Japan-US Aviation Environmental Workshop
Fukutake Hall, University of Tokyo, 29 November 2017

A Flight Procedure Design Method for
RNP to xLS with Shallow Segment

Sonosuke Fukushima, Ryota Mori, Shinji Saitoh
Electronic Navigation Research Institute,
National Institute of Maritime, Port and Aviation Technology

Outline
1. Background
2. “RNP to xLS” Procedure DesignAssumption & Method
3. Full-Flight Simulator Trials
4. Summary

US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 2017

1. Advantage of RNP to xLS
FAF

FAF

FACF

IAF

IntermediateSegment

FAF

RNP ARNo PA

RNP to xLSxLS

PAPAFAF

FACF

IAF

Intermediate
Segment
US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 20173

1. Glideslope Intercept Altitude Intermediate Segment used barometric altitude while
final approach segment depends on geometric altitude.
Hot Day
Normal Day
Cold Day
Intermediate
Segment
Zfap
Zdcp

θDfap
US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 20174

1. Temperature Correction
International Standard Atmosphere (ISA)

Correction (FT)
AltitudeCorrection (FT)

Temp 15°C at Mean Sea Level, Lapse rate ~ –2°C per 1,000 ft600∆ISA = 30°C 10.2 %40020001000

2000

30004000∆ISA = 20°C

6.8 %∆ISA = 10°C

3.4 %

5000

Altitude on MLS (FT)

Altitude on MLS (FT)US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 20175

1. Difficulty of Procedure Design
 GS should be captured after capturing LOC.
 For short intermediate design, GS capture may
happen before LOC capture.

GS Capture Point
LOC Capture PointHot Day
Normal Day
Cold Day

US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 20176

1. Shallow segment
 FAA PARC reported RNP to xLS procedure
design using Shallow Intermediate Segments
 Improving flight efficiency: Long level segment decrease it.
 Considering capture condition and guideline.
Hot Day∆ISA > 0°C

Normal Day
Intercept Point∆ISA = 0°C∆ISA < 0°C

Cold Day

LengthAngle

Discussing more detail, and optimum design method
US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 20177

2. Assumption of procedure design
1. ARINC 424 compliance424-19 (2008)424-20 (2011)

 “All such approach proceduresmust begin at the FACF”
 “The rules of coding GLS
approach procedure areunderstood to be identical tothose of LOC coding”

 “The final approach codingof GLS instrument
approach procedures does
not require the coding ofa FACF waypoint”

ARINC 424-19 specification are supposed
All type of aircraft does not support 424-20

2. Hottest day temperature∆ISA = 30°C 113°F

US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 2017

MSL8

2. Assumption of procedure design
3. Glideslope & Localizer capture timing
Type A aircraft
allows Glideslope
capture before
Localizer capture

Type B aircraft
inhibits Glideslope
capture beforeLocalizer capture

Type A aircraft are supposed

Critical

4. Glideslope pointer exceed one dot
Pilots need a buffer for pushing APP switch

5. Glideslope capture boundary
US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 2017a half dot
92. Procedure design
MAX 180KIAS

WP 4

WP 3

At 3189FTAt 3189FTWP
1WP
4WP
3WP
2

TF LEG
X.X NM

5.0
2.5NM

7.85

X.X

TOTAL 17.85
RF LEG

GLS: GKW(FREQ: 21475)

LEN

ANG

TF LEG

CF LEG
3.0 NM

2.0 NMLEN

RW24R V/A 3.0

V/A 3.0

ANG（90FT）

GS intercept alt: 1700FT
GS crossing alt: 1053FTWP 0WP 1FAF

FACF

WP 2ABCLEN(NM)
1.0
1.5
2.0

US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 2017

ANG(deg)
1.4
1.5
1.6
10

2. Deviation & Capture points
CaptureCase-B

Deviation (dot)2∆ISA = 0°C

GS Capture

1∆ISA = 30°C0FAF
LOC Capture-1

FACF
GS Dev∆ISA30°C

-2012

3

4

5

Distance to FAF (NM)US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 2017

VNAV∆ISA0°C
112. Calculation of ANGmax
Iteration Algorithm

get close toCapture

Given LEN, others
ANG = ANG + ∆FAFCalc
FAA ORDER 8260.58A, PANS-OPSFACFGS Dev

IF dist( ) < dist( )& Max GS > 1.0 dot0°C

Output ANGmax
dist () : distance along RF to∆ISA30°C

VNAV
from FAF

US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 201712

3. Simulator Trials
 Standard procedures based on ARINC 424 specification
were coded by NAV database provider
 FMS vender checked the database quality, andconverted to FMS loadable database Flight simulations with variable temp were conducted in
ANA flight training center

US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 201713

3. Comparison with FFSIMFFSIM

CACLULATED

Deviation (DOT)

230°C∆ISA=0°C(NO WIND CASE)
2GS

110015°C

-1LOC

-201

34LOC

-25GS

15°C

-1A
230°C

∆ISA=0°C

01A
2345Horizontal distance to FAF along RF course (NM)US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 201714

3. Comparison with FFSIM
FFSIM

Deviation (DOT)CACLULATED∆ISA=0°C2100-115°C 45°C

-1B

-2LOC

-212

∆ISA=0°C

2345

10015°C-1LOC-201241B

2∆ISA=0°C

35GS15°C

LOC-2
5430°C-1C
3LOC
01GS30°C

15°C 45°C

2GS30°C∆ISA=0°C

2

GS30°C

10

Deviation (DOT)(NO WIND CASE)

012C
34

Horizontal distance to FAF along RF course (NM)US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 2017

515Altitude Variation (FT)

3. Altitude Variation before FAF
Severe Turbulence

4040200None Wind202000-20

Altitude Variation

160IAS(KT)

FLAP 25-20

FLAP 20FLAP 5-40-4001234

Distance to FAF (NM)5012345

Distance to FAF (NM)

 Altitude Variation is affected by the Flap Extension,and not exceed +20 FT even severe turbulence condition
US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 201716

Maximum intermidiate segment angle (deg)Max intermediate segment angle (deg)

4. Intermediate LEN .vs. ANG
LTP 36 ft, TCH 54ft, Length of LOC to THD 4320 m, Course width 210 m2∆ISA = 30°C

1.8

1.6

1.4

1.2

10.8

Length of intermediate segment (NM)
2.0
1.9
1.8
1.7
1.4
1.6
1.3
1.5
1.2

0.6

1.1
0.4

Additional assumption
By FFSIM experiments+50FT (20FT + Margin)

Direct Proportion
LEN .vs. ANG
Inverse Proportion
FAF ALT. vs. ANG

1.0

0.2
1500

2000

2500

3000

3500

40004500

FAF altitude (FT)FAF altitude (FT)US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 201717

5. Summary
 Development of RNP to xLS procedures withshallow intermediate segment were discussed
 The design method of shallow intermediatesegments were proposed based on theassumptions
 Full flight simulator trials confirmed that themethod enables to design procedure even in thehigh temperature condition
 Findings also revealed altitude variations
required a buffer The revised algorithm will enable thedevelopment of the procedures design criteria
US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 201718

Thank you for your attention !

Quoted from :Sonosuke Fukushima, Ryota Mori, Shinji Saitoh,“Geometric Approach for RNP Transition to xLS Procedure Design,”
36th Digital Avionics Systems Conference, Sept. 2017.
US-Japan Aviation Environmental Workshop, University of Tokyo, 29 Nov. 2017