Title: CPDLC - Change of Variable Name "DistanceOffset" to "DistanceSpecified"

PDR Reference:				97100036
Originator Reference:			disoff
SARPs Document Reference:		CPDLC SARPs, Sections 2.3.4.2.1, 2.3.7
Status:					ADOPTED
PDR Revision date:			29/10/97 (SUBMITTED -> RESOLVED
PDR Submission Date:			24/10/97
Submitting State/Organization:	FAA
Submitting Author Name:			Hamelink, J
Submitting Author E-mail Address:	jhamelin@adsystech.com
Submitting Author Supplemental
Contact Information:	
						Tel: 1 301 589 3434 x114
						Fax: 1 301 589 9254
SARPs Date:					IV1.1, March 97 
SARPs Language:				English

Summary of Defect:

The ADSP Manual is being aligned to existing ICAO annexes.  In this process is was found that the term "distance offset" has a particular meaning of "parallel to existing track".  Thus operationally a variable name "DistanceOffset" is considered operationally unacceptable in a DEVIATING message element.  

Rather than change the variable DistanceOffset to Distance as proposed by the ADSP secretariat, which would affect "bits on the wire", it was agreed that the ADSP Manual would change the variable name DistanceOffset to DistanceSpecified for every occurrence.  This becomes a variable name change only and preserves "bits on the wire".  Technically the DistanceOffset variable is a limited range of the Distance variable. 

Assigned SME:				Sub-Volume II SME

Proposed SARPs amendment:

1. Change the DistanceOffset variable to SpecifiedDistance in section 2.3.4.2.1 from: 

--	OFFSET [distanceOffset][direction] OF ROUTE	
--			Urg(N)/Alr(M)/Resp(W/U) 
	uM64DistanceOffsetDirection  [64] DistanceOffsetDirection,

--	AT [position] OFFSET [distanceOffset] [direction]
--	OF ROUTE	 Urg(N)/Alr(M)/Resp(W/U)
	uM65PositionDistanceOffsetDirection
			[65] PositionDistanceOffsetDirection,

--	AT [time] OFFSET [distanceOffset][direction] OF ROUTE
--			Urg(N)/Alr(M)/Resp(W/U)
	uM66TimeDistanceOffsetDirection	
			[66] TimeDistanceOffsetDirection,

--	CLEARED TO DEVIATE UP TO [distanceOffset]
--	 [direction] OF ROUTE
--			Urg(N)/Alr(M)/Resp(W/U)
	uM82DistanceOffsetDirection	
			[82] DistanceOffsetDirection,

--	WHEN CAN YOU ACCEPT [distanceOffset] 
	[direction] OFFSET	Urg(N)/Alr(M)/Resp(Y)
	uM152DistanceOffsetDirection	
			[152] DistanceOffsetDirection,

--	REQUEST OFFSET [distanceOffset] [direction] OF ROUTE
--			Urg(N)/Alr(L)/Resp(Y)
	dM15DistanceOffsetDirection	
			[15] DistanceOffsetDirection,

--	AT [position] REQUEST OFFSET [distanceOffset] [direction] OF ROUTE
--			Urg(N)/Alr(L)/Resp(Y)
	dM16PositionDistanceOffsetDirection
			[16] PositionDistanceOffsetDirection,

--	AT [time] REQUEST OFFSET [distanceOffset] [direction] 
--	OF ROUTE	Urg(N)/Alr(L)/Resp(Y)
	dM17TimeDistanceOffsetDirection			
			[17] TimeDistanceOffsetDirection,

--	REQUEST WEATHER DEVIATION UP TO 
--	[distanceOffset] [direction] OF ROUTE 
--			Urg(N)/Alr(L)/Resp(Y)
	dM27DistanceOffsetDirection		
			[27] DistanceOffsetDirection,

--	OFFSETTING [distanceOffset] [direction] OF ROUTE
--			Urg(U)/Alr(H)/Resp(N)
	dM60DistanceOffsetDirection 	
			[60] DistanceOffsetDirection,

--	DEVIATING [distanceOffset] [direction] OF ROUTE
--			Urg(N)/Alr(M)/Resp(N)
	dM80DistanceOffsetDirection				
			[80] DistanceOffsetDirection,

--	WE CAN ACCEPT [distanceOffset] [direction] AT [time]
--			Urg(N)/Alr(L)/Resp(N)
	dM85DistanceOffsetDirectionTime			
			[85] DistanceOffsetDirectionTime,

--	WE CANNNOT ACCEPT [distanceOffset] [direction]
--			Urg(N)/Alr(L)/Resp(N)
	dM86DistanceOffsetDirection				
			[86] DistanceOffsetDirection,

DistanceOffset ::= CHOICE
	{
	distanceOffsetNm	[0]	DistanceOffsetNm,
	distanceOffsetKm 	[1]	DistanceOffsetKm
	}

DistanceOffsetDirection ::=  SEQUENCE
	{
	distanceOffset		DistanceOffset,
	direction		Direction
	}

DistanceOffsetDirectionTime ::=  SEQUENCE
	{
	distanceOffsetDirection		DistanceOffsetDirection,
	time				Time
	}

DistanceOffsetKm ::= INTEGER (1..500) 
--	unit = Kilometer, Range (1..500), resolution = 1

DistanceOffsetNm ::= INTEGER (1..250) 
--	unit = Nautical Mile, Range (1..250), resolution = 1




To:

--	OFFSET [distanceSpecified][direction] OF ROUTE	
--			Urg(N)/Alr(M)/Resp(W/U) 
	uM64DistanceSpecifiedDirection  [64] DistanceSpecifiedDirection,

--	AT [position] OFFSET [distanceSpecified] [direction]
--	OF ROUTE	 Urg(N)/Alr(M)/Resp(W/U)
	uM65PositionDistanceSpecifiedDirection
			[65] PositionDistanceSpecifiedDirection,

--	AT [time] OFFSET [distanceSpecified][direction] OF ROUTE
--			Urg(N)/Alr(M)/Resp(W/U)
	uM66TimeDistanceSpecifiedDirection	
			[66] TimeDistanceSpecifiedDirection,

--	CLEARED TO DEVIATE UP TO [distanceSpecified]
--	 [direction] OF ROUTE
--			Urg(N)/Alr(M)/Resp(W/U)
	uM82DistanceSpecifiedDirection	
			[82] DistanceSpecifiedDirection,

--	WHEN CAN YOU ACCEPT [distanceSpecified] 
	[direction] OFFSET	Urg(N)/Alr(M)/Resp(Y)
	uM152DistanceSpecifiedDirection	
			[152] DistanceSpecifiedDirection,

--	REQUEST OFFSET [distanceSpecified] [direction] OF ROUTE
--			Urg(N)/Alr(L)/Resp(Y)
	dM15DistanceSpecifiedDirection	
			[15] DistanceSpecifiedDirection,

--	AT [position] REQUEST OFFSET [distanceSpecified] [direction] OF ROUTE
--			Urg(N)/Alr(L)/Resp(Y)
	dM16PositionDistanceSpecifiedDirection
			[16] PositionDistanceSpecifiedDirection,

--	AT [time] REQUEST OFFSET [distanceSpecified] [direction] 
--	OF ROUTE	Urg(N)/Alr(L)/Resp(Y)
	dM17TimeDistanceSpecifiedDirection			
			[17] TimeDistanceSpecifiedDirection,

--	REQUEST WEATHER DEVIATION UP TO 
--	[distanceSpecified] [direction] OF ROUTE 
--			Urg(N)/Alr(L)/Resp(Y)
	dM27DistanceSpecifiedDirection		
			[27] DistanceSpecifiedDirection,

--	OFFSETTING [distanceSpecified] [direction] OF ROUTE
--			Urg(U)/Alr(H)/Resp(N)
	dM60DistanceSpecifiedDirection 	
			[60] DistanceSpecifiedDirection,

--	DEVIATING [distanceSpecified] [direction] OF ROUTE
--			Urg(N)/Alr(M)/Resp(N)
	dM80DistanceSpecifiedDirection				
			[80] DistanceSpecifiedDirection,

--	WE CAN ACCEPT [distanceSpecified] [direction] AT [time]
--			Urg(N)/Alr(L)/Resp(N)
	dM85DistanceSpecifiedDirectionTime			
			[85] DistanceSpecifiedDirectionTime,

--	WE CANNNOT ACCEPT [distanceSpecified] [direction]
--			Urg(N)/Alr(L)/Resp(N)
	dM86DistanceSpecifiedDirection				
			[86] DistanceSpecifiedDirection,

DistanceSpecified ::= CHOICE
	{
	distanceSpecifiedNm	[0]	DistanceSpecifiedNm,
	distanceSpecifiedKm 	[1]	DistanceSpecifiedKm
	}

DistanceSpecifiedDirection ::=  SEQUENCE
	{
	distanceSpecified	DistanceSpecified,
	direction		Direction
	}

DistanceSpecifiedDirectionTime ::=  SEQUENCE
	{
	distanceSpecifiedDirection	DistanceSpecifiedDirection,
	time				Time
	}

DistanceSpecifiedKm ::= INTEGER (1..500) 
--	unit = Kilometer, Range (1..500), resolution = 1

DistanceSpecifiedNm ::= INTEGER (1..250) 
--	unit = Nautical Mile, Range (1..250), resolution = 1

2. Change table 2.3.7-8 in section 2.3.7 from:

Table 2.3.7-8.  Lateral Offsets (uplink)

	Message Intent/Use	Message Element		URG	ALRT	RESP
64	Instruction to fly a	OFFSET [distance offset] N	M	W/U
	parallel track to the	[direction] OF ROUTE
	cleared route at a 
	displacement of the 
	specified distance in 
	the specified direction.	

65	Instruction to fly a	AT [position] OFFSET 	N	M	W/U
	parallel track to the	[distance offset] 
	cleared route at a	[direction] OF ROUTE  
	displacement of the 
	specified distance in 
	the specified direction
	and commencing at the 
	specified position.	

66	Instruction to fly a	AT [time] OFFSET 	N	M	W/U 
	parallel track to the	[distance offset] 
	cleared route at a	[direction] OF ROUTE  
	displacement of the 
	specified distance in 
	the specified direction 
	and commencing at the 
	specified time.	
to:
Table 2.3.7-8.  Lateral Offsets (uplink)

	Message Intent/Use	Message Element		URG	ALRT	RESP
64	Instruction to fly a	OFFSET [distance  	N 	M	W/U
	parallel track to the	specified][direction]
	cleared route at a	OF ROUTE 
	displacement of the 
	specified distance in 
	the specified direction.	

65	Instruction to fly a	AT [position] OFFSET 	N	M	W/U
	parallel track to the	[distance specified] 
	cleared route at a	[direction] OF ROUTE  
	displacement of the 
	specified distance in 
	the specified direction
	and commencing at the 
	specified position.	

66	Instruction to fly a	AT [time] OFFSET 	N	M	W/U 
	parallel track to the	[distance specified] 
	cleared route at a	[direction] OF ROUTE  
	displacement of the 
	specified distance in 
	the specified direction 
	and commencing at the 
	specified time.	

3. Change table 2.3.7-9 in section 2.3.7 from:

82	Approval to deviate	CLEARED TO DEVIATE 	N	M	W/U 
	up to the specified	UP TO [distance offset] 
	distance from the 	 [direction] OF ROUTE 
	cleared route in the 
	specified direction.	
To:

82	Approval to deviate	CLEARED TO DEVIATE 	N	M	W/U 
	up to the specified	UP TO [distance specified] 
	distance from the 	 [direction] OF ROUTE 
	cleared route in the 
	specified direction.

														
4. Change table 2.3.7-9 in section 2.3.7 from:

152 	Instruction to report	WHEN CAN YOU ACCEPT	N	L	Y
	the earliest time when	[distance offset] 
	the specified offset	[direction] OFFSET	 
	track can be accepted.	

To:

152 	Instruction to report	WHEN CAN YOU ACCEPT	N	L	Y
	the earliest time when	[distance specified] 
	the specified offset	[direction] OFFSET	 
	track can be accepted.

4. Change table 2.3.7-19 in section 2.3.7 from:

15	Request that a parallel	REQUEST OFFSET 		N	L	Y
	track, offset from the	[distance offset]  
	cleared track by the	[direction] OF ROUTE	 
	specified distance in 
	the specified direction, 
	be approved.	

16	Request that a parallel	AT [position] REQUEST 	N	L	Y 
	track, offset from the	OFFSET [distance offset] 
	cleared track by the	[direction] OF ROUTE	 
	specified distance in 
	the specified direction, 
	be approved from the 
	specified position.	

17	Request that a parallel	AT [time] REQUEST OFFSET N	L	Y 
	track, offset from the 	[distance offset] 
	cleared track by the	[direction] OF ROUTE	 
	specified distance in the 
	specified direction, be 
	approved from the 
	specified time.

To:

15	Request that a parallel	REQUEST OFFSET 		N	L	Y
	track, offset from the	[distance specified]  
	cleared track by the	[direction] OF ROUTE	 
	specified distance in 
	the specified direction, 
	be approved.	

16	Request that a parallel	AT [position] REQUEST 	N	L	Y 
	track, offset from the	OFFSET [distance specified] 
	cleared track by the	[direction] OF ROUTE	 
	specified distance in 
	the specified direction, 
	be approved from the 
	specified position.	

17	Request that a parallel	AT [time] REQUEST OFFSET N	L	Y 
	track, offset from the 	[distance specified] 
	cleared track by the	[direction] OF ROUTE	 
	specified distance in the 
	specified direction, be 
	approved from the 
	specified time.

5. Change table 2.3.7-22 in section 2.3.7 from:

27	Request for a weather	REQUEST WEATHER 	N	M	Y 
	deviation up to the	DEVIATION UP TO  
	specified distance off	[distance offset] 
	track in the specified	[direction] OF ROUTE	  
	direction.

To:

27	Request for a weather	REQUEST WEATHER 	N	M	Y 
	deviation up to the	DEVIATION UP TO  
	specified distance off	[distance specified] 
	track in the specified	[direction] OF ROUTE	  
	direction.	

6. Change table 2.3.7-25 in section 2.3.7 from:

60	Notification that the	OFFSETTING [distance 	U	H	N 
	aircraft is deviating	offset] [direction] 
	the specified distance	OF ROUTE  
	in the specified direction 
	off the cleared route and 
	maintaining a parallel 
	track due to an emergency.	

80	Notification that the	DEVIATING [distance 	U	H	N 
	aircraft is deviating	offset] [direction]  
	from the cleared route	OFF ROUTE	 
	by the specified distance 
	in the specified direction 
	due to an emergency.

To:

60	Notification that the	OFFSETTING [distance 	U	H	N 
	aircraft is deviating	specified] [direction] 
	the specified distance	OF ROUTE  
	in the specified direction 
	off the cleared route and 
	maintaining a parallel 
	track due to an emergency.	

80	Notification that the	DEVIATING [distance 	U	H	N 
	aircraft is deviating	specified] [direction]  
	from the cleared route	OFF ROUTE	 
	by the specified distance 
	in the specified direction 
	due to an emergency.

7. Change table 2.3.7-28 in section 2.3.7 from:

85	We can accept a		WE CAN ACCEPT [distance L	L	N 
	parallel track offset	offset] [direction] at 
	the specified distance	[time]	  
	in the specified direction 
	at the specified time.	

86	We cannot accept a	WE CANNOT ACCEPT 	L	L	N 
	parallel track offset	[distance offset] 
	the specified distance	[direction]	  
	in the specified 
	direction.	

To:

85	We can accept a		WE CAN ACCEPT [distance L	L	N 
	parallel track offset	specified] [direction] at 
	the specified distance	[time]	  
	in the specified direction 
	at the specified time.	

86	We cannot accept a	WE CANNOT ACCEPT 	L	L	N 
	parallel track offset	[distance specified] 
	the specified distance	[direction]	  
	in the specified 
	direction.	

SME Recommendation to CCB:			-

CCB Decision:					CCB-3: RESOLVED