Welcome Guest. Sign in or Signup

3 Answers

Correction In Attitude indicator

Asked by: 2039 views Aircraft Systems, Commercial Pilot, Flight Instructor, Instrument Rating

https://www.flightliteracy.com/straight-and-level-flight-pitch-control-part-one/ 

 

Hello sir!!!   I don't understand this sentence  

Movement of the horizon bar above or below the miniature aircraft of the attitude indicator in an airplane should not exceed one-half the bar width. [Figure 6-6]

If further change is required, an additional correction of not more than one-half horizon bar wide normally counteracts any deviation from normal flight.
Ref) IFH Chap6 p.6-5  

what dose horizontal bar width??  Is this a lateral length??

Ace Any FAA Written Test!
Actual FAA Questions / Free Lifetime Updates
The best explanations in the business
Fast, efficient study.
Pass Your Checkride With Confidence!
FAA Practical Test prep that reflects actual checkrides.
Any checkride: Airplane, Helicopter, Glider, etc.
Written and maintained by actual pilot examiners and master CFIs.
The World's Most Trusted eLogbook
Be Organized, Current, Professional, and Safe.
Highly customizable - for student pilots through pros.
Free Transition Service for users of other eLogs.
Our sincere thanks to pilots such as yourself who support AskACFI while helping themselves by using the awesome PC, Mac, iPhone/iPad, and Android aviation apps of our sponsors.

3 Answers



  1. Mark Kolber on Jun 03, 2020

    Think about it for a minute.

    The horizontal measurement of a traditional round dial AI is about 3 inches. Do you think they are recommending you correct minor deviations from straight and level by:

    1. moving the reference all the way to the top or bottom of the instrument way begin the pitch scale into to an unusual steep climb or steep descent pitch attitude

    Or

    2. moving the reference a degree or two at a time based on the vertical measurement of the horizon bar

    ?

    0 Votes Thumb up 0 Votes Thumb down 0 Votes



  2. Richard Eastman on Jun 03, 2020

    I suspect you’re confused by the pictures. When the words say <>, they seem to be talking about the wider bars that indicate 10 and 20 degrees of nose-up pitch — NOT the smaller bars that define degrees of nose-up between 0 and 10 as the picture depicts. In most general aviation aircraft, nose-up (or nose-down) pitch are increments of the spread between the 10 and 20 degree nose-up (or down) lines pictured.

    Most general aviation aircraft have a critical angle of attack (AoA) between 15 and 18 degrees. AoA is a function of the wing chord moving through the relative air mass — but the attitude indicator generally provides a fairly accurate indication (particularly in normal flight conditions). If a wing stalls at 15-degree (i.e. AoA is 15-degrees), it’s fairly obvious that one would not pitch the airplane nose above 15-degrees in normal flight conditions intentionally.

    Thus, normal flight maneuvers would be less than 15-degrees. In fact, for most general aviation aircraft, Vx (maximum rate of climb) is around 12 1/2-degrees (12.5) nose-up with full power; Vy (maximum rate of climb) is around 7 1/2-degrees (7.5) nose-up with climb power. Cruise climb is generally 2 1/2-degrees (2.5) nose-up.

    Most descents in general aviation aircraft are at a level attitude or 1 1/2-degrees to 2 1/2-degrees (1.5 to 2.5) nose down — depending on the power setting. Addition of flaps can add to a nose-down flap attitude of 5-degrees with full flaps deployed.

    // Richard Eastman
    CFIIMEI

    0 Votes Thumb up 0 Votes Thumb down 0 Votes



  3. Craig on Jun 05, 2020

    The horizon bar “width” is the “thickness” of the horizontal white line that separates the blue sky from the brown ground indication on the AI. Think about the thickness (“width”) of a 2 cm horizontal line drawn with a pencil vs. a fat marker.

    0 Votes Thumb up 0 Votes Thumb down 0 Votes


The following terms have been auto-detected the question above and any answers or discussion provided. Click on a term to see its definition from the Dauntless Aviation JargonBuster Glossary.

Answer Question

Our sincere thanks to all who contribute constructively to this forum in answering flight training questions. If you are a flight instructor or represent a flight school / FBO offering flight instruction, you are welcome to include links to your site and related contact information as it pertains to offering local flight instruction in a specific geographic area. Additionally, direct links to FAA and related official government sources of information are welcome. However we thank you for your understanding that links to other sites or text that may be construed as explicit or implicit advertising of other business, sites, or goods/services are not permitted even if such links nominally are relevant to the question asked.