Go Back  PPRuNe Forums > Aircrew Forums > Military Aviation
Reload this Page >

Crosswind landings

Military Aviation A forum for the professionals who fly military hardware. Also for the backroom boys and girls who support the flying and maintain the equipment, and without whom nothing would ever leave the ground. All armies, navies and air forces of the world equally welcome here.

Crosswind landings

Old 25th Oct 2018, 20:31
  #41 (permalink)  
Ecce Homo! Loquitur...
 
Join Date: Jul 2000
Location: Peripatetic
Posts: 13,739
Likes: 0
Received 0 Likes on 0 Posts
Never needed any of that kicking off drift nonsense in the F4.....
Just followed the grooves in the concrete from the last landing.....
ORAC is online now  
Old 26th Oct 2018, 08:10
  #42 (permalink)  
 
Join Date: Sep 2005
Location: UK
Posts: 184
Likes: 0
Received 0 Likes on 0 Posts
I’m a bit confused by some of the discussion above, mainly from OAP.

I can only speak from previous experience of a big jet with low podded engines and a maximum 5 degree angle on bank on touchdown (otherwise you scrape the pod). We were always taught to crab and “kick” off the drift at 20 ft after the thrust levers came to idle. This prevented any lateral drift by “kicking” drift too early. Wings had to be maintained level with a significant amount of coordinated into wind aileron. The landing gear was structurally allowed to take full crab at touchdown at maximum crosswind of 30kts, however, doing this would lead to a touchdown that felt less-than-smooth and also a very late spike of aileron which was difficult to coordinate with wire flying controls. Indeed, by “kicking” drift off, you had much more feel for the amount of aileron required.

Historically, I believe engine scrapes came not from maximum crosswind landings but half-maximum (15-20kts) where the pilot didn’t really anticipate the technique beforehand, reacted, then ended up scraping an upwind pod because they spiked in too much into wind aileron as a late reaction to keeping the wings level.

What confuses me is the chat about wing down for commercial operators (crabbing not being an approved technique?)...mainly from Onceapilot...I’ve never seen a video of a commercial airliner wing down and I assume this risks scraping an engine. The Boeing test video above shows no jet with wing down. They all crab and either align in the flare or allow the bogeys to take the crab on touchdown.

I now fly a high-wing jet and we use the wing down technique. Much easier to coordinate because you can align straight down the runway with wing down from short finals. The bank angle can be quite significant and a good crosswind landing will have the upwind wheels touch before the downwind wheels then the nose wheel. I couldn’t imagine doing that on my previous type without completely trashing both upwind engines!

Last edited by VigilantPilot; 26th Oct 2018 at 08:30.
VigilantPilot is offline  
Old 26th Oct 2018, 10:31
  #43 (permalink)  
 
Join Date: Dec 1999
Location: uk
Posts: 902
Likes: 0
Received 0 Likes on 0 Posts
VP. Morning.

Hope I haven’t contributed to confusion. Mr Boeing’s FCTM for 75/76 does indeed allow all three techniques (wing down, crap n kick, crab alone). I’m guessing your experience is 4 jet which is likely to be more problematic than my 2 jet. All that being said, our company teaching ( and my pref) both sim and ac is crab and straighten. If the ‘kick’ is a touch too early then maybe a little wing down to keep on the cl. There is also the ‘throw it on the rwy like a sack of spuds’ technique which has served me well on the grounds that 150T of Boeing at 150kts is a lot of inertia!

Finally for accuracy and clarity any aob applied for A/L is removed when ‘rollout’ engages at 5’radio, but i’m usually so pleased to have got that far that I don’t really notice that bit.

rgds
deltahotel is offline  
Old 26th Oct 2018, 12:10
  #44 (permalink)  
 
Join Date: Oct 2006
Location: East Sussex
Age: 84
Posts: 277
Likes: 0
Received 0 Likes on 0 Posts
When I trained in Canada (1956) I was taught the wing down technique. It worked a treat, particularly on Harvards (a well known beast). Back to the UK, where the QFIs considered Canadian trained students to be incompetent, I was forced to use the "kick of drift" method. I always prefered the former. And so it continued until, as a TP at Boscombe, I was tasked to investigate X wind landing techniques for Nimrods going into Stanley and C130s in really tough conditions. There was no doubt that the wing down method was the best. I subsequently flew the Lanc. Previous OCBBMS's told me horror stories of truly awful Xwind landing experiences using the RAF "KOD". Not surprisingly I elected to us wing down and I can honestly say that the heart rate never flickered! The Lanc also made me realise that, using wing down, the aircraft always reached terra firma with the controls exactly as required for the roll out whereas with KOD you touch down any old how. I subsequently taught civilian students wing down and they took to it like ducks to water. As I am sure readers will understand this is my pet subject. SORRY!
pontifex is offline  
Old 26th Oct 2018, 14:16
  #45 (permalink)  
 
Join Date: Oct 2006
Location: UK
Posts: 5,223
Likes: 0
Received 0 Likes on 0 Posts
As a passenger who used to fly in the smoking area down the back of a 747 the wing down technique was by far the preferred option.

The alternative lurch sideways when a pilot kicked off drift just before touchdown would empty your glass of wine slightly before one had planned to.
Fareastdriver is offline  
Old 26th Oct 2018, 14:54
  #46 (permalink)  
 
Join Date: Dec 2004
Location: UK
Posts: 482
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by BEagle View Post
Only that part of the 'aviation world' which persists in using incorrect descriptions!
You reallly must need some long therapy if your constant need to be correct over an almost universally accepted term is so strong! It is draining to read in most of your posts.

Can I suggest the following link to help you explore your defensive and inhibitory emotions.

Sent with love, not for an argument or requiring any reply....

https://www.hilaryjacobshendel.com/w...triangle-c18dd
heights good is offline  
Old 26th Oct 2018, 16:08
  #47 (permalink)  
Thread Starter
 
Join Date: Oct 2007
Location: London
Age: 78
Posts: 499
Likes: 0
Received 0 Likes on 0 Posts
Thank you for your replies, v interesting!

I have discussed the issue with an ex Concorde and DC10 colleague, crab, push off drift approved on both types.

So, OAP, it is a fact that, having covered Boeing , Airbus, MacD and Concorde, all of which approve crab and drift removal I think, contrary to your statement that it IS a generally approved technique in commercial airliner ops!

No idea what you are talking about, first, second or third person nonsense. ( and if you are ex RAF Tristar. I doubt if you have flown one at twice the weight of a 767 ER, it’s only 65 k lighter than the 1011)

However, the question was what is the RAF teaching, seems it’s mixed.

I still remember an interesting discussion at Boeing . They explained that the crosswind limit was the maximum DEMONSTRATED during certification by them, and the aircraft controllability was almost certainly able to handle greater limits.

I used my crab technique on my conversion in Seattle , they were happy with that and signed me off.

They also explained that that a fully crabbed landing was acceptable because less skilled line pilots might do it! The structure could handle it.

However, because it it could be done didn’t mean it SHOULD be done if a smoother technique, such as wing down, crab /drift removal could be used.

I am more than happy to take the word of the manufacturer’s test and training pilots !

Anyway I think we have put the issue to bed.

Thank you for your replies.

Last edited by RetiredBA/BY; 26th Oct 2018 at 19:02.
RetiredBA/BY is offline  
Old 26th Oct 2018, 16:22
  #48 (permalink)  
 
Join Date: May 2002
Location: Downeast
Age: 74
Posts: 17,671
Received 27 Likes on 21 Posts
I thought all RAF landings were Crab landings.
SASless is offline  
Old 26th Oct 2018, 17:17
  #49 (permalink)  
 
Join Date: Jun 2002
Location: east ESSEX
Posts: 4,241
Received 3 Likes on 2 Posts
On the naughty step,,,,SAS
sycamore is online now  
Old 26th Oct 2018, 17:51
  #50 (permalink)  
 
Join Date: Dec 2004
Location: UK
Posts: 482
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by SASless View Post
I thought all RAF landings were Crab landings.


Made I chuckle... a lot!
heights good is offline  
Old 26th Oct 2018, 17:56
  #51 (permalink)  
 
Join Date: Dec 2004
Location: UK
Posts: 482
Likes: 0
Received 0 Likes on 0 Posts
In some the smaller types none of those techniques were used, it all rather... redundant.

Just point into wind, reduce speed to zero and land..... once the skids/wheels are on, disembark pax or shutdown. Simples!
heights good is offline  
Old 26th Oct 2018, 18:10
  #52 (permalink)  
 
Join Date: Feb 2001
Location: The Winchester
Posts: 6,375
Likes: 0
Received 0 Likes on 0 Posts
Comments about the F4 and drift..agreed

747 and crab vs. Wing low....wing low really not liked in the flare where/when I flew it outboard engines, pod clearance in the flare etc ...

FWIW from current 777 FCTM...

”Crosswind Landing Techniques-Three methods of performing crosswind landings are presented. They are the de-crab technique (with removal of crab in flare), touchdown in a crab, and the sideslip technique.”

Touchdown in full crab approved for slippery runways.
Sideslip with zero crab allowed in up 28 knot crosswind.
Dry crosswind limit 45 knots (removal of crab in flare)...



wiggy is offline  
Old 26th Oct 2018, 22:03
  #53 (permalink)  
 
Join Date: Sep 2004
Location: Yorkshire
Posts: 586
Likes: 0
Received 0 Likes on 0 Posts
Dry crosswind limit 45 knots (removal of crab in flare)...
So why do the RAF always seem to put such a crap limit on the max crosswind for most types - invariably 25kts? Hugely limiting on flying in the windy UK! Or is it simply the way it is with risk adversity moving ever higher up the list?
H Peacock is offline  
Old 26th Oct 2018, 23:38
  #54 (permalink)  
 
Join Date: Apr 2009
Location: Wherever it is this month
Posts: 1,676
Likes: 0
Received 0 Likes on 0 Posts
The fins of modern airliners seem proportionally larger than those of older in-service types like E-3 and RJ. But are modern RAF transport aircraft like Voyager and C17 so limited? 25kts sounds more like a limit associated with fast jets or trainers, possibly with small fin/rudder or external stores.
Easy Street is offline  
Old 27th Oct 2018, 17:44
  #55 (permalink)  
 
Join Date: Jan 2008
Location: Blighty (Nth. Downs)
Age: 76
Posts: 2,085
Likes: 0
Received 0 Likes on 0 Posts
Must beg the forbearance of you military and ex-military types for one of my occasional intrusions into your forum. But, as you seem to be talking about the comparatively banal task of landing transports, I reckon we've all been playing the same ball-game. Like RetiredBA/BY, since retirement I've been surprised by the increasing prevalence - judging from videos taken from near the approach lights - of guys making no noticeable attempt to de-crab. The Boeing video from Duchess Driver shows four landings, of which only the third shows a full de-crab. The fourth shows a partial de-crab with the simultaneous introduction of a little wing-down. When test pilots refrain from de-crabbing, they would no doubt tell us they were simply demonstrating that the L/G can cope with the sloppiest technique on a dry runway...

Plenty of good stuff here, but I'll take this one for discussion:
Originally Posted by H Peacock View Post
Wing-down will always work, ensuring you land with no lateral drift, but it does mean a podded engine may be too close to the ground. Conversly, if you elect to crab, then unless you get it exactly right you're either going to land with lateral drift (ie you kicked the drift off too soon) or you'll still be crabbed off (ie kicked the drift off too late).
Agreed, except that, as well as PPPP-PP, practice helps. Unfortunately, the long-haulers don't get much of that.
Originally Posted by H Peacock View Post
Of the various RAF ME types I've operated I've used both techniques, or even a blend of them (ie a bit of wing down but also some crabbing). The geometry of the tailwheel types requires them to be flown accurately aligned and with absolutely no lateral drift - so had to be flown wing-down, but also to a relatively low crosswind limit. The tricycle types will always yaw themselves straight after touchdown if you've not got it right, but it can feel very uncomfortable and can't do the gear much good.
Agreed, although Onceapilot has a point.
Originally Posted by H Peacock View Post
Dont think I've ever seen a modern airliner using the wing-down technique.
Evidently not a 'plane-spotter!

IMO, the (roughly-speaking) three dry-runway techniques - [1] wing-down; [2] slight (late) wing-down during de-crab, and [3] wings-level (full) de-crab - are chosen as appropriate to the aircraft type.
Looking back on a short-list of various types, the following are my suggestions.
Heron [3] or [2], but minding the upwind prop.
C-47: [1], and wheel it on.
Dart Herald: [1], but avoiding wheel-barrowing and ensuring downwind wheels firmly on the ground before using any downwind brake .
VC10: [2]. Although the only limiting factor was the outboard flaps, I never saw [1] demonstrated, and perhaps the tanker guys will comment, pod-wise;
B707-320 (JT3D turbofans): [3], due to outboard engine nacelles, but no doubt the experts could use [2]. The later KC-135s with CFM-56 engines presumably stick with [3]?
BAC1-11: [1] or [2].
A310: [2], bank slightly limited by engine nacelle;
DC-10: [2], although the auto-land adopted [1] at 138'R - but only enough for a 20-knot crosswind, if memory serves. Cockpit needed to be well upwind of the centreline prior to de-crab.
A320: [2], although - being FBW - the manufacturer recommended [3], claiming that the zero roll-rate command from the side-stick would prevent the upwind wing rising during de-crab, and that crossed controls were not recommended. But [2] works very well. I imagine the A330-200/Voyager (with similar FBW) would be comparable?
Chris Scott is offline  
Old 27th Oct 2018, 19:53
  #56 (permalink)  
 
Join Date: Jan 2007
Location: Weston Super Mare/UAE
Age: 59
Posts: 405
Likes: 0
Received 0 Likes on 0 Posts
The A380 requires the crab technique but, bizarrely, the aircraft decrabs around the cockpit - more or less. God alone knows what the FCS does to achieve this. Previous types, for me, had me sat over the grass before a decrab and the cockpit was at the end of a long arc as you de-crabbed. My turbo-prop time was on a high wing and lent itself well to the wing down method, although one ex RN chief pilot of mine professed much alarm at this technique, claiming never to have heard of it before when I demonstrated it, whereas I was taught it on the Bulldog from the word go. I used to teach this method on light singles and had much success with low hour pilots....the 380 geometry would not allow this though.
captainsmiffy is offline  
Old 27th Oct 2018, 20:18
  #57 (permalink)  
 
Join Date: Jan 2014
Location: Lincolnshire
Age: 52
Posts: 206
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by H Peacock View Post


oh dear me. The entire aviation world understands the concept of 'kicking off the drift' except Beagle!
The terminology IS important.

In the 90s the USAF lost a C130 doing asymmetric training because the training Captain told the Co pilot to ‘boot the ball’ - which he did leading to fin stall and the loss of all on board.

The worst landing I have experienced in a large aircraft came when an inexperienced FO read the OM which said words to the effect of ‘kick off the drift’. As he flared he did just that! We dropped like a brick, bounced (despite ground spoiler deployment) before settling on the runway. Easyjet at the hold even transmitted a disparaging comment!

To answer the original quote, though. The RAF do not have a standard teaching, the technique deemed appropriate for each type, whether by the OEM or Handling Sqn, is taught. So for the Herc, which has to be landed straight due to undercarriage design, it is wing down. For Sentry, Sentinel etc, it is crab.
DCThumb is offline  
Old 27th Oct 2018, 20:23
  #58 (permalink)  
 
Join Date: Oct 2011
Location: In a hold
Posts: 161
Likes: 0
Received 0 Likes on 0 Posts
De-crab in the flare, adjusting aileron into wind is what’s primary on the 737-800 for what it’s worth with a 40kt x-wind landing limit Wet/Dry. I guess the P-8 would be similar...
Fly26 is offline  
Old 27th Oct 2018, 21:16
  #59 (permalink)  
 
Join Date: Sep 2004
Location: Yorkshire
Posts: 586
Likes: 0
Received 0 Likes on 0 Posts
But, as you seem to be talking about the comparatively banal task of landing transports,..
Hey, CS, that's probably the only bit of handling an airline driver gets these days!

DCT - The 'concept' is a far removed from the actual airborne instruction/brief! If you tell a co who perhaps doesn't know better (not an RAF co then) to 'boot the rudder' then more fool you for not anticipating his possible mis-interpretation.
So why do you have to use wing-down in the Herc; if you correctly kick off the drift in the flare you still land straight and with no drift (the whole point of this thread is it not - apart from the do nothing option and land without aligning to the runway orientation)

H Peacock is offline  
Old 27th Oct 2018, 21:54
  #60 (permalink)  
 
Join Date: Jan 2014
Location: Lincolnshire
Age: 52
Posts: 206
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by H Peacock View Post


Hey, CS, that's probably the only bit of handling an airline driver gets these days!

DCT - The 'concept' is a far removed from the actual airborne instruction/brief! If you tell a co who perhaps doesn't know better (not an RAF co then) to 'boot the rudder' then more fool you for not anticipating his possible mis-interpretation.
So why do you have to use wing-down in the Herc; if you correctly kick off the drift in the flare you still land straight and with no drift (the whole point of this thread is it not - apart from the do nothing option and land without aligning to the runway orientation)

The C130 crosswind technique is the most reliable method of landing straight - any sideways force on landing damaged the ‘shelf brackets’ on the undercarriage. It makes absolute sense. Why risk someone misjudging the flare and damaging the aircraft, when they can get it straight pointing down the runway first? With a high wing, there is no disadvantage to it. The touchdown order is often one side mains, nosewheel then opposite mains! It’s what you get used to!

DCThumb is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright © 2022 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.