Just noticed the AOA display on our 737-800's...http://members.ozemail.com.au/~b744er/737/AOA.jpgNote the red bug and the readout. I have no idea what this represents and why the AOA in PMDG is different. Any clues?Thanks.Cheers.Ian.P.S. BTW, the IRU's were not aligned and the aircraft was on Ext Power.

Stick shaker indicator, blank if AOA signal is invalid.. http://forums.avsim.net/user_files/39046.jpg[h4]Best Wishes,Randy J. Smithhttp://img.villagephotos.com/p/2003-8/196432/winglets_lg.jpg [h3] AMD XP 2200 |MUNCHKIN 512 DDR RAM |ECS[/b ][i] K7S5A MB[/i] |GF2 MX 32 MEG and still runs GOOD!|WIN XP PRO |MITSUBISHI DIAMOND PLUS 91 19"[/h3]

Why is my pitch indication reading 7.5 degrees, And the AOA indicating 0 degrees? Am I missing something? Thank's From Jim ;) http://forums.avsim.net/user_files/39047.jpgHere is a max GW climbout, They still don't match. http://forums.avsim.net/user_files/39052.jpghttp://forums.avsim.net/user_files/39053.jpg

I am just a simple RL GA pilot and I dont even own this software, but somebody correct me if I am wrong here. Pitch and angle of attack are not the same thing and would only match in a very specific case. One is the body angle of the deck (attitude) and the other is the angle of incidence of air flow relative to the wing.I may be wrong but the two images above actually seem correct to me.anyone??

I would think that EADI pitch and body angle were one and the same?

I think Mike is correct. He is not saying EADI pitch and body angle are different (although they may be, I guess, depending on how they are defined). What he is saying is that pitch angle and angle of attack are two separate quantities. As far as I am aware, this is a true and correct statement.

Thanks, Randy...Any idea why the 1.0 in my pic, rather than 0.0?I think I'll leave the debate on body AOA, airplane attitude and wing AOA alone for the moment ;-) I do know various corrections are applied to AOA for some cockpit indications, but I don't know which ones.Cheers.Ian.

hehe, yes Mike is on to something ;), think relative! Weird Ian, it says it should be 0.0 so who knows lol...[h4]Best Wishes,Randy J. Smithhttp://img.villagephotos.com/p/2003-8/196432/winglets_lg.jpg [h3] AMD XP 2200 |MUNCHKIN 512 DDR RAM |ECS[/b ][i] K7S5A MB[/i] |GF2 MX 32 MEG and still runs GOOD!|WIN XP PRO |MITSUBISHI DIAMOND PLUS 91 19"[/h3]

Mike,Based on my knowledge of aviation I would say you are right. You might actually check this with cross-checking pitch angle, AoA-readout and FPA on the DES page during descent.And from what I've seen PMDG is calculating the difference correctly. Though it seems like the AoA differs from real AoA at ground. See below. (EDIT: Possibly due to IRUs not aligned.)Regards,

Hi all,Talking about AoA. I've noticed that during level flight the A/C has an AoA of about zero degrees. To my knowledge the 737 is famous for having an approx 3 degree nose up attitude (a posh lady this 737 ;-)) during level flight with CoG within normal limits.Anyone care to comment on this?PS. Ian, could the 1 degree readout be caused by the IRUs not being aligned, as Randy stated the AoA is derived from the ADIRU?Regards,

Here is a discription of the F-18 Hornet's system, Which gives the pilot revelent info as far as being at the optimum Lift over drag approach speed. In the 737-700 POH I have, On the discription of the FMC decent page, FPA is defined as" The actual flight path angle based on current ground speed & verticle speed (that is, the present verticle bearing being flown) So my question is, What is being indicated on the EADI? Body angle, Wing AOA or a combination of both. And what does this tell the 737 crew?http://forums.avsim.net/user_files/39076.jpg

MatsFor you to see an AoA of about zero degrees in level flight you must have been light, low, and fast. For example, take a look at this.http://forums.avsim.net/user_files/39074.jpgWe're in the -700 with a gross weight of about 121,000 lbs at 11,000 ft, blasting along with an IAS of 330 kts. Our AoA is 0.4 degrees. This is indeed pretty close to zero.Now take a look at this.http://forums.avsim.net/user_files/39075.jpgAt FL370 doing Mach 0.759 our AoA is now 2.9 degrees - this is the 3 degrees you've heard about. If we had a bigger fuel load on the AoA would be even higher.One other interesting thing I noticed when performing these tests. You get the same AoA for the same IAS (assuming weight isn't significantly different) IRRESPECTIVE of the altitude. At first this surprised me but then I realised it is correct. The increased AoA at FL370 comes about precisely because our IAS is so much lower than it was at 11,000 ft. If I could get the aircraft to 330 kts IAS at FL370 without breaking it I'm sure the AoA would be pretty close to 0.4 degrees.Anyway, hope you find this of interest.

Craig,Great post! I was indeed light and fast when I noticed yesterday. It was only me and my F/O (221 kg with the flight manuals...lol) doing a test flight at FL350 at M0.78.I will test with a big bunch of Economy Class livestock once I get home today. ;-)Regards,

Please keep in mind AoA is defined as the angle between the relative wind and the wing's mean chord line. It has absolutely nothing to do with the body.Lee Hetherington (KBED)

> So my question is, What is being indicated on the EADI?>Body angle, Wing AOA or a combination of both. And what does>this tell the 737 crew?>AOA is what indicated on the EADI. Mike had it right, AOA is independent of body pitch angle. Angle of attack is the angle between the relative wind and the wing chord line. (Wing chord line is a straight line connecting the leading and trailing edges of the wing.) In contrast, the pitch angle shown on the EADI is relative to the horizon.In a climb or descent (like those illustrated in the examples shown in the original post), the relative wind is canted relative to the horizon. That is why the AOA and the pitch angle are not the same.What does it tell the pilot? Well, it is not a primary control parameter. Pitch attitude is the control instrument used to control to an airspeed. AOA can provide a backup to check for things like airspeed instrument problems, very large gross weight errors, incorrect flap settings, etc.Don S.