Confined Area Training

[CBiPilotFL]

Good Afternoon All,

 

I am closing in on my PPL checkride and have been doing confined area approaches and landing and I constantly seem to be getting into a high rate of descent at the last part during the final approach. I end up having to pull a lot power to recover and am worried because this can be a perfect setup for settling with power . How do you guys teach confined areas and what are some things I can do to avoid this situation?

 

Thanks in advance and fly safe.

[FauxZ]

I've had similar problems and I can offer my advice on what I've done, only 150+ hours though, so I could still be doing it wrong. Honestly, I'm just now doing the study for my CFI, so any criticisms are very welcome.

 

Anyway, try to shallow your approach farther out when you still have airspeed. Try to fix your angle out there. If that still fails, pull in power and stop the ROD before you get below ETL. Pulling in power is going to lower your decent rate, which I think looks weird and is the hardest thing for me to overcome, but it's going to slow you down too. If you don't want to slow down, make sure you slightly lower the nose as you pull power so you don't balloon up.

 

The most important thing to remember is don't be afraid to go around. If you have your approach and departure routes setup, and it all looks bad, call a go around, even on your check ride. You're going for Private, your good judgment is just as important as good flying. Just make sure you correct your mistakes and do it right the second time.

[nsdqjr]

Good Afternoon All,

 

I am closing in on my PPL checkride and have been doing confined area approaches and landing and I constantly seem to be getting into a high rate of descent at the last part during the final approach. I end up having to pull a lot power to recover and am worried because this can be a perfect setup for settling with power . How do you guys teach confined areas and what are some things I can do to avoid this situation?

 

Thanks in advance and fly safe.

 

Like FauxZ said, try to shallow out the approach as much as you can and still safely enter the confined area. Normally the approach is going to be a steep approach and this is how I teach my students: As soon as you intercept the sight picture for the approach, back your airspeed off until you feel the shudder of the Transverse Flow Effect. Riding the shudder all the way to the ground allows you to maintain ETL while flying as slowly as possible. If you keep it slow like that you shouldn't have any problems at the bottom. Hope it helps!

[JDHelicopterPilot]

Like FauxZ said, try to shallow out the approach as much as you can and still safely enter the confined area. Normally the approach is going to be a steep approach and this is how I teach my students: As soon as you intercept the sight picture for the approach, back your airspeed off until you feel the shudder of the Transverse Flow Effect. Riding the shudder all the way to the ground allows you to maintain ETL while flying as slowly as possible. If you keep it slow like that you shouldn't have any problems at the bottom. Hope it helps!

 

nsdqjr put very well. I teach it the same way. I always see students come in too fast, faster than they do for their normal app back at the airport. This is most due to depth perception. We use apparent rate of closure when on final which works well over level terrian. For off airport when you use apparent rate of closure and flying over valleys and ridges you feel as if you are going slow when over the valleys since they are farther below you than your landing zone. This leads to coming in too fast. Follow nsdqjr's advise, slow it down sooner to ETL and ride it down. Higher DA's this is good as the power will be brought in sooner so the helicopter will have more time to react to the power change which takes longer in higher DA's. So it is a win win situation. After some time you will be able to do your approach faster rather than riding ETL all final, but it will come with time. In the mean time slow to ETL sooner and ride it home. Good luck.

[CBiPilotFL]

nsdqjr put very well. I teach it the same way. I always see students come in too fast, faster than they do for their normal app back at the airport. This is most due to depth perception. We use apparent rate of closure when on final which works well over level terrian. For off airport when you use apparent rate of closure and flying over valleys and ridges you feel as if you are going slow when over the valleys since they are farther below you than your landing zone. This leads to coming in too fast. Follow nsdqjr's advise, slow it down sooner to ETL and ride it down. Higher DA's this is good as the power will be brought in sooner so the helicopter will have more time to react to the power change which takes longer in higher DA's. So it is a win win situation. After some time you will be able to do your approach faster rather than riding ETL all final, but it will come with time. In the mean time slow to ETL sooner and ride it home. Good luck.

 

Thanks for the advice... I will put it to use. In reference to checkrides, what are the most common errors you see students make?

[HelliBoy]

Power check before a confined. On site.

[joker]

surely you mean 'no power Check'?

 

Another mistake is to forget to call 'committed' at LDP

[HelliBoy]

surely you mean 'no power Check'?

 

Are you arguing semantics or saying not to do an available power check near your confined??

[delorean]

The lower you go, the slower you go......

 

When you enter you steep approach you're probably around 60 knots and setup for a 500-1000 fpm decent. As you get closer to your spot, you're slowing down. As soon as you drop below 50 kts, you're on the backside of the power curve so it takes more power to maintain a/s and alt. As you continue to slow, you're ROD will continue to rise if you don't pull in power.

 

One trick that always helps, when you get ready to turn base leg, count to ten, then turn base. This will give you plenty of time to get your a/s, attitude, etc set before that site picture appears.

[CBiPilotFL]

The lower you go, the slower you go......

 

When you enter you steep approach you're probably around 60 knots and setup for a 500-1000 fpm decent. As you get closer to your spot, you're slowing down. As soon as you drop below 50 kts, you're on the backside of the power curve so it takes more power to maintain a/s and alt. As you continue to slow, you're ROD will continue to rise if you don't pull in power.

 

One trick that always helps, when you get ready to turn base leg, count to ten, then turn base. This will give you plenty of time to get your a/s, attitude, etc set before that site picture appears.

 

 

Thanks again for all the replies. Flying again Friday... I'll let you guys know about the checkride. Should be before the end of the month...

[flyby_heli]

Looks like you might be flying Schweizers....in that case your best lift/drag ratio is at around 40 kts (where it requires the least amount of power to keep the same airspeed and altitude.)

 

One thing that might help you, is to start slowing down your airspeed before you start your approach. Remember if you are going 60 kts vs 40 kts on final, you are closing in on your spot almost twice as fast this means you have to have almost twice the descent rate to keep your approach angle constant. And we all know a high descent rate is one of the factors to swp.

Slowing down the approach first will allow you more time on the approach, a lower descent rate, which again means less/smaller power changes and it just makes your job easier and makes the approach feel more comfortable.

And as other people have pointed out, start bringing in the power early at the end.

 

Hope this helps.

[LostHeliBoy]

Remember if you are going 60 kts vs 40 kts on final, you are closing in on your spot almost twice as fast this means you have to have almost twice the descent rate to keep your approach angle constant. And we all know a high descent rate is one of the factors to swp.

 

Slowing down the approach first will allow you more time on the approach, a lower descent rate, which again means less/smaller power changes and it just makes your job easier and makes the approach feel more comfortable.

 

And as other people have pointed out, start bringing in the power early at the end.

YES YES YES ... Rate of closure and Slowing down will give you more time!!! I concur!! later when you fly PAX the little things like coming back out of ETL is apparently one of the reasons people don;t like to ride in helicopters.. is freeks them out.. I guess they think its going to make the helicopter fall out of the sky.. although its just another part of the aerodynamics inherant in flying a spinning wing..

 

GOOD LUCK on your Chx ride!!

 

CHEERS!!

[joker]

Are you arguing semantics or saying not to do an available power check near your confined??

 

Yes, I am querying your sematics.

 

 

The original questin was:

what are the most common errors you see students make?

 

To which you replied:

 

Power check before a confined. On site.

 

This reply is ambiguous. Does it mean that doing a PC on site is an error? Or does it mean that the method being used is done wrong?

 

So I simply wanted to clear up your meaning to avoid anyone going away with the wrong impression.

 

Joker

Edited February 11, 2007 by joker

[JDHelicopterPilot]

Yes, I am querying your sematics.

The original questin was:

what are the most common errors you see students make?

 

To which you replied:

 

Power check before a confined. On site.

 

This reply is ambiguous. Does it mean that doing a PC on site is an error? Or does it mean that the method being used is done wrong?

 

So I simply wanted to clear up your meaning to avoid anyone going away with the wrong impression.

 

Joker

 

I hate to hijack the thread a bit but when it comes to power checks...... While doing my training I had sugested to my CFI I should do a power check on my Commercial check ride when doing off airport. I like to be sure I can not only get in but also out. He came back with a valid point....where in the 300CB or R-22 POH is there anything in the performance or limitations section on power checks? In other words... where did it come from? Say you have 2" of MP to play with what kind of approach can I do? I have a power check list of my own that I use. But what I am saying is other than our own knowledge and our CFI's imput, where do we get info on power checks? He said the examiner wouldn't like me to do a power check as I would not be able to back it up with performance data. I did it anyway on my checkride and when I announced I was doing it I sort of got a stare but he never asked or said anything about it afterwards. I do checks do checks when off airport and teach my students what I know. But it's info that has been passed on and my own knowledge as well. Where else can we get info on power checks from? PS I did all my training in a 300CB/CBI except my Instrument which was in the R-22 and now teach in them as well.

Edited February 11, 2007 by JDHelicopterPilot

[joker]

Power check thread May 2006

 

http://helicopterforum.verticalreference.com/helicopterfor...?showtopic=4222

[JDHelicopterPilot]

Power check thread May 2006

 

http://helicopterforum.verticalreference.com/helicopterfor...?showtopic=4222

 

I saw that thread before. I was just saying my instructor said not to do one since there is no performance data given in the performance or limitations sections of the POH. Like I said I do teach them since I know what to expect from experience. I have had many students pass Commercial Checkrides with out doing one and it never came up. I will ask around for some opinions and let u know what I find out.

[West Coaster]

I was just saying my instructor said not to do one since there is no performance data given in the performance or limitations sections of the POH.

 

Does it have to be written in stone before you can do it? Kudos to you for doing the power check despite your instructors caution. Always better safe than sorry.

 

We do power checks operationally all the time, so why is it common practice to omit them in flight tests? Would be embarassing to make an examiner walk to a larger clearing because you landed in a spot you couldn't both fly out of.

[nsdqjr]

This is an interesting discussion because there are a million methods for doing power checks, none of which are stated in the POH (R-22 at least). Most of the power check methods I have heard have you flying about 500' AGL and slowing down to 40 or 50 KIAS. Now in the POH there IS a Height/Velocity diagram. Some of these power check methods get you pretty close to the shaded area, which is every bit as dangerous as entering a confined area that you can't escape. Due to the different techniques and lack of hard numbers I find the relevence and accuracy questionable. Also the power checks leave out some key factors: Ground Effect and Translational Lift. Alot of instructors teach their students to pull max MAP and climb out as vertically as possible. I always teach to get as much airspeed (Translational Lift) as the area permits. Even just a couple knots of forward airspeed can be the difference between flying out or walking out. The bottom line for all of this is judgement. Teach the students the performance factors, make them check the IGE and OGE performance charts for the day, and encourage them to make wise decisions based on the individual situation.

[joker]

I was just saying my instructor said not to do one since there is no performance data given in the performance or limitations sections of the POH.

 

Interesting statement: Surely the performance section of the POH contains performance data!?

 

Should we do a power check?

 

I believe yes. I think it is important to know how much power you have available before entering a confined area, and thus make sure you can get out. I think this is prudent (especially in a low powered aircraft). As West Coaster says, where I work ,we calculate power required to ensure we have CAT A performance, based on temp, DA and AUW before each takeoff.

 

How should we do a power check?

 

There is more than one way to assess your power margin. In the real world, you do what you have to do.

 

The rules of thumb (+1=IGE, +2=OGE, +3=Vertical Climbout Margin or whatever you use) that many people talk about are good rules of thumb, tried and tested over the years. Why not use them?

 

On the other hand, by refering to the OGE hover diagram (and other manufacturers published data) you can also make a determination of your power margins. Yes, it's a little more trouble to do an OGE hover, but it works. Yes, it's a little more trouble to extrapolate your All-up weight on the charts, the temperature and DA, but it works. (See the other thread for more details)

 

What about during checkrides?

 

A look through the PTS reveals that the term 'power check' does not exists in the PTS, nor in the rotorcraft flying handbook.

 

Two pertinent objectives do exist though.

 

Exhibits knowledge of the elements related to confined area

operations.

 

Selects a suitable takeoff point, considers factors affecting

takeoff and climb performance under various conditions.

 

So it is the student's perogotive to 'demonstrate' those two items. How he does this is up to him...that's what's not written.

 

However, which ever way the student demonstrates the knowledge and understanding, he must be able to explain the factors and issues with that method. The only indisputable method is by using 'manufacturer's published data'. On the other hand, if the student feels confident enough to justify in a checkride debrief using the 'old tried and tested numbers' then great...go for it.

 

So what I am saying is that during a checkride you have to exhibit knowledge and consider factors etc..etc.. as per the PTS. How you do this is up to you, so long as you can explain it. The examiner might question anything that is unpublished, but can't query manufacturer's data.

 

Just as NSQDJR has just posted (as I type this post), it is important to teach students all the different methods of checking power margins and ensure they understand them well enough to be able to use them in the field or explain them to an examiner on the ground.

 

Likewise it is important to show your student the variety of different methods used for getting out of a confined area, even thought the PTS / Rotorcraft Flying Handbook describes only one. (vertical takeoff vs altitude over airspeed takeoff).

 

Armed with a good grounding in these subjects, the student will be able to meet the objectives of the PTS I stated above, either in the air or on the ground.

 

Joker

Edited February 11, 2007 by joker