Is the MD-11's third engine slightly nose up?
From my visual inspection, the third engine (the engine on the horizontal stabilizer) is slightly "nose up", especially compared to the engines on the wing. That means, the front part of the engine is lifted slightly. Am I correct? If yes, what is the intention?
aircraft-design aircraft-performance md-11
edited 2 days ago
Pondlife
50.3k8135278
asked 2 days ago
AirCraft LoverAirCraft Lover
400112
add a comment |
From my visual inspection, the third engine (the engine on the horizontal stabilizer) is slightly "nose up", especially compared to the engines on the wing. That means, the front part of the engine is lifted slightly. Am I correct? If yes, what is the intention?
aircraft-design aircraft-performance md-11
edited 2 days ago
Pondlife
50.3k8135278
asked 2 days ago
AirCraft LoverAirCraft Lover
400112
Closely related
– Pondlife
2 days ago
add a comment |
From my visual inspection, the third engine (the engine on the horizontal stabilizer) is slightly "nose up", especially compared to the engines on the wing. That means, the front part of the engine is lifted slightly. Am I correct? If yes, what is the intention?
aircraft-design aircraft-performance md-11
edited 2 days ago
Pondlife
50.3k8135278
asked 2 days ago
AirCraft LoverAirCraft Lover
400112
From my visual inspection, the third engine (the engine on the horizontal stabilizer) is slightly "nose up", especially compared to the engines on the wing. That means, the front part of the engine is lifted slightly. Am I correct? If yes, what is the intention?
aircraft-design aircraft-performance md-11
aircraft-design aircraft-performance md-11
edited 2 days ago
Pondlife
50.3k8135278
asked 2 days ago
AirCraft LoverAirCraft Lover
400112
edited 2 days ago
Pondlife
50.3k8135278
asked 2 days ago
AirCraft LoverAirCraft Lover
400112
edited 2 days ago
Pondlife
50.3k8135278
edited 2 days ago
Pondlife
50.3k8135278
edited 2 days ago
Pondlife
50.3k8135278
50.3k8135278
asked 2 days ago
AirCraft LoverAirCraft Lover
400112
asked 2 days ago
AirCraft LoverAirCraft Lover
400112
asked 2 days ago
AirCraft LoverAirCraft Lover
400112
400112
Closely related
– Pondlife
2 days ago
add a comment |
Closely related
– Pondlife
2 days ago
Closely related
– Pondlife
2 days ago
Closely related
– Pondlife
2 days ago
add a comment |
3 Answers
3
active
oldest
votes
Yes, there is a slight tilt to the engine. Engines are heavy, so placing them on the tail shifts the center of mass towards the tail, which is not good for stability. To counter this, aircraft with rear engines often tilt the engines slightly, so the thrust they produce can offset their own weight, helping with stability. It's extremely slight though, as large angles can produce major pitch oscillations with power changes (something known as pitch coupling).
answered 2 days ago
Nathan ChetramNathan Chetram
1162
New contributor
Nathan Chetram is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
I believe it has a 4deg incline to align the exhaust with the drag from the fuselage.
It appears more because the inlet is higher than the engine.
http://drawingdatabase.com/mcdonnell-douglas-md-11/
answered 2 days ago
AnilvAnilv
2,7591011
add a comment |
It may be for the same reason down thrust angle is commonly put into tractor engine mounts - to compensate for pitch up tendency of air craft as they accelerate from added thrust leading to increased velocity.
The third engine of the tri-jet is simply pushing the tail up as thrust is applied. This is something very beneficial in the event of a power-on stall as it assists the elevator in
lowering the nose.
Adding up thrust in the back to compensate for weight imbalance would have to be questioned from an engineering point of view, as failure of this engine would create a dangerous aft CG imbalance. It is wise not to rely on thrust or trim to correct an out of safe
range CG. Better to move the wing back a bit, as long as it is still directionally stable.
answered yesterday
Robert DiGiovanniRobert DiGiovanni
1,6331315
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "528"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2faviation.stackexchange.com%2fquestions%2f58858%2fis-the-md-11s-third-engine-slightly-nose-up%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
Yes, there is a slight tilt to the engine. Engines are heavy, so placing them on the tail shifts the center of mass towards the tail, which is not good for stability. To counter this, aircraft with rear engines often tilt the engines slightly, so the thrust they produce can offset their own weight, helping with stability. It's extremely slight though, as large angles can produce major pitch oscillations with power changes (something known as pitch coupling).
answered 2 days ago
Nathan ChetramNathan Chetram
1162
New contributor
Nathan Chetram is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
Yes, there is a slight tilt to the engine. Engines are heavy, so placing them on the tail shifts the center of mass towards the tail, which is not good for stability. To counter this, aircraft with rear engines often tilt the engines slightly, so the thrust they produce can offset their own weight, helping with stability. It's extremely slight though, as large angles can produce major pitch oscillations with power changes (something known as pitch coupling).
answered 2 days ago
Nathan ChetramNathan Chetram
1162
New contributor
Nathan Chetram is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
Yes, there is a slight tilt to the engine. Engines are heavy, so placing them on the tail shifts the center of mass towards the tail, which is not good for stability. To counter this, aircraft with rear engines often tilt the engines slightly, so the thrust they produce can offset their own weight, helping with stability. It's extremely slight though, as large angles can produce major pitch oscillations with power changes (something known as pitch coupling).
answered 2 days ago
Nathan ChetramNathan Chetram
1162
New contributor
Nathan Chetram is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Yes, there is a slight tilt to the engine. Engines are heavy, so placing them on the tail shifts the center of mass towards the tail, which is not good for stability. To counter this, aircraft with rear engines often tilt the engines slightly, so the thrust they produce can offset their own weight, helping with stability. It's extremely slight though, as large angles can produce major pitch oscillations with power changes (something known as pitch coupling).
answered 2 days ago
Nathan ChetramNathan Chetram
1162
New contributor
Nathan Chetram is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 2 days ago
Nathan ChetramNathan Chetram
1162
New contributor
Nathan Chetram is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 2 days ago
Nathan ChetramNathan Chetram
1162
answered 2 days ago
Nathan ChetramNathan Chetram
1162
1162
New contributor
Nathan Chetram is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Nathan Chetram is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Nathan Chetram is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
add a comment |
I believe it has a 4deg incline to align the exhaust with the drag from the fuselage.
It appears more because the inlet is higher than the engine.
http://drawingdatabase.com/mcdonnell-douglas-md-11/
answered 2 days ago
AnilvAnilv
2,7591011
add a comment |
I believe it has a 4deg incline to align the exhaust with the drag from the fuselage.
It appears more because the inlet is higher than the engine.
http://drawingdatabase.com/mcdonnell-douglas-md-11/
answered 2 days ago
AnilvAnilv
2,7591011
add a comment |
I believe it has a 4deg incline to align the exhaust with the drag from the fuselage.
It appears more because the inlet is higher than the engine.
http://drawingdatabase.com/mcdonnell-douglas-md-11/
answered 2 days ago
AnilvAnilv
2,7591011
I believe it has a 4deg incline to align the exhaust with the drag from the fuselage.
It appears more because the inlet is higher than the engine.
http://drawingdatabase.com/mcdonnell-douglas-md-11/
answered 2 days ago
AnilvAnilv
2,7591011
answered 2 days ago
AnilvAnilv
2,7591011
answered 2 days ago
AnilvAnilv
2,7591011
answered 2 days ago
AnilvAnilv
2,7591011
2,7591011
add a comment |
add a comment |
It may be for the same reason down thrust angle is commonly put into tractor engine mounts - to compensate for pitch up tendency of air craft as they accelerate from added thrust leading to increased velocity.
The third engine of the tri-jet is simply pushing the tail up as thrust is applied. This is something very beneficial in the event of a power-on stall as it assists the elevator in
lowering the nose.
Adding up thrust in the back to compensate for weight imbalance would have to be questioned from an engineering point of view, as failure of this engine would create a dangerous aft CG imbalance. It is wise not to rely on thrust or trim to correct an out of safe
range CG. Better to move the wing back a bit, as long as it is still directionally stable.
answered yesterday
Robert DiGiovanniRobert DiGiovanni
1,6331315
add a comment |
It may be for the same reason down thrust angle is commonly put into tractor engine mounts - to compensate for pitch up tendency of air craft as they accelerate from added thrust leading to increased velocity.
The third engine of the tri-jet is simply pushing the tail up as thrust is applied. This is something very beneficial in the event of a power-on stall as it assists the elevator in
lowering the nose.
Adding up thrust in the back to compensate for weight imbalance would have to be questioned from an engineering point of view, as failure of this engine would create a dangerous aft CG imbalance. It is wise not to rely on thrust or trim to correct an out of safe
range CG. Better to move the wing back a bit, as long as it is still directionally stable.
answered yesterday
Robert DiGiovanniRobert DiGiovanni
1,6331315
add a comment |
It may be for the same reason down thrust angle is commonly put into tractor engine mounts - to compensate for pitch up tendency of air craft as they accelerate from added thrust leading to increased velocity.
The third engine of the tri-jet is simply pushing the tail up as thrust is applied. This is something very beneficial in the event of a power-on stall as it assists the elevator in
lowering the nose.
Adding up thrust in the back to compensate for weight imbalance would have to be questioned from an engineering point of view, as failure of this engine would create a dangerous aft CG imbalance. It is wise not to rely on thrust or trim to correct an out of safe
range CG. Better to move the wing back a bit, as long as it is still directionally stable.
answered yesterday
Robert DiGiovanniRobert DiGiovanni
1,6331315
It may be for the same reason down thrust angle is commonly put into tractor engine mounts - to compensate for pitch up tendency of air craft as they accelerate from added thrust leading to increased velocity.
The third engine of the tri-jet is simply pushing the tail up as thrust is applied. This is something very beneficial in the event of a power-on stall as it assists the elevator in
lowering the nose.
Adding up thrust in the back to compensate for weight imbalance would have to be questioned from an engineering point of view, as failure of this engine would create a dangerous aft CG imbalance. It is wise not to rely on thrust or trim to correct an out of safe
range CG. Better to move the wing back a bit, as long as it is still directionally stable.
answered yesterday
Robert DiGiovanniRobert DiGiovanni
1,6331315
answered yesterday
Robert DiGiovanniRobert DiGiovanni
1,6331315
answered yesterday
Robert DiGiovanniRobert DiGiovanni
1,6331315
answered yesterday
Robert DiGiovanniRobert DiGiovanni
1,6331315
1,6331315
add a comment |
add a comment |
Thanks for contributing an answer to Aviation Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2faviation.stackexchange.com%2fquestions%2f58858%2fis-the-md-11s-third-engine-slightly-nose-up%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Closely related
– Pondlife
2 days ago