What is "slow flight" instruction?

[201er]

Not sure if everybody has the same definition or does it the same way. So when it comes to a BFR, MAPA safety, your instructor, you as an instructor, or what you personally practice, what is "slow flight?" Walk us through your specific routine, what happens, and what is learned. Everybody keeps talking about it but I'm not sure if we all think of the same thing or not.

[takair]

The commercial pilot PTS defines it as 1.2 Vs1 +_5kt.  It then includes maintaining specified altitude, heading, turns to a heading  and maintaining specified bank angles.  This typically puts you riding the stall horn while flying a requested series of turns to headings.  Forces the pilot to coordinate not just rudder, aileron and elevator, but power as well.  At the lower end of the speed you can feel the buffet and know you are getting close.  In the turns you get close to the stall unless you bring in power to accommodate the loss of lift.  I find the key to doing it reasonably well is to be gentle on any movements and lead turns with rudder and use minimal aileron while maintaining coordinated flight.  

[Hank]

Nailed it, Rob. I've surprised more than one CFI by happily flying along, maintaining altitude and airslowness while turning in both directions. Maybe it was the constant buzzing of the stall horn? Maybe Mooneys are supposed to magically fall out of the air?

[Mooneymite]

Slow flight instruction:  Teaching someone to fly something other than a Mooney.

 

[201er]

15 minutes ago, Mooneymite said:

Slow flight instruction:  Teaching someone to fly something other than a Mooney.

 

HAHAHA! Very well put!

[Deb]

The FAA recently released a Safety Advisory for Operators (SAFO) regarding slow flight and the Private Pilot Airplane Airman Certification Standards (ACS) (formerly the PTS) in June, 2016. 

"The revised evaluation standard states:

Establish and maintain an airspeed, approximately 5-10 knots above the 1G stall speed, at which the airplane is capable of maintaining controlled flight without activating a stall warning."

https://www.faa.gov/other_visit/aviation_industry/airline_operators/airline_safety/safo/all_safos/media/2016/SAFO16010.pdf

The SAFO goes on to state that this will be reflected in the next revision of the Airplane Flying Handbook which the FAA anticpates will be in October, 2016.

The SAFO does not address the Commercial standards.

[takair]

Thanks Deb, had not seen this.  Interesting change.  I have to agree, and have stated previously, that it is contradictory teaching stall prevention, yet asking students to keep pulling into the stall horn.  That said, I do have mixed feelings about this.  There is something to be learned inside the stall horn.  I suppose that is why they still have you do the stall sequence and perhaps they will retain it for advanced ratings.  In some purpose built trainers, I have seen methods of failing student instruments.  One extreme thought would be to have a method of failing the stall horn for the student so they could experience stall detection without the horn...in case of failure of the stall warning system.  Don't think it will happen and I haven't convinced myself that it would help.  Perhaps it would be a good simulator trick....

as a side note in all of these different stall discussions, one thing that I haven't seen discussed is the affect of ground speed on the pilot and the illusion it causes when down low.  Many of the stall/spin accidents occur when turning downwind base and base to final.  If not monitoring airspeed or AOA or not carrying enough margin, the ground can give the pilot the illusion of excess airspeed.  Complicating this is the tendency to overshoot final.  It's the perfect setup for an accident.  The pilot senses that he is carrying excess speed and then tightens the turn.  Add a lack of stall awareness (failed warning system, or lack of familiarity) and one can imagine the margin tightening to the point of stall.  This is one of the things that we do not experience at altitude when doing slow flight or stalls...no ground rush or reference.  I'm not advocating practicing down low, but the activity is intended to teach the other clues that we are close to the margin and this includes aerodynamic cues, airpseed and AOAi if we have it.

[N9201A]

Read Rod Machado's take, "black belt stall prevention." The trained impulse that kills people isn't pulling into a stall because they've been training in stall recognition, it's pulling the yoke because that's what they've been trained brings the nose up 99.999% of the time ... except maybe in stall practice for the PPL ages ago. Not contradictory at all to teach mastery of slow flight and recognition of what that angle of attack feels like, and recovery therefrom by pushing/unloading, so that the ingrained, panic impulse to "pull" is replaced by the trained motor memory to push.

It's a great read, very sensible and compelling.

[201er]

16 minutes ago, N9201A said:

Read Rod Machado's take, "black belt stall prevention." The trained impulse that kills people isn't pulling into a stall because they've been training in stall recognition, it's pulling the yoke because that's what they've been trained brings the nose up 99.999% of the time ... except maybe in stall practice for the PPL ages ago. Not contradictory at all to teach mastery of slow flight and recognition of what that angle of attack feels like, and recovery therefrom by pushing/unloading, so that the ingrained, panic impulse to "pull" is replaced by the trained motor memory to push.

It's a great read, very sensible and compelling.

Well, when you're flying "fast" pulling up really does make you go up and most pilots spend the majority of their time on the fast side of the drag curve. It's only when you get to the backside of the drag curve that this no longer applies and worse yet kills you. The other problem is deciding how fast is on the fast side or not and that's more to do with angle of attack.

 

But enough with the book answers. I understand what the book says. How do you or your instructors actually go and practice slow flight? Not for a checkride. Not for a specific purpose. But simply for the purpose of proficiency or good airmanship?

[donkaye]

2 hours ago, Deb said:

The FAA recently released a Safety Advisory for Operators (SAFO) regarding slow flight and the Private Pilot Airplane Airman Certification Standards (ACS) (formerly the PTS) in June, 2016. 

"The revised evaluation standard states:

Establish and maintain an airspeed, approximately 5-10 knots above the 1G stall speed, at which the airplane is capable of maintaining controlled flight without activating a stall warning."

 

No problem with the new ACS.  Just pull the stall warning and gear circuit breaker (NOT the gear actuator circuit breaker) and you won't activate the stall warning by slow flying just above the stall.

[ArtVandelay]

No problem with the new ACS.  Just pull the stall warning and gear circuit breaker (NOT the gear actuator circuit breaker) and you won't activate the stall warning by slow flying just above the stall.

Unless you train in a Cessna that does not use electric stall switch.

[Mooneymite]

8 hours ago, donkaye said:

No problem with the new ACS.  Just pull the stall warning and gear circuit breaker.....

Don, pulling circuit breakers for training purposes has fallen out of favor, and in my opinion for very valid reasons.  The 121 carriers stopped that a long time ago and most of the training organizations I'm familiar with no longer permit, or encourage pulling circuit breakers unless called for in an abnormal/emergency checklist.  You might warn your students about the "new view" of cb operation if/when you do that.

[midlifeflyer]

It's an excellent question, although perhaps an  obvious in light of the arguments about the new ACS task.

My personal definition of "slow flight" is pretty broad - any speed below best glide. From there down to stall, drag increases, the airplane behaves a bit differently than in cruise flight, control inputs become progressively less effective, and positive control of coordination more important.

My use of the word "progressively" is deliberate. I don't see "slow flight" as one and only one configuration but as a continuum. I even teach it that way. The first slow flight lesson do starts with best glide and then gets slower and slower and slower and..., watching and understanding the changes along the way. 

[donkaye]

45 minutes ago, Mooneymite said:

Don, pulling circuit breakers for training purposes has fallen out of favor, and in my opinion for very valid reasons.  The 121 carriers stopped that a long time ago and most of the training organizations I'm familiar with no longer permit, or encourage pulling circuit breakers unless called for in an abnormal/emergency checklist.  You might warn your students about the "new view" of cb operation if/when you do that.

A joke in reference to the new ACS.  No sense of humor on this list...

[Mooneymite]

51 minutes ago, donkaye said:

No sense of humor on this list...

Sorry. I guess I missed it.  I haven't read the new ACS, so it went right over my head. 

[BDPetersen]

Seems to me we used to have two speeds, "minimum controllable" (not to be confused with the multi engine demo) where you flew at the nibble edge of a stall, and "slow flight" which was just that, flight at a specific speed with a stall margin.

[midlifeflyer]

1 hour ago, BDPetersen said:

Seems to me we used to have two speeds, "minimum controllable" (not to be confused with the multi engine demo) where you flew at the nibble edge of a stall, and "slow flight" which was just that, flight at a specific speed with a stall margin.

I don't recall whether or not the PTS referred to it by that name but all of my logbook entries for it in my logbook when I was a student pilot referred to "MCA".

Of course, MCA has Avery specific meaning for multis.

[Guest]

7 hours ago, donkaye said:

A joke in reference to the new ACS.  No sense of humor on this list...

Its hard to tell when it comes from someone reputed as a top notch instructor.  I took it as you typed it, pulled the c/b's.

Clarence

[201er]

I'm still waiting to hear some personal stories from pilots or instructors on what actual happens during the "slow flight" procedures. What exactly are you doing step by step (ex. slow to 73 knots, reduce power to 20"/2000RPM, do 20 degree bank 360 degree turns in each direction, etc whatever it actually is)? Besides what you do, what is the purpose? I'm really trying to find out how others do it.

[donkaye]

1 hour ago, M20Doc said:

Its hard to tell when it comes from someone reputed as a top notch instructor.  I took it as you typed it, pulled the c/b's.

Clarence

Beechtalk has emojis to choose from--none here that I have found, although someone figured out how to add one.

[Mooneymite]

1 minute ago, donkaye said:

Beechtalk has emojis to choose from--non here that I have found, although someone figured out how to add one.

, etc.

[Guest]

39 minutes ago, donkaye said:

Beechtalk has emojis to choose from--non here that I have found, although someone figured out how to add one.

More than a few to choose from on an IPad.

Clarence

[1964-M20E]

and who said hieroglyphics were dead

[mooniac15u]

Emojis are also available in MooneySpace by clicking on the little smiley face...

[BDPetersen]

Like stuffing for turkey, emojis are evil.