Go Back  PPRuNe Forums > Aircrew Forums > Rotorheads
Reload this Page >

Downwind approaches

Rotorheads A haven for helicopter professionals to discuss the things that affect them

Downwind approaches

Old 27th Sep 2003, 22:23
  #21 (permalink)  
 
Join Date: Sep 2001
Location: Australia.
Posts: 292
Received 8 Likes on 6 Posts
DBChopper, I am surprised that your training school didn't expose you to downwind operations during the course of your training. It is good to see you are trying to learn more and erring on the side of safety with regard to them. I would recommend that you book in with an experienced instructor and do some.

Considerations with downwind approaches:

Only do them when you have to.

Make sure you are not out of your depth for your level of experience.

You must have HOGE power available.

Prioritise your potential hazards. Of course you should have a planned course of action should the engine fail as PPRUNE FAN #1 mentioned. However, the chances of the engine failing are extremely remote compared to you putting it into a vortex ring state or overpitching it due to insufficient power available. It is not much good finding yourself in VRS because you have flown a downwind profile to suit the remote possibility of an engine failure.

The R22 flight manual stipulates hover controllability has been demonstrated up to 17KTS from any direction. (This may have legal/insurance implications should something go wrong above 17KT)


The technique I used to teach was this:

Is it the only way?

Do a power check to ensure you have sufficient power available.

Make your approach angle on the shallower side of normal to ensure your ROD during the approach is manageable, and definitely no more than what you would have during a normal approach.

Keep the GROUNDSPEED during the approach comfortable and slightly slower than what you would have during a normal approach.

Regularly assess your airspeed versus your groundspeed during the approach, to determine if the downwind component is excessive AND to anticipate the loss of translational lift. Be aware that as you come out of translational lift the aircraft will want to sink out, and that sink if you let it happen may be all that it takes to bring about the onset of VRS. Anticipate the sink and don't let it happen.

If at any stage it feels too fast or doesn't feel right, initiate maximum power and go around.


I don't think downwind approaches are "extremely risky" or always unsafe as PPRUNE FAN#1 describes. Provided you are:

Not operating the aircraft beyond its limits,
Not beyond your own personal limits and level of experience,
Aware of the potential risks and how to avoid them.

You should be able to safely do one if you need to.
the coyote is offline  
The following users liked this post:
Old 28th Sep 2003, 00:01
  #22 (permalink)  
 
Join Date: Dec 2001
Location: SE England
Posts: 409
Likes: 0
Received 0 Likes on 0 Posts
The Coyote,

I thought about it before posting originally, but I don't remember doing any downwind operations during my PPL(H) training. It was done at a large airfield with marked helistrips, so some was done with a slight crosswind but that was it. That's propbably why it took me by surprise, as a new boy, on those initial post-PPL cross-countries when I was given out of wind approaches. I take your point about practice and I will book some time with an instructor to have a proper play. Thanks for the post.
DBChopper is offline  
Old 28th Sep 2003, 05:22
  #23 (permalink)  
 
Join Date: Apr 2003
Location: USA
Age: 76
Posts: 3,012
Likes: 0
Received 0 Likes on 0 Posts
A sure sign of senility is the belief that everything is really just a repeat. That being said, this whole thread is remarkably like:

http://www.pprune.org/forums/showthr...light=downwind

As I posted in the past, downwind is not a horrible, deathly, stupid thing to do, in fact, under some cirumstances it is the only thing to do, and modern helicopters are designed to do it well. Attack helicopters, rescue helicopters and others need excellent power margins and powerful yaw control because they regularly fly, approach and hover downwind.
Here is a simple poster that says it all:

http://safety.army.mil/pages/media/pubs/ff/windsock.pdf

This does not mean that a PPH should run right out and start the habit, just that he/she should appreciate that many things called gospel in early years (don't play with electricity, don't cross the street, don't kiss girls) are artifacts of the restricted world of the newly initiated.

Last edited by NickLappos; 28th Sep 2003 at 22:43.
NickLappos is offline  
Old 29th Sep 2003, 05:47
  #24 (permalink)  
 
Join Date: Jan 2003
Location: Europe
Posts: 406
Likes: 0
Received 0 Likes on 0 Posts
Anything downwind is not a part of the FAA CPL curriculum, which is ridiculous. Some schools teach them anyway but I actually left one that didn't. It's like not doing autos because "it's not a part of the normal procedure".

What are the recommendations in regards to downwind take-offs?
Martin1234 is offline  
Old 29th Sep 2003, 15:57
  #25 (permalink)  

The Original Whirly
 
Join Date: Feb 1999
Location: Belper, Derbyshire, UK
Posts: 4,326
Likes: 0
Received 0 Likes on 0 Posts
I did them for my PPL(H). I was told it was an advanced exercise to learn control of the helicopter, and to understand what was happening, NOT something that I should do. I think this is essential.

Maybe you should consider the following story. As a fairly low hours PPL(H), I flew into a friends large-ish field. There was very little wind, but what there was, was a bit gusty and changing direction a lot. He had a windsock in the field, and I approached what appeared to be into wind. He was talking to me on a handheld radio, and as I reached about 200 ft, he said; "Be careful; you've got a tailwind". Well the wind was all of about 6 or 7 knots, so I made sure I had a low rate of descent, and lots of room since my groundspeed would be higher than my airspeed, and it was no problem. Hardly a really difficult situation, I'm sure you'll all agree, even for a low hours pilot. For a TRAINED low hours pilot, that is! But for one with NO training at all as to what the situation meant, and what could happen....
Whirlybird is offline  
Old 29th Sep 2003, 17:04
  #26 (permalink)  
 
Join Date: Aug 2003
Location: uk
Posts: 32
Likes: 0
Received 0 Likes on 0 Posts
PPRUNE Fan#1

I asked a genuine question re : the FAA syllabus because I did not know whether downwind approaches were included in the training regime. I gather that they are not from the various posts from DBChopper etc., and so I was surprised by your 'it should be obvious' quote.

I cannot agree with you that downwind approaches should never be required because of circumstances - and from the posts others don't agree with you either.

It is a fact of helicopter flying that downwind approaches may be required, and indeed are sometimes the only option possible.

To quote you, 'that should be obvious ......'

Fly safely all
Head Bolt is offline  
Old 30th Sep 2003, 10:21
  #27 (permalink)  
 
Join Date: Oct 2002
Location: US...for now.
Posts: 396
Likes: 0
Received 1 Like on 1 Post
Loose Head Bolt:
I cannot agree with you that downwind approaches should never be required because of circumstances - and from the posts others don't agree with you either.

It is a fact of helicopter flying that downwind approaches may be required, and indeed are sometimes the only option possible.

To quote you, 'that should be obvious ......'
Downwind approaches..."required," eh? So that is a FACT, eh? Hmm. Let's see, 10,000+ hours as a commercial helicopter pilot, and I can count on one hand the number of times a downwind approach has been "required" of me. I'm thinking back now...you know, it's hard to keep track of every single landing when you've logged more than 60,000 of them. But I'm really trying to recall a time when I was forced to land downwind without being able to find a suitable and safer alternative.

Nope, can't do it.

I must've lead a very sheltered life as a pilot, eh what! Or...maybe I'm just creative enough to figure out how to keep myself from doing something really, really stupid. And Head Bolt, when they're PAYING you to fly, you have to take it seriously and be more responsible than saying dumb things like "it is a fact that downwind approaches are sometimes required." Such a premise seems awfully immature.

I have had some rather extreme and weird and exciting crosswinds (you know, times when I've circled overhead whilst trying to decide whether it would be better to take the left or right crosswind on the way in, depending on what would happen at the bottom). But when you're downwind, your margins are extremely thin, perhaps nonexistent.

But me...see, I would take a nearly-vertical, between-the-pedals-steep approach into the wind rather than land directly downwind. Especially if I was heavy and most especially if the wind was strong. I don't like downwind; I don't mind steep. I think the risks of a very steep into-the-wind approach are far less than doing it downwind. Steep and into the wind, I can control the ship better. Downwind, you never know when the shudder you're feeling is simply the rotor going in and out of ETL or the onset of VRS. Again, your mileage may vary.

Methinks that Head Bolt and others ought to rethink their "approach" to safety. It's basically pretty simple. There is no reason to think that a downwind landing should in FACT ever be "required"...unless you're doing something where people are shooting at you.

That should be obvious.

Now watch, tomorrow I'll go out and have to land someplace downwind and end up eating all of these delicious words. But I kind of doubt it
PPRUNE FAN#1 is offline  
The following users liked this post:
Old 30th Sep 2003, 10:57
  #28 (permalink)  
 
Join Date: Nov 2000
Location: White Waltham, Prestwick & Calgary
Age: 72
Posts: 4,166
Likes: 0
Received 29 Likes on 14 Posts
I see no real problem with landing downwind as such - it's a tool at our disposal that is low on the list, that's all. Nobody's forcing anyone to land into wind, either, but you can still get the job done as long as you realise what you're doing, as someone mentioned before. Having said that, it should not be attempted without being taught properly - it was standard on my Army course.

Faced with a vertical climb over trees to stay into wind, or clear access (especially for emergency vehicles) and a downwind takoff, I have often chosen the latter. Sometimes you have no choice on a log pad hanging off the side of a mountain - just make sure you ain't heavy and you have an escape route

phil
paco is offline  
The following users liked this post:
Old 30th Sep 2003, 18:53
  #29 (permalink)  
PPRuNe Enigma
 
Join Date: Feb 2001
Location: Scotland
Posts: 427
Likes: 0
Received 0 Likes on 0 Posts
Shortly after getting my PPL I flew into a small airfield down south. The R/T gave the wind direction as from the south and the runway in use 32.

I thought this was a bit odd, decided I'd rather go with the wind direction and stated I'd be making my approach from the north. To which the guy said "no problem" and the approach and landing went safely, into wind, on 14.

Once on the ground it was obvious that 32 had a very noticeable upslope. With a light tailwind I guess this was still the best choice for fixed wings - but as we all know, helicopters fly differently than aeroplanes.

In this case, the guy was happy for me to choose the approach I wanted - so don't be afraid to ask for the approach you want rather than the one you are given.
Grainger is offline  
Old 30th Sep 2003, 19:09
  #30 (permalink)  
 
Join Date: Aug 2000
Location: UK
Posts: 3,680
Likes: 0
Received 1 Like on 1 Post
Pprune No#1

C'mon now, surely you're not that inflexible?
Everyone who flies helos for a profession, knows that a downwind landing is always available, should the need arise. Provided one takes charge of the situation, they are not procedures one should shy away from.

I have done a fair number of downwind approaches to land whilst tasked on EMS; why? because there is no-where else to land - plain and simple. Do I cancel the landing because there is no other alternative, of course not.

One of the benefits of a helo is that it is versatile in this instance. If a pilot knows their limits and operates cautiously then there is absolutely no reason NOT to employ a downwind landing...WHEN THERE IS NO ALTERNATIVE (there's the rub).

Try it some time...you'll be amazed...
Thomas coupling is offline  
The following users liked this post:
Old 2nd Oct 2003, 02:07
  #31 (permalink)  
 
Join Date: Sep 2001
Location: Australia.
Posts: 292
Received 8 Likes on 6 Posts
kissmysquirrel,

One technique I use for a downwind departure, if you have a wee bit of room. Hover into wind, as you lower the nose to accelerate and begin to move (into wind), progressively begin to turn downwind and continue to lower the nose and accelerate throughout the turn downwind. You will be through translational lift prior to being downwind and away you go. Of course your groundspeed is fast as you accelerate and turn downwind. In a light helicopter you maybe only need 20m in front of you and about 50-75m out to the side you are turning.

A direct downwind departure, just be prepared for it to sink out as you accelerate, catch up with the wind and come out of translational lift. Be ready on the power and dont let it sink. You will have a pretty quick groundspeed (maybe 10-15KT + the tailwind) before you regain translational lift as you 'come out the other side'.

Don't forget the climb gradient is not as good and you need more distance for obstacle clearance, as Nick Lappos previously pointed out.
the coyote is offline  
The following users liked this post:
Old 3rd Oct 2003, 21:03
  #32 (permalink)  
 
Join Date: Sep 2003
Location: THE MANGROVE SWAMPS (RETIRED)
Posts: 201
Likes: 0
Received 0 Likes on 0 Posts
PPF#1

Wow, 10,000 hours eh - you'd be a low-time pilot on my operation, (average hours 12,000+) where we have to carry out downwind approaches on a regular basis. I guess that's why the UK CAA include them on the syllabus for the CPL(H), though I agree that it's probably unwise for inexperienced or non-current PPLs to go out and attempt them in anything other than a light wind with plenty of room to spare.
I guess you've led a very sheltered life
Mama Mangrove is offline  
Old 4th Oct 2003, 00:58
  #33 (permalink)  
 
Join Date: Apr 2002
Location: Up north
Posts: 687
Likes: 0
Received 1 Like on 1 Post
Before MM and PPF#1 get their handbags out let us return to the topic; which I believe is should a low time pilot make a downwind approach.

I like PPF#1 have flown many hours (not going to tell in case MM says he has more than me ) in many roles, ranging from basic Stage 1 drills with the Army to SAR display pilot and now bus driving in the N Sea. Also like PPF#1 I have made very few downwind approaches as I have always strived to make the final approach into wind.

I know of many cases where a downwind approach appeared the favoured choice but on reflection it would have ended in, at the best an over torque and worst a bent a/c. Examples of this are an approach into a bowl with the wind blowing into the bowl. The approach to one of the radar sites in the Falklands (Alice? memory going!!) where the HLS was below the ridge line and the curl over turned the 45kt headwind at +500ft into a 30kt tailwind on short finals.

The morale of this is that if possible make your final approach into wind. There will be time when this is not possible but if you are a low time pilot who is not practised and very comfortable with downwind approaches then land somewhere else.

HF
Hummingfrog is offline  
Old 4th Oct 2003, 16:15
  #34 (permalink)  
 
Join Date: Aug 2000
Location: UK
Posts: 3,680
Likes: 0
Received 1 Like on 1 Post
Catch 'em early and train them well...this is a helo they are flying, not a flaming 747. Use the a/c for what it was designed, but with common sense and within its individual capabilities.

This industry isn't quite a nanny state
Thomas coupling is offline  
Old 4th Oct 2003, 20:59
  #35 (permalink)  
 
Join Date: Nov 2000
Location: White Waltham, Prestwick & Calgary
Age: 72
Posts: 4,166
Likes: 0
Received 29 Likes on 14 Posts
Quite.




The system said I couldn't use just one word so I have to fill out the message with this stuff

Phil
paco is offline  
Old 7th Oct 2003, 19:13
  #36 (permalink)  
 
Join Date: Aug 2003
Location: uk
Posts: 32
Likes: 0
Received 0 Likes on 0 Posts
PPF#!

As I said before, it would appear that despite your enormously impressive CV, your peers just do not agree with you.

I think TC has said all that needs to be said about the downwind approach.
Head Bolt is offline  
Old 5th May 2013, 04:22
  #37 (permalink)  
 
Join Date: May 2013
Location: india
Age: 52
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
tail wind approaches on helicopter

dear all
I have a genuine query. please advise if there's anything wrong in carrying out a downwind approach on RW at sea level free from all around obstructions; tail wind component of not more than 05-10 knots; ROD not exceeding 300-400 fpm on a seaking, culminating in a running landing.
Keeping in mind principles of LTE and ETL, my personal experience has been to compensate 5-10 knots of tail wind with reduction of IAS while keeping the ground speed constant. This obviates the requirement of excessive nose up attitude prior to touch down in order limit the landing speed(undercarriage considerations).
comments pse
navy pilot
navy pilot is offline  
Old 5th May 2013, 09:12
  #38 (permalink)  
 
Join Date: Mar 2009
Location: Planet Earth
Age: 58
Posts: 75
Likes: 0
Received 0 Likes on 0 Posts
tail wind approaches on helicopter

Where is the question?
What you describe can be found in every second AOP. So what should be wrong with it?
Harry the Hun is offline  
Old 5th May 2013, 09:31
  #39 (permalink)  
 
Join Date: Jan 2001
Location: North Queensland, Australia
Posts: 2,980
Received 15 Likes on 8 Posts
Just be a bit cautious with vortex ring, I think.

If you're flying a similar approach angle and closure rates as you would into wind, there will come a point where you drop through zero airspeed but still have a fair rate of descent on, possibly setting you up for vortex ring state.

Having said that, I suppose if you're using a max of 10 knots tailwind and you do a 10 knot run-on, it would be similar to doing a zero-zero approach on a calm day so it might not be a drama.
Arm out the window is offline  
Old 5th May 2013, 09:40
  #40 (permalink)  
hueyracer
Guest
 
Posts: n/a
free from all around obstructions;
If the area is free of all obstructions-why would you want to land downwind?

There is a simple rule regarding helicopter operations:
You can do (almost) ANYTHING-as long as you fully UNDERSTAND what you´re doing there...

Your question cannot be answered, as many factors are missing...
Weather conditions, PA, Weight of the aircraft (fuel on board, pax,cargo), dimensions and structure of the landing area and the surroundings and much more...
 

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.