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sai001
18th Feb 2007, 16:51
I am interested in knowing what sort of maximum pitch angles occur in the current (large civil) fleet during normal operation at take-off? My guess is that a light 757 operating out of somewhere like John Wayne would be near the maximum seen in practice but does anyone know what this is?
My interest stems from looking at low noise operations of future aircraft so am more interested in limits imposed by airlines for passenger comfort than limits imposed by aircraft capability. Any references to published documentation would be great.
Thanks.

hetfield
18th Feb 2007, 16:52
Most Buses use 20 degr.

kenparry
18th Feb 2007, 17:21
My experience is of Boeing only - B737-200, 757, 767-200/300, all now some years ago.
The Boeing Flight Crew Training Manuals did not impose a maximum body angle, but the UK airline that I flew for had a limit of 20 degrees nose-up for all the above, mainly out of consideration for the passengers. This angle could be achieved on all those types.

javelin
18th Feb 2007, 17:26
A330, out of maintenance - empty, engineers asked for a full power takeoff.................

Full back stick after normal rotation to stop speed going silly, settled at about 28 degrees, 8,500 f.p.m climb :ok:

hetfield
18th Feb 2007, 17:30
"what sort of maximum pitch angles occur"

Sorry didn't get that in my previous post.

Don't know, cause we are limited to 20 degr.:O

Intruder
19th Feb 2007, 18:13
747 stick shaker starts at 17-17.5 deg, so we never intentionally go above that.

411A
19th Feb 2007, 23:28
Max pitch on the L1011 after takeoff is 17.5 degrees...seldom achieved unless very light.
Follow the flight director, as it indicates the proper pitch vs weight (mass for our European folks), and is quite accurate, even for an old design.

During approach, 7.5 degrees is normal, for all weights.
DLC works good....:D

V2+ A Little
19th Feb 2007, 23:56
Is that 17 - 17.5 degrees angle of atack surely. Don't think it has to do with the actual aircraft pitch angle. I don't know the 747, so just speculating.

Intruder
20th Feb 2007, 02:43
The AOA input may activate it earlier at heavier weights, but IIRC it also activates at the pitch limit of 17-17.5 deg.

Clean, stall buffet occurs WELL before stick shaker.

vwreggie
20th Feb 2007, 04:11
normal pitch on a 747 was 13 degrees 4 engine and 11for an engine inop. Cant remember a max as described above but I got twitchy as a fo if anyone hit 15 and I only ever saw that in the sim.
On a 737 the understood max is 20 because if you are reacting to a little shear with an increasing headwind then as soon as you pass through the shear the bunt forward is uncomfortable and unprofessional. The flight directors are set at 15 degrees for the takeoff roll until some seconds after takeoff and then targets v2 +15 tov2 +25 which works out around 15 degrees on two engines and 12 on one

sai001
20th Feb 2007, 16:22
Thanks for the responses - sounds like 20 degrees is pretty common for a large twin.
It will be interesting to see what next generation of twins are capable of (B787 for example) as they have significantly higher bypass ratios than even the new 777s leading to much more take-off thrust being available (at least in theory).

Mad (Flt) Scientist
20th Feb 2007, 17:18
Since the regulatory requirements for single engine climb capability aren't going to change (significantly) and no-one is going to design for excess performance just for the sake of it, chances are that the performance-limited pitch attitudes will be pretty similar.

But in any case the 20 degree number seems to be a pax comfort limit anyway.

xetroV
20th Feb 2007, 18:29
85 degrees, give or take a few. (http://www.youtube.com/watch?v=ygh5dGuCWkc)






Oh, I see you were talking about normal operation. ;)

Intruder
20th Feb 2007, 18:31
normal pitch on a 747 was 13 degrees 4 engine and 11for an engine inop.
Depends on TO Gross weight. It can be as low as 11 deg at max TOGW and as high as 16 deg at near-empty weights.

Loose rivets
20th Feb 2007, 20:36
I have always thought that it is important to really know your airplane. Going way outside normal operating angles is just one invaluable piece of practice.

It gives a huge amount of confidence when being thrashed in a storm for example.

A roll in a 707 is a non event, but I'm really surprised that Johnson did a chandelle. I always found it very difficult to maintain less than 1.5 g on this maneuver, and almost always nearing 2g.

The real problem is that so often the second manouevre of a string goes pear-shaped. The temptation to put an even sightly stressed airplane back in the hanger--and say nothing, is too great. As said above, ready for some unsuspecting colleague to take it over.

misd-agin
22nd Feb 2007, 03:10
Company limit of 25 degrees.

Departing SNA (John Wayne), just south of LAX, and standard pitch attitude is 22-23 degrees depending on a/c weight.

Jgossett
22nd Feb 2007, 06:01
I use to live a couple miles from SNA and always travel out of that airport because of the accent. Ont and Lax just aren't as fun :}

wileydog3
22nd Feb 2007, 09:30
The SNA departure was more like an airshow. Combined with the steep pitch (22-24deg) and the immediate cutback on power to quietly exit the area, we were required to brief the passengers on the very unusual departure. The difference in noise from climb power to cutback sounded like the engines had flamed out..

The concern a lot of crews had was what would happen if you had a catastrophic engine failure with the nose parked up at 20+deg and just about when you were doing the cutback.

For normal ops, we were limited to 20deg pitch.