Steep spiral question

[Yellow Snow]

I am beginning training to get my CSEL add on. In reviewing the PTS and highlighting the areas that I will be graded on I came across the steep spiral. The PTS is very vague on the correct way to do this maneuver. I did my multi comm back in 2000 and the steep spiral wasn't even part of the PTS then.
Could you nice CFI's out there please tell me the right way to do steep spirals.
What is proper speed?
What is configuration (clean, flaps etc)?
I'm using a 172 what power settings would be recommended?
Thanks in advance for the info.

 

[Kream926]

upwind entrance 1/8 of a mile away from point

im assuming 75 KIAS, 70 in a 52. clean config, i'd use carb heat since throttle will remain idle for a while. and after each turn clear the engine.

 

[mattpilot]

kream - stop posing as a CFI.

What is proper speed?

90 kts in a 172RG, 80 in a regular 172.

What is configuration (clean, flaps etc)?

clean

I'm using a 172 what power settings would be recommended?

Idle - if you apply power, you will just race down.

I did my multi comm back in 2000 and the steep spiral wasn't even part of the PTS then.

It still isn't.

 

[moxiepilot]

easiest way to think of the maneuver is that it's a turn around a point, but you're going down
maintain a constant descent airspeed and that's it. its really that easy

 

[mattpilot]

one more thing..

I see kream recommends a upwind entry.

I would recommend a downwind entry - thats what most people do, but anyhow - the PTS doesn't specify.

The reason you should do it downwind is because your groundspeed will obviously be the fastest = steepest bank. Should you be to close to your selected point, and you apply the maximum bank angle (no more than 60), all that will happen is that you drift outside further, giving you a correct distance from the reference point, until that <60 degree of bank maintains your radius.

Should you enter upwind, you will obviously start with a shallower bank - but when you come around to the downwind side, with an increasing groundspeed, you will find that 60 degrees of bank may not be enough to maintain the distance you've selected.

 

[Singlecoil]

90 kts in a 172RG, 80 in a regular 172.

That sounds too fast to me, but I haven't taught this maneuver in many years. I don't know why the speed would be faster in the RG for one thing. 80kts might work at gross weight in the 172, but 72 kts or so would be more realistic when practicing solo. To get the proper feel for the maneuver, you need to be up near your max coefficient of lift on the ol' angle of attack vs. coefficient of lift curve. Being up there on the curve gives you a high angle of attack and high aerodynamic drag which lets you come down quickly in a tight spiral. Too many times you will see this maneuver performed incorrectly at too high of an IAS which results in too wide of a radius of turn.
Some students will express concern that they will stall at those speeds in a 45 degree bank.
If you never hear the stall warning going off, you probably aren't doing it right.

 

[lowlycfi]

The FAA's Airplane Flying Handbook (FAA-H-8083-3) has a good description of it. Chapter 6.

 

[Fly_Chick]

The steep spiral has practical application in providing a procedure for dissipating altitude while remaining over a selected spot in preparation for an emergency landing.

It was easiest for me to chose a "landing spot" i.e. field, as opposed to point or landmark in which to spiral down.

When you move to a complex aircraft to do this manuever, the flaps should remain up yet I have heard many comments to the gear position. With gear down, you will lose more altitude, yet you are also simulating "preparation for emergency landing". With gear up, you will lose less altitude.

I agree with mattpilot on a downwind entry, to start the maneuver with the steepest bank angle, and you may want to consider clearing the engine on the upwind (adding a little power then pulling it out).

Another practical application is to remain in your block of airspace assigned by ATC when you are spiraling down 71 miles to Earth in SpaceShipOne.

 

[Yellow Snow]

Ok this is an add on to my Cmel so its in a fixed leg 172 no worries about prop or gear. I want idle power and come down as quickly as reasonable while keeping airspeed constant at around 70 to 80. If I understand you guys correctly its like a turn on point so I'm basically graded on constant speed, wind drift correction by properly adjusting bank angle, and maintaining correct spacing from the point I have selected, all while loosing altitude.

Anything I missed?
Thanks for the help you-ns!

 

[minitour]

I had to learn the maneuver at best glide....is that incorrect?

I just think of it as a turn around a point with a descent at best glide.

-mini

 

[bigD]

I had to learn the maneuver at best glide....is that incorrect?

I just think of it as a turn around a point with a descent at best glide.

-mini

There's no correct or incorrect on the speed. The PTS has you maintain a selected speed, but does not mention what that speed should be. The majority of people I know use best glide for this, however I've seen all sorts of things, including a DPE that insists the applicant do it at Va. Like someone else mentioned, the faster you go (above best glide, of course), the faster your descent rate will be, and you'll have to start higher to get the 3 turns out of it.

 

[FracCapt]

The steep spiral has practical application in providing a procedure for dissipating altitude while remaining over a selected spot in preparation for an emergency landing.

It was easiest for me to chose a "landing spot" i.e. field, as opposed to point or landmark in which to spiral down.

When you move to a complex aircraft to do this manuever, the flaps should remain up yet I have heard many comments to the gear position. With gear down, you will lose more altitude, yet you are also simulating "preparation for emergency landing". With gear up, you will lose less altitude.

If you are over your intended landing point, you don't need to worry about how long you can stay in the air. You need to worry about making the spot, and getting the gear down as early as you can(and still make the spot) because you don't know if you will have to manually extend it or not. IIRC, the 172RG has an electric gear pump. If you're VFR, and can make your intended landing area(without a doubt), extend the gear ASAP.....so that if you have to pump it down, you have plenty of time to do it.

Just my opinion.

 

[midlifeflyer]

If you are over your intended landing point, you don't need to worry about how long you can stay in the air.

It depends on the nature of the emergency. The "emergency" that the steep spiral contemplates isn't necessarily an engine out where, as you, say, you may be more concerned with where you land than how fast or slowly you get there. It might be an engine fire where you want to get down =now!= with a high airspeed.

 

[nosehair]

It depends on the nature of the emergency. The "emergency" that the steep spiral contemplates isn't necessarily an engine out where,.

This is NOT an "emergency" maneuver. It can be used and combined with a forced landing, but the maneuver is a stand-alone maneuver which, according to the Airplane Flying Handbook, should be terminated no lower than 1000', unless it is being perfomed in conjunction with a forced landing. If I am doing a forced landing in a retract, I always assume I will land gear-up unless I am pretty darn sure the surface area will be smooth an hard enough to roll-on. Seriously, landing gear-up and staining the belly with grass stains is much preferable to nosing over and exploding because the nose wheel digs into the soft mush or a gopher-hole.
The speed should be best glide speed. The objective of the maneuver is to "improve pilot techniques for power-off turns, wind drift control, planning, orientation, and division of attention." Also, as the Airplane Flying Handbook says, the engine should be cleared when into the wind so that the addition of power will have less effect on groundspeed, therfore, I enter into the wind and clear on each 360 turn. I personally don't like entering at the steepest point. I only do that on the Private turns around a point because that is how it is described in the book. I suspect that you should do them from random positions if it is being used in conjuction with a forced landing. The angle of bank does not effect stall speed UNLESS you are maintaing a constant altitude. The only thing that causes a stall is increased back pressure(angle of attack).

 

[midlifeflyer]

This is NOT an "emergency" maneuver.

No, it's not. But like many PTS maneuvers, the steep spiral doesn't exist in a vacuum. it has a potential practical application. In this case (sentence after the one you quoted), "The steep spiral is not only a valuable flight training maneuver, but it has practical application in providing a procedure for dissipating altitude while remaining over a selected spot in preparation for landing, especially for emergency forced landings." (Heck of a lot better than the last time it was in the PTS, when folks used to talk about its use for flying through a hole in an overcast!)

I was only commenting on the selection of airspeed, something that the AFM and PTS is pretty silent on, except to say to keep it constant.

 

[nosehair]

"The steep spiral is not only a valuable flight training maneuver, but it has practical application in providing a procedure for dissipating altitude while remaining over a selected spot in preparation for landing, especially for emergency forced landings."

I know, Midlife, and I didn't mean to ignore that practical application, but I wanted to emphsize the MAIN OBJECTIVE of the maneuver is GOOD GLIDE CONTROL which is indicated in the first part of the sentence "valuable flight traning maneuver". I have noticed over the years, since this maneuver was removed from the PTS that most pilots (private and commercial) have 3 hour student pilot proficiency in gliding turns. The steep spiral and the 180 power off that was added is basiclly to re-institute training in gliding turns, which of course becomes important in the event of an emergency landing, but also in all basic flying maneuvers.