FAA Aircraft Categorisation
How wide does an airport runway need to be ? The answer depends on which
international standards you choose to follow.
The USA's Federal Aviation Administration(FAA) is a world-recognised body
which defines standards for airport planning and design.
Australian airports generally follow the International Civil
Aviation Organisations (ICAO) recommendations, which are often,
but not always, less stringent than the FAA recommendations.
Americans tend to care more about losing a few hundred people
in an air accident than do other countries. And really, the US
got its big kick in aviation when the first jet, the UK manufactured
Comet, proved to crash rather too often (because they hadn't yet
learned about metal fatigue caused by
cabin pressurisation cycling).
The Australian standards are described on
another page.
These facts can help you make a judgement
on the truth of BAL's answers on whether a 737 could operate
at Bankstown, on the present 30 meter wide 11C/29C runway:
The FAA provides the following categorisations of aircraft.
- Categorisation by Stall Speed
(which determines the basis of landing or approach speed):
Table 1 - Aircraft Approach Category
Aircraft Category
|
1.3 Times the
Stall Speed in Knots
|
Maximum Speed
(Circling Approaches)
|
Typical
Aircraft in This Category
|
A
|
less than 91 knots
|
90 knots
|
small single
engine |
B |
91 to 120 knots |
120 knots |
small multi engine |
C |
121 to 140 knots |
140 knots |
airline jet |
D |
141 to 165 knots |
164 knots |
large jet/military
jet |
E |
above 166 knots |
|
special military |
source: FAA, 1976,
United States standards for Terminal Instrument
Procedures, 3d ed, FAA Handbook 8260.3B)
By contrast with this 5 part categorisation, the ICAO and Australian
standards use a 4 part number code that is based on the Aeroplane
Reference Field Length (ARFL). From a physics point of view, the
length of runway needed will depend on the speed (velocity) and
mass of the aircraft during take-off and landing operations. The
landing approach speed will usually be a good representation of
this, so that the FAA aircraft category should give similar results
to the ICAO/Australian standard.
Flexibility in Australia practice allows the US standard to be
used for any aircraft manufactured in the US.
- Categorisation by Wingspan
A further grouping by aircraft size is
made according to the wingspan of the aircraft.
This is called the Aircraft Design Group (ADG),
and determines the width requirements of runways and taxiways:
Table
2 - Aircraft Design Group (WingSpan
Classification)
Group |
WingSpan |
Runway
Width |
I |
up
to but not including 15 m (49 ft) |
100
ft (30 m) |
II |
15 m
(49 ft) up to but not including 24 m (79
ft) |
100
ft (30 m) |
III |
24 m
(79 ft) up to but not including 36 m (118
ft) |
100
ft (30 m) |
IV |
36 m
(118 ft) up to but not including 52 m
(171 ft) |
150
ft (45 m) |
V |
52 m
(171 ft) up to but not including 65 m
(214 ft) |
150
ft (45 m) |
VI |
65 m
(214 ft) up to but not including 80 m
(262 ft) |
200
ft (60 m) |
- Particular aircraft are described by a
combined speed/size Airport Reference Code using
the above two tables. A representative sample is
given here:
Table
3 - Representative Aircraft Type (by FAA Airport
Reference Code)
Make/Model |
Airport
Reference Code |
Approx
Approach Speed (knots) |
WingSpan
(feet) |
Max
Takeoff Weight (Pounds (metric tons)) |
Cessna
150 |
A-I |
55 |
32.7 |
1,600 (0.7 t) |
Beech-King
Air B100 |
B-I |
111 |
45.8 |
11,800 (5.3) |
Gates
Learjet 54-56 |
C-I |
128 |
43.7 |
21,500 (9.8 t) |
Dornier
LTA |
A-II |
74 |
58.4 |
15,100 (6.8 t) |
DHC-8,
Dash-8 300 |
A-III |
90 |
90 |
41,100 (18.6 t) |
Fairchild
F-27 |
B-III |
109 |
95.2 |
42,000 (19 t) |
Boeing
727-200 |
C-III |
138 |
108 |
209,500
(95 t) |
Boeing
737-400 |
C-III |
138 |
94.8 |
150,000
(68 t) |
Boeing
767-300 |
C-IV |
130 |
156.1 |
350,000 (158 t)
|
Boeing
747-200 |
D-V |
152 |
195.7 |
833,000 (377 t) |
(source: FAA, 1991c, Airport
Design, Advisory Circular, AC150/5300-13, change
1)
From these last two tables, it can be
concluded that Boeing 727's, and 737's are
category III aircraft and require only a 30 meter
runway according to USA standards. They are in
the same group as Dash-8's which BAL has admitted
use Bankstown airport already.
Also, note that this table tends to
show the heaviest model of a particular
aircraft. Most 737's are, for example, under 63 tons
MTOW and the 737-100 is below 47 tons
First Published 1997, Last Revised
Last Change: vdeck mod
Visitor
since Sat 21-Feb-2004.
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