Safety through AOA
07-30-2013, 05:04 AM
#1
Gets Weekends Off
Thread Starter
Joined APC: Mar 2008
Position: FAA 'Flight Check'
Posts: 13,835
Safety through AOA
The forum has had recent discussions on the use of AoA - particularly on the value added to GA. This FAASafety brief came through the email this morning.
FAA Safety Team | Safer Skies Through Education
What’s your angle?
Notice Number: NOTC4886
Want to help reduce GA accidents? Know your angle. Angle of attack, that is…
The majority of GA accidents occur when a pilot loses control of the aircraft. This usually happens in airplanes when a wing stalls and the plane enters a spin. The wing stalls when the critical angle of attack (AOA) is exceeded.
Remember, the wing (and aircraft) can stall at:
· Any airspeed
· Any attitude
· Any power setting
But, the wing always stalls at the same AOA.
The stall speed published in the airplane flight manual is only valid for:
· Unaccelerated flight (1g load factor)
· Coordinated flight (ball centered)
· At (usually) max gross weight
So, a pilot may be surprised to find the wing has stalled above the published stall speed.
AOA can be very useful in enhancing safety. Having an AOA meter is the best way to remain aware of your AOA.
If you don’t have an AOA meter, here’s a quick tip on how to manage your critical AOA:
Want to learn more?
What’s your angle?
Notice Number: NOTC4886
Want to help reduce GA accidents? Know your angle. Angle of attack, that is…
The majority of GA accidents occur when a pilot loses control of the aircraft. This usually happens in airplanes when a wing stalls and the plane enters a spin. The wing stalls when the critical angle of attack (AOA) is exceeded.
Remember, the wing (and aircraft) can stall at:
· Any airspeed
· Any attitude
· Any power setting
But, the wing always stalls at the same AOA.
The stall speed published in the airplane flight manual is only valid for:
· Unaccelerated flight (1g load factor)
· Coordinated flight (ball centered)
· At (usually) max gross weight
So, a pilot may be surprised to find the wing has stalled above the published stall speed.
AOA can be very useful in enhancing safety. Having an AOA meter is the best way to remain aware of your AOA.
If you don’t have an AOA meter, here’s a quick tip on how to manage your critical AOA:
- See it – in the pitch attitude and airspeed indication.
- Hear it - in the existing stall warning systems.
- Feel it – in the seat of your pants when the wing begins to buffet.
- Recover it – by reducing the pitch of the aircraft.
Want to learn more?
- Get out there and practice!
- Online courses at FAASafety.gov
- ALC-214: Avoiding Loss of Control
- ALC-63: Performance and Limitations
- ALC-36: Positive Aircraft Control
- FAA-H-8083-3A, Airplane Flying Handbook, chapter 4, page 4-3, figure 4-2
- FAA-H-8083-15B, Instrument Flying Handbook, chapter 4, page 4-6, figure 4-8
- FAA-H-8083-25A, Pilot’s Handbook of Aeronautical Knowledge, chapter 4, page 4-22
- NAVAIR 00-80T-80, Aerodynamics For Naval Aviators, Chapter 1, Figure 1.11
- Contact: Kevin Clover: [email protected]
07-30-2013, 05:36 AM
#2
Runs with scissors
Joined APC: Dec 2009
Position: Going to hell in a bucket, but enjoying the ride .
Posts: 7,643
If you want to learn more about AOA and spins, in addition to picking up one of those books above, go out and find a good acro instructor and go flying. Books are great but there's no substitute for experience in an airplane, that's where you will develop the 'feel' for what the airplane is telling you.
Start looking for good Acro IP's, and read some good stuff, free right here:
http://eaa.org/intheloop/issues/default.asp
Hey, with enough practice, you could even land upside down, like this:
http://www.youtube.com/watch?v=1ApSDpnA2k0
Start looking for good Acro IP's, and read some good stuff, free right here:
http://eaa.org/intheloop/issues/default.asp
Hey, with enough practice, you could even land upside down, like this:
http://www.youtube.com/watch?v=1ApSDpnA2k0
Last edited by Timbo; 07-30-2013 at 06:10 AM.
07-30-2013, 02:56 PM
#4
Gets Weekends Off
Joined APC: May 2010
Position: Baja Vermont
Posts: 5,162
USMCFLYR
It would nice if the FAA Safety guys went down the hall or across the country and met with the Aircraft Certification guys. AoA is not recognized as a legal "tool" for performance. Current Bombardier planes now have AOA indications on the panel and, where installed, in the HUD, but, because it can't be used legally, the AFM contains not data, there are no markings or data for different performance points--like on-speed for Vref, V2, etc. The C-5 manual had specific numbers-7.2 units for approach, 9 units for V2.
GF
It would nice if the FAA Safety guys went down the hall or across the country and met with the Aircraft Certification guys. AoA is not recognized as a legal "tool" for performance. Current Bombardier planes now have AOA indications on the panel and, where installed, in the HUD, but, because it can't be used legally, the AFM contains not data, there are no markings or data for different performance points--like on-speed for Vref, V2, etc. The C-5 manual had specific numbers-7.2 units for approach, 9 units for V2.
GF
07-30-2013, 03:01 PM
#5
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Thread Starter
Joined APC: Mar 2008
Position: FAA 'Flight Check'
Posts: 13,835
Originally Posted by galaxy flyer
USMCFLYR
It would nice if the FAA Safety guys went down the hall or across the country and met with the Aircraft Certification guys. AoA is not recognized as a legal "tool" for performance. Current Bombardier planes now have AOA indications on the panel and, where installed, in the HUD, but, because it can't be used legally, the AFM contains not data, there are no markings or data for different performance points--like on-speed for Vref, V2, etc. The C-5 manual had specific numbers-7.2 units for approach, 9 units for V2.
GF
It would nice if the FAA Safety guys went down the hall or across the country and met with the Aircraft Certification guys. AoA is not recognized as a legal "tool" for performance. Current Bombardier planes now have AOA indications on the panel and, where installed, in the HUD, but, because it can't be used legally, the AFM contains not data, there are no markings or data for different performance points--like on-speed for Vref, V2, etc. The C-5 manual had specific numbers-7.2 units for approach, 9 units for V2.
GF
Yes - It would be nice to merge the two and actually get something useful (and safe) out to the GA world quickly.
I agree about the military's use of AoA in operations (and I didn't even know that other communities outside of the Strike/Fighter one used AoA as much), but we had AoAs for nearly everything - especially tactically, but including max range, max endurance, and of course LANDING!!
07-30-2013, 04:55 PM
#6
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Joined APC: Jul 2013
Position: FAA ATSI VSRP ERC
Posts: 218
Originally Posted by USMCFLYR
As I am learning in my job, stovepipe is still a term in use in the FAA
07-30-2013, 05:49 PM
#7
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Position: Baja Vermont
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USMCFLYR
The numbers were published for the C-5, but it wasn't trained firmly. I learned to use it as an IP from old IPs who were saved by watching it. Especially good on 3-engine missed approaches, if the student got overly aggressive and as a clue on configuring.
There are absolutely no numbers published for Bombardier planes, we were told to get back to the engineers with our observations on the AOA presentation. OTOH, the Citations, from Day One, had the standard military chevron and donut display in the glare shield.
GF
The numbers were published for the C-5, but it wasn't trained firmly. I learned to use it as an IP from old IPs who were saved by watching it. Especially good on 3-engine missed approaches, if the student got overly aggressive and as a clue on configuring.
There are absolutely no numbers published for Bombardier planes, we were told to get back to the engineers with our observations on the AOA presentation. OTOH, the Citations, from Day One, had the standard military chevron and donut display in the glare shield.
GF
07-30-2013, 05:54 PM
#8
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Joined APC: Jul 2009
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Posts: 974
Originally Posted by USMCFLYR
As I am learning in my job, stovepipe is still a term in use in the FAA
Yes - It would be nice to merge the two and actually get something useful (and safe) out to the GA world quickly.
I agree about the military's use of AoA in operations (and I didn't even know that other communities outside of the Strike/Fighter one used AoA as much), but we had AoAs for nearly everything - especially tactically, but including max range, max endurance, and of course LANDING!!
Yes - It would be nice to merge the two and actually get something useful (and safe) out to the GA world quickly.
I agree about the military's use of AoA in operations (and I didn't even know that other communities outside of the Strike/Fighter one used AoA as much), but we had AoAs for nearly everything - especially tactically, but including max range, max endurance, and of course LANDING!!
07-30-2013, 06:05 PM
#9
Gets Weekends Off
Thread Starter
Joined APC: Mar 2008
Position: FAA 'Flight Check'
Posts: 13,835
Originally Posted by galaxy flyer
USMCFLYR
The numbers were published for the C-5, but it wasn't trained firmly. I learned to use it as an IP from old IPs who were saved by watching it. Especially good on 3-engine missed approaches, if the student got overly aggressive and as a clue on configuring.
There are absolutely no numbers published for Bombardier planes, we were told to get back to the engineers with our observations on the AOA presentation. OTOH, the Citations, from Day One, had the standard military chevron and donut display in the glare shield.
GF
The numbers were published for the C-5, but it wasn't trained firmly. I learned to use it as an IP from old IPs who were saved by watching it. Especially good on 3-engine missed approaches, if the student got overly aggressive and as a clue on configuring.
There are absolutely no numbers published for Bombardier planes, we were told to get back to the engineers with our observations on the AOA presentation. OTOH, the Citations, from Day One, had the standard military chevron and donut display in the glare shield.
GF
I wonder though if they used 'green' for slow and 'red' for fast as Naval Aviation does or if the civilian world considers 'red' as near stall. Looking at the other video posted of the amphib, that display used red as the dangerously slow region color of warning.
07-30-2013, 06:07 PM
#10
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Joined APC: May 2010
Position: Baja Vermont
Posts: 5,162
I don't have any Citation books, it's been 30 years since I flew it, but I think it was AF presentations--red = slow, green = good. And I could be wrong there, too. It's been almost 30 Yeats since I bailed out, literally and figuratively, from the A-10, the last AF plane I flew having that display.
The AOA presentation is so small on the Global screens, you really have to look for it. I flew with an ex-French Navy pilot recently and we both missed it.
GF
The AOA presentation is so small on the Global screens, you really have to look for it. I flew with an ex-French Navy pilot recently and we both missed it.
GF
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