Boeing 757 turn rate?

[Garyurbach]

Can anybody here tall me what the standard rate of turn is in a 757? Is it the
same as small palnes, i.ei, is it universal at 360 degrees in 2 minutes?

I've got someone telling me the Boeing 757 that hit the Pentagon did some
impossible turn before flying into the building, and it sounds like a turnign
decent to me.

Any help would be appreciated.

[zatatime]

On 04 Jun 2004 16:57:20 GMT, (Garyurbach) wrote:

>Can anybody here tall me what the standard rate of turn is in a 757? Is it the
>same as small palnes, i.ei, is it universal at 360 degrees in 2 minutes?
>
>I've got someone telling me the Boeing 757 that hit the Pentagon did some
>impossible turn before flying into the building, and it sounds like a turnign
>decent to me.
>
>Any help would be appreciated.
>


A standard rate turn is 360 degrees in 2 minutes for all planes.
However the bank angle required to accomplish this depends on
airspeed. For most large jets the cruise airspeed standard rate turn
would exceed 30 (maybe 45) degrees of bank. Therefore they are
restricted to 25 degrees of bank.

Now, this does not mean a 757 can't physically turn more steeply than
that, it just states how they are governed. I'm sure a 757 would have
no problem performing a 60 or greater degree bank angle, just as the
707 had no problem being rolled during its test flight.

HTH.

z

[Arbr64]

The Standard Rate turn for jets is HALF of that of small airplanes.

I.E. 4 minutes to complete 360 degrees or 1.5 degrees per second, as opposed
to 2 minutes to complete 360 degrees, or 3 degrees per second.

"Garyurbach" > wrote in message
...
> Can anybody here tall me what the standard rate of turn is in a 757? Is it
the
> same as small palnes, i.ei, is it universal at 360 degrees in 2 minutes?
>
> I've got someone telling me the Boeing 757 that hit the Pentagon did some
> impossible turn before flying into the building, and it sounds like a
turnign
> decent to me.
>
> Any help would be appreciated.
>
>
>

[Arbr64]

> A standard rate turn is 360 degrees in 2 minutes for all planes.
> However the bank angle required to accomplish this depends on
> airspeed.
The Standard Rate Turn is a concept created a long time ago to standardize
turns so that they are predictable for both piltos and controllers.
They allow a pilot to perform any course change or turn while flying in
clouds without a compass or a heading indicator.
For instance, to change heading by 30 degrees, the pilot executes a
10-second Standard-Rate-turn if it's a small airplane, or a 20-second turn
in a jet.
The Standard Rate Turn is the rate-of-turn used by the autopilots when it
executes turns.

This however, has nothing to do with the aircraft's ability to perform steep
turns (45 degrees and beyond), or even rolls if the pilot wanted to.

> For most large jets the cruise airspeed standard rate turn
> would exceed 30 (maybe 45) degrees of bank.
This is the reason the Standard Rate turn in a jet is 1.5 degrees per second
or 4 minutes for 360 degrees turns.
Just a quick note : Airliners execute turns of AT LEAST 30 degrees bank
every time, except when performing small course corrections while in cruise.

> Therefore they are restricted to 25 degrees of bank.
Where did you get this from ? There is no such thing. Airliners execute 45
degree banks on every flight.
25 degrees of bank doesn't produce much of a heading change in a jet, test
it yourself in FS.

> Now, this does not mean a 757 can't physically turn more steeply than
> that, it just states how they are governed. I'm sure a 757 would have
> no problem performing a 60 or greater degree bank angle, just as the
> 707 had no problem being rolled during its test flight.

Correct. They can and they do perform steep turns every day.
The 757 and the 707, as well as all other Boeings (except the 777) have
"conventional" controls, meaning, the control surfaces are directly
connected to the cockpit (they may be hydraulically assited), and therefore,
they can do whatever the pilot wants them to do.
The newer "Fly-By-Wire" airplanes like the A320 and the subsequent Airbuses
have certain limitations built into the software to prevent sudden maneuvers
and to protect the airplane from undesired things such as stalling, but even
these will allow steep turns.

[zatatime]

On Tue, 08 Jun 2004 07:18:13 GMT, "Arbr64"
> wrote:

>> Therefore they are restricted to 25 degrees of bank.

>Where did you get this from ? There is no such thing. Airliners execute 45
>degree banks on every flight.
>25 degrees of bank doesn't produce much of a heading change in a jet, test
>it yourself in FS.


From some test I had to take in life (Ican't remember if it was a
written, or just a test in a different class). What I omitted was
"aircraft with a Flight Director/Autopilot installed are permitted to
use the maximum rate of turn commanded by the FD/AP (which is
generally 25 degrees)."

I've also learn from following this thread that airlines do 4 minute
turns as a general rule.

z

[Bas Jansen]

Arbr64 wrote:

> The Standard Rate Turn is a concept created a long time ago to standardize
> turns so that they are predictable for both piltos and controllers.
> They allow a pilot to perform any course change or turn while flying in
> clouds without a compass or a heading indicator.
> For instance, to change heading by 30 degrees, the pilot executes a
> 10-second Standard-Rate-turn if it's a small airplane, or a 20-second turn
> in a jet.
> The Standard Rate Turn is the rate-of-turn used by the autopilots when it
> executes turns.

The standard rate turn is just that... a _standard_. No use for a
'standard' if it differs from airplane type, right? A standard rate is
the same across the board. Whether it be an airliner or a small single
engine prop...

> This is the reason the Standard Rate turn in a jet is 1.5 degrees per second
> or 4 minutes for 360 degrees turns.
> Just a quick note : Airliners execute turns of AT LEAST 30 degrees bank
> every time, except when performing small course corrections while in cruise.

I'm sorry but you're wrong here. The autopilot logic regarding
bank_angle is more or less the same for every passenger plane. I fly the
Boeing 737 5 days a week and it never exceeds 30 degrees of bank except
when it intercepts a localizer or VOR radial at a high angle... When
it does it certainly won't exceed 35 because warning bells would go off
(voice warning "bank angle!").

In order to maintain a standard rate turn the required bankangle will
increase as speed increases. I don't have the formula here but I can
tell you that if your doing i.e. 300kts you need more than 25 degrees to
maintain a standard rate turn. Airlines try to keep a standard rate turn
except when it requires a bankangle steeper than 25. The reason is,
primarily, passenger comfort.

In cruise the bankangle depends on the autopilot mode. Usually its in
LNAV (lateral nav. mode) whereby the autoflight system is coupled to the
FMS or RNav system. In that case the bankangle limit is set at 15
degrees (or some low value depending on aircraft type). If the
autoflight system is in HDG (heading mode) it limits bankangle to
whatever is selected on the flight director panel. Usually 25 degrees
with a maximum of 30 degrees and a minimum of 10.


> Where did you get this from ? There is no such thing. Airliners execute 45
> degree banks on every flight.

No they never do, see explanation above.

> 25 degrees of bank doesn't produce much of a heading change in a jet, test
> it yourself in FS.

Mickey$oft FS is crap. Are you trying to prove your point by referring
to a game?

I turn with 25 degrees or LESS almost every day and I have no problems.
I have yet to have a controller yell at me for turning too slow. As a
matter of fact, if I were to turn with 45 degrees of bank I'd be in the
chief-pilots office the very same day... and it won't be a social call!

Zatatime, don't listen to what Arbr64 says. I don't know where he gets
his information from but he either misunderstood or has no clue whatsoever.

Regards.

[zatatime]

On Mon, 14 Jun 2004 08:08:01 +0200, Bas Jansen
> wrote:

>Arbr64 wrote:
>
>> The Standard Rate Turn is a concept created a long time ago to standardize
>> turns so that they are predictable for both piltos and controllers.
>> They allow a pilot to perform any course change or turn while flying in
>> clouds without a compass or a heading indicator.
>> For instance, to change heading by 30 degrees, the pilot executes a
>> 10-second Standard-Rate-turn if it's a small airplane, or a 20-second turn
>> in a jet.
>> The Standard Rate Turn is the rate-of-turn used by the autopilots when it
>> executes turns.
>
>The standard rate turn is just that... a _standard_. No use for a
>'standard' if it differs from airplane type, right? A standard rate is
>the same across the board. Whether it be an airliner or a small single
>engine prop...
>
>> This is the reason the Standard Rate turn in a jet is 1.5 degrees per second
>> or 4 minutes for 360 degrees turns.
>> Just a quick note : Airliners execute turns of AT LEAST 30 degrees bank
>> every time, except when performing small course corrections while in cruise.
>
>I'm sorry but you're wrong here. The autopilot logic regarding
>bank_angle is more or less the same for every passenger plane. I fly the
>Boeing 737 5 days a week and it never exceeds 30 degrees of bank except
> when it intercepts a localizer or VOR radial at a high angle... When
>it does it certainly won't exceed 35 because warning bells would go off
>(voice warning "bank angle!").
>
>In order to maintain a standard rate turn the required bankangle will
>increase as speed increases. I don't have the formula here but I can
>tell you that if your doing i.e. 300kts you need more than 25 degrees to
>maintain a standard rate turn. Airlines try to keep a standard rate turn
>except when it requires a bankangle steeper than 25. The reason is,
>primarily, passenger comfort.
>
>In cruise the bankangle depends on the autopilot mode. Usually its in
>LNAV (lateral nav. mode) whereby the autoflight system is coupled to the
>FMS or RNav system. In that case the bankangle limit is set at 15
>degrees (or some low value depending on aircraft type). If the
>autoflight system is in HDG (heading mode) it limits bankangle to
>whatever is selected on the flight director panel. Usually 25 degrees
>with a maximum of 30 degrees and a minimum of 10.
>
>
>> Where did you get this from ? There is no such thing. Airliners execute 45
>> degree banks on every flight.
>
>No they never do, see explanation above.
>
>> 25 degrees of bank doesn't produce much of a heading change in a jet, test
>> it yourself in FS.
>
>Mickey$oft FS is crap. Are you trying to prove your point by referring
>to a game?
>
>I turn with 25 degrees or LESS almost every day and I have no problems.
>I have yet to have a controller yell at me for turning too slow. As a
>matter of fact, if I were to turn with 45 degrees of bank I'd be in the
>chief-pilots office the very same day... and it won't be a social call!
>
>Zatatime, don't listen to what Arbr64 says. I don't know where he gets
>his information from but he either misunderstood or has no clue whatsoever.
>
>Regards.


Thanks.. I had already lauged off his reply. I know someone who flew
the 57 and 67 for American for many years. He idn't go into as much
detail as you, but summarized the same facts. Usenet has to be taken
with a grain of salt many times. I appreciate your input.

z