The FAA has released InFO 11009, "Failure to Comply with Minimum Crossing Altitudes at Stepdown Fixes Located on Instrument Landing System (ILS) Inbound Courses," and updated the guidance on this topic in the Aeronautical Information Manual (AIM). These changes are as a result of the NBAA Access Committee’s involvement in the Aeronautical Charting Forum.
On ILS approaches, step-down fixes are established for obstacle avoidance or for the purpose of traffic separation between aircraft underflying or overflying the final approach course or being vectored on the final approach course of the adjacent runway. For all practical purposes, the ILS glide slope remains stationary regardless of atmospheric temperature. Conversely, step-down fixes are published for a pilot to fly using indicated altitude, which varies with temperature changes. Therefore, the indicated altitude at each step-down fix in reference to the glide slope, changes with the temperature.
What this means to pilots is that on some approaches, outside the final approach segment, on a cool day, you might be able to follow the glide slope and remain above all the published minimum step-down fix altitudes. However, on hotter than ISA standard days, an aircraft tracking a glide slope will fly below the minimum altitude for the published step-down fixes. This could result in loss of separation between parallel or crossing traffic maintaining assigned altitude by reference to an altimeter. To avoid a loss of separation, and a possible pilot deviation filing by ATC, pilots flying an ILS with step-down fixes prior to the final approach fix must comply with the minimum step-down altitude, even if it means remaining above the ILS glide slope until reaching the final approach fix.
On some approaches, a maximum or mandatory altitude may be published at a step-down fix for traffic separation purposes, e.g., the mandatory 1,500 ft. MSL altitude at DANDY on the TEB ILS Runway 06. The position of the glide slope at these fixes may be well above the published maximum or mandatory altitude at the fix. To avoid a loss of separation, pilots must comply with the published maximum or mandatory altitude at each step-down fix.
The ILS glide slope is intended to be intercepted at the published glide slope intercept altitude. This point marks the precision approach final approach fix (PFAF) and is depicted by the “lightning bolt” symbol on U.S. government charts or the beginning of the feather in the profile view on Jeppesen charts. Intercepting the glide slope at this altitude marks the beginning of the final approach segment and ensures required obstacle clearance during descent from the glide slope intercept altitude to the lowest published decision altitude for the approach. Interception and tracking of the glide slope prior to the published glide slope interception altitude does not necessarily ensure that minimum, maximum, and/or mandatory altitudes published for any preceding fixes will be complied with during the descent. If the pilot chooses to track the glide slope prior to the glide slope interception altitude, they remain responsible for complying with published altitudes for any preceding step-down fixes encountered during the subsequent descent.
There have been numerous pilot deviations filed at various airports around the country, including Los Angeles International Airport (LAX), Hartsfield - Jackson Atlanta International Airport (ATL), Salt Lake City International Airport (SLC) and Teterboro Airport (TEB).
The following additional advisory language will be added to the AIM 5-4-5 b:
2. The ILS glide slope is intended to be intercepted at the published glide slope intercept altitude. This point marks the PFAF and is depicted by the “lightning bolt” symbol on U.S. Government charts. Intercepting the glide slope at this altitude marks the beginning of the final approach segment and ensures required obstacle clearance during descent from the glide slope intercept altitude to the lowest published decision altitude for the approach. Interception and tracking of the glide slope prior to the published glide slope interception altitude does not necessarily ensure that minimum, maximum, and/or mandatory altitudes published for any preceding fixes will be complied with during the descent. If the pilot chooses to track the glide slope prior to the glide slope interception altitude, they remain responsible for complying with published altitudes for any preceding step-down fixes encountered during the subsequent descent.
View FAA InFO 11009, "Failure to Comply with Minimum Crossing Altitudes at Stepdown Fixes Located on Instrument Landing System (ILS) Inbound Courses"
1. Rockford Approach Control provides air traffic control service, VFR, and IFR, to the following airports:
Janesville Rock County (JVL) Rochelle Municipal (RPJ)
Monroe Municipal (EFT) Dixon Municipal (C73)
Beloit (44C) Sterling Whiteside County (SQI)
Poplar Grove (C77) Freeport Albertus (FEP)
Delavan Lake Lawn (C59) DeKalb (DKB)
2. Rockford Approach Control will provide separation and sequencing service, until the appropriate final approach fix (FAF) inbound, for aircraft practicing instrument approaches at the airports listed above. Rockford Approach Control frequencies are: East -121.0; West–126.0
3. Services are provided on a workload-permitting basis. There may be occasions when the controller, due to traffic volume or other considerations, may be unable to approve a practice instrument approach or may withdraw a previous approval. In these circumstances, the controller will attempt to give an estimated time when these services may be resumed.
4. Pilots requesting a practice instrument approach should provide the controller with the aircraft call sign, type aircraft, type of approach, and how the approach will terminate.
5. Clearance for a practice instrument approach does not constitute approval for the execution of the published missed approach procedure. Execution of the published missed approach procedure must be specifically requested by the pilot and approved by the controller.
6. This service does not relieve pilots of their responsibility to see and avoid other aircraft operating in VFR weather conditions, nor does it relieve pilots of maintaining VFR conditions equal to or greater than those specified in FAR 91-105. If a clearance issued by a controller would cause the pilot to be in non-compliance with FAR 91-105, the pilot should advise the controller immediately.
Last week's Runway Safety Council meeting again noted that pilots caused two-thirds of runway incursions, and of those, 80 percent were general aviation operations. As instructors, we have a responsibility to help our students and customers remain vigilant in avoiding runway incursions. While knowledge is important, so is simple situational awareness. Many pilots know what a hold short line is, but when they're distracted, they may find themselves inadvertently crossing it while looking down to program a GPS, deciphering an unfamiliar airport layout, or fumbling over a complex clearance; indeed, 75 percent of pilot-caused runway incursions include crossing a hold short line without a clearance.
The FAA's continuing focus on runway-incursion prevention will soon lead to a change in practical tests; incursions will no longer be a special emphasis item, they'll be an area of operation in the future. This is expected to begin with the CFI practical test standards (PTS), followed by the private pilot, instrument pilot, and commercial pilot PTS. We support this change, and we recommend that instructors emphasize this material with their students, even before it becomes an area of operation on practical tests. We'll be sure to provide an update when this change occurs, including when updates to any of the practical test standards are made.
While serious incursions are down for the year-to-date, the overall rate is slightly higher than FAA's targeted rate, even while overall GA operations are down. Take the time to work with your local airport users; this isn't a positive trend, and the flight instructor community has the ability to reverse it for the remainder of the year.
Pilot altitude deviations often occur when flying a published departure or standard arrival procedure. Many procedures have published altitudes that ATC expects the pilot to follow. A thorough understanding of the following ATC phraseology and ILS altitude information will reduce deviations and subsequent danger to pilots and passengers.
“DESCEND AND MAINTAIN”- Instructs the pilot to descend now (at a standard rate) to the newly assigned altitude and maintain that altitude until a new altitude assignment is received. The pilot will disregard all altitudes published on the STAR.
“DESCEND VIA” – Instructs a pilot to vertically navigate on the STAR and comply with published speeds.
“RESUME THE ARRIVAL” – Instructs a pilot to rejoin the lateral confines of the arrival only. Previously issued speeds and altitudes are still required.
“CLIMB AND MAINTAIN” – Instructs the aircraft to climb now (at a standard rate) to the newly assigned altitude and maintain that altitude until a new altitude assignment is received. Pilots will disregard all altitudes published on the SID.
“RESUME NORMAL SPEED” – Instructs a pilot to comply with speeds published on the SID.
“DELETE SPEED RESTRICTIONS” – Instructs the pilot to disregard all previously issued speeds including speeds on upcoming portions of an RNAV SID.
“RESUME THE DEPARTURE” – Instructs a pilot to rejoin the lateral confines of the departure only. Previously issued speeds and altitudes are still required.
A Precision Final Approach Fix (PFAF) and/or a Glideslope Intercept Point defines the final approach segment (the end of the “feather”) as depicted in the Profile View on the approach plate. From the PFAF or Glideslope Intercept Point to the runway, use of the approach mode (APP) is the proper way to navigate the ILS. Without explicit guidance otherwise, there is no provision for capturing the glideslope beyond the PFAF or Glideslope Intercept Point and all altitude constraints must be met. Published altitudes at fixes outside of the Precision Final Approach Fix are part of the initial or intermediate segments of the approach and provide vertical separation from obstructions or other aircraft. An extension of the glideslope may not satisfy the minimum altitudes published outside the PFAF.
A review of Chapter 5 in the Aeronautical Information Manual (AIM) can refresh your understanding of Departure, Enroute, and Arrival procedures. Here is a direct link which you can copy and paste into your browser: http://www.faa.gov/air_traffic/publications/ATpubs/AIM/chap5toc.htm
(This information is provided to all pilots, those with instrument ratings and those without, because the principle of following established procedures applies to all. In addition, just in case you are getting your instrument rating next week, we wanted you to have this information, as well.)