5-4-15. Simultaneous Close Parallel ILS PRM Approaches (Independent) and Simultaneous Offset Instrument Approaches (SOIA) (See FIG 5-4-18.)
 
RUNWAY CENTERLINES SPACED LESS THAN 4300 ft APART, 
          RADAR MONITORING AND PRM REQUIRED

APUSA INT. established where 3200’
altitude intercepts glide slope. NTZ begins.

3200’

2200’

      Radar monitoring    
            provided to
        ensure lateral or
      vertical separation  
         between aircraft
    on parallel localizers
   prior to the beginning
          of the NTZ

Radar monitoring provided to .5NM 
beyond departure end to ensure separation
during simultaneous missed approaches.

.5 NM

.5 NM

Intercept glide
slope at 2200’

Figure 5-4-18 Simultaneous Close Parallel ILS Approaches

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a.	System. 

1. ILS/PRM is an acronym for Instrument Landing System/Precision Runway Monitor.
An approach system that permits simultaneous ILS/PRM approaches to dual runways with centerlines separated by less than 4,300 feet but at least 3400 ft for parallel approach courses, and at least 3000 ft if one ILS if offset by 2.5 to 3.0 degrees.  The airspace between the final approach courses contains a No Transgression Zone (NTZ) with surveillance provided by two PRM monitor controllers, one for each approach course. To qualify for reduced lateral runway separation, monitor controllers must be equipped with high update radar and high resolution ATC radar displays, collectively called a PRM system. The PRM system displays almost instantaneous radar information. Automated tracking software provides PRM monitor controllers with aircraft identification, position, speed and a ten-second projected position, as well as visual and aural controller alerts. The PRM system is a supplemental requirement for simultaneous close parallel approaches in addition to the system requirements for simultaneous parallel ILS/MLS approaches described in paragraph 5-4-14, "Simultaneous Parallel ILS/MLS Approaches (Independent)." 
Simultaneous close parallel ILS/PRM approaches are depicted on a separate Approach Procedure Chart titled ILS/PRM Rwy XXX (Simultaneous Close Parallel). 
2. SOIA is an acronym for Simultaneous Offset Instrument Approach, a procedure used to conduct simultaneous approaches to runways spaced less than 3000 ft, but at least 750 ft apart. The SOIA procedure utilizes an ILS/PRM approach to one runway and an offset Localizer-Type Directional Aid (LDA)/PRM approach with glide slope to the adjacent runway. 

The ILS/PRM approach plates used in SOIA operations is identical to other ILS/PRM approach plates, with an additional note, which provides the separation between the two runways used for simultaneous approaches. The LDA/PRM approach plate displays the required notations for closely spaced approaches as well as depicting the visual segment of the approach, and a note which provides the separation between the two runways used for simultaneous operations.

Controllers monitor the SOIA ILS/PRM and LDA/PRM approaches with a PRM system using high update radar and high-resolution ATC radar displays in exactly the same manner as is done for ILS/PRM approaches. The procedures and system requirements for SOIA ILS/PRM and LDA/PRM approaches are identical with those used for simultaneous close parallel ILS/PRM approaches until near the LDA/PRM approach missed approach point (MAP)---where visual acquisition of the ILS aircraft by the LDA aircraft must be accomplished. Since the ILS/PRM and LDA/PRM approaches are identical except for the visual segment in the SOIA concept, an understanding of the procedures for conducting ILS/PRM approaches is essential before conducting a SOIA ILS/PRM or LDA/PRM operation.

In SOIA, the approach course separation (instead of the runway separation) meets established close parallel approach criteria. Refer to Figure 5-4-19 for the generic SOIA approach geometry. A visual segment of the LDA/PRM approach is established between the LDA MAP and the runway threshold.  Aircraft transition in visual conditions from the LDA course, beginning at the LDA MAP, to align with the runway and can be stabilized by 500 feet above ground level (AGL) on the extended runway centerline.  Aircraft will be "paired" in SOIA operations, with the ILS aircraft ahead of the LDA aircraft prior to the LDA aircraft reaching the LDA MAP.  A cloud ceiling for the approach is established so that the LDA aircraft has nominally 30 seconds to acquire the leading ILS aircraft prior to the LDA aircraft reaching the LDA MAP.  If visual acquisition is not accomplished a missed approach must be executed.

FIG 5-4-19

SOIA Approach GEOMETRY

                                                                       SAP                           LDA MAP

500 ft

                                            LDA glide slope

     LDA Runway

SAP	=	The SAP is a design point along the extended centerline of the intended landing runway on the glide slope at 500 above the landing threshold.  It is used to verify a sufficient distance is provided for the visual maneuver after the missed approach point (MAP) to permit the pilots to conform to approved, stabilized approach criteria.

MAP	=	The point along the LDA where the course separation with the adjacent ILS reaches 3,000.  The altitude of the glide slope at that point determines the approach minimum descent altitude and is where the NTZ terminates.  Maneuvering inside the MAP is done in visual conditions.

Angle	=	Angle formed at the intersection of the extended LDA runway centerline and a line drawn between the LDA MAP and the SAP.  The size of the angle is determined by the FAA SOIA computer design program, and is dependent on whether Heavy aircraft use the LDA and the spacing between the runways.

Visibility	=	Distance from MAP to runway threshold in statute miles (light credit applies).

Procedure	=	LDA aircraft must see the runway landing environment and, if less than standard radar separation exists between the aircraft on the adjacent ILS course, the LDA aircraft must visually acquire the ILS aircraft and report it in sight to ATC prior to the LDA MAP.

CC	=	Clear Clouds.

b.       Requirements. 
Besides system requirements as identified in item (a) above all pilots must have completed special training before accepting a clearance to conduct ILS/PRM or LDA/PRM Simultaneous Close Parallel Approaches.

1.  Pilot Training Requirement: Pilots must complete special pilot training, as outlined below before accepting a clearance for a simultaneous close parallel ILS/PRM or LDA/PRM approach.  

For operations under Part 121, 129, and 135 pilots must comply with FAA approved company training as identified in their Operations Specifications.  Training, at a minimum, must require pilots to view the FAA video “ILS PRM AND SOIA APPROACHES: INFORMATION FOR AIR CARRIER PILOTS.”  Refer to http://www.faa.gov/AVR/AFS/PRMtraining/ for additional information and to view or download the video. 

For operations under Part 91:

Pilots operating transport category aircraft must be familiar with PRM operations as contained in this section of the Aeronautical Information Manual (AIM). In addition, pilots operating transport category aircraft must view the FAA video "ILS PRM AND SOIA APPROACHES: INFORMATION FOR AIR CARRIER PILOTS".  Refer to http://www.faa.gov/AVR/AFS/PRMtraining/ for additional information and to view or download the video. 

Pilots not operating transport category aircraft must be familiar with PRM and SOIA operations as contained in this section of the AIM.  The FAA strongly recommends that pilots not involved in transport category aircraft operations view the FAA video, “ILS PRM AND SOIA APPROACHES: INFORMATION FOR GENERAL AVIATION PILOTS” Refer to http://www.faa.gov/AVR/AFS/PRMtraining/ for additional information and to view or download the video. 
2. ATC Directed Breakout: An ATC directed "breakout" is defined as a vector off the ILS or LDA approach course in response to another aircraft penetrating the NTZ, the 2000 ft wide area located equidistance between the two approach courses that is monitored by the PRM monitor controllers.
3. Dual Communications: The aircraft flying the ILS/PRM or LDA/PRM approach must have the capability of enabling the pilot/s to listen to two communications frequencies simultaneously
c.       Radar Monitoring. Simultaneous close parallel ILS/PRM and LDA/PRM approaches require that final monitor controllers utilize the PRM system to ensure prescribed separation standards are met. Procedures and communications phraseology are also described in paragraph 5-4-14, "Simultaneous Parallel ILS/MLS Approaches (Independent)." A minimum of 3 miles radar separation or 1,000 feet vertical separation will be provided during the turn-on to close parallel final approach courses. To ensure separation is maintained, and in order to avoid an imminent situation during simultaneous close parallel ILS/PRM or SOIA ILS/PRM and LDA/PRM approaches, pilots must immediately comply with PRM monitor controller instructions. In the event of a missed approach, radar monitoring is provided to one-half mile beyond the most distant of the two runway departure ends for ILS/RPM approaches. In SOIA, PRM radar monitoring terminates at the LDA MAP. Final monitor controllers will not notify pilots when radar monitoring is terminated. 
d.      Attention All Users Page. .  ILS/PRM and LDA/PRM approach charts have an "Attention All Users Page" associated with them that must be referred to in preparation for conducting the approach. This page contains the following instructions that must be followed if the pilot is unable to accept an ILS/PRM or LDA/PRM approach. 

At airports that conduct PRM operations, (ILS/PRM or, in the case of airports where SOIA's are conducted, ILS/PRM and LDA/PRM approaches) pilots not qualified to accept PRM approaches  must contact the FAA Command Center prior to departure (1-800-333-4286) to obtain an arrival reservation (see FAA Advisory Circular 90-98). Arriving flights that are unable to participate in ILS/PRM or LDA/PRM approaches and have not received an arrival reservation are subject to diversion to another airport or being delayed. Pilots enroute to a PRM airport designated as an alternate, unable to reach their filed destination, and who are not qualified to participate in ILS/PRM or LDA/PRM approaches must advise ATC as soon as practical that they are unable to participate. Pilots who are qualified to participate but experience an enroute equipment failure that would preclude participation in PRM approaches should notify ATC as soon as practical.

The Attention All Users Page covers the following operational topics:

1. ATIS. When the ATIS broadcast advises ILS/PRM approaches are in progress (or ILS PRM and LDA PRM approaches in the case of SOIA), pilots should brief to fly the ILS/PRM or LDA/PRM approach.  If later advised to expect the ILS or LDA approach (should one be published), the ILS/PRM or LDA/PRM chart may be used after completing the following briefing items:

Minimums and missed approach procedures are unchanged.
PRM Monitor frequency no longer required.
ATC may assign a lower altitude for glide slope intercept.

Note:  In the case of the LDA/PRM approach, this briefing procedure only applies if an LDA approach is also published.
  
In the case of the SOIA ILS/PRM and LDA/PRM procedure, the Attention All Users Page describes the weather conditions in which simultaneous approaches are authorized:  

Simultaneous approach weather minimums are X,XXX feet (ceiling), x miles (visibility)

2.  Dual VHF Communications Required.. To avoid blocked transmissions, each runway will have two frequencies, a primary and a monitor frequency. The tower controller will transmit on both frequencies. The monitor controller's transmissions, if needed, will override both frequencies.  Pilots will ONLY transmit on the tower controller's frequency, but will listen to both frequencies.  Begin to monitor the PRM monitor controller when instructed by ATC to contact the tower. The volume levels should be set about the same on both radios so that the pilots will be able to hear transmissions on at least one frequency if the other is blocked. Site specific procedures take precedence over the general information presented in this paragraph.  Refer to the Attention All Users Page for applicable procedures at specific airports.

3.  Breakouts. Breakouts differ from other types of abandoned approaches in that they can happen anywhere and unexpectedly. Pilots directed by ATC to break off an approach must assume that an aircraft is blundering toward them and a breakout must be initiated immediately.

a. Hand-fly breakouts. All breakouts are to be hand-flown to ensure the maneuver is accomplished in the shortest amount of time.

b.  ATC Directed “Breakouts”.  ATC directed breakouts will consist of a turn and a climb or descent.  Pilots must always initiate the breakout in response to an air traffic controller's instruction.  Controllers will give a descending breakout only when there are no other reasonable options available, but in no case will the descent be below the minimum vectoring altitude (MVA) which provides at least 1,000 feet required obstruction clearance.  The Attention All Users Page provides the MVA in the final approach segment as X,XXX feet at (Name) Airport.

Phraseology – “TRAFFIC ALERT."  If an aircraft enters the “NO TRANSGRESSION ZONE” (NTZ), the controller will breakout the threatened aircraft on the adjacent approach.  The phraseology for the breakout will be:

“TRAFFIC ALERT”, (aircraft call sign) Turn (left/right) IMMEDIATELY, HEADING (degrees), CLIMB/DESCEND AND MAINTAIN (altitude).”

4. ILS/PRM Navigation: The pilot may find crossing altitudes along the final approach course. The pilot is advised that descending on the ILS glideslope ensures complying with any charted crossing restrictions.

SOIA AAUP differences from ILS PRM AAUP 

5. ILS/PRM LDA Traffic (only published on ILS/PRM AAUP when the ILS PRM approach is used in conjunctions with an LDA/PRM approach to the adjacent runway):  To provide better situational awareness, and because traffic on the LDA may be visible on the ILS aircraft's TCAS, pilots are reminded of the fact that aircraft will be maneuvering behind them to align with the adjacent runway.   While conducting the ILS/PRM approach to Runway XXX, other aircraft may be conducting the offset LDA/PRM approach to Runway XXX. These aircraft will approach from the ((left/right)-rear and will re-align with runway XXX after making visual contact with the ILS traffic. Under normal circumstances these aircraft will not pass the ILS traffic. 

 SOIA LDA/PRM AAUP Items: The Attention All User's Page for the SOIA LDA/PRM approach contains most information found on ILS/PRM AAUP's.  It replaces certain information as seen below and provides pilots with the procedures to be used in the visual segment of the LDA/PRM approach, from the time the ILS aircraft is visually acquired until landing.

4.	SOIA LDA/PRM Navigation (replaces ILS/PRM #4 and #5 above). The pilot may find crossing altitudes along the final approach course. The pilot is advised that descending on the LDA glideslope ensures complying with any charted crossing restrictions. Remain on the LDA course until passing XXXXX (LDA MAP name) intersection prior to maneuvering to align with the centerline of runway XXX.

5.  SOIA (Name) Airport Visual Segment (replaces ILS/PRM #5 above). Pilot procedures for navigating beyond the LDA MAP are spelled out. If ATC advises that there is traffic on the adjacent ILS, pilots are authorized to continue past the LDA MAP to align with runway centerline when 

       a) the ILS traffic is in sight and is expected to remain in sight, 
	  b) ATC has been advised that "traffic is in sight."	 
       c) the runway environment is in sight. 
 
Otherwise, a missed approach must be executed.  Between the LDA MAP and the runway threshold, pilots of the LDA aircraft are responsible for separating themselves visually from traffic on the ILS approach, which means maneuvering the aircraft as necessary to avoid the ILS traffic until landing, and providing wake turbulence avoidance, if applicable.   Pilots should advise ATC, as soon as practical, if visual contact with the ILS traffic is lost and execute a missed approach unless otherwise instructed by ATC.

e.     SOIA LDA Approach Wake Turbulence: Pilots are responsible for wake turbulence avoidance when maneuvering between the LDA missed approach point and the runway threshold.  
  
f.      Differences between ILS and ILS/PRM approaches of importance to the pilot. 
1. Runway Spacing. Prior to ILS/PRM and LDA/PRM approaches, most ATC directed breakouts were the result of two aircraft in-trail on the same final approach course getting too close together. Two aircraft going in the same direction did not mandate quick reaction times. With PRM approaches, two aircraft could be along side each other, navigating on courses that are separated by less than 4,300 feet.  In the unlikely event that an aircraft "blunders" off its course and makes a worst case turn of 30-degrees toward the adjacent final approach course, closing speeds of 135 feet per second could occur that constitute the need for quick reaction. A blunder has to be recognized by the monitor controller, and breakout instructions issued to the endangered aircraft. The pilot will not have any warning that a breakout is eminent because the blundering aircraft will be on another frequency. It is important that, when a pilot receives breakout instructions, he assumes that a blundering aircraft is about to or has penetrated the NTZ and is heading toward his approach course.  The pilot must initiate a breakout as soon as safety allows. While conducting PRM approaches, pilots must maintain an increased sense of awareness in order to immediately react to an ATC instruction (breakout) and maneuver as instructed by ATC, away from a blundering aircraft.
2. Communications. To help in avoiding communication problems caused by stuck microphones and two parties talking at the same time, two frequencies for each runway will be in use during ILS/PRM and LDA/PRM approach operations, the primary tower frequency and the PRM monitor frequency. The tower controller transmits and receives in a normal fashion on the primary frequency and also transmits on the PRM monitor frequency. The monitor controller's transmissions override on both frequencies. The pilots flying the approach will listen to both frequencies but only transmit on the primary tower frequency. If a breakout is initiated by the PRM monitor controller and the primary frequency is blocked by another transmission, the breakout instruction will still be heard on the PRM monitor frequency. 
3. Hand-flown Breakouts. The use of the autopilot is encouraged while flying an ILS/ PRM or LDA/PRM approach, but the autopilot must be disengaged in the rare event that a breakout is issued. Simulation studies of breakouts have shown that a hand-flown breakout can be initiated consistently faster than a breakout performed using the autopilot. 
4. TCAS.  The ATC breakout instruction is the primary means of conflict resolution.  TCAS, if installed, provides another form of conflict resolution in the unlikely event other separation standards would fail. TCAS is not required to conduct a closely spaced approach.
 
The TCAS provides only vertical resolution of aircraft conflicts, while the ATC breakout instruction provides both vertical and horizontal guidance for conflict resolutions. Pilots should always immediately follow the TCAS Resolution Advisory (RA), whenever it is received.  Should a TCAS RA be received before, during, or after an ATC breakout instruction is issued, the pilot should follow the RA, even if it conflicts with the climb/descent portion of the breakout maneuver.  If following an RA requires deviating from an ATC clearance, the pilot shall advise ATC as soon as practical.  While following an RA, it is extremely important that the pilot also comply with the turn portion of the ATC breakout instruction unless the pilot determines safety to be a factor.  Adhering to these procedures assures the pilot that acceptable "breakout" separation margins will always be provided, even in the face of a normal procedural or system failure. 

5. Breakouts. The probability is extremely low that an aircraft will "blunder" from its assigned approach course and enter the NTZ, causing ATC to "breakout" the aircraft approaching on the adjacent ILS course.  However, because of the close proximity of the final approach courses, it is essential that pilots follow the ATC breakout instructions precisely and expeditiously.  The controller's "breakout" instructions provide conflict resolution for the threatened aircraft, with the turn portion of the "breakout" being the single most important element in achieving maximum protection. A descending breakout will only be issued when it is the only controller option. In no case will the controller descend an aircraft below the Minimum Vectoring Altitude (MVA) which will provide at least 1,000 feet clearance above obstacles. The pilot is not expected to exceed 1,000 feet per minute rate of descent in the event a descending breakout is issued.