Pitch Attitude in Percent Instead of Degrees
Thread Starter
Joined: Nov 2004
Posts: 1,324
Likes: 156
From: Here, there, and everywhere
Pitch Attitude in Percent Instead of Degrees
Just reading an accident report on a Partenavia P68 and they have a discussion about the required pitch attitude at a certain point in flight. They say that they were informed by an experienced pilot at an 11%(6.3 degrees) pitch attitude is required.
Are there some aircraft types or artificial horizons that use percent as pitch attitude rather than degrees?
Are there some aircraft types or artificial horizons that use percent as pitch attitude rather than degrees?
Joined: Dec 2001
Aviation Qualifications: ATPL
Posts: 3,765
Likes: 424
From: GA, USA
It’s a little hard to comprehend without any further context.
Percentage of what exactly?
A pitch instrument could be marked with anything really, apples for up and oranges for down.
Being called an “attitude indicator” or “artificial horizon” it would mean show the difference between level flight and higher or lower pitch attitudes.
Considering everything else which is measured or indicated in degrees: flight control defection, roll rates and pitch rates.
It would be most logical to have a degree scale.
I have flown with angle of attack indicators that were color coded.
You also need to consider international design standards and certification requirements.
Doesnt answer your question I guess.
Percentage of what exactly?
A pitch instrument could be marked with anything really, apples for up and oranges for down.
Being called an “attitude indicator” or “artificial horizon” it would mean show the difference between level flight and higher or lower pitch attitudes.
Considering everything else which is measured or indicated in degrees: flight control defection, roll rates and pitch rates.
It would be most logical to have a degree scale.
I have flown with angle of attack indicators that were color coded.
You also need to consider international design standards and certification requirements.
Doesnt answer your question I guess.
Joined: Dec 2003
Posts: 2,349
Likes: 841
From: Tring, UK
Joined: Jul 2021
Posts: 281
Likes: 72
From: In the Pusta
Joined: Jan 2025
Aviation Qualifications: Non-Aircrew
Posts: 640
Likes: 782
From: New Zealand
Measuring slope in percentage or permille is pretty common in railway especially if you're using metric, as it makes some of the maths easier. E.g. at 1 permille, you gain/lose 1 meter per kilometer. 50‰ = 50m per km.
I could see the Russians using it but I don't think I've ever heard of it.
Sounds more useful for flight path/glideslope than for AoA or actual deck angle, though.
I could see the Russians using it but I don't think I've ever heard of it.
Sounds more useful for flight path/glideslope than for AoA or actual deck angle, though.
Joined: Mar 2002
Aviation Qualifications: ATPL
Posts: 9,225
Likes: 992
From: Seat 1A
Originally Posted by Someone Somewhere
Sounds more useful for flight path/glideslope than for AoA or actual deck angle, though.
Joined: Oct 2019
Aviation Qualifications: Non-Aircrew
Posts: 1,704
Likes: 1,085
From: USA
Slope is easier to determine directly - measure the vertical rise and divide by the horizontal run and the above number is the result. It also directly converts into climb rate vs. ground speed which would also take into account wind speed. As long as the latter ratio is bigger than the former one, whatever obstacle there is to clear will be cleared.
Joined: Apr 2009
Aviation Qualifications: Non-Aircrew
Posts: 1,601
Likes: 704
From: DM33
In over 45 years as an avionics systems developer and over 45 years as a pilot (some overlap but not coincident) I never saw pitch attitude expressed as a percentage of anything. I was always degrees with a range of -90 to +90.
What was the context of the referenced report?
What was the context of the referenced report?
Thread Starter
Joined: Nov 2004
Posts: 1,324
Likes: 156
From: Here, there, and everywhere
"The Investigation was also provided with information from an experienced P68 pilot. The pilot informed the investigation that to maintain a speed of approximately 90 kts, a pilot would need to hold the aircraft at a pitch angle of approximately 11% [6.3 degrees]."
Page 33 of this report:
2025-001.pdf
Joined: Apr 2009
Aviation Qualifications: Non-Aircrew
Posts: 1,601
Likes: 704
From: DM33
Joined: Sep 2004
Aviation Qualifications: ATPL(H)
Posts: 2,392
Likes: 889
From: Canada
JOKE
Why use those silly. outmoded, inaccurate degrees?
“If it needs to be complicated …..it’s worth making it really, really complicated!”
Hey, why not use an Attitude indicator and Dg marked in Mils up/down , left/right as used by the military for Land Nav, Artillery Spotting and suchwhat.
”Ok Bloggins, at rotate I will raise the nose to 180 mils! At 1000 feet I will bank 360 Mils to port to join our course of 4500 mils.”
Here's a more detailed breakdown from AI
Why use those silly. outmoded, inaccurate degrees?
“If it needs to be complicated …..it’s worth making it really, really complicated!”
Hey, why not use an Attitude indicator and Dg marked in Mils up/down , left/right as used by the military for Land Nav, Artillery Spotting and suchwhat.
”Ok Bloggins, at rotate I will raise the nose to 180 mils! At 1000 feet I will bank 360 Mils to port to join our course of 4500 mils.”
Here's a more detailed breakdown from AI
- Mils as a unit: A mil is a milliradian, which is one-thousandth of a radian.
- Theoretical value: There are approximately 6283 mils in a full circle.
- Practical rounding: Military compasses and instruments often use 6400 mils, simplifying calculations.
- Application: Mils are used for measuring angles, especially in military applications like artillery, aiming, and navigation.
- Relationship to distance: One mil corresponds to one meter of displacement at a range of 1000 meters.
- One degree = +/- 18 mils (my edit)
Last edited by albatross; 8th May 2025 at 16:59.
Joined: Jun 2001
Posts: 265
Likes: 148
From: SEA
Many civilian aircraft have an AoA indicator which shows not actual AoA but a 'normalized AoA' with a range of 0 to 1. 0 is zero g and 1 is stall speed.
https://www.code7700.com/angle_of_attack.htm#section3
https://www.code7700.com/angle_of_attack.htm#section3
Joined: Apr 2009
Aviation Qualifications: Non-Aircrew
Posts: 1,601
Likes: 704
From: DM33
Joined: Jun 2008
Posts: 240
Likes: 35
From: Cambridge UK
Surely not a typo when the stated % and degrees matched? Just accurate reporting of the pilot's statement, and conversion for consistency with the rest of the report?
document: a pitch angle of approximately 11% [6.3 degrees]
angle converter program: An angle of 6.3 degrees converts to: 11.04 Percent of a Slope
Joined: Apr 2009
Aviation Qualifications: Non-Aircrew
Posts: 1,601
Likes: 704
From: DM33
Joined: Sep 2004
Aviation Qualifications: ATPL(H)
Posts: 2,392
Likes: 889
From: Canada
Dazed and Confused
Not a joke but feel free to laugh at me.
Now if and that’s a big IF what is being referred to is that 100% of Pitch up or down is 90 degrees then what % of 100 is 6.3 degrees?
So IF 90 degrees = 100% 1 degree is 100/90 or 1.111% so 6.3 degrees is 6.3 x1.111 should equal 6.999 % .( pretty darn close to 7 degrees of pitch)
Using this completely illogical theory 11% of 90 degrees of pitch = 9.9 degrees of pitch. ( I even asked Google what 11% of 90 is to confirm.)
However I found this site which purports to reflect truth regarding % of slopes that an 11% slope agrees with the 6.3 degree figure from the test pilot and now my head hurts.
( Convert Percentage slope/gradient/pitch to Ratio or Degrees
11% = 9.1 Ratio or 6.281 Degrees )
Link to the site below.
https://www.mountainpassessouthafric...d=449&catid=48
Joined: Apr 2009
Aviation Qualifications: Non-Aircrew
Posts: 1,601
Likes: 704
From: DM33
Joined: Sep 2004
Aviation Qualifications: ATPL(H)
Posts: 2,392
Likes: 889
From: Canada