randesvous positions as per iamsar

8/4/2019 Randesvous Positions as Per IAMSAR

1/7

Section 2. A distressed aircraft should not be asked to change its heading for adirect intercept unless the aircraft:

D is l


2/7

Section 2 - RenderingAssis{anceSpeed 12 knotsTrack 260"

B 0900

10150900

\r\r^.r\i^r\r\ \

'\\,\.\\i_r..ASpeed 8 knotsTrack 080' A and B 25 NM apart at 0900

Head-on methodThe overtaking direct interept solution:a plot the simultaneous position of SAR facility and distressed crafttr the SAR facility moves along the same track to that of thedistressed crafto compute the distance between the simultaneous position plotsand the rate of closuren divide the distance separating the two craft by rate of closure todetermine the time of interceptionOr (graphical solution):a plot the relative positions of both the distressed craft (A) and tre

intercepting craft (B) for that time at which the intercepting SAR 'facility is ready to prOceedjoin the two positions with a,line and,project it a reasonabledistance (BCi. This line is the course made good of both craftlay off a line at 90o to the intercepting SAR facility's course andproject it a reasonable distance (BD)along this line, measure off the distance the intercepting SARfacility will cover in one hour, based on the speed it can make igood along its intended course, and mark the position with an Xlay off a line at 90' to the distressed craft's course and project it areasonable distance {AE)on the same side as BD

t.5I'1

243


3/7

Section 2 - Rendering Assistancen along this line, measure off the distance the distressed craft willcover in one hour, based on the speed it is making good, andmark the position with a Ytr join the positions X and Y with a line and project it until it cuts thecourse line at F. This is the intercept positionu to find the time for the intercept, measure the distance from theinitial position of either craft to the position of the intercept, and

.divide this disiarrce by the speeci of the chosen craft.rooo 1

Overtaking method

The offset or beamon intercept:. The offset or beamon intercept is used when the SAR facitity is toone side of the track being made good by the distressed craft.o The SAR facility intercepts the track of the distressed aircraft.o When the distressed craft has the greater ground speed, the SAR {facility will have to be closest to the point of intended landing to . \.make the offset interception possible. There are three methods forperforming offset or beamon intercepts.Method t:n plot the relative positions of both the distressed craft (A) and theintercepting SAR facility (B) for that time at which the interceptingSAR facility is ready to proceedn join these two positions with a line (AB)n lay off the distressed craft's track in the direction of its heading and' . {project it a reasonable distance on the chart'(AC)2-44 :

/t(

II

,{I(({tt(a

Ir{ I:("ta

..,aCC,t6


4/7

Sectron 2 - RendeirngAssrstance

Offset or bearnon intercept rnthod 1o along this projected track or course line of the distressed craft,measure off the distance it will cover in one hour, based on itsspced through the air (TAl,for aircr.n) o'' *ater (vessers), andmark the position with an XD transfer the line joining the two craft through the protted position,x (xY)o with the centre of dre cinde being tfie point of departure of rheintercepting sAR facility, and usinf" ;fi;'"qual ro rhe distance irwill cover in the rime intervarur"o"r* n" Jrr,l.*J;dlscribpan arc and mark the spot (w) udwe ttre arc cuts the transferredlineNote: tf.the speed of theintercqpted u interceptingyesse/ rs suchthat the sca/e af the chart -* ;t unreas onabre to use a furthonr, then it wiil be necessa ,y ti uru " )roportionar interuar oftime to .ensure that the radius of the [rc cuts the transferredline. :c draw a line from rhe ;rositiqn of the intercepting sAR facility' through the spot where the arc cuts the transferred rine - this is' the intercept h.eading/course for the i","*"p,ing sAR facility. gyprojecting this line until it.cuts the proje.i*a ,ro.k or course line of

:+:.tzi'.ftiq 'iiij .::,i:l rlrii

, ):.;l:., ,jj;i.:iii,if}i':!r it'iif; *; ,ii: ?liiiiifl*iF &-',1:

ii &*il: FJ;i: "g: lr,r &J;il * I': r.-l,., e.i::. f ii qii:; i.:i :: :I irl,: J:i, i l!. -' liJir'- I1 jj: llr.iiilif - i1- lit!l,li

j 'ff-4lt


5/7

Seclion 2 - Rendering Assisfancethe distressed craft, one finds the position where the intercept willtake place (D)

f-l to find the time it witl take for the intercept, measure the disranr_efronl the initial position of the intercepting vessel rrr the Jroipt ofintercept and divide this distance (BD) by the speed of rh,intercepting vcsset.Meti:tod 2 (with wind/current effects):t-l piot the simultaneous positions of the distressed aircraft (A) andthe SAR aircrafr (B)tl a ten-minute leacl to the position of the Cistressed aircrafi isallowed fo:" na..,igationa! ei-i,ors iC) arrtl the pnsition of the

distressc'd aircraft one rrour later (o1 r, plottedn plot these dead-reckoning (DR) p'sitions based on speed in knotsand course rnade gooci over the groundn a line of constant rrearins (LCB) is drawn lretween positions Band Ct-' a second LCB, parallel to BC, is drarvn through point Dr a wind vector (BF), drawn downwind frorn the original position ofthe SAR aircraft, is drar,vrrii an arc equal to the sAR aircraft TAS is swung through the secondLCB, using the end of the wind vector (F) ai the ce-ntre of originI the liearing and distance of the line drawn from the originalposition of the sAR aircraft (B) to point (c) represent interceptiontrue course and ground speed. rf necessary, this line is exterdeduntil it crosses the projected true courru oi the distressed aircraft" lil distance to intercept the inrended track "a,r" r-;";"-,"aircraft is measured between the original position of the sARaircraft (B) and the point at which th-e interception true coursecrosses the projected true course of the distressed aircraft (Hia the en-route time for this distance and closure time for the leaddistance are computed and added to determine tcltal timerequired for collision point intercept with the distressed aircraftr: depencling on the speed differential, the SAR aircraft miry execute "a turn to the reciprocal of the track of the distressed aircraft whenthe c'urse of the distressc,cl aircraft rr., rr**n ',il;.,r,;;"

{

tii!{

:{

,1

{


6/7

Sectrbn 2 - Rende ring , ssisiance0+ 10 DR

@,()Joig,(\,I

Ei

Offset or boam-on intercept method 2o interception of the course of the distressed aircraft can beconfirmed by DF from the distressed aircraft.M ethod 3 ( u si n g d i rectio n-fi n d ing equp me n t) :o This procedure requires that the SAR aircraft have DF equiprnentthat can receive transmission from the distressed aircraft and isexecuted as shown in the following figure, using magnetkbearings.

-----sgFffis-EffrfrG TNACK OFDISTRESSEDAIRCRAFT,

aircraft

-I r--\ 93?MAG BEARtf-tCl

POINTOFINTERCEPITON

Offset orbepmon intercept method 3247


7/7

Section 2 - Rendering Assrstahie" ff:::f,lj1"-?:i:g.,:.*h" d,:I,":sed aircraft, turn tr,u sanlircrafr ro a heagins is" r,o* il;;;;#;"";;"'t;.i:"ffiifr.distressed aircraft is-flying -"' rl maintain a rerative bearing of 45" by checking Df, bearingsn if the DF check revears thlt the n"rrinf ;;, rhe sAR aircraft hasncreascd, the interception course shoJrd be increasecJ twice then"cunt of the change between the rast -r*o beuringsI if the check reveats that the bearing from the sAR aircraft hasecreased, the interception .or^e shourd be decreased twice themount of change between the frrt t*o Ul.ringsr by bracketing thg bearings ,, a"roi;", ;"e, an inrerceprionourse is determineci, maintaining a rine oilonr,unt bearing.vLrL'.'!'rrc(J' rrarntarnrng a rine of constant bearing. (t h,linimum Time to Scene Intercept (h4ffsl)ol*I,iT;fl i:"#;#:f ,;:.:iliil:"J'"0,',"oescorrhigher-speedc because of speed differentiar, it r* o" necessar y forthe sRUircraft to tuin short of the intercefiio,i point on rhe distressedircraft track to minimize the timetoicele (provide maximumescue avairabirity) over the remaining distanct. to be frownD compute the SRU,s maxinD compute rhe rime ro rrunJlT",:iiliting distanceD compute the time at which.the sRU shourd turn around (timeteum or TTT ) and atow the distreir"a "ir.rr, to begin ouertating itwhen the sRU reaches the,turn-around point, its timeto*cenerom rhere ro the distr"ri"a aircrafti ;fi"" should eoua:,:y#i;ii,., time ; il; a",tin.tioll;lh; ;;; ;"=ii,1lJl,""o, C.tn keep the distressed aircraft informed of the Vpe and the status ofhe interception being performe;.-- "'o The MTTSI should be used when all of the following conditions exist:the distressed aircraft is not, nor expected to be, in immediateanger of ditching, .r"ih trnaing, ;Ii.iirr, before ir reaches theRU,s maximum operating distancen the sRU wit depart and return to the same aerodrome that is the.istressed aircraft,s destination . io the sRU's true air speed is less than that of the distressed aircraft2-48

randesvous positions as per iamsar

Documents