols
On the ICAO chart you will see a lot of other symbols. Obviously navigation aids
such as TACANs, NDBs, VORs and DMEs do not matter to us, but we should avoid
non-ATZ airfields, microlight, gliding and parascending sites unless visiting by
prior arrangement.
Summary
A simple summary could be ‘if in doubt, keep out’, but if in doubt you should
not be considering cross-country flying at all. If you have not passed your BHPA
Pilot exam (and therefore have not had your understanding of air law and
airspace proven) you should not fly cross- country. Even for non-cross-country
flying at your local site, you should know the local airspace requirements.
Air—misses (Airprox)
Any pilot who considers his or her flight safety to have been compromised by the
proximity of another aircraft may file an Airprox. The United Kingdom Airprox
Board investigates all such reports in order to ascertain what lessons can be
learned for the future. (They have no remit to take punitive action or to
apportion blame.)
If a BHPA member wishes to file an Airprox, the procedure should ideally be as
follows:
1 Inform the BHPA Airspace Officer (should this not be possible, do not delay
the initial telephone report; this would reduce the likelihood of being able to
trace the other aircraft involved).
2 Initial Report — call the Aeronautical Information Section (M) on
01895 426153 or 01895 4267 17/4267 18, who will start tracing procedures and
inform the UK Airprox Board.
3 Confirmation Report — follow up within seven days with a completed report form
CA 1094. (Forms are available from the BHPA Office on request.)
4 Complete a BHPA Incident Report form.
If you are in any doubt or have any questions, please contact the BHPA Airspace
Officer or any of the BHPA technical staff. Note that Airprox reports cover
conflicts with both military and civilian aircraft.
References
The information in this chapter is only a brief synopsis of the airspace rules
as they affect glider pilots, and is believed to be accurate at the time of
writing. In case of doubt, the authoritative primary sources should be
consulted. These are:
• the Air Navigation Order
• the Rules of the Air Relations
• the UK Aeronautical Information Publication, Pilots requiring clarification on
airspace rules should contact the BHPA Airspace Officer, whose telephone number
is always given in Skywings magazine.
Abbreviations
AIM Area of Intense Aerial Activity
AlP Aeronautical Information Publication
ATC Air Traffic Control
ATZ Aerodrome Traffic Zone
CAA Civil Aviation Authority
CTA Control Area
CTR Control Zone
FIR Flight Information Region
FL Flight Level
HIRTA High Intensity Radio Transmission Area
ICAO International Civil Aviation Organisation
IFR Instrument Flight Rules
IMC Instrument Meteorological Conditions
MATZ Military Aerodrome Traffic Zone
NOTAM Notice to Airmen
TMA Terminal Control Area
UIR Upper Flight Information Region
VFR Visual Flight Rules
VMC Visual Meteorological Conditions
The aeronautical chart
From the foregoing explanation of UK airspace, it should now be abundantly clear
that you must have an up-to-date aeronautical chart if you intend making any
sort of cross-country flight.
Types of chart
Charts are available in two scales: 1:250,000 and 1:500,000, and come
plastic-laminated. The laminated finish allows you to draw on the map with a
chinagraph pencil or washable felt-tip pen and then wipe it clean afterwards.
ICAO aeronautical charts
Scale 1:500,000 (United Kingdom)
These charts (known as ‘half mil.’ charts) show all airspace. Half mil. charts
are the best ones to use for long-distance cross-country flights, simply because
you can fly a lot further without going off the edge of the map! If you travel
around the country a lot you will only need three charts: Scotland, Orkney and
Shetland; Northern England and Northern Ireland; and Southern England and Wales.
Topographical air charts
Scale: 1:250,000 (United Kingdom)
These charts (known as ‘quarter mil.’) only show airspace that has a lower limit
below 5000 ft AMSL or Flight Level 55, and so are of limited use if your flight
goes above that altitude — unless you are prepared to buy the half mil. and add
the extra detail yourself. These charts (with the added information!) are better
for local flying and for triangle, out-and IMC return or short cross-country
flights, and also for giving retrieve information, but if you travel around the
country you will need more charts to cover the required area (seven for the UK).
Keeping charts up to date
Airspace is regularly changed as civil airports grow, military aerodromes are
abandoned, airways are raised or lowered and other changes occur. The CAA
replaces charts as required, and this can be as often as within twelve months of
the previous issue. You should therefore check at least annually to make sure
you are using the most up-to-date issue. But even with an up-to-date chart, the
information is only valid on the day of issue! In order to keep your chart fully
up to date between new editions, it is necessary to consult the Aeronautical
Information Publication (AlP) and NOTAMs (Notices to Airmen) that the CAA issues
and amend your chart as necessary. Ideally your Club should have access to
NOTAMs. Don’t forget to read the Airspace Update column in Skywings. It should
be remembered that all these charts contain long-term information only and there
is nothing about those Royal Flights or Red Arrows displays that we must avoid.
Where to get them?
You can obtain these charts from a number of different sources, some of which
advertise in Skvings. When ordering, you should always check which edition you
will be sent. You can also order them from the CAA’s main chart agent: CAA Chart
Sales, tel. 0161 499 0013, fax. 0161 499 0298. They take credit cards, so it is
possible to order by telephone.
Using a chart
It’s difficult to read and understand airspace dimensions and rules, work out
where you are and where you are heading, and centre in a thermal all at the same
time — so planning a cross country in advance will always make the flight
easier.
Navigation techniques are the same whichever scale of chart or type of map you
decide to use. Take the time to sit down with the charts or whatever maps you
choose to use, and draw on them the line of your proposed track, whether it is a
downwind cross-country, a triangle or an out-and-return.
First look for any airspace along your route that you must avoid (the reference
block at the bottom of the chart explains what each symbol represents) and
highlight the boundaries in an obvious way (e.g. a bright red line). Redraw your
track if necessary — although you may be able to continue your flight underneath
some airspace that you are not allowed into. If this is the case, besides the
boundaries mark the altitude that you must keep below, and remember to set your
altimeter properly. (If you get near to the local airway base height it is wiser
to leave, as many light- aeroplane pilots find it convenient to follow airways
just under their base height.) Flying over airspace that you are not allowed in
is pushing your luck; gravity has a way of cutting short your flight when you
least want it to!
Secondly, look for airspace which you can enter; but where you must obey certain
rules. Are you prepared and able to fly by those rules? If not, then mark them
as areas to avoid; if you are able and prepared then mark those boundaries in a
different but still obvious way (e.g. a line of bright red dashes) — learn the
relevant rules and fly by them.
Thirdly look for landmarks that you can use to check your position in flight:
recognisable road junctions, isolated large towns, railway junctions and disused
airfields are just some examples (remember; woods and forests can change, and
objects like radio masts are virtually invisible from above!). Highlighting a
landmark every five to ten miles along the track should be enough.
Finally, when folding your map to put it into your map-holder, make sure that
your take-off site is positioned near the bottom of the visible bit and that
your intended track runs up the map away from you and in the direction of
flight. It is much easier to follow like that: landmarks that appear on the
right of your drawn track-line will appear on the right as you fly.
If on a flight you run out of map, you have run out of information; sooner or
later you will also run out of luck, and so you should land and not put others’
lives and our sport at risk by irresponsibility
Using an altimeter
Aeronautical charts show vertical limits expressed using a variety of terms
such as ‘ALT’ and ‘FL’ or ‘Flight Level’. Part of learning how to use a chart
involves understanding what these terms mean, and learning how to use your
altimeter correctly.
Atmospheric pressure reduces with increased height, by approximately 1 millibar
(mb) per 10 m (30 ft) at lower levels. Altimeters are effectively
pressure-measuiing devices that display this reduced pressure as height in feet.
In order for these devices to be used to judge height relative to blocks of
airspace and other aircraft, agreed altimeter_setting datums have to be used.
These allow for the fact that atmospheric pressure also changes as weather
systems move across the country, and that some airfields are sited on hills and
others in the lowlands. Three standard altimeter-setting datums are used: QFE,
QNH and Flight Level — these are detailed below. Aircraft altimeters have a
sub-scale and knob to change the pressure setting, allowing them to use any of
these three datum bases.
QFE
QFE is the pressure setting that results in the altimeter showing zero on a
particular airfield. If you are going to remain flying around the airfield, then
the altimeter will provide accurate height information. If you choose to fly to
another airfield, then when you get there you will need to get (by radio) the
current QFE setting at that field to enable you to reset your altimeter to give
the accurate height above that particular airfield.
QNH
When flying between airfields, pilots set their altimeters to the current
pressure reading at mean sea level. This is given the code QNH, and vertical
distance measurements using this datum are known as altitudes. The country is
divided into altimeter setting regions (shown on air charts as ASRs), and within
each region the regional QNH value (updated hourly) is available from ATC and
advised routinely to pilots whenever they contact ATC for instructions. This
ensures that all pilots in that area are operating with the same pressure
information, so making it possible for them to rely on their altimeters when
judging safe terrain clearance and vertical separation from other aircraft.
Flight Levels
Aircraft cruising well above the terrain and crossing many regions and countries
would constantly have to change altimeter settings to each regional QNH value.
Since at cruising levels accurate separation from other aircraft is the prime
consideration, it is safer and easier for all aircraft to use a standardised
pressure setting. The International Standard Atmosphere (ISA) sea-level pressure
setting of 1013.2 mb is used. (On any given day this could be above or below the
actual pressure at sea-level.) The vertical position measured on an altimeter
set to this datum is referred to as a Flight Level. FL95 thus means 9500 ft
above the level at which tiw pressure is 1013.2 mb.
Below the
Transition Altitude, aircraft pilots alter their altimeters to give an altitude
reading (QNH) rather than a Flight Level reading. Except around airports, where
it may be increased, the Transition Altitude in the UK is 3000 ft.
Hang gliders and paragliders
If just flying locally (e.g. ridge-soaring) where there are no airspace
restrictions, most pilots will use QFE, zeroing their altimeters at take-off or
at the intended landing-point.
If you are planning to fly cross-country, you will need to set your altimeter to
QNH. One way to do this is to accurately determine your altitude from an OS map
before launch and adjust the altimeter to that indication. This (local QNH)
setting will enable you to avoid controlled airspace where the lower levels are
defined by altitudes. When the lower levels of controlled airspace are defined
by Flight Levels, your altimeter will need to be set to 1013.2 mb to determine
your proximity to the controlled airspace. Most modern altimeters have the
ability to be switched to such a setting — it is sometimes (incorrectly) labeled
QNE.
