Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

Belavia 737 landing accidents lessons for the unwary.

Tech Log The very best in practical technical discussion on the web

Belavia 737 landing accidents lessons for the unwary.

Old 9th May 2020, 07:58
  #1 (permalink)  
Thread Starter
 
Join Date: Jun 2000
Location: Australia
Posts: 3,973
Belavia 737 landing accidents lessons for the unwary.

Two same company B737 landing incidents with common denominator.
.EW-290PA 737-500 Runway Excursion Landing in Fog
EW-336PA 737-300 Runway Excursion on Landing

During simulator training it is quite common for see crews leaving the autothrottles engaged during manual flying. That includes manual landing. This is what happened in the 737-300 incident at Kiev. The FCTM states "Autothrottle use is recommended during takeoff and climb in either automatic or manual flight. During all other phases of flight autothrottle use is recommended only when the autopilot is engaged in CMD. The autothrottle ARM mode is normally not recommended because its function can be confusing.".

Another common observation in the simulator is the complete cancellation of reverse thrust at the 60 knots call by the PM. Snapping the reverse thrust levers to fully down at 60 knots means significant forward thrust occurs as the translating sleeves move towards close and the N1 is still relatively high on the way down to ground idle. The FCTM states the thrust levers should be positioned to reverse idle by taxi speed and then only full down after the engines have decelerated to idle.

The final report on both accidents has been published but is only available in Russian language. Does anyone know if English language versions are available?

Centaurus is offline  
Old 9th May 2020, 11:42
  #2 (permalink)  
 
Join Date: Mar 2006
Location: USA
Posts: 1,613
On the second point, I often observe people go from max reverse to fwd idle at once- on multiple types. Never really understood the rush.
Check Airman is online now  
Old 9th May 2020, 13:12
  #3 (permalink)  
 
Join Date: Jan 2014
Location: N5109.2W10.5
Posts: 647
Originally Posted by Centaurus View Post
The final report on both accidents has been published but is only available in Russian language. Does anyone know if English language versions are available?
Google Translate does a excellent job.
Goldenrivett is offline  
Old 9th May 2020, 13:41
  #4 (permalink)  
 
Join Date: Sep 2002
Location: La Belle Province
Posts: 2,147
The autothrottle ARM mode is normally not recommended because its function can be confusing.
That's an incredibly mealy-mouthed sentence, and I notice it's in the FCTM, which I assume is an unapproved document. I assume the AFM doesn't actually prohibit use in the mode discussed? But I then wonder "why not?" given the statement about confusion. I think you'd have some issues certifying a system that could be described in such terms today.
Mad (Flt) Scientist is offline  
Old 9th May 2020, 15:19
  #5 (permalink)  
 
Join Date: Jan 2006
Location: US
Posts: 2,177
Originally Posted by Check Airman View Post
On the second point, I often observe people go from max reverse to fwd idle at once- on multiple types. Never really understood the rush.
The crazy part is feeling the plane accelerate as they stow the buckets. The N1's are still spinning in the mid 30's if you rapidly stow the reversers. That's a lot of thrust, more then you'd ever need at landing weight, for taxi power. On the bigger jets the N1 spool down is even slower. So it's not uncommon to have the transfer of control back to the Captain with the engines still in reverse.
misd-agin is offline  
Old 9th May 2020, 17:23
  #6 (permalink)  
 
Join Date: Apr 2010
Location: IRS NAV ONLY
Posts: 892
Originally Posted by Mad (Flt) Scientist View Post
That's an incredibly mealy-mouthed sentence, and I notice it's in the FCTM, which I assume is an unapproved document. I assume the AFM doesn't actually prohibit use in the mode discussed? But I then wonder "why not?" given the statement about confusion. I think you'd have some issues certifying a system that could be described in such terms today.
Sure, it's not forbidden to use A/T in ARM mode for landing. A lot of things come down to airmanship and common sense, not everything is a hard limitation. And if the manufacturer doesn't recommend something and does not include such procedure / technique in their SOP, there is probably a good reason for it.

The following is from FCOM NP:
For a single channel approach, disengage the autopilot and disconnect the autothrottle no later than minimum use height for single autopilot operation.
​​​​​​See how it says disconnect autothrottle and not "deselect SPD mode".
FlyingStone is online now  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.