Wikiposts
Search
Military Aviation A forum for the professionals who fly military hardware. Also for the backroom boys and girls who support the flying and maintain the equipment, and without whom nothing would ever leave the ground. All armies, navies and air forces of the world equally welcome here.

Buff upgrade

Thread Tools
 
Search this Thread
 
Old 21st Oct 2022, 18:41
  #21 (permalink)  
 
Join Date: Apr 2004
Location: Dorset UK
Age: 70
Posts: 1,899
Likes: 0
Received 15 Likes on 12 Posts
Globalnav:
Yes they were used over Bosnia, 1998/99.
I remember seeing 5 going SW over my house in Somerset one morning and also hearing them calling London one evening when inbound to Fairford while we were inbound to Stansted.
dixi188 is offline  
Old 21st Oct 2022, 19:31
  #22 (permalink)  
 
Join Date: Jun 1999
Location: Lost
Posts: 387
Received 4 Likes on 4 Posts
Great reads:

Amazon Amazon
Dunhovrin is offline  
Old 22nd Oct 2022, 07:47
  #23 (permalink)  
 
Join Date: Oct 2018
Location: Ferrara
Posts: 8,469
Received 364 Likes on 213 Posts
Of course they should have been re-engined years ago - they could be on their 3rd or 4th set of engines if the investment has been made - but all the cash goes on designing shiny new toys - some of which even make it into production - and then fade away whilst the B-52's just keep going
Asturias56 is offline  
Old 22nd Oct 2022, 10:58
  #24 (permalink)  
 
Join Date: Nov 2004
Location: Here, there, and everywhere
Posts: 1,125
Likes: 0
Received 12 Likes on 7 Posts
Originally Posted by k3k3
One of the main problems with the idea of four big fans, was the lack of rudder authority in the event of losing an outboard engine in a critical phase of flight .
Take a look at the size of the rudder in terms of chord as compared to the vertical stab. It is amazingly small. Same with the elevator. Compare it with the 4-engine KC-135.

It is no wonder the B-52 has crosswind landing gear……it needs it.

https://aviation.stackexchange.com/q...-a-tiny-rudder
punkalouver is online now  
Old 22nd Oct 2022, 15:46
  #25 (permalink)  
Ecce Homo! Loquitur...
 
Join Date: Jul 2000
Location: Peripatetic
Posts: 17,444
Received 1,602 Likes on 734 Posts

Last edited by ORAC; 22nd Oct 2022 at 16:20.
ORAC is online now  
Old 22nd Oct 2022, 16:18
  #26 (permalink)  
 
Join Date: Oct 2018
Location: Ferrara
Posts: 8,469
Received 364 Likes on 213 Posts
its blank ORAC
Asturias56 is offline  
Old 22nd Oct 2022, 16:21
  #27 (permalink)  
Ecce Homo! Loquitur...
 
Join Date: Jul 2000
Location: Peripatetic
Posts: 17,444
Received 1,602 Likes on 734 Posts
Working perfectly for me - absolutely standard youtube link.

ORAC is online now  
Old 22nd Oct 2022, 16:46
  #28 (permalink)  
 
Join Date: Jan 2008
Location: Glorious Devon
Posts: 2,700
Received 949 Likes on 563 Posts
Originally Posted by ORAC
Working perfectly for me - absolutely standard youtube link.
Blank for me too, you forgot to put the link in quotes
Ninthace is online now  
Old 22nd Oct 2022, 16:47
  #29 (permalink)  
Gnome de PPRuNe
 
Join Date: Jan 2002
Location: Too close to Croydon for comfort
Age: 60
Posts: 12,637
Received 300 Likes on 168 Posts
Works for me...
treadigraph is offline  
Old 22nd Oct 2022, 17:22
  #30 (permalink)  
Ecce Homo! Loquitur...
 
Join Date: Jul 2000
Location: Peripatetic
Posts: 17,444
Received 1,602 Likes on 734 Posts
You don’t have to put youtube links in quotes, they usually work with just a straight paste.
ORAC is online now  
Old 22nd Oct 2022, 17:44
  #31 (permalink)  

"Mildly" Eccentric Stardriver
 
Join Date: Jan 2000
Location: England
Age: 77
Posts: 4,142
Received 224 Likes on 66 Posts
Click on "quote". You should find it in there.
Herod is offline  
Old 22nd Oct 2022, 18:46
  #32 (permalink)  
 
Join Date: May 2002
Location: Downeast
Age: 75
Posts: 18,290
Received 517 Likes on 215 Posts
I did not use Quotation Marks for the YouTube video I posted.....just a copy of the highlighted information in the address bar and paste in the Message Block here.

Perhaps there is a bit of delay in the linked video appearing?
SASless is online now  
Old 22nd Oct 2022, 20:11
  #33 (permalink)  
 
Join Date: Jan 2008
Location: Glorious Devon
Posts: 2,700
Received 949 Likes on 563 Posts
Originally Posted by ORAC
You don’t have to put youtube links in quotes, they usually work with just a straight paste.
Fact remains, I can see your quoted Youtube link but not the original which is still a blank.
Ninthace is online now  
Old 22nd Oct 2022, 20:21
  #34 (permalink)  
 
Join Date: Apr 2004
Location: Dorset UK
Age: 70
Posts: 1,899
Likes: 0
Received 15 Likes on 12 Posts
I wonder if it is still true that "The father of the last B52 pilot is yet to be born"?
I heard that about 30 years ago.
dixi188 is offline  
Old 22nd Oct 2022, 20:58
  #35 (permalink)  
 
Join Date: Jan 2008
Location: Reading, UK
Posts: 15,822
Received 206 Likes on 94 Posts
Originally Posted by ORAC
You don’t have to put youtube links in quotes, they usually work with just a straight paste.
PPRuNe has its own (Youtube) tag, which tends to work more reliably than simply using a (URL) tag. Using square brackets, obviously:



(quote this post to see the code)
DaveReidUK is offline  
Old 22nd Oct 2022, 21:12
  #36 (permalink)  
 
Join Date: Feb 2021
Location: E Midlands
Posts: 1
Received 1 Like on 1 Post
Originally Posted by k3k3
One of the main problems with the idea of four big fans, was the lack of rudder authority in the event of losing an outboard engine in a critical phase of flight .
that is my understanding of the issue as well.
NicolaJayne is offline  
Old 22nd Oct 2022, 22:01
  #37 (permalink)  
 
Join Date: Dec 2014
Location: The wrong timezone
Posts: 271
Received 11 Likes on 3 Posts
Originally Posted by DaveReidUK
Many reasons why not, some alluded to above.

You could start by simply comparing the fan diameter of the F130/BR700 with that of any of the current big fans.
The main issue is that if you lose an engine (with a quarter of the thrust, rather than an eighth), the rudder would need to be larger to counteract the swing. I imagine that might also require the fuselage to be rebuilt for greater strength to accommodate the greater forces that a new rudder would bring. Additionally if the engines have to be moved forward like on the 737 debacle, then you'd also possibly need better elevators too and a stronger tailplane. At that point probably easier to go for a clean sheet design. Don't quote me on this but I imagine these are the main considerations.
anson harris is offline  
Old 22nd Oct 2022, 22:36
  #38 (permalink)  
 
Join Date: Jan 2008
Location: Reading, UK
Posts: 15,822
Received 206 Likes on 94 Posts
Originally Posted by anson harris
Additionally if the engines have to be moved forward like on the 737 debacle, then you'd also possibly need better elevators too and a stronger tailplane.
The difference in diameter between the big fans and the F130 is much greater than that between the 737NG's CFM56 and the Max's LEAP, so I don't think any pylon configuration would allow a 4-engine option.

Unless they stuck them on top of the wing à la HondaJet/VFW614.
DaveReidUK is offline  
Old 23rd Oct 2022, 02:24
  #39 (permalink)  
 
Join Date: Aug 2013
Location: Washington.
Age: 74
Posts: 1,077
Received 151 Likes on 53 Posts
Originally Posted by dixi188
Globalnav:
Yes they were used over Bosnia, 1998/99.
I remember seeing 5 going SW over my house in Somerset one morning and also hearing them calling London one evening when inbound to Fairford while we were inbound to Stansted.
Thank you, I supposed so. I remember thinking how lame USAF A&D was during the 70’s and 80’s not to come up with a suitable replacement for the venerable BUFF. But now I’m just grateful for the skill and hard-nosed leadership and engineering that wrought it. The KC135 too has been a capable and faithful work horse, even relatively primitive as it is compared to the alternatives. Nothing seems to beat quality and robust design.

I don’t want to forget, either, the sacrifices in peacetime and combat of the heroic crews who flew them, nor all the skilled ground support that kept them flying. I’m so proud to have served in the USAF during those years, proud of what I belonged to.
GlobalNav is offline  
Old 23rd Oct 2022, 03:14
  #40 (permalink)  
 
Join Date: Mar 2005
Location: N/A
Posts: 5,951
Received 397 Likes on 210 Posts
From the flight manual.

FLIGHT CHARACTERISTICS WITH ENGINE FAILURE

SINGLE ENGINE FAILURE

The loss of an engine at any time during takeoff or while in flight is considered an emergency, regardless of the amount of thrust still available, since some emergency procedure must be executed. The loss of an engine during takeoff can be controlled easily by correct application of rudder pedal force and a slight amount of lateral control force. The rudder pedal force required in the event of an outboard engine failure is about 40 pounds at speeds below takeoff speed with zero trim. The force increases to about 80 pounds at the recommended climbout speed. All of this rudder correction usually can be removed by application of rudder trim. The rudder trim limits should be observed. See "Airspeed Limitations, " Section V.

MULTI-ENGINE FAILURE ON ONE SIDE
During inflight emergencies involving multi-engine failures on one side, applications of large amounts of rudder and lateral control are necessary in order to maintain control when extreme amounts of asymmetrical thrust exist or are applied, Application of this control creates severe loads on the aircraft structure. These loads vary in magnitude in accordance with the degree of thrust dissymmetry, degree of deflection of corrective rudder. rate of rudder application, amount of yaw/roll displacement that has taken place prior to rudder application, abruptness with which engine thrust is removed, indicated airspeed, gross weight, center oi‘ gravity, fuel distribution, amount oi air turbulence present, aircraft configuration including flaps and landing gear positions, missile loading, external tank loading, etc. If these variables occur in certain combinations, critical structural loads can result. In view of the difficulty in controlling these variables, close observance of the following procedure will minimize the possibility of structural overload.

1. If asymmetrical thrust develops abruptly, the resulting yaw/roll tendency should be counteracted with lateral control followed by steady rudder application. Trim as required to balance control forces.
2. If thrust requirements permit, readjust the power on the remaining engines to minimize control surface deflections‘ Power adjustments should be applied slowly and simultaneously with control surface movement.
3. Avoid turbulent air and limit bank angle to 20° maximum.

PERFORMANCE - WARNING - Nonzero lateral trim resulting from inoperative engines must not be compensated for by fuel manipulation because an uncontrollable roll may occur when power is reduced on approach for landing.

This aircraft is unique in its ability to handle asymmetrical thrust conditions provided the prescribed procedures are followed. See "Multi-Engine Failure on One Side, " this section. The takeoff and climbout performance of the aircraft with inoperative engines is shown in Parts 2, 3, and 4 of the Appendix, In each case, the inoperative engines are assumed to be in the most outboard positions and all on the same side. This is the most adverse condition from the stand point of trim drag which is associated with control surface deflections. Advancing the throttles to full travel in an emergency situation will give maximum thrust. This may exceed normal engine limits. Overthrusting the engines will accentuate the aircraft control problems and reduce engine life. All instances of overthrust. as indicated by excessive EGT and/or rpm will be recorded can Form 781. See "Engine Limitations," Section V.
megan is offline  


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

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.