LKTB - Surveillance Radar Approach

Basic Information

What is SRA?

A Surveillance Radar Approach (SRA or ASR) is a type of instrument approach provided with active assistance from ATCo during the final approach phase. It requires no special equipment in addition to a standard surveillance radar system used by ATCo. It thus differs from most other instrument approaches which utilize a radio navigation system to provide guidance during the final approach.

As it requires no special equipment to be carried on board an aircraft, an SRA is considered a fall-back approach for aircraft that are having instrument or electrical problems and therefore cannot rely on on-board instruments; it is also sometimes provided to runways that do not usually receive instrument traffic and therefore do not have any other approach aids provided.

During the approach, the controller provides headings to keep the aircraft on the runway centerline as viewed on radar. The controller also reads out advisory altitudes based upon the observed range from touchdown: pilots can use these as assistance with their descent planning. Since only lateral guidance is provided, SRA is a non-precision approaches. The controller guidance terminates at between 2 NM and 0,5 NM from TDZ, at which point the pilot must either have visual reference, or must go around.

According to special ground equipment necessary for providing the service, SRA is used mainly as a reserve for emergency situation.

In the Czech Republic, SRA procedures are published only for Airport Brno - Tuřany and are provided in case of emergency, training or special event.

Further Information

What to expect at the beginning

While approaching the aerodrome, ATC gives you vectors near the RWY centerline and hands you off to the ATC position that provides SRA (SRA ATCo). SRA ATCo gives you all necessary information (RWY heading, angle of descend, OCA, MDA, terminal range and missed approach procedure). SRA ATCo also gives you vectors into intermediate approach track (onto RWY centerline, horizontal flight).

Check Your Minimums

SRA ATCo gives obstruct clearance altitude; however, pilot should have his/ her own minimums (same or higher then given by ATCo).

For example, EU based airlines use JAR-OPS (EU-OPS) document where the minimums are determined like this:

SRA (terminating at 1,0 NM): 250 ft

SRA (terminating at 1,5 NM): 300 ft

SRA (terminating at 2,0 NM): 350 ft

In such case, either these minimums or OCH are used; whichever are greater.

Final Approach Configuration

For the successful SRA, one of the most important things is to begin the approach in final approach configuration. Since at least 1 NM before passing FAF till touch-down, it is necessary to hold final approach speed (or Vref) and to be in landing configuration, all the time.

Every other modification of approaching speed changes vertical velocity! For the rate of descend determination, it’s useful to use simple rule:

GS [kt] x 5 = VS [fpm].

For example if the ground speed is 150 kt, the rate of descend is 750 fpm. Ground speed is easily recognized by equipment of an aircraft or it could be set as IAS plus/ minus wind correction at the aerodrome.

Utilized Equipment

For the real SRA adventure, it’s very important not to use any navigation equipment (FMC, DME, GPS, VOR, ILS, NDB, etc.). For SRA, just altimeter, horizon, gyroscope and radio are enough.

Final Approach Track

SRA as such begins shortly before passing FAF. SRA ATCo requests not to acknowledge further information and reports passing FAF. At this moment, pilot starts to descend by the calculated VS and listens carefully to the instructions given by SRA ATCo.

Altitude

For every nautical mile, the altitude decrements by approximately 320 ft. Because of rounding, the decrease is 300 ft (sometimes 400 ft) for 1 NM. So, don’t get under stress if you altitude is about 100 ft different from recommended one, just slightly modify your VS. Maximal deviation should be 200 ft.

This information is not valid for OCA. Pilot are not allowed to be lower then OCA, any time.

Landing Clearance

Landing clearance is delivered during the approach by SRA ATCo (not by TWR). The reason is that the pilot does need to change to a new frequency during the most difficult part of the approach.

SRA ATCo instructs the pilot when and which frequency to contact. It’s usually happens after landing, during vacating the RWY.

Missed Approach

Pilot follows the missed approach procedures if:

• he/ she has not sufficient visual reference at terminal range (RWY or approach light system is not in sight),
• it is not possible to finish the approach at terminal range (aircraft is too high, out of centerline heading, etc.),
• shift from the RWY centerline is too great during the approach,
• a radiocommunication fails,
• he/ she is commanded by ATCo.

Brno Tuřany SRA Procedures

Basic Values

Designation	Value
RWY	10/ 28
Altitude of Intermediate Approach	3000 ft/ 914 m AMSL*
Final Approach Fix	7 NM/ 13,0 km from TDZ
Angle of Descent	3°
Terminal Range	2,1 NM/ 3,9 km from TDZ
Obstacle Clearance Altitude (OCA)	1430 ft/ 437 m AMSL **
Obstacle Clearance Height (OCH)	(OCH) 670 ft/ 204 m AGL ***

* Low temperature altitude used from 15 NOV to 15 MAR is 3160 ft/ 960 m unless otherwise published by NOTAM.

** Low temperature altitude used from 15 NOV to 15 MAR is 1480 ft/ 450 m unless otherwise published by NOTAM.

*** Low temperature altitude used from 15 NOV to 15 MAR is 710 ft/ 217 m unless otherwise published by NOTAM.

Radiocommunication Failure

In case of radiocommunication failure, climb to 3000 ft AMSL to BNO VOR and follow radiocommunication failure procedures.

Phraseology

English Phraseology

ATC: This will be surveillance radar approach runway X terminating at Y NM from touchdown, final approach track W degrees, glide path angle V(3) degrees, in case of go around ...(continue on hdg X, climb Y and contact Z), obstacle 6 clearance altitude Z ft, check your minimums.

A/C: Surveillance radar approach runway X, minimums checked.

ATC: 2NM from FAF, reduce to Final Approach Speed and check gear down and locked

A/C: Reducing to final approach speed, gear down and locked.

ATC: 1 NM from FAF, do not acknowledge further transmissions.

ATC: 7 NM from touchdown, commence descent now, establish a 3 degree glide path

ATC: 6 NM from touchdown, altitude should be 2700 ft, heading is good.

ATC: 5 NM from touchdown, altitude should be 2400 ft, right of track, turn 3 degrees to the left, new heading 272.

ATC: 4 NM from touchdown, altitude should be 2000 ft, on track, turn 2 degrees to the right, new heading 274.

ATC: 3,5 NM from touchdown, altitude should be 1890 ft, slightly left of track, turn 2 degrees to the right, new heading 276.

ATC: 3 NM from touchdown, altitude should be 1700 ft, well left of track, turn 3 degrees to the right, new heading 279;cleared to land runway 10, wind 100 degrees 5 knots.

ATC: 2,5 NM from touchdown, altitude should be 1570 ft, closing from the left, continue heading 279.

ATC: 2 NM from touchdown, altitude should be 1410 ft, on track, turn 2 degrees to the left, new heading 276.

ATC: 1,6 NM from touchdown, altitude should be 1270 ft, approach completed.

Czech Phraseology

ATC: Toto bude přiblížení přehledovým radarem na dráhu X končící ve vzdálenosti Y NM od bodu dotyku, úhel trati konečného přiblížení W stupňů, sestupový úhel V(3) stupně, v případě průletu..., bezpečná altitude nad překážkami Z stop, prověřte vaše minima.

A/C: Přiblížení přehledovým radarem na dráhu X, minima prověřena. ATC: 2 NM od bodu začátku konečného přiblížení, prověřte vysunutí a zajištění podvozku, snižte na přibližovací rychlost.

A/C: Podvozek vysunut a zajištěn, snižuji na přibližovací rychlost.

ATC: 1 NM od FAF, nepotvrzujte další vysílání.

ATC: 7 NM od bodu dotyku, zahajte klesání teď, udržujte sestupovou dráhu 3 stupně.

ATC: 6 NM od bodu dotyku, altitude má být 2700 stop, kurz je dobrý.

ATC: 5 NM od bodu dotyku, altitude má být 2400 stop, vpravo od trati, točte o 3 stupně doleva, nový kurz 272.

ATC: 4 NM od bodu dotyku, altitude má být 2000 stop, na trati, točte o 2 stupně 7 doprava, nový kurz 274. ***

ATC: 3,5 NM od bodu dotyku, altitude má být 1890 stop, mírně vlevo od trati, točte o 2 stupně doprava, nový kurz 276.

ATC: 3 NM od bodu dotyku, altitude má být 1700 stop, hodně vlevo od trati, točte o 3 stupně doprava, nový kurz 279; dráha 10 přistání povoleno, vítr 100 stupňů 5 uzlů.

ATC: 2,5 NM od bodu dotyku, altitude má být 1570 stop, blížíte se zleva, pokračujte kurzem 279.

ATC: 2 NM od bodu dotyku, altitude má být 1410 stop, na trati, točte o 2 stupně doleva, nový kurz 276.

ATC: 1,6 NM od bodu dotyku, altitude má být 1270 stop, přiblížení ukončeno.

*** od 4 NM má ATC trvale zaklíčováno

Abbreviations

Abbreviations

AMSL Above mean sea level Nad střední hladinou moře

ASR Aerodrome surveillance radar Letištní přehledový radar

ATCo Air traffic control officer Řídící letového provozu

DME Distance measuring equipment Měřič vzdálenosti

FAF Final approach fix Bod konečného přiblížení

FMC Flight management computer Počítač systému řízení a optimalizace letu

GPS Global position system Globální navigační systém

ILS Instrumental landing system Standardní systém přesných přibližovacích majáků

MDA Minimum descend altitude Minimální (nadmořská) výška klesání

NDB Non-direction radio beacon Nesměrový radiomaják

NM Nautical mile Námořní míle

NOTAM Notice to airmen Oznámení pro letecký personál

OCA Obstacle clearance altitude Bezpečná (nadmořská) výška nad překážkami

OCH Obstacle clearance height Bezpečná (relativní) výška nad překážkami

RWY Runway Vzletová a přistávací dráha (VPD)

SRA Surveillance radar approach Přiblížení přehledovým radarem

SRA ATCo Surveillance radar approach Řídící letového provozu poskytující

        air traffic control officer     službu přiblížení přehledovým radarem

TDZ Touchdown zone Dotykové pásmo

TWR Tower Věž

VOR VHF omnidirectional radio Všesměrový radiomaják