FAA Issues SAFOs re: ATC Closures in Terminal Airspace and Loss of ATC Services in Oceanic Airspace

SAFO 20012 re: ATC Closures in Terminal Airspace

SAFO 20011 re: Loss of ATC Services in Oceanic Airspace

FAA Publishes 2 New KTEB IAPs and a Redesigned ILS – Effective May 21, 2020

Updated May 22, 2020

The long-awaited RNAV (GPS) Y RWY 19 and RNAV (GPS) RWY 24, as well as a redesigned ILS RWY 19, are now available in Chart and Navigation Databases, effective May 21, 2020.

All of these procedures include RNAV transitions, and the RNAV (GPS) Y RWY 19 and ILS RWY 19 offer the same minima. The RNAV (GPS) Y RWY 19 is essentially an overlay to the ILS that eliminates the latter procedure’s glide slope perturbation issue. Both the RNAV (GPS) Y and redesigned ILS RWY 19 feature the same Missed Approach Procedure. For all of these reasons, we are advocating in favor of the RNAV (GPS) Y RWY 19 as the primary IAP when KTEB operates on a southerly flow.

Please note that if you accept a clearance to fly the ILS RWY 19, the procedure now requires RNAV 1-GPS due to the new Missed Approach Procedure.

As the RNAV (GPS) RWY 24 will require Air Traffic Controller training in the Sim Lab, now restricted due to COVID-19, it’s unclear when this procedure will first be utilized.

We’ve posted extracts (Not For Navigation) from the FAA’s Terminal Procedures Publication below so that users can begin to familiarize themselves with these new IAPs.

The RNAV (GPS) X RWY 19 is another IAP under development and features an offset final approach course, but is expected to be published in 2021 due to delays in Environmental Assessment.

A representative from NY TRACON will discuss these new procedures during our upcoming TUG WebEx Meeting, scheduled for June 17 at 1000. TUG will publish the WebEx invitation, details and full agenda at our earliest opportunity.

Not For Navigation

Not For Navigation

NY TRACON LETTER TO AIRMEN re: KTEB RNAV (GPS) X Rwy 6

Please see the following N90 LTA.

Note also when executing this approach that the Missed Approach Point is JEBUV, which is located 1.1 nm prior to the runway threshold on the 063 final approach course. Upon reaching JEBUV, the FMS will no longer provide lateral and vertical guidance to the runway.

Lessons Learned: Non-Precision Approaches

A business jet crew on arrival to KTEB prepared to fly the ILS Rwy 19. Upon retrieval of the most recent ATIS, however, they learned that the G/S was OTS. The crew then briefed the LOC Rwy 19 approach, and confirmed that the avionics were properly configured for the localizer only. Consistent with best practices for a stabilized approach, they planned to execute a Continuous Descent Final Approach (CDFA), and so calculated a Derived Decision Altitude (DDA) of 630’ (50’ above MDA). The crew used APP mode to capture the localizer and Path/Vertical Speed mode to initiate the descent. During the final approach segment, they learned that the preceding aircraft had executed a Missed Approach. At their DDA of 630’, the crew hadn’t visually acquired the runway environment, and similarly executed a Missed Approach. Pursuant to their interpretation of the published procedure, they began an immediate climbing right turn to a 205 heading, and noticed that the flight guidance was inconsistent with their lateral track. The FMS did not appear to have sequenced to the Missed Approach Segment as expected. Consequently, the crew manually flew the Missed Approach procedure. Once established on the published 278 course to MORNS, they manually sequenced the FMS direct to MORNS.

The crew then elected to conduct a second approach, but this time chose to perform a “Dive & Drive” as opposed to a CDFA.  Prior to reaching the Missed Approach Point, they visually acquired the runway environment and made a normal descent to landing.

The crew subsequently forwarded the following observations, and requested comment:

– The missed approach point for this procedure is not co-located with the runway end.

– The FMS coding, however, takes you all the way to the runway end.

– “Dive & Drive” generated a successful result, whereas CDFA did not.

TUG forwarded the crew’s narrative to NBAA’s Access Committee for review and comment.

For reference, here is the FAA chart:

The review revealed that the FMS behaved correctly. However, the crew did not follow the published Missed Approach procedure.  Upon reaching the DDA of 630’ on a CDFA Localizer only approach, they had not reached the published LOC Missed Approach Point of I-TJL 1.9D, 0.8 NM from the runway threshold as depicted in the profile view:

In order to maintain safe clearance from the WABC antenna just west of the Final Approach Course, it’s necessary to continue straight ahead until passing the I-TJL 1.9D MAP before commencing the turn to heading 205. The aircraft is protected in the same way if the pilot flies the ILS 19 to the published DA of 307’.

ARINC 424 FMS coding conventions have indeed created inconsistencies. TERPS & PANS-OPS utilize specific methodologies that are independent of ARINC 424, and mis-matches occasionally occur. Let’s further explore this example using the Garmin 750:

As is typical of ILS approaches, RW19 is coded as the Missed Approach Point, followed by a straight climb to 409’, and then direct to TROVA. Although inconsistent with the published procedure specification of an immediate right turn to heading 205, once the aircraft has passed the RW19 MAP and climbed above 409’ MSL, the FMS should sequence Direct to TROVA as depicted below:

Since the airplane on the Missed Approach is already at least 630’ (LOC Rwy 19 DDA), the CA (Course to Altitude) leg’s 409’ altitude constraint is already satisfied.  Therefore, after passing the RW19 MAP waypoint, the FMS should cycle immediately to the second part of the Missed Approach: the DF (Direct to Fix) leg to TROVA. In other words, the flight guidance should initiate a turn to TROVA after passing the RW19 MAP waypoint.

There is indeed an inconsistency between the ARINC 424 coding and the published procedure: The published MAP for the ILS or LOC Rwy 19 approach is not the RW19 threshold waypoint as coded in the NDB (Navigation Data Base). However, this is standard ARINC coding practice for conventional procedures. Although ARINC 424 specifications exist for moving a MAP from the runway threshold, thereby creating a “MAP” waypoint, no such coding was defined for this procedure.

Even considering this inconsistency, TERPS standards have removed the use of the word “immediate” on departures and approaches. When flying the ILS Rwy 19 approach, executing a Missed Approach at the 307’ DA will result in the aircraft reaching 409’ MSL at approximately the point where the RW19 MAP sequences. The FMS and Flight Director would then command a direct-to TROVA leg, making it highly improbable that any loss of obstacle clearance or traffic separation could occur during this interval.

As to the question of CDFA vs. “Dive & Drive”, operational experts fully support CDFA and stabilized approaches as a best practice. However, Flight Procedures in OKC develop NPAs (Non-Precision Approaches) with the intent that the aircraft is level at MDA with enough time to visually acquire the runway environment (approach lights, runway, etc.), and then make a normal descent to the runway.  A level segment at MDA gives the pilot the opportunity not afforded by the visibility minima and DDA on a CDFA NPA.  In other words, it makes a missed approach more likely. Pick your poison: Risk of unstable approach vs. higher risk of a missed approach. And there are times, like a circling approach where “dive and drive” is appropriate.

Comment:

  • Pursuant to AIM 5-4-21, be sure not to initiate the Missed Approach turn prior to the Missed Approach Point.
  • Review the Missed Approach legs. Note where the Missed Approach is coded to begin (e.g., RW19, MAP24, etc.). That’s where the FMS will sequence to the coded Missed Approach Segment.
  • Note the leg type of the first segment of the Missed Approach. Is it a VA-DF or CA-DF leg? NDB coding does not always match the published procedure.
  • CDFA vs. “Dive & Drive” each offer advantages and disadvantages. Determine which is best for the specific operation, and realize that your decision does not alleviate all risks. You may be trading one risk for another.