Another Question For Warren Stutt, concerning altitude Options

[Craig Ranke CIT]

Warren Stutt,

You must be aware that people are referencing you to suggest that your findings contradict the statements by P4T that the last reported altitude in the NTSB data shows a value too high to hit the light poles and the building.

Are you willing to set the record straight here and at j.ref by publicly agreeing that your findings in the data concerning altitude CONFIRM the findings of P4T that it shows the plane too high to hit the light poles and the building?

[rob balsamo]

Warren,

DCA weather values are not precise to the degree. I explained this to you above. Your initial input skews all the rest.

I will admit I dont have the time nor the desire to cross check your math. Also, if you are going to link an 86 page pdf, it might be nice to let readers know its a big pdf file before they click on it. Its just nice internet etiquette.

Bottom line...

You can spend hours upon hours attempting to fit the data to an impact, but this list will still grow with professionals who understand the big picture when reviewing the data and information. We have another update coming soon.

3 sets of independent data match. FMS, Airport and Pitot-Static. This is basic aeronautical knowledge and is why you dont see the Romper Room acting up over it, instead they are making fools of themselves over -15.6 AOA in which it appears the majority of them havent even looked at the parameter data in the files.. (I took a gander over at the cesspool tonight, what a mess...lol).

If you want to compare apples to apples further, try comparing envelopes and margins of error. Still, this would not be in your range for impact. Keep in mind, Airspeed errors are +/- 6 knots according to documents provided by apathoid. Altitude is +/-75 feet. Your correlation doesnt even start till you exceed those initial margins of error.

It would also be nice if you would inform the Romper Room regarding the fact that the data presented in your decode and the NTSB csv file has already underwent the conversion from raw data to "engineering units" using the DFL formula's. It appears apathoid is the only one who actually looked at the data in the files, found out it is in fact showing -15.6 deg for a "level AOA", decided to once again use the DFL conversion on data which has already been converted, and still got it wrong as the product would be a negative value...lol. Of course he also couldnt miss out on an opportunity to make another post loaded with personal attacks. You might want to bring some jelly over there when you inform them as Im sure they are getting tired of eating their shoe raw. Too funny.

For those interested. See attached for a clear picture of what we been talking about regarding AOA and pitch angles. (We've already had enough laughs at Will's expense. I suppose it's time to throw him a bone.. you're welcome Will, and thanks for all the laughs when you attempted to use FD Pitch for aircraft attitude).

Attached File(s)

 Pitch_aoa_altitude_airspeed.csv ( 327.03K ) Number of downloads: 26

 

[wstutt]

Warren,

DCA weather values are not precise to the degree. I explained this to you above. Your initial input skews all the rest.

Fair enough. Presumably the wind direction is rounded to the nearest 10 degrees or in other words is +/-5°. In that case, when I use a wind direction of 330° - 5° = 325°, I get a true altitude of -22 feet. When I use a wind direction of 330° + 5° = 335°, I get a true altitude of 46 feet.

.... Also, if you are going to link an 86 page pdf, it might be nice to let readers know its a big pdf file before they click on it. Its just nice internet etiquette.

True. Sorry about that. I see a mod has added a note.

<Snip>

3 sets of independent data match. FMS, Airport and Pitot-Static. This is basic aeronautical knowledge and is why you dont see the Romper Room acting up over it, instead they are making fools of themselves over -15.6 AOA in which it appears the majority of them havent even looked at the parameter data in the files.. (I took a gander over at the cesspool tonight, what a mess...lol).

I've told them that you got that AoA value from my decode.

If you want to compare apples to apples further, try comparing envelopes and margins of error. Still, this would not be in your range for impact. Keep in mind, Airspeed errors are +/- 6 knots according to documents provided by apathoid. Altitude is +/-75 feet. Your correlation doesnt even start till you exceed those initial margins of error.

Those margins of error may not need to be exceeded. Do you know the margins of error for ground speed? If the ground speed errors are +/-6 knots like the airspeed errors, then subtracting 6 knots from the ground speed gives me a true altitude of -219 ft and adding 6 knots to the ground speed gives me a true altitude of 245 ft. Can you cite a reference showing that the ground speed is inertial and not reliant on pitot-static data?

It would also be nice if you would inform the Romper Room regarding the fact that the data presented in your decode and the NTSB csv file has already underwent the conversion from raw data to "engineering units" using the DFL formula's. It appears apathoid is the only one who actually looked at the data in the files, found out it is in fact showing -15.6 deg for a "level AOA", decided to once again use the DFL conversion on data which has already been converted, and still got it wrong as the product would be a negative value...lol. ....

<snip>

He was only trying to explain why the AoA values have such large negative values. I see he is now looking for an alternative explanation. I don't really know anything about AoA, although I see the typical lift coefficient graph on this Wikipedia page only goes down to -5° for a 0 lift coefficient. Do you have any better information on what AoA values we should expect?

Warren.

[rob balsamo]

Can you cite a reference showing that the ground speed is inertial and not reliant on pitot-static data?

Groundspeed is calculated by the FMS using all types of Nav data, not just inertial. In RO2, groundspeed is listed under the Nav parameters IIRC. The FMS uses many different sources for its calculations and navigation. VOR/VOR, VOR/DME, DME/DME, the list goes on depending on equipment. I have plenty of sources for this sitting on my shelves and in my flight bag. Feel free to search the web.

To attempt to correlate possible (again, not proven) "groundspeed" errors to pressure altitude is completely and utterly intellectually dishonest as i explained in past posts on this thread and again is the reason not even the Romper Room has jumped on it. But knock yourself out if thats what you need to do to sell the impact theory to yourself.

He was only trying to explain why the AoA values have such large negative values.

Wrong, he (and his cohorts) found an opportunity to write another post personally attacking me and it blew up in their face.

Do you have any better information on what AoA values we should expect?

Read this again Warren.

I dont care if the data shows -1000 degrees under AOA. Maybe thats the way they want it calibrated.. .who knows. We did explore this "mystery" early in our research years ago and one of our guys did come up with a good explanation, but i dont recall the reason. Its probably somewhere here on the forum. Feel free to search.

Again, bottom line.. In order to get a "fix" for "level AOA", all you have to do is correlate it with pitch and phase of flight as i did in the attached csv file in this post. Of course, first, one would actually have to look at the data, of which many from the cesspool didnt even bother and ended up putting their foot in their mouth.