Boeing stickshakers & pushers
Joined: Jan 2002
Posts: 960
Likes: 0
From: Brisbane, Australia
Right, I thought!!!
Only UK regestered, or previously regestered aircraft had 'stick - pushers'.
The B747 has two different stall warning systems -
* the normal one, which we all are familiar with, with two seperate systems installed, (most times) gives a stick shaker, according to AIS and flap position set.
* the other, is actually an 'over-rotation' system, and ONLY works during take-off, after the NLG has departed the runway, and continues until the MLG tilts detect they also have departed the runway.
It's info, regarding the rate of rotation, is sensed by the #1 INS system.
The B747 can only tolerate about 11.5 degrees of nose up, with the MLG still on the ground, before a tail-strike is likely.
(We used to have SO much trouble with those new FOs, from the B737 fleet, prior to the -700 series, with them 'reefing' the nose up at rotation!)
And the lever latch is the most 'instant' indication that the body-gear wheels have left the ground!
Cheers
Only UK regestered, or previously regestered aircraft had 'stick - pushers'.
The B747 has two different stall warning systems -
* the normal one, which we all are familiar with, with two seperate systems installed, (most times) gives a stick shaker, according to AIS and flap position set.
* the other, is actually an 'over-rotation' system, and ONLY works during take-off, after the NLG has departed the runway, and continues until the MLG tilts detect they also have departed the runway.
It's info, regarding the rate of rotation, is sensed by the #1 INS system.
The B747 can only tolerate about 11.5 degrees of nose up, with the MLG still on the ground, before a tail-strike is likely.
(We used to have SO much trouble with those new FOs, from the B737 fleet, prior to the -700 series, with them 'reefing' the nose up at rotation!)
And the lever latch is the most 'instant' indication that the body-gear wheels have left the ground!
Cheers
Joined: Feb 2002
Posts: 554
Likes: 0
From: The Sandpit
ASFKAP,
Didn't know 73's had stick pushers, I thought it was just the superstall suseptable a/c, i.e. T-tail types like the 727, which I know for sure had pushers installed. (but as previously stated only on UK reg'd a/c) In fact US reg'd a/c didn't require 2 stick shakers either, and I think they were only fitted to homogenise the production line
The 757/767 do not have pushers, only shakers, but they also have a additional recovery system in that if slats are at the intermediate position they will go to fully extended in the event of a stall warning.
The second system which detent is talking about is a speed trim system (more akin to mach trim than stall warning) and as he has stated prevents over rotation of the a/c due to the rotational torque produced by thousands of tons of thrust from engines slung under the wing.
Didn't know 73's had stick pushers, I thought it was just the superstall suseptable a/c, i.e. T-tail types like the 727, which I know for sure had pushers installed. (but as previously stated only on UK reg'd a/c) In fact US reg'd a/c didn't require 2 stick shakers either, and I think they were only fitted to homogenise the production line
The 757/767 do not have pushers, only shakers, but they also have a additional recovery system in that if slats are at the intermediate position they will go to fully extended in the event of a stall warning.
The second system which detent is talking about is a speed trim system (more akin to mach trim than stall warning) and as he has stated prevents over rotation of the a/c due to the rotational torque produced by thousands of tons of thrust from engines slung under the wing.
Guest
Posts: n/a
All Boeings will have stickshakers. Can't say I've seen any stick pushers on the newer, larger Boeings tho'.
Our company 747-400 Wiring Schematics show an Overrotation Warning system. However, neither I nor my fellow engineers have seen the components associated with it or worked on this mysterious system. Perhaps a mistake made by the Boeing printers?
Rgds.
Q.
Our company 747-400 Wiring Schematics show an Overrotation Warning system. However, neither I nor my fellow engineers have seen the components associated with it or worked on this mysterious system. Perhaps a mistake made by the Boeing printers?
Rgds.
Q.
Joined: Jul 2000
Posts: 1,424
Likes: 0
From: Smogsville
Stick Nuggers or Pushers are an option as is the over rotation warning system.
I believe the FAA don't allow Pushers though, as I worked on a couple of ANA classics that had been sold and were to be re registered under the FAA, Nxxxxx.
We had to remove the Pushers and a number of other Items, even the fake leather on the staircase handrails, we were told all items being removed were an FAA requirement, then their inspectors came along and checked all the paperwork before giving it a new registration.
It seeems strange not to allow pushers does anyone know of any FAA registered A/C with a pusher.
I believe the FAA don't allow Pushers though, as I worked on a couple of ANA classics that had been sold and were to be re registered under the FAA, Nxxxxx.
We had to remove the Pushers and a number of other Items, even the fake leather on the staircase handrails, we were told all items being removed were an FAA requirement, then their inspectors came along and checked all the paperwork before giving it a new registration.
It seeems strange not to allow pushers does anyone know of any FAA registered A/C with a pusher.
Joined: Apr 2002
Posts: 734
Likes: 0
From: Nirvana South
All the Bombardier biz-jets and RJs have pushers which are all TCA, JAA and FAA certified. They use the same basic pusher originally built by Jet Electronics.
To meet the requirements for "unintentional push" both L & R channels must independently trigger their side of the Pusher plus the crew have instinctive disconnect switches on the yoke.
To meet the requirements for "unintentional push" both L & R channels must independently trigger their side of the Pusher plus the crew have instinctive disconnect switches on the yoke.
Joined: Feb 1998
Aviation Qualifications: ATPL
Posts: 1,595
Likes: 0
From: Formerly of Nam
Id like to know if the 737 local stick-pusher mods affect Boeings windshear-recovery technique. Given that flying a handful of knots above the stall may prevent a prang, Id be hard-pressed to trust anything trying to slam-dunk me into the hills!
