A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Soaring
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Round out and flare with fully open spoilers in a PW-6? Other gliders?



 
 
Thread Tools Display Modes
  #1  
Old March 27th 18, 12:47 AM posted to rec.aviation.soaring
son_of_flubber
external usenet poster
 
Posts: 1,550
Default Round out and flare with fully open spoilers in a PW-6? Other gliders?

The PW-6 has very effective spoilers, and some other gliders have even more effective spoilers. Assuming C.G. is within limits and runway is level, is it possible to round out and flare with the spoilers fully open? Does one need extra airspeed? How much extra? (Yep. I know it is advisable to reduce spoilers before entering roundout.)

How do you teach steep descent to students? How steep? How fast?

I saw this question come up in a discussion of a fatal accident in a SZD 51-1 Junior. Student pilot opened 'full spoilers' and failed to flare.

Is a 'full spoiler flare' required to obtain glider certification in EASA?

And finally, does the PW-6 have spoilers or airbrakes?
  #2  
Old March 27th 18, 02:28 AM posted to rec.aviation.soaring
George Haeh
external usenet poster
 
Posts: 167
Default Round out and flare with fully open spoilers in a PW-6? Other gliders?

I witnessed a fatal Junior crash in 2007:

http://www.bst-tsb.gc.ca/eng/rapports-
reports/aviation/2007/a07o0233/a07o0233.asp

The report left a lot out.

Yes, full spoilers were put out in a panic move, but the small stature
student
rotated her shoulders to get them out and inadvertently pushed the stick
forward.

Ergonomics played a much bigger part than aerodynamics.

A high flare with full spoilers will likely result in a hard landing, but
futzing with
spoilers low down can destabilize a landing. I recall three landings in my
first
solo in a certain two seater not that long ago.

A low flare at good speed with full spoilers can work. Reducing spoilers at
that
point can add a few hundred yards to the landing.

  #3  
Old March 27th 18, 02:56 AM posted to rec.aviation.soaring
Tom[_21_]
external usenet poster
 
Posts: 48
Default Round out and flare with fully open spoilers in a PW-6? Other gliders?

Well - you've gotten me to bite.

From the PW-6 AFM:

AIR BRAKE OPERATION
With the air brakes extended fully, the sailplane gliding ratio at the approach speed is 6.4. Diving at 45° with air brakes extended fully does not exceed the airspeed of 141 kts. Extending and retracting the air brakes do not cause the sailplane to pitch up or down. Operation of the air brakes is allowed within the whole airspeed range. The brakes can be retracted at the airspeed below 89 kts.

NOTE:
When extending the air brake at the airspeed above 108 kts
the negative vertical acceleration is significant. Therefore the air brake should be extended gently. The aircrew should have the safety belts fastened tightly.

My thoughts - the full air brake usage on a normal landing, stabilized descent by 100', on speed is not going to be what "gets you". Just like in any aircraft if you throw in a configuration change close to the ground and don't compensate for it you'll pay a price down the line - too little and you'll float, too much and you'll land way short of where you want. There is a lot of elevator authority to arrest the descent rate even with the air brakes fully open.

Speed would be a factor - meaning if one (for some bizarre reason) flew the darn thing straight at the ground at high rate of descent and speed with the air brakes out (or in for that matter) if you started your round out and flare late you'd break people and glider.

I've landed the PW-6 numerous times and coached students through it. It does some things well on landing - the controls are very effective, the feedback is pretty excellent, the air brakes are very effective and easy to adjust in small increments resulting in being able to "dial it in" well. I like that the brake is a lever on the air brake handle (hate it when people land with the air brakes on all the way in the ASK21 and pull it back actuating the wheel brake smoking the tire on touchdown. Also the geometry between the nose wheel and the tailwheel allows more of a margin to help prevent a tail strike.

And as always, your results may vary.

Regards Tom
  #4  
Old March 27th 18, 03:09 AM posted to rec.aviation.soaring
George Haeh
external usenet poster
 
Posts: 167
Default Round out and flare with fully open spoilers in a PW-6? Other gliders?

I witnessed a fatal Junior crash in 2007:

http://www.bst-tsb.gc.ca/eng/rapports-
reports/aviation/2007/a07o0233/a07o0233.asp

The report left a lot out.

Yes, full spoilers were put out in a panic move, but the small stature
student
rotated her shoulders to get them out and inadvertently pushed the stick
forward.

Ergonomics played a much bigger part than aerodynamics.

A high flare with full spoilers will likely result in a hard landing, but
futzing with
spoilers low down can destabilize a landing. I recall three landings in my
first
solo in a certain two seater not that long ago.

A low flare at good speed with full spoilers can work. Reducing spoilers at
that
point can add a few hundred yards to the landing.

  #5  
Old March 27th 18, 07:58 AM posted to rec.aviation.soaring
krasw
external usenet poster
 
Posts: 668
Default Round out and flare with fully open spoilers in a PW-6? Other gliders?

tiistai 27. maaliskuuta 2018 2.47.36 UTC+3 son_of_flubber kirjoitti:
The PW-6 has very effective spoilers, and some other gliders have even more effective spoilers. Assuming C.G. is within limits and runway is level, is it possible to round out and flare with the spoilers fully open? Does one need extra airspeed? How much extra? (Yep. I know it is advisable to reduce spoilers before entering roundout.)

How do you teach steep descent to students? How steep? How fast?

I saw this question come up in a discussion of a fatal accident in a SZD 51-1 Junior. Student pilot opened 'full spoilers' and failed to flare.

Is a 'full spoiler flare' required to obtain glider certification in EASA?

And finally, does the PW-6 have spoilers or airbrakes?


Full spoilers landing is essential technique to teach students as this is the configuration they will use in 95% of the future outlandings. Requirements for speed control and timing of the flare are more demanding and some firm touchdowns inevitably follows.
  #6  
Old March 27th 18, 11:50 AM posted to rec.aviation.soaring
Tango Eight
external usenet poster
 
Posts: 962
Default Round out and flare with fully open spoilers in a PW-6? Other gliders?

The yellow triangle on the ASI has a specific meaning. It's the recommended approach speed at maximum gross weight in calm conditions. A skilled pilot should be able to make a well executed full airbrake approach / flare / touchdown starting at this approach speed. The roundout will be brief. Adding a little speed (5 kts) gives a little more time in the transition from steep approach to landing for learning purposes.

With most airbrakes, the reduction in lift (at constant speed, AoA) happens in the first 2" of deployment, while the effect on drag is fairly linear over the whole range. The pilot must coordinate pitch attitude appropriately with airbrake deployment to control airspeed. If the airbrakes are opened just slightly and held there, a little back stick pressure may be required. If opened more fully, some forward stick is almost always required. That's a general characteristic of gliders with Schempp Hirth airbrakes.

The 2007 accident sounds like one of Piggot's sub gravity sensation accidents.
  #7  
Old March 27th 18, 12:06 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 94
Default Round out and flare with fully open spoilers in a PW-6? Other gliders?

On Monday, March 26, 2018 at 7:47:36 PM UTC-4, son_of_flubber wrote:
The PW-6 has very effective spoilers, and some other gliders have even more effective spoilers. Assuming C.G. is within limits and runway is level, is it possible to round out and flare with the spoilers fully open? Does one need extra airspeed? How much extra? (Yep. I know it is advisable to reduce spoilers before entering roundout.)

How do you teach steep descent to students? How steep? How fast?

I saw this question come up in a discussion of a fatal accident in a SZD 51-1 Junior. Student pilot opened 'full spoilers' and failed to flare.

Is a 'full spoiler flare' required to obtain glider certification in EASA?

And finally, does the PW-6 have spoilers or airbrakes?


It is essential that full spoiler landings to a spot are taught during the training process for glider pilots. I have argued this for many years, there is no room for high energy approaches while landing off field. Back in my early days of training and I do go back for a long time ago, we were taught to make full spoiler landings to a certain spot. This came in pretty handy back in the late 70's when I made my first off field landing at a state prison facility. Believe me, there was no room for error and the interrogation afterwards was worse than the landing.
Now I see students being taught to make approaches to landing using very little spoiler and continuous adjustments until touchdown. I call it the power approach, I have stressed to some of the instructors that at some point the full spoiler approach to touchdown could be very helpful and increase the glider pilots skill.
  #8  
Old March 27th 18, 02:30 PM posted to rec.aviation.soaring
Tom[_21_]
external usenet poster
 
Posts: 48
Default Round out and flare with fully open spoilers in a PW-6? Other gliders?

I'd agree that the full air brake or spoiler or dive brake approach to a spot landing is a critical skill. It's one more tool in the tool kit - ready to be used when needed. Pilots should be able to adapt, configure and fly the approach and landing as needed. Some student have been taught to apply full air brakes or spoiler or dive brakes abeam the touchdown point and hold that all the way until touchdown (excitement for sure). Some have been taught to not apply until short final. Some are not capable of adapting their pattern for winds, sink and or other variables,

Looking at the SSF and other data for landing accidents/incidents show, among other things, we can do a better job of teaching students and pilots to maintain a good situational awareness, adapt the pattern as necessary and actuall fly the glider all the way through the landing.

Regards Tom
  #9  
Old March 27th 18, 04:49 PM posted to rec.aviation.soaring
Dan Marotta
external usenet poster
 
Posts: 4,601
Default Round out and flare with fully open spoilers in a PW-6? Othergliders?

Just curious - was the terrain outside the wall unlandable?Â* Sounds like
an interesting story, did I see it in "Soaring" long ago?

On 3/27/2018 5:06 AM, wrote:
On Monday, March 26, 2018 at 7:47:36 PM UTC-4, son_of_flubber wrote:
The PW-6 has very effective spoilers, and some other gliders have even more effective spoilers. Assuming C.G. is within limits and runway is level, is it possible to round out and flare with the spoilers fully open? Does one need extra airspeed? How much extra? (Yep. I know it is advisable to reduce spoilers before entering roundout.)

How do you teach steep descent to students? How steep? How fast?

I saw this question come up in a discussion of a fatal accident in a SZD 51-1 Junior. Student pilot opened 'full spoilers' and failed to flare.

Is a 'full spoiler flare' required to obtain glider certification in EASA?

And finally, does the PW-6 have spoilers or airbrakes?

It is essential that full spoiler landings to a spot are taught during the training process for glider pilots. I have argued this for many years, there is no room for high energy approaches while landing off field. Back in my early days of training and I do go back for a long time ago, we were taught to make full spoiler landings to a certain spot. This came in pretty handy back in the late 70's when I made my first off field landing at a state prison facility. Believe me, there was no room for error and the interrogation afterwards was worse than the landing.
Now I see students being taught to make approaches to landing using very little spoiler and continuous adjustments until touchdown. I call it the power approach, I have stressed to some of the instructors that at some point the full spoiler approach to touchdown could be very helpful and increase the glider pilots skill.


--
Dan, 5J
  #10  
Old March 27th 18, 05:28 PM posted to rec.aviation.soaring
Charlie M. (UH & 002 owner/pilot)
external usenet poster
 
Posts: 1,383
Default Round out and flare with fully open spoilers in a PW-6? Other gliders?

I agree with "pushing the limits" a bit in a controlled situation.
When I was flying a -20A and -20C, I would get a couple local flights in during the spring.
Then, I would intentionally come in rather high, on final, "hang it all out" (landing flaps, full dive brakes) and remember how much I had to stuff the nose over to maintain speed as well as watch the ground come up fast. Then, land.

Better to remember/practice in a known environment than going into a small field under possible duress.

I do similar in other gliders (from a 1-26 SN002 to ASG-29 and lots in between) just to remember what they do/how hey behave when pushing them a bit.
I think everyone should do this every spring and a few times during the season.
Again, better to practice a tight fit with minimal variables so you have a current basis in a tight situation.

No, I don't practice tree or water landings. Hope I realize a bad situation before I need to exercise those skills..... Small fields can be bad enough.
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
New open class gliders at Aero Dave Nadler Soaring 5 April 20th 11 09:13 AM
Open Cockpit Gliders? DL152279546231 Soaring 17 December 25th 08 09:14 AM
Comparison of older Open Class gliders SoaringXCellence Soaring 5 March 15th 08 06:02 PM
Open Spoilers Alarm on tow tango4 Soaring 12 March 17th 04 07:18 PM
Aviation art website fully functional Christopher Drew Aviation Marketplace 0 January 29th 04 11:43 AM


All times are GMT +1. The time now is 03:40 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AviationBanter.
The comments are property of their posters.