Predictive windshear warning

[Stabmotion]

Originally Posted by Derfred

Not in my Boeing… could you elaborate? Or copy/paste?

I cannot find it in google so I copy/paste from the manuals in my computer.

Note this bulletin is version 3, and is applicable to a specific version of the weather radar equipped by different Boeing aircrafts. It’s not the Multiscan.

It happened to me in different operators with different Boeing models in airports not listed in this bulletin. Previous experience is something to consider always.



Number: CEX-19 R3
Issue Date: May 17, 2021
Subject: Predictive Windshear System Anomaly
Reason: This bulletin informs flight crews of the susceptibility of certain airports to false Predictive Windshear System (PWS) alerts.
This bulletin is being revised to update the list of affected airport/runway combinations. Information in this bulletin is recommended by The Boeing Company, but may not be FAA approved at the time of writing. In the event of conflict with the FAA approved Airplane Flight Manual (AFM), the AFM shall supersede. The Boeing Company regards the information or procedures described herein as having a direct or indirect bearing on the safe operation of this model airplane. THE FOLLOWING PROCEDURE AND/OR INFORMATION IS EFFECTIVE UPON RECEIPT
Background InformationAirlines have reported false Predictive Windshear System (PWS) alerts at a number of airports. The anomaly is only applicable to PWS alerts; all reactive windshear alerts which occur are valid. These false alerts are limited to airplanes equipped with the Honeywell weather radar with the following PWS weather radar processor part numbers:

• 066-50008-0406 (All listed airports)

• 066-50008-0408 (All listed airports)

• 930-1000-001 (SBRJ airport only)

• 930-1000-002 (SBRJ airport only)

• 930-1000-003 (SBRJ airport only)

Honeywell has reviewed data provided by the affected airlines and has attempted to determine if particular airports and runways may be susceptible to “false alerts”. In addition, data have been analyzed to determine if the alerts are more likely during takeoff or on approach.

Honeywell has accumulated sufficient data to suggest that the following airport/runway combinations are susceptible to false PWS alerts:

• EHAM (Amsterdam), Runway 9, Takeoff

• GCRR (Lanzerote), Runway 3, Approach

• KBOS (Boston), Runway 27, Approach

• KOAK (Oakland), Runway 29, Approach

• KPHL (Philadelphia), Runway 35, Approach

• KSNA (John Wayne Orange County), Runway 19R, Approach

• KSTL (St. Louis), Runway 12 (L and R), Approach

• LEBL (Barcelona), Runway 25, Approach

• LFMN (Nice), Runway 4L, Approach

• LGSR (Santorini), Runway 34R, Approach

• RJTT (Tokyo, Haneda), Runways 16 and 22, Approach

• RKPK (Busan, Gimhae), Runways 36L and 36R, Takeoff

• RKSI (Seoul, Incheon), Runway 33R, Approach

• SBRJ (Rio de Janeiro), Runway 20L, Approach

Although these particular airports appear to be more susceptible to false alerts, the data indicates the majority of operations at these airports do not experience false PWS alerts.

Flight crews should use the following criteria to help determine if windshear exists:

• reports of windshear from other aircraft

• visual indications

• tower windshear alerts

• differences between computed winds in the airplane and reported winds from the tower.

Honeywell has developed software modifications that should significantly reduce the occurrences of false PWS alerts. These modifications also include numerous other changes and enhancements. Service Letters 737-SL-34-188 and 737-SL-34-189 provide additional information about these changes.

As Honeywell continues to develop a software solution and to process data, operators are encouraged to continue reporting incidents to Honeywell and Boeing in order to provide the most effective solution possible to this anomaly.

Operating InstructionsIf windshear is encountered, perform the Windshear Escape Maneuver.

It is recommended operators establish policies for flight crews operating into one of the reported airport and runway combinations in the event a PWS alert occurs. The following windshear criteria may be beneficial in establishing policies:

• reports of windshear from other aircraft

• visual indications

• tower windshear alerts

• differences between computed winds in the airplane and reported winds from the tower.

Administrative Information
This bulletin replaces bulletin CEX-19 R2, dated October 22, 2018. Revise the Bulletin Record Page to show bulletin CEX-19 R2 as “CANCELLED” (CANC).Insert this bulletin behind the Bulletin Record page in Volume 1 of your Flight Crew Operations Manual (FCOM). Amend the FCOM Bulletin Record page to show bulletin CEX-19 R3 "In Effect" (IE).

Please send all correspondence regarding Flight Crew Operations Manual Bulletin status, to the 737 Manager, Flight Technical Data, through the Service Requests Application (SR App) on the MyBoeingFleet home page.