Why are 757, 767, 777 throttles offset towards copilot
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Why are 757, 767, 777 throttles offset towards copilot
As I have seen in my experience, the throttle levers are often placed in the center on large jetliners so they can be used by either pilot. On smaller planes like single pilot or turboprop aircraft, they are sometimes offset towards the captain as he may be the only pilot or to make space for condition levers on turboprops.
The 757, 767 & 777's throttle levers are the only ones I've ever seen where they are slightly offset towards the first officer or copilot. These three boeing jets along with the MD-80/90 and MD-11 are the only planes I know of (apologies in advance if there are many more i don't know of) that have this 'slight right' throttle offset. All boeing jets before and after (yes the 787) have perfectly center aligned throttles.
Anyone know the reason behind this? My best guess would be to make room for the trim levers (or switch in later 75/767) or is it due to some research that right handed people seem to stretch their right hand further more comfortably or some stuff like that?
The 757, 767 & 777's throttle levers are the only ones I've ever seen where they are slightly offset towards the first officer or copilot. These three boeing jets along with the MD-80/90 and MD-11 are the only planes I know of (apologies in advance if there are many more i don't know of) that have this 'slight right' throttle offset. All boeing jets before and after (yes the 787) have perfectly center aligned throttles.
Anyone know the reason behind this? My best guess would be to make room for the trim levers (or switch in later 75/767) or is it due to some research that right handed people seem to stretch their right hand further more comfortably or some stuff like that?
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I'm not a Boeing pilot but if you look at this pic (http://cdn-www.airliners.net/aviatio.../5/2225594.jpg) you'll see that the
'box' the thrust levers are on is right in the centre. The thrust levers are offset because of the trim and speed-brake levers to the left of it. It makes sense to separate the speed-brake lever and the flap lever so I guess someone decided it was best to put the trim lever on the left side and that was that! Someone who flies Boeings might be able to provide more insight.
By the way, on jet engines the 'throttle' is called a thrust lever(s), on turboprops they're called power levers, and on piston engines they're called throttles. The definition of a throttle is "a mechanism by which the flow of a fluid is managed by constriction or obstruction." In a piston, the power is controlled by restricting the amount of air the engine can get. If you open the throttle, it'll mix with more fuel and the engine will increase in RPM. In a turbojet (very loud but used for very high and fast airplanes), turbofan (modern airliners), or turboprop (essentially a turbojet with a prop on the front) [all three are gas turbine engines], you control the engine by adding more fuel into the burner can which burns hotter/faster (harder, better, stronger..... haha jk) and that faster rushing hot air now goes through the turbine section of the gas turbine which turns it faster which is connected to the compressor at the front which sucks in more air and compresses it further which is good for the burner can because then it can add even more fuel and get the engine spinning even faster. In the end, you accelerate the particles (air and fuel) through the engine faster when you push the thrust lever forward and that creates more thrust.
'box' the thrust levers are on is right in the centre. The thrust levers are offset because of the trim and speed-brake levers to the left of it. It makes sense to separate the speed-brake lever and the flap lever so I guess someone decided it was best to put the trim lever on the left side and that was that! Someone who flies Boeings might be able to provide more insight.
By the way, on jet engines the 'throttle' is called a thrust lever(s), on turboprops they're called power levers, and on piston engines they're called throttles. The definition of a throttle is "a mechanism by which the flow of a fluid is managed by constriction or obstruction." In a piston, the power is controlled by restricting the amount of air the engine can get. If you open the throttle, it'll mix with more fuel and the engine will increase in RPM. In a turbojet (very loud but used for very high and fast airplanes), turbofan (modern airliners), or turboprop (essentially a turbojet with a prop on the front) [all three are gas turbine engines], you control the engine by adding more fuel into the burner can which burns hotter/faster (harder, better, stronger..... haha jk) and that faster rushing hot air now goes through the turbine section of the gas turbine which turns it faster which is connected to the compressor at the front which sucks in more air and compresses it further which is good for the burner can because then it can add even more fuel and get the engine spinning even faster. In the end, you accelerate the particles (air and fuel) through the engine faster when you push the thrust lever forward and that creates more thrust.
Last edited by Virtus; 25th Apr 2013 at 17:09.
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BOAC - I don't know. But this is what a throttle is: https://en.wikipedia.org/wiki/Throttle
"What is often termed a throttle (in an aviation context) is more correctly called a thrust lever."
AutoThrust-Levers is a little long to say. I'm not sure of the reasoning or history behind calling them AutoThrottles - possibly since they can be in speed or thrust mode for a Boeing. Airbus calls it AutoThrust.
"What is often termed a throttle (in an aviation context) is more correctly called a thrust lever."
AutoThrust-Levers is a little long to say. I'm not sure of the reasoning or history behind calling them AutoThrottles - possibly since they can be in speed or thrust mode for a Boeing. Airbus calls it AutoThrust.
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And we are all clever enough to know what the other means. Forward = more, back = less. Bit like that port and starboard crap. And please don't get me started on "hectopascals". 
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Thing is, auto thrust/throttle doesn't matter. The name (for the man sized lever - Boeing/comedy control - Airbus) as defined in the A320/A380/737/747/767/777 QRH's are thrust levers. Not a throttle in sight....
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It's because us 75/76 Captains are fatties......living the life of luxury of crew meals and (several)ex-wives !!! Stress adds on the pounds......
Last edited by FLCH; 26th Apr 2013 at 01:10.
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Thrust levers, throttles who cares what they're called? Call them whichever you want. Forward = fast, back = slow. Getting worked up over whichever is a sign you need to out more and meet some real human beings.
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? I've been working on 757/67/77 for 10 years now and I never noticed that offset. I checked some pictures and it's really there, what a revelation... I always thought that throttles and fuel switches were in dead center of the pedestal regardless of what was left and right of them.
Well, I can only guess that it's because the speedbrake lever on these 3 Boeing types has a whole mechanism underneath the pedestal, which is strictly located on the left side. It's a big lump which connects speedbrakes, spoilers, thrust reversers, LVDTs, etc. The flap lever doesn't have a big mechanism underneath, so there is more place on the right side.
Well, I can only guess that it's because the speedbrake lever on these 3 Boeing types has a whole mechanism underneath the pedestal, which is strictly located on the left side. It's a big lump which connects speedbrakes, spoilers, thrust reversers, LVDTs, etc. The flap lever doesn't have a big mechanism underneath, so there is more place on the right side.
Last edited by Piper19; 28th Apr 2013 at 23:08.
As to why the (OK) thrust levers are off-center in the 7(5/6/7)7, this is because there is only one trim control, meaning an odd (5) number of controls to center on the pedestal. Thrust levers had to be offset one way or the other (as to why right, in a PM/PF situation, whose hand is most often on the levers? - EDIT: or as Piper19 says, mechanical requirements)
On the 737, stab. trim is a dual wheel on both sides of the pedestal, making centering easy
Tr - Sb - Th - Th - F - Tr
On the 787 (as I understand it) stab. trim is now off the main part of the pedestal altogether, in the little well behind the captain's wrist rest (balanced by the Alt. Flaps switches of the FO's side), also making centering easy.
Sb - Th - Th - F
Tr - --- - --- - AF
On the 737, stab. trim is a dual wheel on both sides of the pedestal, making centering easy
Tr - Sb - Th - Th - F - Tr
On the 787 (as I understand it) stab. trim is now off the main part of the pedestal altogether, in the little well behind the captain's wrist rest (balanced by the Alt. Flaps switches of the FO's side), also making centering easy.
Sb - Th - Th - F
Tr - --- - --- - AF
Last edited by pattern_is_full; 28th Apr 2013 at 23:28.
