Share your secrets on demonstrating a cross-control stall/spin in a C172!

[Close-your-eyes!]

How do you do this!?

[PilotDAR]

Without wanting to sound sarcastic, the way the flight manual says.

The 172 is not an aerobatic plane, so only maneuvers approved in the flight manual/limitations placard may be flown, and must be entered as the flight manual says.

[Close-your-eyes!]

Thanks DAR. That's great advise. You sound like you're a real seasoned flight instructor! Got it . . . read that POH!

[Bede]

I think where he's going is that he'd like to demonstrate a spin from a position that we tell students to avoid (ie cross controlled). Problem is a 172 wont spin except from a totally unrealistic -stick full back, kick rudder.

[PilotDAR]

I think where he's going is that he'd like to demonstrate a spin from a position that we tell students to avoid (ie cross controlled)

Sure, I get it. But a spin cannot be entered without some element of cross control (required to be un coordinated). It's not necessary to have the ailerons hard over the other way, and not representative anyway. Approaching stall wings close to level, and ease in full rudder, and that's about the best you're going to get out of a 172, large amounts of aileron will not add to the learning value. The 172 will enter a spin (usually), and thereafter, it's just is it a neat spin, or messy, the recognition and recovery will be more or less the same. If there is an intention to train really abused spins, the 172 is a poor choice of type.

More importantly, yes, teach the hazards of a departure stall/spin, so the student knows to avoid this scenario.

In my opinion, if a pilot is anywhere near a departure stall spin, they have already ignored the hazard of a low altitude climb out below Vy, which to me is the bigger, more general flying safety lesson in terms of entering a glide following engine failure.

[photofly]

In my opinion, if a pilot is anywhere near a departure stall spin, they have already ignored the hazard of a low altitude climb out below Vy, which to me is the bigger, more general flying safety lesson in terms of entering a glide following engine failure.

(Minor) point of order, Mr. Speaker:

A “departure stall” is by definition one with a high power setting at the time the critical angle of attack is achieved. If a stall follows from a pilot’s actions subsequent to a loss of engine power, that would be classified as a “power off” stall, not a departure stall.


Advice for the OP in demonstrating different kinds of stalls can be found in TC document TP 13747 - Google it.

Here’s a relevant part:

Although some aircraft types are difficult to spin and require special techniques, forcing an aircraft into a spin by aggressive control inputs is not as effective for teaching as a well executed simulation.

[PilotDAR]

A “departure stall” is by definition one with a high power setting at the time the critical angle of attack is achieved. If a stall follows from a pilot’s actions subsequent to a loss of engine power, that would be classified as a “power off” stall, not a departure stall.

Is very true!

Thread drift alert...

'Not the first time I've ranted about it here, but training includes departure stall awareness (very good), and the differences between a Vy and YX climb after takeoff. What seems to be missing in there is the training about the hazard of low altitude climbs slower than Vy, considering an engine failure in that phase of flight, and difficulty in establishing a safe glide speed as the plane descends. The hazard of the [now power off] stall in that scenario is at the bottom, when you pull to flare.

My point being that if you're anywhere near a departure stall/spin entry, the training should already have included the awareness of the hazard of even being slower than Vy. If it is possible to takeoff, accelerate to Vy, and then climb away at that speed, there is no risk of a departure stall, and you're in a better situation if the engine stops.

[RedAndWhiteBaron]

Sure, I get it. But a spin cannot be entered without some element of cross control (required to be un coordinated).

That's not entirely true, in my experience. I recently did some spin training in an airframe with washed-in, laminar flow wings. If you stall it in a turn, it spins - almost every time, and with with no cross control input.

(Unless you were specifically referring to the 172?)

[PilotDAR]

If you stall it in a turn, it spins - almost every time, and with with no cross control input.

Such airplanes exist, but would not meet the design requirements in effect since 1949. I have test flown one which does this, which is a 1930's design, before this characteristic was designed out by regulation. I have also test flown a recent type which did this, and was agreed (with TC staff) to be very non compliant with the design requirements, and not airworthy.

In two recent test programs I have flown (both small mods to Grand Caravan), TC required me to demonstrate spin resistance by stalling to the pitch down in a 30 degree bank turn each way, with power at 75%, and cross controlled each way one ball out. The Caravan withstands this handling abuse quite well (but I still do it at altitude, prepared to recover a spin).

A properly rigged, modern normal certified GA plane should not spin out of a coordinated, wings within 30 degrees of level, power off stall.

[Emadkz]

In C172
Put the plane in slow flight
20 degree flap
20 degree bank to the right
(If you look at the control input you have right radar and left ailerons at this point)— cross control
Then keep pulling back till you stall.
Recovery is just normal recover: break the stall opposite radar and full power

[robshelle]

Isn’t intentional spins prohibited with flaps extended in C172’s? I would suggest that even if you are doing an immediate recovery, you are still entering the incipient stage of the spin at the point of the cross controlled stall, so I have never taught these with flaps extended. Please correct me if I’m wrong.

I use climbing partial powered turns, or powered off descending turns, and just have to use a whole lot of aileron to get it to go over, and it has almost always worked for me every time.

Robshelle

[JasonE]

We did spin training in gliders from a banked stall. The idea was demonstrating getting too slow on base to final turn and what can happen.

[rookiepilot]

Thread drift, but a good part of the teaching you’re possibly after…is doing some circuit teaching with a strong tailwind on base, and the risk of a cross controlled spin after overshooting base to final.

If there’s a situation that’s led to more fatal pilot-induced LOC accidents in VFR conditions, I can’t think of it.

[PilotDAR]

Isn’t intentional spins prohibited with flaps extended in C172’s?

That is correct. Largely because of the very real possibility that you could well exceed flaps extended speed during what could become a spin recovery - so, read the flight manual!