Downwind approaches [Archive]

bintanglagi

8th May 2002, 22:43

Chitchat,
There is a fallacy about helicopters being able to do everything. We're certainly more flexible than the fix-wing guys and I guess thats why it's rewarding.
An aeroplane pilot has charts and graphs to accept or decline a tailwind component on his runway, and many a time they'll say no due to performance limitatations.
You lucky b....... has quite often have to make that decision by arriving in the middle of nowhere, with one way in and one way out (that's why they asked for a helicopter).
On jobs I've been on before, the guys who have damaged themselves or the equipment or been very scared taking off or landing, have 99% of the time been heavy. I think most of them knew the machines pretty well and all it came down to was a lack of judgement , probably on a routine job.
The previous replies have all said how it should be done, and that is the way to do it. However, always make sure you're comfortable, or take someone else along who's done it and bail out when he starts twittering.:cool:

Nigel Osborn

9th May 2002, 02:27

What everyone has said is good advice. Obviously you are going in downwind due lack of choice. You cant look up any performance figures for downwind approaches but check on the helicopter's downwind and cross wind limits, also make sure you are not nose heavy. I once had problems at 4000 feet in a nose heavy downwind approach in a 206; couldn't stop the forward movement, most embarasing! Also try a practise approach in an unrestricted area at various weights.

ChitChat

9th May 2002, 06:49

Thanks to everyone.

I guess the upshot is:

Adequate power margin
Plan escape route
Shadow descent
Low rate of descent once you are committed to going in.

The one added benefit if the wind doesn't change is that when you take-off you will be going into wind :)

DBChopper

26th Sep 2003, 00:58

Here's a question for you more experienced rotary types, whether private or commercial...

I write as a PPL(H) with about 120 hours on the R22. In my perambulations around SE England, I have been given a few weird and wonderful approach and departure directions to/from various airfields. One of my first ever post-PPL solo trips presented me with a completely downwind approach into a grass field that left me wishing I'd been more authoritative and refused it. These days, a couple of years down the line, if I am given an approach that puts me in what I consider to be an unsafe situation, I decline and ask to join the circuit instead (or request it at the briefing stage over the phone, which I've found often works). I'm not sure whether this is done to keep helis away from the fixed wing circuits, due to differences in speed and climb/descent angles, or to allow helicopters quicker approaches or departures from the field.

Just recently I have watched helicopters at a number of airports carrying out downwind departures and arrivals. So, the question is, am I over reacting and should I accept out-of-wind ops, or am I right to request a change? And have any more of you inexperienced types found the same thing?

What are your opinions folks?

DBChopper
:confused:

Camp Freddie

26th Sep 2003, 01:48

Factors to bear in mind on a downwind approach below.
In practice I think downwind approaches are ok as long as you can run on a long way if no room to turn, but mostly I just turn it into wind at the end and try to keep 30 kts or so in the turn.

I think as long as you know you are downwind and have a plan as to what you will do, then dont be unduly concerned about them

Factors :-
500’ slower approach maybe 50 kts or so
Shallow Approach / Extended Approach
Gentle Inputs
High Groundspeed / Low Airspeed
Early Loss Of Translational Lift
Establish Low Hover (Run on if Necessary)

Go Around if:
High Power Settings on Approach
Directional Instabilty Excessive
High Rate of Descent

Randy_g

26th Sep 2003, 03:00

Last year Transport Canada's helicopter safety magazine published a few tips. Landing downwind was one of them. With the editor's permission (you'll grant me that won't you CTD ??;) )I'll quote it here.

When Downwind is the Only Way

From our first flights in a helicopter, it is drilled into our heads that we should approach helipads into wind. So what do you do, when the only way into a pad is downwind? Anyone who has a little experience knows there are times when approaching and even landing downwind is the only safe option. A very experienced pilot demonstrated the following when I was still very new to Bell medium helicopters, and I’ve used it ever since.

Start off with a fairly normal approach, following the safest path in. It’s important to keep your airspeed and your rate of descent under control while doing this approach. As you get closer to the ground, and to your spot, slow your rate of descent and airspeed. At approximately 50-100 ft back, and 20-30 ft above ground level (AGL) as you slow the helicopter below translation, ensure that you have stopped all downward movement of the aircraft. This will help prevent you from entering vortex ring state. You should now be at a walking pace and less than a rotor diameter from your spot. Watch the ground, as you want to see when your downwash passes you. Once the downwash has passed, you can then resume your descent and land at your spot.

Just remember, that when landing downwind, that there are many points to remember and things to watch for:

You must be certain that you have Hover Out of Ground Effect (HOGE) power.

Make sure you minimize your rate of descent as your airspeed decreases.

You may run out of aft cyclic with a forward center of gravity (CG) and as you reach the helicopter’s cross/tailwind limits

Pay careful attention to aircraft limitations.

The tail will be lower to the ground, so be careful of any stumps, bushes, etc.

Be aware that the aircraft will want to weathercock, and will not be as stable in yaw

As a result pilot workload will be higher when performing a downwind landing.

Landing downwind can be safely done, as long as you have planned it out in advance.

Cheers

Vfrpilotpb

26th Sep 2003, 03:39

With a low time pilot, downwind approaches should in my opinion NOT be attempted if the wind is over 10 Knts, and then be done so carefully as to remind you not to do it again, your problem is one of stick authority, you will run out of it if you are not very careful,

then what do you do!!

Untill that machine fits you like a glove and vice versa you will be better alway having the wind in you face,:ok:

RDRickster

26th Sep 2003, 04:02

Thanks for posting that. That little tid-bit may prevent me from balling one up in the future. Good stuff!

PPRUNE FAN#1

26th Sep 2003, 05:19

As with most everything associated with helicopter flying, there is no simple answer to the question: Are downwind landings safe? There are just too many variables to make blanket statements.

But what are we really asking? Are we merely looking for reasons to justify landing downwind rather than exploring options that might take more technique?

Remember a couple of things:
1) A downwind approach could very easily mean a downwind autorotation if the engine picks that time to quit. Is that a big risk? Me, I haven't practiced any "for real" touchdown autos from inside the H-V curve. Your mileage may vary.

2) A downwind approach will certainly require more power to stop at the bottom, and there will be the real possibility that there won't be enough power, which will then require a run-on landing. The amount of risk here is dependant on how heavy you are, how high the wind speed is, and how big, flat and level the LZ is. Is there room to run it on? Can you run it on without rolling it over?

Let's look first at off-airport site landings. If I arrive at a site landing and find that all into-the-wind or crosswind approaches are blocked by a ring of orphanages, churches hearing Mass, chicken coops with irate, hat-wielding farmers and thatched-roof circumcision clinics, leaving my ONLY selection as a directly-downwind approach, I might decide that I don't really need to be landing there that day. If there was some urgency the compelled me to land, I'd consider the above risks very carefully. Then I'd follow the procedures outlined in that Transport Canada article, which is very good.

But philosophically, I'd weigh the risk of landing downwind with the risk of a very steep into-the-wind (or crosswind) approach, if one was indeed possible at all. Few site landings are so bad that you absolutely, positively cannot get in from some other azimuth than straight downwind. And of course helicopters have infinitely variable approach speeds, paths and angles. I'd use me noggin' and try to come up with an alternative. There is usually more than one single way to make an approach. I'd explore all possibilities before settling on "directly downwind."

The good news is that if you have a site that only allows a downwind landing, that'll usually mean that your take-off will be into the wind. That's good.

Finally, recognize that when you're making a downwind landing to an off-airport site, there'll come a time when a go-around is impossible. And that time might be pretty high up the approach. Once you fall back below ETL you are HOGE at high power. Sure, you might have enough excess power to initiate a go-around, but you'll surely lose altitude as you try to regain forward ETL, and your downwind angle of climb will not be impressive. How tall are those obstacles around your LZ?

So much for off-airport. What happens if you arrive at an airport and the Tower guy directs you to land downwind? Well, controllers do forget or sometimes neglect that we helicopters need to land into the wind just like the planks. Remember, our radios are transceivers. We can talk back to them, too. A gentle reminder might do the trick. "Umm, say there old bean, doing it that way will put me directly downwind. Might we come up with something else?" In my experience, this will elicit a response of "Do whatever you need to do, just remain clear of..." whatever.

No controller will force you to land downwind (unless the winds are really, really light). Even so, landing downwind to a taxiway is usually no big deal (let's just not make a habit of it). Oh, and don't expect me to always be able to do that to a small, congested non-movement area.

This of course presumes that prior to entering the traffic pattern you have visualised the airport layout, the buildings, the wind and where the Tower will likely have you land. If you have not done this, then you have not done your flight-planning properly. Remember, it's NOT GOOD ENOUGH to show up at the field boundary and be told to do something unwise, and then do it simply because you "didn't have time" to come up with another plan.

Helicopter pilots must be masters of improvisation. We make it up as we go along. Plan all you want, but there's always something that comes along to mess with you. So you have to be ready.

Any other simple questions?

Whirlybird

26th Sep 2003, 05:35

DBChopper,

ATCOs tend to think that helicopters can do anything, not realising that low hours helicopter pilots can't do everything. Why land downwind at an airfield, unless you want the practice? It's harder and more dangerous, for all the reasons given. But ATC probably don't know that. I tend to phone up first, and ask if they have special procedures for helicopters. If not, I ask for what I want to do. I prefer not to join the f/w circuit, since R22s are slower than most f/w aircraft, and we slow down before we land. But if you explain in advance, you'll often get what you want, or at least know what's expected.

I learned this the hard way too. Heading for a fly-in to a busy airfield, I could hear that the circuit was crowded, and see where I wanted to land, straight into wind. I asked, and an obviously stressed FISO asked me to join the circuit like everyone else, as they were busy. I finally managed to explain that I was a helicopter, I didn't need a runway, and what I'd asked for would keep me well out of the way. He agreed. So bmuch so, that when I came to leave, he wanted me to depart the same way, now with a 25kt tailwind. :eek: I refused, and explained why. But you see, someone with more experience than I had then might have agreed, so how was he to know?

DBChopper

26th Sep 2003, 22:59

Many thanks for some very informative posts so far folks.

Whirly, with the little more experience I now have I take your approach, phone first, explain and, if necessary, re-negotiate over the radio.

Camp Freddie, Randy G and Pprune Fan #1, I shall be printing your posts off to inwardly digest!

:ok:

Randy_g

26th Sep 2003, 23:49

RDRickster No worries. :)

Obviously we should try to approach into wind, it is the safest, and easiest way to approach. If you are flying into airports all of the time, then there usually are no reasons to approach downwind. However, as pilots we need to evaluate all of our options, and decide on the safest way to conclude each flight.

For instance; if the choice is between a very steep/nearly vertical descent from +150', or a shallow downwind approach, I may decide that a downwind (or cross-wind) approach is safer. Assuming that I have the power margin, and that the wind is below the a/c's demonstrated limits. The safest route in, may not be straight into wind.

In the job that I do, terrain sometimes leaves me with few choices in the direction of approach or landing. Prior to your flights, you should check the performance charts prior to firing up, to determine weight and alt that you can HOGEwith the expected temps. This is essential when flying power limited a/c (like R22, B206, 204, etc). Once you lift off, see what power is required to HOGE, and see if it matches what the manual predicted. You did calculate your weight I hope, so you'll be able to make a meaningful comparison ??

The rule of thumb I use is; if the a/c can hover OGE with less than MCP, then I should have enough power for any hover OGE, downwind hover (in case we have to perfom hover-exits), or a landing downwind, assuming we're not power limited due to temp/alt, and I'm operating at a similar or lower altitude.

Cheers

inthegreen

27th Sep 2003, 04:00

That's a tricky question actually. In common practice, all other risks being equal, take the approach into the wind. Your job as a pilot is mostly about risk management. A traffic pattern at an airport should never place you downwind just for the controllers convenience. You are accepting additional risk with no benefit.

The reason the question is tricky, though, is this. I advocate becoming skilled at downwind approaches. I actually think it should be part of the curriculum. Learn to recognize the signs of a downwind condition, (faster than normal closure rate, further aft cyclic position, changing power demands, etc.) and how to safely execute the approach or perform a go around. At some point, whether you're prepared or not, you'll find yourself in a downwind condition, even if you've read the wind perfectly just moments before. It's best to practice downwind approaches under controlled conditions and become proficient. If you don't feel comfortable doing this on your own, book some tiime with an instructor and practice approaches with the wind at various points around the azimuth. You'll make yourself a far more proficient pilot. Good luck

Head Bolt

27th Sep 2003, 18:15

Inthegreen

Are downwind approaches not in the FAA syllabus for the PPL(H) ?

They are covered in the JAA license, but I find that they are rarely taught well or given the right emphasis - the student is usually given a demo and then told to avoid them, which really doesn't help them in their future operations.

If downwind approaches are not part of the FAA syllabus, how do the students acquire the skills and knowledge required to perate safely if circumstances require a downwind approach ?

:)

PPRUNE FAN#1

27th Sep 2003, 20:50

Head Bolt asked:If downwind approaches are not part of the FAA syllabus, how do the students acquire the skills and knowledge required to perate safely if circumstances require a downwind approach ?Well...circumstances should never "require" a downwind approach. And students (i.e. candidates for a Private certificate) shouldn't be taught those "skills." That should be obvious.

Downwind approaches are an advanced technique. They are not "as safe" as an into-the-wind approach. Nor are they even "safe" on their own. Just the opposite; they are extremely risky. And we should not minimize that risk by the casual admission that downwind approaches are "just sometimes necessary." Not all of us feel that way. I will do everything in my power to avoid a downwind approach. (Of course, the aircraft I fly has a strong weathervaning tendency which complicates the termination of a downwind landing, especially if a run-on is required.)

For the FAA to include and recommend them, it would be tantamount to endorsing downwind approaches as an acceptable procedure. And there is no way they're going to do that - just as there is no way that they'd approve teaching "no-flare" autos. Sure, such an auto can be done, but is it safe? And would you want to teach a low-time student to do a no-flare auto? I don't think so. As with downwind landings, there are just too many variables. The FAA's attitude has always been that the safest aircraft is one that does not fly. If it's not safe, then just don't do it. To the FAA, it really is as simple as that.

The trouble is, helicopters don't fly within the confines of a book. They fly out there in the real world, where the helicopter pilot is sometimes faced with conditions that are not ideal. The amount of challenge each pilot accepts will vary, depending on his own perceived skill level, knowlege and guts. Even at my advanced hour level, there have been situations in which something was asked of me and I've said, "Not today, guys. At least, not with me at the controls." The task may not have been all that difficult, and another pilot might have attempted it willingly.

But looking back over the years, I've heard about many, many accidents. And of those that did not involve the aircraft simply coming apart, my first question was almost always, "Where was the wind?" The direction of the wind is critical to safe helicopter flying. Operating with it on your tail is something that must be done very cautiously, and by pilots who are well acquainted with the hazards and risks. In other words, not students.

the coyote

27th Sep 2003, 22:23

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.

DBChopper

28th Sep 2003, 00:01

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.

NickLappos

28th Sep 2003, 05:22

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/showthread.php?s=&threadid=18873&highlight=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.

Martin1234

29th Sep 2003, 05:47

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?

Whirlybird

29th Sep 2003, 15:57

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....

Head Bolt

29th Sep 2003, 17:04

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

PPRUNE FAN#1

30th Sep 2003, 10:21

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 ;)

paco

30th Sep 2003, 10:57

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

Grainger

30th Sep 2003, 18:53

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.

Thomas coupling

30th Sep 2003, 19:09

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...

the coyote

2nd Oct 2003, 02:07

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.

Mama Mangrove

3rd Oct 2003, 21:03

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;)

Hummingfrog

4th Oct 2003, 00:58

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:rolleyes: ) 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.:D

HF

Thomas coupling

4th Oct 2003, 16:15

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 :ouch:

paco

4th Oct 2003, 20:59

Quite.

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

Phil

Head Bolt

7th Oct 2003, 19:13

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.

navy pilot

5th May 2013, 04:22

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

Harry the Hun

5th May 2013, 09:12

Where is the question?
What you describe can be found in every second AOP. So what should be wrong with it?

Arm out the window

5th May 2013, 09:31

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.

hueyracer

5th May 2013, 09:40

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...

John Eacott

5th May 2013, 10:11

Since this is a run-on landing to a runway and there is no implication of touching down with less than a positive airspeed and within U/C limits: what is the problem?

Unusual, certainly; but technically it sounds within limits and hardly something to be alarmed about. Out in the 'other' world of GA and aerial work you'll be coming in downwind, crosswind and vertically so there will be the usual plethora of Rotorhead views opined here, but this is my two pennyworth :ok:

P1DRIVER

5th May 2013, 11:37

tail wind approaches on helicopter

Mmmmmmmmm ???

1 If you know your downwind
2 If you keep checking you have enough Aft cyclic (to slow down)
3 You have checked the Power available and know you have enough. ( to stop the R o D )

YOU WON,T HAVE A PROBLEM.

The problems happen when the pilot either:
1 Doesn,t realise he,s downwind
2 Lets a High RoD develop

wmy

5th May 2013, 18:24

:ok:..just to add point 0.1 to P1drivers list:

0.1 If you don't have the option of a headwind landing

as for the rest, P1Driver said it all...

ShyTorque

5th May 2013, 18:47

Some Class A performance profiles prohibit a tailwind.

Apart from that, I see no issues; in fact I sometimes need to carry out that type of approach.

hargreaves99

18th Sep 2023, 18:41

To revive an old thread.....when teaching downwind approaches on the CAA PPL(H) syllabus, does everyone teach a "shallower than normal" approach angle?

Robbiee

18th Sep 2023, 20:38

Can I lean on all your experiences and ask what is the correct technique for approaching confined areas downwind if there is no way of approaching into wind.

I guess this comes down to the advanced techniques. What are your experiences.

Thanks

If you are light enough to HOGE, back it off to just about ETL and ride that vibration in nice and slow at like 150-200fpm.

,...and keep your feet awake, lol. :cool:

Hmm, just saw this thread is like twenty years old. Maybe have a statute of limitations on these things, 'cause,...dude!

SASless

18th Sep 2023, 20:50

Shy.....quick question for you.....Is Cat A and Confined Areas a rather rare combination?;)

love flying

19th Sep 2023, 07:18

Remind me the power check procedure (eg for 44 and 66)

Hughes500

19th Sep 2023, 08:41

H99 like all helicopter stuff it is all to do with energy ( power )management.

Show your student it takes more energy to hover downwind ( due to us not being able to hold a steady hover ). This then moves on to losing translational lift early and at some distance and height from LZ. Therefore more energy required !
So engine can only give so much energy, so we know we are going to use more energy to hover and last bit of approach. Add to this the amount of energy ( power ) required to slow the aircraft both horizontally and vertically . So easy answer to use less energy, ( so one has more energy to play with ) is to have a shallow approach ! Try a normal approach then turn it round ( ie same heights, distance and ground speed ) student will immediately slow helicopter down and have a larger rate of decent to get down, therefore building up a lot of energy in the airframe ! Does the engine have enough energy to arrest the rate of descent, student pulls lever up , result nose goes up slowing the rate of descent, or so he thinks , but at the risk of coming off of translational lift, more energy required, which will rapidly increase ROD, thrust is now not vertical it is is behind as student is flaring the helicopter, so more energy required, now tail wants to weather cock, so more energy required, still out of ground effect so more energy required, sloppy handing as shown in hovering downwind so more energy required and so on

SASless

19th Sep 2023, 13:42

For a look back into history re this topic of discussion.....we have been here before.

https://www.pprune.org/rotorheads/18873-t-o-downwind-v-power-available-2.html

Robbiee

19th Sep 2023, 14:57

Remind me the power check procedure (eg for 44 and 66)

Pull into HOGE, look at MAP.

ShyTorque

19th Sep 2023, 16:41

Shy.....quick question for you.....Is Cat A and Confined Areas a rather rare combination?;)

Having managed to avoid Public Transport for the last twenty years of flying for my B, L and T, Class A wasn't mandatory in my job (in fact I only flew PT for two years of my four decades plus of flying), but I did always try to fly iaw Class A procedures whenever possible. However, regularly faced with a particular confined area landing site with only one clear route in and out, I often had to do one or the other downwind. I'd rather go in downwind light if it meant flying into wind when loaded up, for all the usual reasons.

No longer my problem though. These days I keep myself busy doing all sorts of stuff rather than aviation. :cool:

[email protected]

19th Sep 2023, 17:11

Is Cat A and Confined Areas a rather rare combination? The AW139 RFM, and I'm sure many other aircrafts RFMs, has a procedure for CAT A/PC1 confined area approaches and departures so not too rare.

Robbiee - if you don't have HOGE performance, downwind approaches would be very unwise.

The rotor doesn't know it is downwind so any variations in power hovering downwind are to do with overcontrolling on the pedals.

For a safe downwind approach, fly shallower than normal, get the airspeed off early and maintain a sensibly slow groundspeed.

If you are too fast at the end, the temptation is to flare but you don't get any benefit from a change in RAF when you are already downwind.

If in doubt overshoot early.

Make sure you have at least HOGE performance before trying it.

Robbiee

19th Sep 2023, 18:08

Robbiee - if you don't have HOGE performance, downwind approaches would be very unwise.

Lol, are downwind approaches ever really wise?

212man

19th Sep 2023, 19:47

Lol, are downwind approaches ever really wise?
They’re unavoidable sometimes

ApolloHeli

19th Sep 2023, 20:42

To revive an old thread.....when teaching downwind approaches on the CAA PPL(H) syllabus, does everyone teach a "shallower than normal" approach angle?
I don't teach CPL(H) but back when I was being taught, 'shallower than into wind' was certainly the theme. Various plausible explanations as to why, but I certainly feel more at peace flying a shallower approach if landing downwind.

Robbiee

19th Sep 2023, 20:45

They’re unavoidable sometimes

Sure, when you're getting paid, shot at,...or rescuing a hot chick from a hoard of zombies.

The three easiest ways to get a guy to do something that is "unwise", lol.

pilotmike

19th Sep 2023, 21:16

My money's on this thread being resurrected again in 2033.

212man

19th Sep 2023, 21:21

My money's on this thread being resurrected again in 2033.
along with a debate on VRS, H/V graphs and, for FW pilots, the “impossible turn”!

SASless

20th Sep 2023, 03:01

Sure, when you're getting paid, shot at,...or rescuing a hot chick from a hoard of zombies.

Having no experience with hoards of zombies....and knowing you have to be around to spend money.....I cannot assign a probability of such things being an encouragement.

As to getting shot at....that will make you do a lot of things you would not ordinarily do.

Now as to the Blonde....if you are going to set a trap for helicopter pilots....that would be a good start.

[email protected]

20th Sep 2023, 07:53

Sure, when you're getting paid, shot at,...or rescuing a hot chick from a hoard of zombies. quite a few on here will have got two out of three - where is a horde of zombies when you need one?:)

I suspect some UKR helo pilots have got all three ticks in the box now:)

hargreaves99

20th Sep 2023, 08:19

ok, Thanks all. I came across this also

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/1500x1084/2_0bba7f2ce2d81998362493e5d3fa58b0e0a2c9fa.jpg

[email protected]

20th Sep 2023, 11:06

How do you make a run on landing at 0 G/S?:)

I think they mean that your downwash catches up with you on a downwind approach rather than you fly through your downwash.

I thought the R22 was certified to 17kts cross and downwind.

I don't quite follow their logic that if you have room to do a downwind transition then you must have room for an into wind - doesn't take into account obstacles and obstructions.

paco

20th Sep 2023, 13:08

Robbiee

20th Sep 2023, 15:54

I agree - some times next to a hill with the wind coming down it and you are full with geologists you have no choice....

I question the good captaincy statement. Good captaincy dictates that you are aware of the limitations if you choose that way.

I thought good captaincy was knowing when to say, "Sorry fellas we can't land there today, guess we'll have to go with plan B"? I mean, I'm fine risking my own life, but,... :cool:

[email protected]

20th Sep 2023, 16:19

The engine doesn't know you are down wind - if you have the performance and use the correct techniques, there is little additional risk over a 'normal' approach or departure.

Robbiee

20th Sep 2023, 16:25

The engine doesn't know you are down wind - if you have the performance and use the correct techniques, there is little additional risk over a 'normal' approach or departure.

Well, I've seen plenty of videos where guys are crashing perfectly good helicopters flirting with tailwinds. So it kinda makes this "correct technique" seem as common as what we used to call "common sense", lol.

Devil 49

20th Sep 2023, 17:13

I would always fly approaches with the same approach angle and as slow as I could. The best approaches I flew did not require a pitch attitude change from 50 knots (Bells) or 60 knots in AS350/355 at 300' AGL, controlling angle of descent with small power/collective movements. Yes, that can be done, at least in an AS350/355 and a Bell 206 series. Elevated points of landing, especially those being in downwind turbulence may require a change in particulars...

In my opinnion 'flat' approaches make ground speed difficult to judge, potentially leading to a last minute tail-low, hard decel attitude, which could poduce complications and more hazard than one's typical slow approach and angle terminating in a stable hover attitude.

My personal favorite approach was the "high overhead" in which one is constantly turning in a continuously decelerating, descending spiral from the high recon. Delay the yaw around to align the aircraft with ground track until absolutely required. And- it may never be required depending on wind, obstructions, terrain or how you plan to position for the loading/unloading.

It is not absolutely required that the nose be pointed in the direction of travel. You can turn the aircraft sideways to observe the point of landing, ie: in the AS350 I flew on the last job, I would fly the final segment left side forward and align it at the last possible moment. It takes some practice to be able to judge angle and rate of closure with a new aspect. That's not required in an LZ that requires a vertical descent, in which case I would turn the nose such that I had the best view of most threatening obstacle.

[email protected]

20th Sep 2023, 18:18

Well, I've seen plenty of videos where guys are crashing perfectly good helicopters flirting with tailwinds. So it kinda makes this "correct technique" seem as common as what we used to call "common sense", lol. Agreed but they are often due to poor planning and power awareness or not realising they are in fact downwind.

You can fly a safe downwind approach using exactly the same technique as an into wind one - it's not a special technique never taught to pilots, it is the same technique with awareness of the differences in power requirements during the approach.

Devil, you describe an academic approach - selecting the correct decelerative attitude to maintain a constant reduction speed coupled with controlling the glidepath (approach angle) with collective. However the changing airflow over horizontal stabilisers as the rotor downwash moves off them (lower speeds) inevitably requires some cyclic corrections to be made along with the inescapable effects of flap forward (the reverse of flapback)during decel.

Most commercial and military operators wouldn't fly your slow approach way since time costs money for commercial and a slow approach makes you an easy target for military ops.

paco

21st Sep 2023, 06:41

"I thought good captaincy was knowing when to say, "Sorry fellas we can't land there today, guess we'll have to go with plan B"? I mean, I'm fine risking my own life, but,... https://www.pprune.org/images/smilies/cool.gif"

Wait until it's getting to be dusk, the passengers are late, there is no shelter, you can't leave one behind because you won't find them again in the dark and you have to use your tricks of the trade to rescue them from their own screwups.

"The engine doesn't know you are down wind"

Neither do the rotors, except for a little dirty air from the tail rotor.

The big difference in being downwind is the lack of kinetic energy.

An aircraft flying at 30 knots into a 30 knot wind is doing that speed aerodynamically, but is stationary inertially, as it has no kinetic energy. In effect, it is hovering. On the other hand, the same aircraft with a tailwind of 30 knots possesses 60 knots’ worth of kinetic energy from its groundspeed, although, aerodynamically, the conditions are identical. If the downwind aircraft turns through 180°, it will end up with 60 knots of groundspeed and 90 knots of airspeed, so it will climb as the surplus is converted to potential energy. On the other hand, the aircraft starting with the headwind will lose height because it lacks 60 knots’ worth of kinetic energy. A heavy aircraft, or one with less power, could crash.

As long as you are aware of the power requirements and what the air is doing, I don't see a major problem. Of course it's not ideal, but, hey, life isn't perfect.

hargreaves99

21st Sep 2023, 07:07

OvertHawk

21st Sep 2023, 08:43

interesting..

so with an into wind approach the aircraft has less kinetic energy, whereas a downwind approach has more kinetic energy

this would suggest downwind approaches are safer/better. but I know they are not.

No

because during an approach kinetic energy is working against you because you need power, space and time to manage and reduce that kinetic energy.

[email protected]

21st Sep 2023, 09:04

I seem to remember this downwind/into wind argument regarding energy as having been done to death before and it all has to do with the frame of reference.

I know that turning 180 from downwind to into wind won't give me extra energy or make me climb if I maintain attitude, airspeed and power - I will roll out with the same airspeed but a much lower groundspeed. Done it more times than I care to remember without ever having an unwanted climb or having to reduce power.

Aircraft crash turning downwind at low level because the pilot tries to maintain a constant groundspeed in the turn and washes off airspeed.

Hughes500

21st Sep 2023, 09:59

Crab I think we need to remember that we are talking teaching new guys to fly here. So for instance hovering downwind will require more power as they are unable to hold a steady hover as into wind, different for a seasoned pilot. It is the same as making an approach, teaching downwind to a student ( lesson 26 ) one has to be careful what one teaches as they can struggle to process all the information coming into them ( helmet fire to use a UK mil term ) so best to teach a flatter approach so there is a little less going on. Remember within 45 hours they could be off on their own, with very little if any oversight !!!!

[email protected]

21st Sep 2023, 12:11

Valid points Hughes 500 and the patter I used to teach to baby QHIs (and what I was taught back in the day) included those bits of info/technique because they were aimed at basic students.

The lack of mandatory post-graduate training requirements for PPLs scares me and goes a long way to explain a number of accidents.

The main reason for using a flatter approach is to keep the RoD lower than on an into wind approach.

hargreaves99

21st Sep 2023, 12:59

I've always thought the UK/CAA/EASA/JAR (etc) PPL(H) syllabus to be completely unsuited to training civilian pilots.

I think the 10 hours solo (ie flying under your instructors licence) is bonkers. This 10 hours should be done post PPL test, alongside some significant off-airfield "real world" dual training

And..Quickstops, why on earth are they even in the syllabus? Surely a hangover from the military?

paco

21st Sep 2023, 13:07

I think they use the quickstop as a coordination exercise

ShyTorque

21st Sep 2023, 13:52

And..Quickstops, why on earth are they even in the syllabus? Surely a hangover from the military?

A quickstop is a very good way of minimising runway occupancy, for occasions when Class A isn't required. Properly flown, it's as safe as a Clear Area Class A approach, in any case.

[email protected]

21st Sep 2023, 15:57

It's also a very good method of demonstrating flare effect and how to manage the end of a flared approach with respect to power requirements - sorts the 2 o'clock daisy hoverers from the attitude flyers.:ok:

Robbiee

21st Sep 2023, 16:37

hargreaves99

21st Sep 2023, 16:44

Robbiee

21st Sep 2023, 17:38

I agree that solo builds confidence and maybe there is a place for solo circuits pre-PPL test, but letting a student blast off on cross country flights through controlled airspace, and then the instructor getting in the sh*t with the CAA if the student messes up just doesn't seem right.

Well, on those solo flights, I was only allowed to go to places I'd already been to with my instructor, so there was far less a risk of "messing up".

MightyGem

21st Sep 2023, 21:01

and quick stops (aside from teaching coordination) are just fun!
Yes, the handbrake turn of the helicopter world. :E

albatross

22nd Sep 2023, 17:41

Yes, the handbrake turn of the helicopter world. :E

Even better when accompanied by the words “Whoa, Whoa Big Fella!” a la “Lone Ranger”.
A good skill to learn because when you need it - you may need it bad!
Yes they are fun.

[email protected]

23rd Sep 2023, 07:07

Or Yosemite Sam's 'Whoa camel, whoa, I say WHOA' :)

albatross

23rd Sep 2023, 21:13

Or Yosemite Sam's 'Whoa camel, whoa, I say WHOA' :)

You win for that one!

ORAC

26th Sep 2023, 07:33

https://x.com/thenewarea51/status/1706255776971378864?s=61&t=rmEeUn68HhlFHGKbTPQr_A

A textbook example of “Settling with power”…..

[email protected]

26th Sep 2023, 09:29

A classic - not enough power to do what the pilot thinks it should and very probably no consideration pre-flight of HOGE + thrust margin power requirement.

Nr decays as he pulls, TR loses effectiveness due to lower speed, undemanded yaw and an overpitched arrival at the air/ground interface. Lucky it didn't roll over.

Torquetalk

26th Sep 2023, 19:05

Nice crash 👍🏼

206Fan

26th Sep 2023, 23:47

A textbook example of “Settling with power”…..

The report for anyone interested!

https://www.gov.uk/aaib-reports/aaib-investigation-to-robinson-r44-clipper-i-g-clio?fbclid=IwAR0JlKBI29u7QDDIFubhymhz4QfNqUQ8ggy_rHzh7YvQxe BF1VgOAg8BxEM

Robbiee

27th Sep 2023, 03:37

The report for anyone interested!

https://www.gov.uk/aaib-reports/aaib-investigation-to-robinson-r44-clipper-i-g-clio?fbclid=IwAR0JlKBI29u7QDDIFubhymhz4QfNqUQ8ggy_rHzh7YvQxe BF1VgOAg8BxEM

So, this is basically just like that other one not that long ago, where the A-star came in downwind using the wrong technique?

206Fan

27th Sep 2023, 04:16

So, this is basically just like that other one not that long ago, where the A-star came in downwind using the wrong technique?

That investigation is ongoing!

https://www.tsb.gc.ca/eng/enquetes-investigations/aviation/2023/A23W0048/A23W0048.html

https://www.youtube.com/watch?v=24G0Nn5oFZ4

[email protected]

27th Sep 2023, 06:20

I think the Canadian crash is more likely VRS since 350s are much more powerful than Robbos and you would expect HOGE performance to be available at the end of a sortie - and there is no evidence of overpitching unlike the Robbo crash where you can hear the Nr decay.

Perhaps a fine example of the difference between settling with power and VRS. The common factor being a downwind approach and trying to arrest a RoD with power.

ShyTorque

27th Sep 2023, 20:09

The report for anyone interested!

https://www.gov.uk/aaib-reports/aaib-investigation-to-robinson-r44-clipper-i-g-clio?fbclid=IwAR0JlKBI29u7QDDIFubhymhz4QfNqUQ8ggy_rHzh7YvQxe BF1VgOAg8BxEM

According to the report, the pilot had 108 hours TT.

The RAF’s basic helicopter course (Whirlwind 10 in my time) was 110 hours. Students would by then already have completed a basic flying course on the Jet Provost Mk3, of about the same length, and possibly another 35 hours or so on the JP5 before getting streamed to rotary. After the basic RW course they would go on to the twin engined Wessex 2, or 5 for another 35 hours before being presented with “Wings”. After that they would be required to complete the Operational Conversion Unit course before being posted to a squadron. They would need to complete a Combat Ready training syllabus and successfully pass a check ride after 6 months, before which they were very carefully monitored and supervised and often crewed up with an experienced crewman for very basic tasks, such as soldier emplaning and deplaning drills and air experience. They would not be allowed to self authorise until deemed experienced and competent to do so. If the individual didn’t pass the CR check and subsequently failed to do so after a short period of remedial training, *he would be required to surrender his entitlement to wear the “Wings” badge.

*I say “He” because at the time I went through training, females were disallowed to undertake pilot training.

For me, this puts “self auth” helicopter ownership at 108 hours into a quite different perspective.