Search Patterns BMCS WOLFSON HEH! I’M OVER HERE !!!

Search PatternsBMCS WOLFSON

Search PatternsBMCS WOLFSON

HEH!I’M OVER HERE !!!

NomenclatureNomenclature

Maj

or

Axi

s

TWC

LW

Datum

SP


MinorAxis

Maj

or

Axi

s

TWC

LW

Datum

SP


MinorAxis

Maj

or

Axi

s

CommenceSearchPoint(CSP)

CommenceSearchPoint(CSP)

TWC

LW

Datum

SP


MinorAxis

Maj

or

Axi

s(CSP)Plotted 1/2 Track spacefrom corner!

(CSP)Plotted 1/2 Track spacefrom corner!

TWC

LW

Datum

SP


MinorAxis

Maj

or

Axi

sA

xis

CSP

Sea

rch

Leg


Maj

or

Axi

s

CSP

Crossleg

Cross legwill be equalto 1 wholetrack space!

Cross legwill be equalto 1 wholetrack space!

MinorAxis


CSPCSP

Tra

ck s

pac

e


CSP

Direction of Creep

NN

SS

EEWW

Search Pattern Designations


First letter: Pattern TypeFirst letter: Pattern Type

P Parallel track V SectorC Creeping line B BarrierS Square T Trackline

P Parallel track V SectorC Creeping line B BarrierS Square T Trackline



Second letter: Number of Search UnitsSecond letter: Number of Search Units

S Single unit

M Multi-unit

S Single unit

M Multi-unit



Third Letter: Supplementary InformationThird Letter: Supplementary Information

N Non return L LORANR Return or C Coordinated Radar or circleS Spiral d DriftA Aural compensated

N Non return L LORANR Return or C Coordinated Radar or circleS Spiral d DriftA Aural compensated

Which Search Patterndo I use?

Which Search Patterndo I use?

TracklineParallelTracklineParallel

CreepinglineSector

CreepinglineSector

Ask yourself what is....Ask yourself what is....

datum search object search area search units on scene weather probability of detection

datum search object search area search units on scene weather probability of detection

Trackline Search:Trackline Search:

Criteria:Criteria: Search object’s intended track is the only information available.

Rapid coverage of the search object’s proposed track is obtainable.

Usually the first physical search for a missing or overdue craft.

Criteria:Criteria: Search object’s intended track is the only information available.

Rapid coverage of the search object’s proposed track is obtainable.

Usually the first physical search for a missing or overdue craft.


Execution:Execution: For patterns with an odd number of legs, CSP is at one end of the trackline.

For patterns with an even number of legs CSP is offset 1/2 track space to either side.

Execution:Execution: For patterns with an odd number of legs, CSP is at one end of the trackline.

For patterns with an even number of legs CSP is offset 1/2 track space to either side.


AA BB

TSNTSN

Single Unit Non-ReturnSingle Unit Non-Return

AA BB

TSRTSR

Single Unit ReturnSingle Unit Return

CSP


Destination

Drifted TracklineDrifted Trackline

Origin


Single Unit ReturnSingle Unit Return

CSP

TSRTSR

1/2 S

1/2 S1/2 S


Parallel SearchParallel Search

Criteria:Criteria: Used to cover large search areas. Provides uniform coverage. Usually the best pattern when using more

than one search unit.

Execution:Execution: Search legs are parallel to the major axis.

Criteria:Criteria: Used to cover large search areas. Provides uniform coverage. Usually the best pattern when using more

than one search unit.

Execution:Execution: Search legs are parallel to the major axis.

Parallel Search Single Unit (PS)


CSP

CSP CSP

Parallel Search Multi-Unit(PM)

Parallel Search Multi-Unit(PM)

CSP CSP

A-1 A-2



Creeping Line SearchCreeping Line Search

Criteria:Criteria:Provides uniform coverage

of the search area.

Higher probability that the search object is

at one end of the area than the other.

Criteria:Criteria:Provides uniform coverage

of the search area.

Higher probability that the search object is

at one end of the area than the other.

Creeping Line Search Single Unit (CS)Creeping Line Search Single Unit (CS)

CSP

Creeping Line Search Multi-Unit (CM)Creeping Line Search Multi-Unit (CM)

CSP

CSP

Creeping Line Search Single Unit (CSC)

Creeping Line Search Single Unit (CSC)

CSP

CSP

Expanding Square Search (SS)Expanding Square Search (SS)

Criteria:Criteria:Must have a good datum.

Used in small search areas.

Provides uniform coverage.

Criteria:Must have a good datum.


Provides uniform coverage.

Expanding Square SearchExpanding Square Search

Execution:CSP is at datum

First leg is down drift

All turns are 90 degrees to the right

Search leg length is increased by one track space on every other leg.

Execution:CSP is at datum


All turns are 90 degrees to the right

Search leg length is increased by one track space on every other leg.

Expanding SquarePattern (SS)Expanding SquarePattern (SS)

1 S

1

2

2

3

3

4

4

5 5

1 S1 S

1 1

22

22

33

33

6 NM Search Radius / 144 SQ. NM6 NM Search Radius / 144 SQ. NM

SS, 1 NM, 12KTSSS, 1 NM, 12KTS

Expanding SquarePattern (SS)Expanding SquarePattern (SS)

Criteria:Must have good a datum.


Small search objects

Criteria:Must have good a datum.


Small search objects

Sector SearchSector Search

Sector SearchSector Search

Execution:CSP is at datum.


All turns are 120 degreesto the right.

Execution:CSP is at datum.


All turns are 120 degreesto the right.

Sector Search Single Unit (VS)Sector Search Single Unit (VS)

Sector SearchInitial search track spacing:

see page 2-F-3, Table 2-3 CG ADDENDUM

Sector SearchInitial search track spacing:

see page 2-F-3, Table 2-3 CG ADDENDUM

Track spacing(S) is equal to the radius.

Track spacing(S) is equal to the radius.

Second Search:Off set 30 degrees to the right

Second Search:Off set 30 degrees to the right

First search

CSP

CSP

Sector Search Single Unit (VS)Sector Search Single Unit (VS)

Barrier SearchBarrier Search

Criteria:Criteria:

Used where strong currents

exist.

Criteria:Criteria:

Used where strong currents

exist.


Execution:Execution:Major axis is perpendicular

to the direction of drift.

The SRU runs back and forthalong the “down current “ end

of the search area.

Execution:Execution:Major axis is perpendicular

to the direction of drift.

The SRU runs back and forthalong the “down current “ end

of the search area.

Distress PositionDistress Position

CurrentCurrent

Barrier SearchBarrier SearchX


Distress PositionDistress Position

CurrentCurrent

X

SRUSRU

ANY QUESTIONS?ANY QUESTIONS?

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Search Patterns BMCS WOLFSON HEH! I’M OVER HERE !!!