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Flying the Approach.
Timing. Timing is required when the final approach does not terminate at a published fix, as is usually
the case with VOR, NDB, and localizer. If timing is required to identify the MAP, begin timing when
passing the FAF or the starting point designated in the timing block of the approach plate. This point
is usually the FAF, but it may be a fix not co-located with the FAF such as a LOM, NDB, crossing
radial, DME fix, or outer marker. Time and distance tables on the approach chart are based on
groundspeed; therefore, the existing wind and TAS must be considered to accurately time the final
approach. Use timing (when required or as a backup) on all approaches with published timing.
(1). If timing is not specifically depicted on the instrument approach procedure, timing is not authorized as a
means of identifying the MAP.
(2). Timing is the least precise method of identifying the MAP; therefore, when the use of timing is not
authorized for a particular approach because of TERPs considerations, timing information will not be
(3). If other means of identifying the MAP are published (e.g. DME), they should be used as the primary means
to determine the MAP. In these situations, timing is a good backup, but it is not the primary means of
identifying the MAP. For example, if you reach the published DME depicting the MAP, do not delay
executing the missed approach just because you have not reached your timing.
(4). The middle marker may never be used as the sole means of identifying the MAP. The middle marker may
assist you in identifying the MAP on certain localizer approaches provided it is coincident with the
published localizer MAP. To determine the location of the MAP, compare the distance from the FAF to
MAP adjacent to the timing block. It may not be the same point as depicted in the profile view. If the MM
is received while executing such an approach, and your primary indications (DME and/or timing) agree,
you may consider yourself at the MAP and take appropriate action. If the middle marker is the only way to
identify the MAP (i.e., timing is not published), then the approach is not authorized.
Turns. When a turn is required over the FAF, turn immediately and intercept the final approach course
to ensure obstruction clearance airspace is not exceeded.
Descent. Avoid rapid descent requirements on final by crossing the FAF at the published altitude.
Determine the approximate initial descent rate required on final approach by referring to the "rate of
climb/descent table" in the IAP books or by using one of the techniques in section 412. The maximum
descent gradient from the FAF to the threshold that could be required for a straight-in approach is
400 ft/nm (800 ft/min with a groundspeed of 120 knots). However, you should plan to arrive at the
MDA with enough time and distance remaining to identify the runway environment and depart the
MDA from a normal visual descent point (VDP). A common technique to ensure arrival at the MDA
prior to the VDP is to use an 800-1000 FPM rate of descent as a starting point; strong headwinds or
tailwinds and length of the final approach will dictate whether to further increase or decrease this
NOTE: Non-precision approach procedures published in conjunction with an ILS cannot always clearly depict the
FAF crossing altitude. Careful review of the IAP using the following guidance is required. The minimum altitude
to be maintained until crossing the fix following the glideslope intercept point (normally the FAF will be the next fix)
is the published glideslope intercept altitude, altitude published at that fix, or ATC assigned altitude. For most non-
precision approaches the glideslope intercept altitude will be the minimum FAF crossing altitude.
Visual Descent Point. Depending on the location of the MAP, the descent from the MDA often will
have to be initiated prior to reaching the MAP in order to execute a normal (approximately 3) descent
to landing. The VDP will often be published on the approach chart; if not depicted, it may be
computed using techniques described in section 411.
Runway Environment. Descent below MDA is not authorized until sufficient visual reference with the
runway environment has been established and the aircraft is in a safe position to execute a landing.
Thorough preflight planning will aid you in locating the runway environment (lighting, final approach
displacement from runway, etc.).

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