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