I3201

=What To Expect=
 * I. Radial intercepts (inbound, outbound, over-the station, < 45 deg, >45 deg, and >120 deg, inbound-to-outbound and/or outbound-to-inbound)
 * II. TACAN point-to-point and holding (these are great times to do your approach brief!)
 * III. One of the following vol 19 approaches: Jacksonville NAS TACAN RWY 10 or Mayport NAS TACAN RWY 23
 * IV. An EP probably involving an instrument auto

=TACAN procedures= ARCING APPROACH (T-34C RI FTI 3950) [Brackets indicate editing for TH-57]

NIFM Chapter 20, "Low Altitude Approach Procedures;" and Chapter 21, "Tactical Air Navigation (TACAN)."

A. 	Amplification - An arcing approach makes use of an arcing maneuver to position the aircraft inbound on the final approach course. Arcing approaches are normally identified by VOR/DME or TACAN in the approach plate margin meaning DME is required. The margin identification may not require DME if an arcing maneuver is depicted in addition to a procedure turn to establish the aircraft on final approach course. However, when arcing to final, DME is required.

this is for fixed wing, rotary wing goes to 90 KTS at IAF and that's it; your cruising speed of 100 KTS isn't enough of a difference to need to bother with any of the procedures below, but they're good to know anyhow for the brief. Cruise at 100, hold at 80, IAF and on at 90.

ARCING SPEED RULES

I. 	If holding at the IAF, cleared for the approach AND: II. If you hit the IAF at cruise airspeed (no prior holding), cleared for the approach, AND: III. If the term "NO PT" is displayed along the arc, the complete arc will be flown at cruise airspeed regardless of the arc length. When in a position 5 NM from the FAF on the FAC transition to [90 knots]. DME Provides more accurate fixing of an aircraft's position during an approach because it is not affected by wind, unlike the timing used on a pure VOR approach.
 * (1) 	If the distance from the IAF to the final approach course (FAC) is over 45 radials, maintain cruise airspeed until 30 radials from the FAC.
 * (2) 	If the distance from the IAF to the FAC is 45 radials or less, the complete arc will be flown at [90] knots.
 * (1) 	If the distance from the IAF to the FAC is over 30 radials, maintain cruise airspeed until 30 radials from the FAC.
 * (2) 	If the distance from the IAF to the FAC is 30 radials or less, transition to [90] knots at the IAF (IAW 6 T's).

B. 	Procedure -

LEADING THE TURN AT THE IAF

When clearance for the approach is issued, ATC expects an immediate turn in the shortest direction to intercept the initial approach course upon reaching the IAF. Clearance for the approach does not include clearance for the holding airspace. However, normal lead points may be used to intercept the course. If you are approaching the IAF on an acute angle, you may need to maneuver the aircraft for a more favorable alignment prior to starting the approach.

MANEUVERING AIRSPACE is airspace used to allow the aircraft to provide favorable alignment onto the Initial and Intermediate approach course. 1. At the IAF: NOTE: On different approaches the transition at the IAF could involve a descent, a reduction in airspeed or both.
 * If "hitting the IAF" at an acute angle with a requirement for over a 90° turn onto the IAF (or arc), maneuvering airspace is recommended.
 * If maneuvering is desired, first obtain clearance from ATC since clearance for the approach does not include clearance for use of holding or maneuvering airspace. ATC may assign an area and boundary for the maneuver, i.e.
 * "Maneuver NW of JAE between 10 - 12 DME." - In this case, the pilot would conduct his maneuver within this area.
 * Since there are no set procedures on how to conduct this maneuver, the following "techniques" are recommended. Seek the advice of your instructor for various circumstances.
 * 1.	If a holding pattern is depicted at the IAF, the pilot should "request one turn in holding". Remember, you are not actually entering into the holding pattern for a delay - therefore your airspeed would remain at cruise airspeed during the maneuver. Once the turn in holding is complete, continue to track inbound to the IAF on the Initial approach course. At the IAF, perform the "6 T's".
 * 2. If no holding pattern is depicted at the IAF, a teardrop type maneuver is preferred. Turn to a heading 30° away from the Initial Approach course radial, time for 30 - 45 seconds, while maintaining cruise airspeed. At the end of your "outbound timing" make a turn to intercept the Initial approach course inbound. TAIL-RADIAL-TURN. At the IAF perform the "6 T's".
 * While proceeding Point-to-Point to the IAF, ensure the proper course is set in the IND-350 that will be used to identify the IAF.
 * a.	TIME - Not applicable.
 * b.	TURN - To intercept and track inbound to the arc on the depicted course. If there is no short inbound segment from the IAF to the arc, turn onto the arc and begin arcing procedures.
 * c.	TIME - Not applicable.
 * d.	TRANSITION - If a descent is required perform a terminal descent to the minimum altitude for this segment or accelerate to normal cruise if no descent is required.

(1) 	If the radial defining the IAF is within 30 radials of the final/intermediate approach course. Slow to [90] knots and descend if required.

(2) 	If the radial defining the IAF is greater than 30 radials of the final/intermediate approach course, maintain cruise airspeed, and:
 * (a)	If descent required - perform a terminal descent.
 * (b)	No descent required - maintain cruise power, airspeed and altitude.
 * (3) 	If you come within 30 radials of the FAC while in a terminal descent continue the terminal descent. 50'prior to level off altitude start raising the nose to slow to [90] knots. Approaching [90] knots add power and re-trim.
 * e.	TWIST - Ensure that the inbound course is set in the [HSI/CDI]; intercept the course inbound. If there is no short inbound segment to the arc, set the FAC in the [HSI/CDI].
 * f.	TALK - report initial approach fix (IAF) inbound if requested by ATC.

2.	Using the proper lead point, turn to intercept and maintain the arc. This step may occur before the above steps are completed. Once established on the arc, twist in the final approach course.

3.	30 radials prior to the Final Approach Course (FAC), slow to [90] knots. (Remember if the term "NO PT" is displayed along the arc, maintain cruise airspeed until 5 NM from the FAF on the final approach course).

4.	Anticipate interception of the final approach course referencing the tail of the TACAN Needle and the CDI while on the arc. Remember, this is almost a 90° intercept.

NOTE: On approach charts, when the arc-to-final angle exceeds 90°, a published lead radial (designated “LR-XXX”), which provides approximately 2 miles of lead, may be provided as an advisory point, for turning onto the inbound course. For this reason, published lead radials shall not be used by [TH-57C] aircraft. The pilot should calculate the lead radial used to commence the turn onto the inbound course.

=Use of CDI and HSI=

COURSE DEVIATION INDICATOR KDI-206 (C) (NATOPS 18.16)
The CDI (Figure 18-12) is located on the copilot instrument panel (Figure 2-4). The CDI displays TACAN, VOR, LOC, and GS relative bearing information received from the NAV 1 or NAV 2 through the use of a pushbutton located on the copilot GPS panel. Additionally, it provides visual indications of unreliable signals or equipment malfunctions via an intermittent "ToFrom" arrow and NAV flag. The "GS" flag will be displayed whenever you are not operating on a LOC frequency or when the tuned LOC signal is being received intermittently or not at all.

Control and Functions
 * Course pointer - Indicates deviation from selected TACAN VOR radial or LOC path.
 * Course index - Provides reference point for course deviation card.
 * Course deviation card - Manually rotated card driven by OBS control to indicate desired VOR radial directly beneath course index.
 * NAV warning flag - Red NAV flag indicates VOR or LOC signal is unreliably weak or malfunction in receiver.
 * TO/FROM flag - Indicates whether flying selected radial would direct helicopter toward (TO) or from (FR) VOR station.
 * Reciprocal course index - Indicates radial 180° from selected radial.
 * Omnibearing selector (OBS) - Drives course deviation card for course selection.
 * Glideslope pointer - Indicates deviation from glidepath
 * Glideslope warning flag - Red GS flag indicates GS signal is unreliably weak or malfunction in receiver.

(NATOPS 18.17) ……. Deviation information on the pilot's HSI and the copilot's CDI is also selected via the NAV 1 - NAV 2 PBS. When the pilot and copilot select the same NAV source, the copilot's CDI will become a repeater of the HSI, and a corresponding ,CRS INOP light will appear on the copilot's GPS panel. TACAN azimuth will not be displayed when both pilot and copilot have selected NAV 2 (GPS) information. VOR and ADF azimuth will not be affected.

…. The GPS CRS deviation as described above. The GPS CRS OBS-LEG pushbutton switch toggles KLN 900 deviation between OBS and LEG modes. In the OBS mode deviation is given in miles from the selected bearing. In the LEG mode deviation is given in miles from a line connecting two selected waypoints. CDI scale factors vary; see the Pilot's Guide for details. Depressing the OBS-LEG switch on either the pilot's or copilot's side, or the OBS button on the KLN 900 will toggle the function.

HORIZONTAL SITUATION INDICATOR (FIGURE 18-15) (NATOPS 18.18)
The HSI located on the right side of the instrument panel displays a heading card, a course datum, heading selector, glideslope pointer, and course deviation bar. Two flag circuits are incorporated in the instrument: the HDG flag appears if system power of gyro spin motor operation is inadequate; a NAV flag appears if receiver is inadequate.

Control and Functions
 * Heading select marker - Provides reference for selected heading to be flown. The marker moves with compass card except while being mechanically positioned by heading select knob.
 * Dual glideslope pointer- Indicates helicopter position above or below glideslope signal received from NAV radio. Pointers retract when signal is unreliable.
 * Symbolic aircraft- Shows helicopter relationship to the compass and the selected VOR or LOC course.
 * VOR and localizer deviation bar- Indicates position of aircraft in relation to VOR or localizer signal.
 * Course select knob - Used to position course pointer to the desired VOR radial (to or from) for the NAV receiver.
 * Compass card - Displays helicopter magnetic heading against lubber line.
 * Heading select knob - Used to position heading marker.
 * TO-FROM indicator- Indicates flying the selected course on the course pointer, which will direct the helicopter to or from the VOR station.
 * Course select pointer - Indicates the selected VOR radial from NAV radio. Course pointer rotates with adjustment made on course select knob.
 * Compass warning flag - Flag indicates gyromagnetic compass is unreliable or not operating. The magnetic heading under the lubber line will be unreliable.
 * Lubber line- Lubber line points out helicopter magnetic heading as indicated by compass card.
 * NAV warning flag-Flag indicates unreliable signal from NAV 1 receiver.

Operation
 * 1. Heading select knob - Set (as required).
 * 2. Course select knob - Set (as required).

To prepare for an ILS approach, tune the NAV receiver to desired frequency. When a reliable signal is received, the NAV warning flag will disappear.

For a front or back course approach, rotate the course select knob to set the course select pointer on the inbound localizer course. As with normal navigation, the deviation bar represents the desired course. This representation works for both front and back course approaches.

When flying an ILS course and a usable glideslope signal is received, the glideslope deviation pointers will become visible on both sides of display. When in operation, the deviation pointers represent the position of the glideslope path relative to the aircraft.

CAUTION Localizer intercepts within 90° ±10° of the localizer course should be avoided because of antenna signal degradation.

=40- degree lock-off= Primary IFR WB pp. 1-15) The aircraft’s TACAN receiver electronically measures the aircraft’s bearing from the station in the proper 40o sector and then measures the aircraft’s position within that sector. If the aircraft’s TACAN is malfunctioning or the signal reception is weak, the receiver may measure the wrong 40o sector.  This is known as “40o Lock Off.”  The pilot must recognize this phenomena when it occurs.

See INAV WB Appx B for more info.

=Cone of Confusion= (INAV WB pp. 4-6,7) Another place where TACAN differs from VOR is in the cone of confusion. You may recall from previous texts and your flying experiences that VOR bearing information cannot be received when directly over the station. The VOR cone is 40-50 degrees wide and the area covered increases with altitude. TACAN stations also have a cone of confusion, but they are much larger. The TACAN cone is up to 100 degrees wide. This works out to about 15 NM at 40,000 feet, and at an altitude of 5,000 feet, it would be just under two miles wide or about one mile around the station.

Inside the TACAN cone, no bearing information can be received, but slant range information is still reliable. Because of the size of the TACAN cone, holding cannot be accomplished over a TACAN station. Instead, the holding pattern will be oriented at a holding fix at some specified range and bearing from the station. Station passage is also affected by the cone of confusion. Since the slant range still functions, the minimum slant range or minimum DME will designate station passage. In other words, the range will decrease as you approach the station and will increase after you pass it. The point at which the slant range begins to increase again is station passage. Note that the range will probably not decrease to zero, unless you are flying extremely low.

=Cockpit Setup= If you want to know how to do it right refer to the Terasse Gouge.

=Ground Speed Check=
 * Note your DME and time.
 * Wait 6 minutes.
 * Note change in DME
 * Multiply by 10

=Instrument Autorotation to touchdown= INSTRUMENT AUTOROTATION (NATOPS 809) Maneuver Description and Application [Reference: TH-57 NATOPS Section VI, All Weather Operation]

Instrument autorotations are practiced to develop the confidence and ability to execute a safe autorotative descent in the event of an engine failure under actual instrument conditions.

Procedures
 * 1.	The instructor will initiate the maneuver by rolling the twist grip to flight idle and telling the student he has a simulated engine failure.
 * 2.	Establish the aircraft in a stable autorotative descent. Adjust nose attitude to 60 kias and collective to maintain rotor rpm in the green (94-95% optimum).
 * 3.	Turn in direction of last known wind.
 * 4.	Check ng at flight idle rpm. Report nr and ng to your instructor.
 * 5.	Ensure harness is locked, a simulated mayday report is given, and transponder set to 7700.
 * 6.	At 200 feet above the assigned recovery altitude, level your wings whether into the wind or not.
 * 7.	At 150 feet above the recovery altitude, check collective full down and assume an 8 to 10-degree nose up attitude -(flare) on the attitude indicator (depending on gross weight and wind conditions). When established in the flare, smoothly advance the twist grip to the full open position and ensure nf and nr are "married."
 * 8.	At 75 feet above recovery altitude, coordinate up collective and forward cyclic to complete the recovery at the recovery altitude with 40 kias. Recovery altitude will be no lower than 1000 feet msl.
 * 9.	Return to 80 kias at the recovery altitude.

NOTE:	At any time prior to the recovery, the instructor has the option to pull the instrument hood and have the student continue the maneuver as an engine failure at altitude. The student should transition to a VFR scan and fly the aircraft to intercept an autorotative profile to a selected landing site. Waveoff will be completed by the IP no lower 300 feet AGL (initiated at 400 feet AGL).


 * For BIs/RIs, reference proceedures on Inst FTI p3-14,15