Air to Air Refuel

Essentially

What is Air to Air Refueling (AAR)?

AAR is a procedure established to refuel aircraft midflight and thus enable longer flight time. AAR can be either done on a specified air refuelling anchor or en-route on previously coordinated routes or standard AAR routings. For germany, Air Refuelling Anchors are published in GEMIL FLIP MAP, publicly available here: https://www.milais.org/publications.php.

What are the roles for an AAR?

Tanker: The aircraft used to refuel the receiver(s). 

Receiver: The aircraft being refueled by the tanker.

AAR within a published air refuelling anchor.

Air refuelling anchors are predefined procedures, often located within an ED-R/TRA and similar to Formationa flying.civil holding procedure. The Tankerconduct willof beair flyingrefuelling within a pusblished air refuelling anchor normally requires four flight levels on top of each other. The lateral and vertical dimensions of the anchor are defined on the respective anchor chart in aGEMIL patternFLIP orMAP. onLet's look at the GRETCHEN anchor, located within ED-R 207 (TRA Allgäu) as an example:

[CHART NOCH EINFÜGEN]

Laterally, the anchor is defined by the means of four anchor points (AP/TP 1 and 2). Vertically, the anchor extends from FL270 up to FL300.

Use of flight levels within the anchor.

The flight levels within a defined routeair (e.g.refuelling alonganchor anshall airway)be andused jetas aircraftdescribed orhere:

even

FL formationsA: willAlternate joinflight level
The FL above the tanker shall be kept clear for safety actions or exit possibility.

FL B: Refuelling base level
The FL actually used for the refuelling, actual FL of the tanker.

FL C: Entry level of the first receiver(s)
FL below refuelling base level. Used as entry level for the first receiver(s) if no other aircraft is in formation with the tanker. This FL shall be kept clear as long as receiver(s) are in formation with the tanker, used by receivers to descend in an emergency situation.

FL D: Entry level of further receiver(s)
FL below entry level of the first receiver(s). Used as entry level for further receiver(s) if other receiver(s) are already in formation with the tanker.

Separation to and splitwithin air refuelling anchor.

Other traffic shall be separated by the applicable radar or vertical separation from the tanker. IfDuring tanker formation (tanker and receiver), the refuelingradar takesseparation placeshall inbe controlledincreased airspace,by ATC1 hasNM. toThe monitorvertical separation minima shall be maintained above FL A and controlbelow FL D.

Within the mission.anchor, Inthe caserequired separation between tanker and receiver shall be maintained until the receiver reports the tanker in sight and has been cleared to change to refuelling frequency (also called "boomer" frequency).

If the anchor is flyinglocated enroute,within an ED-R/TRA, further missions in the area shall be vertically separated by 2000 ft above FL A and below FL D.

Control Procedures for Tanker and Receiver aircraft.

Following control procedures shall be applied for the conduct of AAR:

Tanker aircraft.

After initial contact has been established with the tanker aircraft, the tanker shall be cleared to enter the anchor area:

"(Callsign), cleared to enter GRETCHEN anchor FL290."

When tanker is within the anchor area, the tanker pilot shall inform ATC about flight conditions (IMC/VMC), possible contrails, refuelling frequency and refuelling speed:

"(Callsign), report flight conditions."
"(Callsign), are you willtrailing?"
"(Callsign), haverequest boomer / refuelling frequency."
"(Callsign), report fuelling speed."

The tanker shall be informed about the number, type and callsign of the receiver(s) as well as the estimated beginning of the rendezvous manoeuvre as soon as possible:

"(Callsign), you receivers are (number) (type), (callsign of receiver), expect rendezvous in (time) minutes."

Receiver aircraft.

If no other receiver are in formation with the tanker, first receivers shall be guided to informthe tanker at FL C. Further receivers at FL D.

After initial contact, receivers shall be informed about callsign, position, refuelling speed and frequency of the nexttanker. sectorAdditionally, they shall be instructed to check the armament safety (switches safe = all weapon switches set to SAFE/OFF) and air pressure setting.

"(Callsign), tanker call sign is (callsign of tanker), refuelling speed (speed)."
"(Callsign), tanker position is (position), squawking (squawk of tanker), he is (not) trailing."
"(Callsign), check switches safe and altimeter settings standard."

While approaching the anchor area, the receiver shall be instructed to report radar contact with the tanker:

"(Callsign), report radar contact."

Position information about the tanker formationshall andbe thatgiven Airat intervals of 10 NM until receiver reports radar contact (also called "Judy").

If radar contact is not reported, the receiver shall be instructed to Airreport refuelingvisual takescontact place.with the tanker:

"(Callsign), report tanker in sight."

As soon as the receiver reports radar or visual contact, he shall be instructed to:

• squawk standby,
• obtain ATC clearance before leaving the refuelling level block,
• in case of visual contact: check nose cold (radar of receiver set to standby),
• establish radio contact with tanker on boomer frequency.

"(Callsign), squawk standby, (check nose cold), for clearance call back on (this) frequency, contact boomer on (boomer frequency)."

 

 

 

 

 

It is important to always keep 4000ft clear for the whole formation as depicted on the right. The tanker will be told to maintain a level block of 4000ft. In this example FL170 is the actual tanker flight level (the tanker pilot should know that he has to fly on the second highest level in the level block). FL160 can be used as an entry level in case there is no other jet within the tanker formation and the tanker is flying alone. If there are other jets, FL160 is used by these jets while they are standing by for refuelling or while they are waiting for their wingmen to refuel. Within the formation of the tanker there will be frequent positon changes to make sure that every aircraft gets fuel. If there are jets in the formation, FL150 will be used as an entry level similar to the paragraph "Formation Join Up". Arriving formations or jets will be cleared on FL150 before the visual join up is approved. FL180 has to be kept clear for leaving aircraft in case of a "Vertical Formation Split" or for evasive maneuvers.

In real life the ATC unit responsible for the tanker formation is a special working position (SWP). If the refuelling takes place enroute the SWP does not have its own airspace (similar to a Feeder in the APP airspace) but is delegated to control the tanker formation and all aircraft entering or leaving. Inside a refuelling area the area is controlled by the SWP but no other aircraft should enter that area unless it's for the purpose of refuelling or unless the tanker has approved. When an aircraft wants to join the formation, Radar will clear that aircraft to climb to the entry level (in our example FL150), give an intercept heading and then send that aircraft to the frequency of the SWP.

Other important notes:

• (if within refueling area) SWP is responsible for separation within the refuelling area. Crossing of the tanker pattern within a refueling area needs to be approved by the SWP
• ATC needs to increase the horizontal separation to the tanker formation by one NM just like with any other formation
• SWP is responsible for separation between tanker and receiver until the join up is approved
• (if enroute) Below the tanker formation the vertical separation should be 2000ft (in our example an aircraft that does not join the formation needs to be at FL130 or lower). In a refuelling pattern the whole refuelling area should be kept clear

Procedure for SWP:

• The Tanker needs to be informed about approaching receivers: "QID5 next receiver GAF123, single Eurofighter"
• The receiver needs to be informed about weather, position, HDG and FL of tanker and number of receivers in formation: "GAF123, weather conditions VMC, Tanker bearing 040, 35NM, FL190, H225, two aircraft in tow"
• The receiver also needs to be asked to check that the QNH/altimeter is set to standard.
• The receiver needs to be informed about the tanker position until the pilot reports the tanker in sight.
• When the receiver has the Tanker in sight, the receiver needs to be asked to set transponder on standby and change to the refuelling frequency (Boom operator or Boomer - no joke ;D). Furhtermore, the receiver has to be told to stay with the tanker and report back after refuelling: "GAF123, after refuelling stay with the tanker and report back on frequency 123.125.
• When one aircraft or formation wants to split from the tanker formation, it should be instructed to climb above the tanker (FL190) and then be instructed to follow a route or heading. Before that a route needs to be coordinated between the ATC sector and the SWP. SWP needs to make sure that this route is followed before the aircraft is transfered back to the ATC sector.

Station	Tanker Operation
GAF123	GAF123 request to join QID5 for refuelling
ATC	Roger, GAF123 fly HDG 050, climb FL150, contact Langen Radar 123.125 (SWP)
GAF123	GAF123 fly HDG 050, climb FL150, contact Langen Radar 123.125
On the SWP Frequency
GAF123	Langen Radar, GAF123 to join QID 5.
SWP	GAF123, Langen Radar, weather conditions VMC, Tanker bearing 040, 35NM, FL170, HDG 225, two aircraft in tow, confirm QNH standard
GAF123	GAF123 roger, QNH standard
SWP	QID5, next receiver GAF123, single Eurofighter
QID5	QID 5 Roger
SWP	GAF123 Tanker is 10 o'clock 6NM report in sight
GAF123	GAF123 in sight
SWP	GAF123 squawk standby, contact BOOM 360.8, after refuelling stay with the Tanker and report back on 123.125
GAF123	GAF123 squawk standby, contact BOOM 360.8, after refuelling stay with the Tanker and report back on 123.125
After Refuelling
GAF123	Langen Radar, GAF123 finished refuelling, request clearance to XXXX
SWP	GAF123 squawk 2115
GAF123	GAF123 squawk 2115
SWP	GAF123 identified, climb FL 190, maintain own separation to tanker, when reaching FL190, turn left HDG 220

Remember that SWP needs to coordinate the planned route/exit route from the refuelling area with the responsible ATC unit.