As an inspiration for coding excellence, it didn’t do much. However, when applied to aviation and the craft of instrument flying, it is an extremely good motto. Why? Because the attitude indicator is at the heart of aircraft control. When I see noticeable altitude and heading deviations, I’m pretty sure the cause is lack of attention to the attitude indicator.
Because of its importance, the attitude indicator is central to most instrument scans. There is no single scan that is right for everyone. I usually have beginning instrument students try out a few different scans to see which one they may prefer. The long-standing hub-and-spoke is often used and has worked well for generations of instrument pilots.
In teaching scan, a useful exercise is to have the student “count” the scan. And I have the student count aloud. It is one way to keep their eyes moving. Let’s look at the traditional hub-and-spoke scan. In this scan, the attitude indicator is the “hub” and the other five flight instruments are the spokes.
When you count this scan, the attitude indicator is “AND” and the other instruments are “ONE”, “TWO”, “THREE” etc. So the count goes like this.
AND-ONE-AND-TWO-AND-THREE-AND-FOUR-AND-FIVE
Start with the attitude indicator “AND” then go to the altimeter “ONE” then back to the attitude indicator “AND” then to the VSI “TWO” then back to the attitude indicator “AND”, etc. So it turns out to be like this.
AI-ALT-AI-VSI-AI-HI-AI-TC-AI-ASI
Having an instrument student count out loud really does help to keep their eyes moving around all the instruments. If heading or altitude start to stray, have the student start counting aloud again. And count with them. You will find it helps keep their eyes moving.
Glass Scan:
Lately I have switched from the traditional hub-and-spoke type of scan to a glass scan. I started using a glass scan when I had an Aspen installed in my plane. The glass scan was reinforced when I started working in a G1000. Interestingly enough however, the glass scan is equally effective in a traditional “six pack” configuration of the flight instruments. In the glass scan, you look at the AI three times, then check the altimeter and VSI together for pitch information, then back to the AI and check it three times, then check the HI and TC for bank information, then back to the AI and check it three times, then check the ASI. Notice I say check the AI three times. The first time you look at the “wings”, the second time at the bank indicator, the third time is back to the “wings” again.
To count this, you say “attitude” three times.
ATTITUDE - check wings for pitch (attitude-1)
ATTITUDE - check bank angle indicator (attitude-2)
ATTITUDE - check wings for pitch (attitude-3)
For the traditional six-pack configuration, the complete glass scan goes like this:
ATTITUDE – ATTITUDE – ATTITUDE
CHECK ALTIMETER AND VSI FOR PITCH INFORMATION
Then go right back to the attitude indicator and check it three times:
ATTITUDE – ATTITUDE – ATTITUDE
CHECK HEADING INDICATOR AND TC FOR BANK INFORMATION
Right back to the attitude indicator and check it three times:
ATTITUDE – ATTITUDE – ATTITUDE
CHECK AIRSPEED
The glass scan utilizes the information presented by the flight instruments in a very efficient manner, and the extra attention paid to the attitude indicator really pays off in terms of heading and altitude control.
So putting it all together, you have a count (and scan) that goes like this.
ATTITUDE – ATTITUDE – ATTITUDE
ALTIMETER & VSI
ATTITUDE – ATTITUDE – ATTITUDE
HEADING INDICATOR AND TC
ATTITUDE – ATTITUDE – ATTITUDE
AIRSPEED
If you practice this scan, I can pretty much guarantee you will noticeably improve heading and altitude control.
Glass Scan on a PFD:
When flying a true PFD, the glass scan becomes even more concentrated. At first it is difficult, because information is not where you expect it to be. Here is a typical PFD layout.
The PFD still shows the AI as you are accustomed to seeing it – the “wings” still near the horizon and the bank information is displayed the same as a traditional AI. But from there things start to change.
The traditional TC is now split into two parts. The slip-skid part is shown as a white trapezoid underneath the white triangle on the bank part of the AI. It works exactly the same way however; if the trapezoid slides out to the right side of the triangle, you “step” on it with right rudder. The standard rate turn information is now shown on the HSI part of the PFD. It is shown as two lines on either side of the current heading (360°). The plane is not turning in t his picture, but if it were, magenta “snakes” would come out in the direction of the turn. The first indicator line, which is shorter, represents a half standard rate turn. The second, longer indicator line is a standard rate turn. Airspeed and altitude are presented in digital formats on tapes on either side of the display. The VSI is a digital readout on the altitude tape. In level flight the VSI box is blank. Below is a graphic of a PFD display for an aircraft in a climbing right turn.
So as you can see, the PFD gives all the information you need, in a concentrated layout.
1. Attitude indicator shows nose slightly up and wings show turning to the right
2. Attitude indicator shows about 15° of bank angle
3. Slip-skid indicator shows coordinated turn
4. VSI shows a 400 fpm climb
5. Altimeter shows current altitude is about 3250’
6. Heading indicator shows current heading of 90°
7. TC shows it is a standard rate turn
8. Airspeed indicator shows 100 knots
Our scan would become something like this. I have indented the “non-AI” items in the scan just to make them stand out a little better and to help show it is the same glass scan.
• Check AI – wings and nose show climbing right turn
• Check AI and TC - 15° bank angle, coordinated turn to the right (slip-skid)
• Check AI – wings and nose show climbing right turn (this is our third ATTITUDE)
- Check altimeter and VSI – climbing at 400 fpm rate
• Check AI and TC - 15° bank angle, coordinated turn to the right
• Check AI – wings and nose show climbing right turn
- Check HSI – turning to the right, current heading 090°
- Check TC (SRT) – in standard rate turn to the right
• Check AI – 15° bank angle and coordination
• Check AI – wings and nose, climbing right turn
- Check ASI – 100 knots
So it’s the same glass scan, but now the information is concentrated in one tight display. It seems very awkward at first, but you quickly become used to it. And the beauty is you can use it on either the standard “six-pack” display or a glass PFD.
So remember, no matter what type of scan you use, the attitude indicator is key to its success. Ignore it and your heading and altitude will suffer. Pay a lot of attention to it, and your heading and altitude control will become much better. I encourage you to try the glass scan. It may seem awkward at first, but it pays off with better heading and altitude control.
Excellence Is Attitude
