aircraft classifications intro

NEXTOR - National Center of Excellence for Aviation Research

1

Analysis of Air Transportation Systems

The Aircraft and the System

Dr. Antonio A. TraniAssociate Professor of Civil and Environmental Engineering

Virginia Polytechnic Institute and State University

Falls Church, VirginiaJan. 9-11, 2008


2

Material Presented in this Section

•

The aircraft and the airport

•

Aircraft classifications

•

Aircraft characteristics and their relation to airport planning

•

New large capacity aircraft (NLA) impacts


3

Purpose of the Discussion

•

Introduces the reader to various types of aircraft and their classifications

•

Importance of aircraft classifications in airport engineering design

•

Discussion on possible impacts of Very Large Capacity Aircraft (VLCA, NLA, etc.)

•

Preliminary issues on geometric design (apron standards) and terminal design

Relevance of Aircraft Characteristics

• Aircraft classifications are useful in airport engineering work (including terminal gate sizing, apron and taxiway planning, etc.) and in air traffic analyses

• Most of the airport design standards are intimately related to aircraft size (i.e., wingspan, aircraft length, aircraft wheelbase, aircraft seating capacity, etc.)

• Airport fleet compositions vary over time and thus is imperative that we learn how to forecast expected vehicle sizes over long periods of time

• The Next Generation transportation system will cater to a more diverse pool of aircraft

NEXTOR - National Center of Excellence for Aviation Research 4

Aircraft Classifications

Aircraft are generally classified according to three important criteria in airport engineering:

• Geometric design characteristics (Aerodrome code in ICAO parlance)

• Air Traffic Control operational characteristics (approach speed criteria)

• Wake vortex generation characteristics

Other relevant classifications are related to the type of operation (short, medium, long-haul; wide, narrow-body, and commuter, etc.)


Geometric Design Classification (ICAO)

ICAO Aerodrome Reference Code Used in Airport Geometric Design

Design Group Wingspan (m)Outer Main

Landing Gear Width (m)

Example Aircraft

A < 15 < 4.5 All single engine aircraft, Some business jets

B 15 to < 24 4.5 to < 6 Commuter aircraft, large busi-ness jets

(EMB-120, Saab 2000, Saab 340, etc.)

C 24 to < 36 6 to < 9 Medium-range transports(B727, B737, MD-80, A320)

D 36 to < 52 9 to < 14 Heavy transports(B757, B767, A300)

E 52 to < 65 9 to < 14 Heavy transport aircraft(Boeing 747, A340, B777)

F >= 65 > 14 A380, Antonov 225


Geometric Design Classification (FAA in US)

FAA Aircraft Design Group Classification Used in Airport Geometric Design

Design Group Wingspan (ft) Example AircraftI < 49 Cessna 152-210, Beechcraft A36

II 49 - 78 Saab 2000, EMB-120, Saab 340, Canadair RJ-100

III 79 - 117 Boeing 737, MD-80, Airbus A-320

IV 118 - 170 Boeing 757, Boeing 767, Airbus A-300

V 171 - 213 Boeing 747, Boeing 777, MD-11, Airbus A-340

VI 214 - 262 A380, Antonov 225


ATC Operational Classification (US)

Airport Terminal Area Procedures Aircraft Classification (FAA Scheme)

Group Approach Speed (knots)a

a. At maximum landing mass.

Example Aircraftb

b. See FAA Advisory Circular 150/5300-13 for a complete listing of aircraft TERP groups and speeds

A < 91 All single engine aircraft, Beechcraft Baron 58,

B 91-120 Business jets and commuter aircraft (Beech 1900, Saab 2000, Saab 340,

Embraer 120, Canadair RJ, etc.)C 121-140 Medium and Short Range Transports

(Boeing 727, B737, MD-80, A320, F100, B757, etc.)

D 141-165 Heavy transports(Boeing 747, A340, B777, DC-10,

A300)E > 166 BAC Concorde and military aircraft


Wake Vortex Aircraft Classification

Final Approach Aircraft Wake Vortex Classification

Group Takeoff Gross Weight (lb) Example Aircraft

Small < 41,000 All single engine aircraft, light twins, most business jets and commuter air-

craftLarge 41,000-255,000 Large turboprop commuters, short and

medium range transport aircraft (MD-80, B737, B727, A320, F100, etc.)

Heavy > 255,000 Boeing 757a, Boeing 747, Douglas DC-10, MD-11, Airbus A-300, A-340,

a. For purposes of terminal airspace separation procedures, the Boeing 757 is classifed by FAA in a category by itself. However, when considering the Boeing 757 separation criteria (close to the Heavy category) and considering the percent of Boeing 757 in the U.S. feet, the four categories does provide very similar results for most airport capacity analyes.

A380 1,234,000 Airbus A380 (pending reductions)



10

IATA Aircraft Classification

Used in the forecast of aircraft movements at an airport based on the IATA forecast methodology.

IATA Aircraft Size Classification Scheme.

Category Number of Seats Example Aircraft

0 < 50 Embraer 120, Saab 340

1 50-124 Fokker 100, Boeing 717

2 125-179 Boeing B727-200, Airbus A321

3 180-249 Boeing 767-200, Airbus A300-600

4 250-349 Airbus A340-300, Boeing 777-200

5 350-499 Boeing 747-400

6 > 500 Boeing 747-400 high density seating


11

Aircraft Classification According to their Intended Use

A more general aircraft classification based on the aircraft use

•

General aviation aircraft (GA)

•

Corporate aircraft (CA)

•

Commuter aircraft (COM)

•

Transport aircraft (TA)

Short-range

Medium-range

Long-range


12

General Aviation (GA)

Typically these aircraft can have one (single engine) or two engines (twin engine). Their maximum gross weight usually is always below 14,000 lb.

Single-Engine GA Twin-Engine GA

Cessna 172 (Skyhawk)Beechcraft 58TC (Baron)

Beechcraft A36 (Bonanza) Cessna 421C (Golden Eagle)


13

Corporate Aircraft (CA)

Typically these aircraft can have one or two turboprop driven or jet engines (sometimes three). Maximum gross mass is up to 40,910 kg (90,000 lb)

Raytheon-Beechcraft

Cessna Citation II

Gulfstream G-V

King Air B300


14

Commuter Aircraft (COM)

Usually twin engine aircraft with a few exceptions such as the DeHavilland DHC-7 which has four engines. Their maximum gross mass is below 31,818 kg (70,000 lb)

Fairchild Swearinger Metro 23

Bombardier DHC-8

Saab 340B

Embraer 145


15

Short-Range Transports (SR-TA)

Certified under FAR/JAR 25. Their maximum gross mass usually is below 68,182 kg (150,000 lb).

Fokker F100

Airbus A-320

Boeing 737-300

McDonnell-Douglas MD 82


16

Medium-Range Transports (MR-TA)

These are transport aircraft employed to fly routes of less than 3,000 nm (typical).Their maximum gross mass usually is usually below 159,090 kg (350,000 lb)

Boeing B727-200

Boeing 757-200

Airbus A300-600R


17

Long-Range Transports (LR-TA)

These are transport aircraft employed to fly routes of less than 3,000 nm (typical).Their maximum gross mass usually is above 159,090 kg (350,000 lb)

Airbus A340-200

Boeing 777-200

Boeing 747-400


18

Future Aircraft Issues

The fleet composition at many airports is changing rapidly and airport terminals will have to adapt

•

Surge of commuter aircraft use for point-to-point services

•

Possible introduction of Very Large Capacity Aircraft (VLCA)


19

VLCA Aircraft Discussion

•

Large capacity aircraft requirements

•

Discussion of future high-capacity airport requirements

• Airside infrastructure impacts

• Airside capacity impacts

• Landside impacts

• Pavement design considerations

• Noise considerations

• Systems approach


VLCA Design Trade-off Methodology

• Aircraft designed purely on aerodynamic principles would be costly to the airport operator yet have low DOC

• Aircraft heavily constrained by current airport design standards might not be very efficient to operate

• Adaptations of aircraft to fit airports can be costly

• Some impact on aerodynamic performance

• Weight considerations (i.e., landing gear design)

• A balance should be achieved


VLCA Impact Framework (I)

Aircraft Design Module

Takeoff Weight Requirement

Mission Profile Definition

Aircraft Wake Vortex Model

Airport Geometric DesignRunway and Taxiway Geometric

Gate Compatibility Modeling

Airside Capacity Analysis

Capacity AnalysisRunway , Taxiway and Gate

Aircraft Separation Standards

Aircraft Separation Analysis

Airport Landside Capacity

Landside SimulationsTerminal Design Modeling

Aircraft Wingspan

Landing Gear Configuration

VLCA Physical Dimensions

Range, Speed, PayloadTakeoff Roll, Gate Comp.

Pavement Design AnalysisFlexible and Rigid PavementsStrut Configurations

Wheel Track, Wheel Length

Landing Gear Configurations

Aircraft Length

Passenger Demand Flows

New Geometric Design Criteria

Modeling

New Capacity Figures of Merit

New Terminal Design Guidelines

Identify Areas of Further Research


VLCA Impact Methodology (II)Airport Landside Capacity

Landside SimulationsTerminal Design Modeling

Landing Gear ConfigurationPavement Design AnalysisFlexible and Rigid PavementsStrut Configurations

Wheel Track, Wheel Length

Landing Gear Configurations

Passenger Demand Flows

Landing Gear ConfigurationVLCA Noise Model

Noise Modeling of VLCALanding AnalysisTakeoff Analysis

Thrust and EPNL/SEL

VLCA Economic Impact

Community ImpactsUser Cost Impacts

New Terminal Design Guidelines

Identify Areas of FurtherResearch

Operations (Ldn contours)Comparison with Current Limits

Trade-off Model


VLCA Specifications (Typical)

Parameter Boeing 747-500X VLCA (A380)

Range (km) 13,000 13,000

Runway Length (m) 3,000 3,000

Payload (kN) 800 1,200

Passengers 500 630-650

Max.TOW (kN) 4,200 5,400

Wingspan (m) 75 80-85

Length (m) 74-76 76-85


VLCA Schematic

• VLCA aircraft will have wingspans around 15-25% larger than current transports

78.57 m81.5 m.

12 o

Four 315 kN Turbofan Engines

AR = 9.5S = 700 m2

Payload = 650 passengersDesign Range = 13,000 km.MTOW = 5,400 kN

9-11o

81-87 m


VLCA Schematic (II)

• Structural weight penalties of folding wings are likely to be unacceptable to most airlines

• The empennage height could be a problem for existing hangars at some airport facilities

75.67 m

Boein g 7 47-400VLCA

24 .87 m

14 o


Airbus A380 - First in a Family of VLCA

Source: Airbus


Development of Subsonic Transport Wings

The graphic below offers some idea on the development of transport wings over three decades

6.0

7.0

8.0

9.0

10.0

11.0

Win

g A

spec

t Rat

io

1940.0 1960.0 1980.0 2000.0 2020.0

Year in Revenue Service

Long Range Aircraft Data

VLCA Aircraft

B777-A

A330/340

DC-8-50

B707-121

B707-320 L1011-200

B767-300

A310-300

B747-200

B747-400

B747-300DC-10-30

B747-100

IL-86DC-8-63

B767-200

DC-10-10

L1011-500

A300-B4


VLCA Design Trade-off Studies

Future VLCA would weight 5,400 kN for a 13,000 km design range mission

3500

4000

4500

5000

5500

6000

6500

7000A

ircr

aft M

axim

um T

akeo

ff W

eigh

t (kN

)

5000 5500 6000 6500 7000 7500 8000

Design Range (Nautical Miles and Kilometers)

AR =10.0

AR = 9.5

AR = 9.0

VLCA Wing Aspect Ratio

B747-400

MTOW

5,400 KN

(9,260) (10,186) (11,112) (12,038) (12,965) (13,890) (14,816)


VLCA Design Trade-off Studies (II)

• It is possible that aircraft designers in the near future will exceed the FAA design group VI limits

65

70

75

80

85

90

VL

CA

Air

craf

t Win

gspa

n (M

eter

s)AR =10.0

AR = 9.5

AR =9.0

VLCA Wing Aspect Ratio

81.5

Group VI Limit

FAA Design

5000 5500 6000 6500 7000 7500 8000(9,260) (10,186) (11,112) (12,038) (12,965) (13,890) (14,816)

Design Range (Nautical Miles and Kilometers)


VLCA Impacts on Airside Infrastructure

• Increase taxiway dimensional standards for design group VI to avoid possible foreign object damage to VLCA engines (increase taxiway and shoulder widths to 35 m and 15 m, respectively)

61 m 31 m

VLCA on DG VI Runway VLCA on DG VI Taxiway


Runway-Taxiway Separation Criteria

• Increase the minimum runway to taxiway separation criteria to 228 m (750 ft.). This should increase the use of high-speed exits

230 m183 m


HS Runway Exits for VLCA

• Larger transition radii (due to large aircraft yaw inertia)

• Linear taper turnoff width from 61 m to 40 m (metric stations 250 to 650)

0

25

50

75

100

0 100 200 300 400 500

VLCA Aircraft

Boeing 747-200

Boeing 727-200

Downrange Distance (m)

Lat

era

l Dis

tan

ce (

m)

HS Exit35 m/s design speed


VLCA Taxiway Fillet Radius Requirements

• The fillet radius design standards for design group VI should suffice for VLCA aircraft

25.00

26.00

27.00

28.00

29.00

30.00

31.00

27.00 28.00 29.00 30.00 31.00 32.00 33.00 34.00

Distance from Main Undercarriage to Cockpit (m.)

Uw = 16.5Uw = 15.0

Uw = 13.5

Undercarriage Width (m.)

VLCA Design Region

Min

imum

Fill

et R

adiu

s (m

)

FAA Design Group VI

Distance from Main Undercarriage to Cockpit (m)


Taxiway Length of Fillet Requirements

• VLCA length of fillet requirements will probably be satisfied using current geometric design criteria

20.00

30.00

40.00

50.00

60.00

70.00

80.00

27.00 28.00 29.00 30.00 31.00 32.00 33.00 34.00

Distance from Main Undercarriage to Cockpit (m.)

Uw = 16.5

Uw = 15.0

Uw = 13.5

Undercarriage Width (m.)

Distance from Main Undercarriage to Cockpit (m)

Fill

et L

engt

h (m

)

VLCA Design Region

FAA Design Group VI


Impacts to Aircraft Separation

• Critical to estimate safe aircraft separation criteria

• Induced rolling acceleration principle ( quotient)

• Tangential speed matching method

• Derived formulation (using quotient principle)

is the separation distance between aircraft i and j in km

, , and are regression constants found to be 6.1000, 0.00378, -0.24593 and 0.44145, respectively

and are 4.7000 and 0.00172 and have been derived using empirical roll control flight simulation data

p

p

δij Max L1 L2Wi+ K1 K+2

Wi, K3 Wj{ }K4

+

=

δij

K1 K2 K3 K4

L1 L2


Aircraft Separation Analysis

• Recommended in-trail separation criteria for approaching aircraft using the quotient criteriaP

4.0

8.0

12.0

16.0

20.0

24.0

Air

craf

t Sep

arat

ion

(km

.)

0.0 750.0 1500.0 2250.0 3000.0 3750.0 4500.0 5250.0

Leading Aircraft Weight (kN)

VLCA

Heavy (747)

Large (B757)

Medium (DC9)

Small (Learjet 23)


Wake Vortex Tangential Speed Estimation

• Predicted tangential speeds of wake vortex using Robinson and Larson semi-empirical vortex model

0

1

2

3

4

5

6

7

20 30 40 50 60 70 80 9

Lateral Distance from Center of Fuselage (m.)

Tan

gent

ial S

peed

(m/s

)

Lockheed C5A (2,060 KN)

Clean aircraftSpeed = 160 knotsSea Level ISA

VLCA (4,400 KN)

Vortex Cores

14 km behind aircraft


Aircraft Separation Analysis (cont.)

• In-trail separation criteria for approaching aircraft using the tangential speed matching method

VLCA Design Range (Nautical Miles and Kilometers)

5500 6000 6500 7000 7500 8000(10,186) (11,112) (12,038) (13,000) (13,890) (14,816)

8

10

12

14

16

Mim

inum

In-

trai

l Sep

arat

ion

(km

)

3500 4000 4500 5000 5500 6000 6500Maximum Takeoff Weight (kN)

Heavy

Medium

Small

Trailing Aircraft

MTOW < 267 kN

267 KN < MTOW < 1,336 kN

MTOW > 1,336 kN

IMC Conditions


Runway Saturation Capacity Impacts

• Small to moderate saturation capacity changes

0

10

20

30

40

50

60

0 25 50 75 100

Departure Saturation Capacity (aircraft/hr)

20%

10%

0%

Percent VLCA

(ai

rcra

ft/h

r)

Independent Parallel Approaches

IMC Weather ConditionsParallel Runway Configuration


40

Airport Terminal Impacts (Landside)

VLCA will certainly impact the way passengers are processed at the terminal in various areas:

• Gate interface (dual-level boarding gates)

• Service areas (ticket counters, security counters, immigration cheking areas, corridors, etc.)

• Apron area parking requirements


41

Airport Landside Effects

• Use of simulation models to estimate landside LOS

count

Immigration

a

Heavy Acft Gate

Heavy Acft Gate

Heavy Acft Gate

Heavy Acft Gate

Heavy Acft Gate

VLCA Deplaning Model

#Exit

33

CustomsCUSTOMSBaggage Claim

b?

a

select

cCirculation

#Exit

0

Arriving Aircraft Gates

Entrance to Landside facilities

Transfer Passengers are seperated here

Transfer Passengers Count

Passengers exiting from the Terminal

F

L W

0

ReadMe

Term inal

490 m.

5 VLCA Aircraf t (or 7 Boeing 747 -400 )


42

Sample Landside Simulation Results

• Analysis using the Airport Terminal Simulation Model

0

100

200

300

400

500

0 30 60 90 120 150

Time (minutes)

5 VLCA at 85% Load

7 Boeing 747-400 at 85% Load

Tota

l No.

Pas

seng

ers

at

Imm

igra

tion

Cou

nter

s

Normal service times (µ=1.0 and σ=0.25 minutes)30 immigration counters


43

Airport Gate Interface Challenges

•

VLCA aircraft could employ dual-level boarding gates to provide acceptable enplanement performance

75.67 m

Boeing 747 - 40 0VLCA

24.87 m

14o

TerminalDual-level Boarding Gates

75.67 m

Boeing 747 - 40 0VLCA

24.87 m

14o

TerminalDual-level Boarding Gates


Noise Impacts

• High by-pass ratio turbofan engines with maximum takeoff thrust of 315-350 kN will be necessary to power VLCA aircraft

• The engine size will probably be determined by takeoff run and engine-out climb requirements

VLCA Thrust Rating (kN)

50

75

100

125

100.00 1000.00

311.76

246.98229.31

174.35

115.43

103.20

44.55

10000.00

Slant Distance (m)

315.60

Sou

nd E

xpos

ure

Leve

l (dB

A)

Slant Range (m)


DNL Takeoff Contours

• Larger engines coupled with smaller initial climb rate capability (compared to twin and three-engine aircraft) could result in expanded noise contours at most airports

0 2000 4000 6000

Scale in meters

Ldn = 55 Prof iles

VLCA Profi le

MD-11(GE) Prof ile

8000 10000

Runway


Pavement Design Impacts

• Multiple triple-in-tandem landing gear configurations are likely to be used for VLCA applications

1 1020

40

60

80

100

120

140

160

180

B747-400

VLCA

B727-200

DC9-50

2 4 6 8 20 30 40

Subgrade Strength, CBR

Quadruple + Triple-in-Tandem

Landing Gear Configuration

Pav

emen

t Thi

ckne

ss (

cm)

CBR Value


Systems Engineering Model

Aircraft Life Cycle IOC

Annual IOC

Aircraft Life Cycle DOC

Annual DOC

Average Utilization

Fuel Oil Costs

Average Utilization

Crew Expenses

Maintenance Cost

Depreciation Cost

Insurance Cost Annual Fuel Consumption

Fuel Unit CostFlight Operations Cost

~

Fleet PurchasesFleet Size

Fleet Additions Fleet Retirement

Property and Equipment Cost

Servicing Flight OPS

Administration & Sales Cost Depreciation Ground Equipment


Sample Application of the Model

Desired Range in Km.and (n.m.)

Aspect RatioCruise Mach Number

VLCA Capacity (pass.)MTOW kN (lbs)Wingspan (m.)

10,186(5,500)

9.50.85650

3,830 (860,000)70

12,965(7,000)

9.50.85650

5,385 (1,210,000)82

13,890(7,500)

9.50.85650

6,100 (1,370,000)87

Airfield Pavement Section Improvement

0 0 0

Noise Mitigation 5,000,000 7,872,000 10,000,000

Runway Improvement 19,250,000 19,250,000 24,319,277

Taxiway Improvement 13,663,234 13,663,237 15,413,237

90 Degree Exit Improv. 276,343 384,694 386,622

Runway Blast Pad Area Improvement

1,200,000 1,200,000 1,589,673

Terminal Apron Area Improve-ment

0 77,685 113,207

Land Acquisition Cost 63,869 229,328 297,101


Airfield Geometric Infrastruc-ture Improvement Cost

39,017,641 48,299,715 59,736,701

Terminal Curb Frontage Improvement Cost

45,900 45,900 45,900

Parking Garage Improvement Cost

2,653,750 2,653,750 2,653,750

Landside Improvement Cost 2,699,650 2,699,650 2,699,650

International Terminal Infra-structure Improvement Cost

77,523,165 77,523,165 77,523,165

Total Airport Infrastructure Improvement Cost

124,240,456 136,394,530 149,959,516

Desired Range in Km.and (n.m.)

Aspect RatioCruise Mach Number

VLCA Capacity (pass.)MTOW kN (lbs)Wingspan (m.)

10,186(5,500)

9.50.85650

3,830 (860,000)70

12,965(7,000)

9.50.85650

5,385 (1,210,000)82

13,890(7,500)

9.50.85650

6,100 (1,370,000)87


Summary

• An integrated life-cycle approach is needed to estimate the impacts of VLCA aircraft

• High-capacity aircraft operating at high-capacity airports will require some changes to current design standards

• Some of the design standards for airside infrastructure should be revised to plan ahead for strategic VLCA aircraft

• The effect of reduced airside capacity will not yield reduced passenger demand flow rates at airport terminals


• High capacity airports could benefit from lower flight frequencies resulting from VLCA operations if the passenger demand flows are the same

aircraft classifications intro

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