Wikiposts
Search

Notices
Flying Instructors & Examiners A place for instructors to communicate with one another because some of them get a bit tired of the attitude that instructing is the lowest form of aviation, as seems to prevail on some of the other forums!

Critical engine

Thread Tools
 
Search this Thread
 
Old 23rd May 2002 | 16:30
  #1 (permalink)  
Thread Starter
 
Joined: Jan 2000
Posts: 26
Likes: 0
From: MK Boy
Question Critical engine

Hi guys,

Recently, a friend of mine asking me how to determine which is the critical engine on BE-76 and Baron?
Appreciated for any explaination!
King Air is offline  
Old 23rd May 2002 | 17:24
  #2 (permalink)  
 
Joined: Oct 2000
Posts: 284
Likes: 0
From: UK
You could try reading the Aircraft Manual.

If the engines are counter rotating there will be no critical engine. I believe this applies to all BE76 models.

If the engines both rotate in the same direction, typically clockwise viewed from behind, the critical engine will be the left (Port) engine
Noggin is offline  
Old 24th May 2002 | 03:36
  #3 (permalink)  
25 Anniversary
 
Joined: Dec 1999
Posts: 1,346
Likes: 132
From: I prefer to remain north of a direct line BNE-ADL
Post

Or technically in a BE-76 the critical engine would be the upwind engine when taking off in a x/wind. Although I'd regard any engine failure in a duchess as "Critical" regardless of which engines!
Angle of Attack is offline  
Old 24th May 2002 | 09:13
  #4 (permalink)  
 
Joined: Mar 2002
Posts: 550
Likes: 0
From: UK
Critical Engine : That engine which if fails will most adversely affect control of the aeroplane.

In the Dutchess and Baron, which both have props rotating in a clockwise sense, the critical engine is the left engine.

Explanation : Primarily due to P-Factor, the thrustline from both props does not go through 'the center' of the engine, but rather is displaced toward the descending blade, particularly at high angles of attack (basic PPL theory). Hence the thrustline of the left engine is closer to the longitudinal axis of the aircraft than the thrustline of the right engine. Hence if the left engine quits then the yawing moment is greater than if the right engine quits.

Torque, and slipstream also play a part in the discussion, but as I said, P factor is the major factor.
The Greaser is offline  
Old 24th May 2002 | 14:08
  #5 (permalink)  
 
Joined: Oct 2000
Posts: 284
Likes: 0
From: UK
Its actually due to asymmetric blade effect which the Americans call P-factor.
Noggin is offline  
Old 24th May 2002 | 14:54
  #6 (permalink)  
 
Joined: Mar 1999
Posts: 45
Likes: 0
From: Greater London
Exclamation !

All this talk about critical engine is a misnomer.

This is because all the V speeds and emergency proceedures for twins are based on a stated case situation which includes the assumption that the engine that has failed is the critical engine. If the other one fails you have something small in hand, BUT DONT TRY TO REMEMBER WHICH IS WHICH, FLY THE AIRCRAFT.

So as long as you fly the way the whole manual INSTRUCTS you to, it doesn't matter which engine has failed. Except from your trousers point of view.

Read the manual.
YouNeverStopLearning is offline  
Old 24th May 2002 | 15:15
  #7 (permalink)  

Beacon Outbound
20 Anniversary
 
Joined: Mar 2002
Aviation Qualifications: ATPL
Posts: 710
Likes: 22
From: "Home is were the answer machine is"
In the Dutchess and Baron, which both have props rotating in a clockwise sense, the critical engine is the left engine.
Gosh, I always thought the Duchess had counter rotating engines. You learn something new every day .

Last edited by IRRenewal; 24th May 2002 at 21:16.
IRRenewal is offline  
Old 24th May 2002 | 20:12
  #8 (permalink)  
25 Anniversary
 
Joined: Dec 1998
Posts: 4,282
Likes: 6
From: Escapee from Ultima Thule
Counter rotating in the BE76 Duchess

Clockwise for both engines in the Baron & Travelair
Tinstaafl is offline  
Old 24th May 2002 | 20:35
  #9 (permalink)  
 
Joined: Mar 2002
Posts: 550
Likes: 0
From: UK
Tinstaafl,

Thanks for clearing that up - I knew the baron had standard props, wasn't quite sure about the dutchess.
The Greaser is offline  

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



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.