First up, to answer the original question:

It is conventional in instrument flight to fly all turns at Rate 1, or 25 degrees AOB, whichever requires less bank. In an Instrument Rating test in a light aircraft this is what you would be expected to do.

Obviously for smaller heading changes (such as corrections when established on the localiser) you are not going to crank on 25 AOB and a good rule of thumb is to use only as much bank as degrees you are turning (i.e. 5 degree heading change = 5 degrees of bank).

However, I am assuming that the OP is referring to airliners in which case nobody is going to be measuring your rate of turn even if you have a turn indicator installed, so as Wilhelm says in practice if you are being vectored around/flying the full ILS procedure etc you are just going to use whatever bank angle you require to maintain the required ground track up to 25 AOB, with due regard for passenger comfort.

On 06/12/2017 at 4:24 PM, scianoir said:

Once the AP is disengaged after a stable approach you should only need to make small directional corrections and in airliners these directional corrections are generally made using more rudder movement than aileron

I must say that I have never encountered anyone advocating steering a swept-wing transport-category jet down an ILS with one's feet (and the light aircraft IRIs I have come across wouldn't recommend it either).

Passengers don't like yaw much, and when you're flying something the length of a football pitch it can be particularly uncomfortable for those down the back when you start booting your size 10s around!

In a large jet, generally speaking rudder pedals = footrests, used in anger only during engine failure, crosswind take-offs or the late stages of a crosswind landing. Most modern jets are equipped with yaw dampers which will mostly take care of turn coordination for small turns and thus there is no need to be dancing on the pedals; just small, coordinated turns (and in an airliner on final approach I would suggest in most cases if you are using more than 5 degrees bank angle that is likely a clue your approach is becoming unstable) to re-establish on the correct heading are all that is required.

Of course, in the very final stages of the approach it will be necessary/desirable to squeeze off the drift and align the aircraft's longitudinal axis with the runway centreline. This obviously is accomplished by applying rudder to straighten up and aileron in to wind to maintain wings level or a slight lowering of the upwind wing -- the main concern with airliners fitted with underslung engines is pod and wingtip clearance and this is why they are not landed in a full sideslip like a high-wing C172 or similar. As such the amount of drift that can be removed is limited by the bank angle available, which in a B744 is virtually zero but in something like a CRJ with tail-mounted engines may be slightly more.

The other important thing is to keep flying the aeroplane after touchdown, with in-to-wind aileron as necessary to prevent the upwind wing from rising.

On 06/12/2017 at 5:58 PM, scianoir said:

Some of those landings really are a testament to the structure of modern airliners - not just the amazing strength of the undercarriage to cope with such hard landings in a crabbed position but of the aircraft as a whole looking at the amount of wing flex and also the considerable 'shaking' of the tailplanes in some of the aircraft after landing. I have no doubt that airliners of an earlier era such as Connies and DC-6/7s (and perhaps even 707s and DC-8s) would have been straight into the maintenance hangar after some of those landings! But I guess the inability of piston airliners to cope with such extreme crosswinds was the reason that airports of their era had so many runways aligned in different directions.

The issue is not one of powerplant but undercarriage. Taildraggers have a nasty habit of ground looping if you land them with any drift on and thus must be landed in a full sideslip with all the drift removed. As mentioned above, the amount of drift you can remove through a sideslip is dependent upon rudder authority and the amount of bank angle you can achieve, so for an aircraft with engines mounted on the wings you will be limited by the amount of propeller tip clearance available in the landing attitude.

This overall makes crosswinds very limiting for taildraggers in particular and this is why early airfields had either many runways or, indeed, were simply a broadly circular field such that takeoff and landing could always be accomplished in to the wind.

Tricycle landing gear is obviously inherently much more stable and hence allows for much greater crosswind limits because you can land on it with drift on.

Well, to answer the original question abour intercepting the localiser, consider this. A guy I was flying with described to me how they would intercept the loc in his previous aircraft. They would approach the loc at a ninety degree angle, and just as the needle started to move off the edge of the hsi, they would roll into a ninety degree bank and pull back on the stick as hard as they can, loading up to maybe 5-6 g’s. With power idle, speedbrakes out, they would decelerate from 350kts to final approach speed in the turn and roll out of the turn gear down, configured, on speed on the ils. He said it works every time. Not sure what kind of aircraft the op was asking about, but this was for the F-16.

23 hours ago, skelsey said:

I must say that I have never encountered anyone advocating steering a swept-wing transport-category jet down an ILS with one's feet (and the light aircraft IRIs I have come across wouldn't recommend it either).

I was making the point that if you have flown a stable ILS approach on the autopilot then, by definition, you should be on the centreline when you disengage the autopilot before touchdown and the corrections you need should be minimal. If there is a crosswind component then drift should be anticipated and you should be ready to apply an appropriate amount of rudder to stay on the centreline after AP disengagement. On the subject of flying the ILS "with one's feet", does the autopilot, once it captures the localiser in a crosswind scenario, then not maintain the centreline primarily using rudder to yaw into the wind? Although I was a PPL with a couple of thousand hours, I have never flown anything larger than an Aztec, so I am open to correction by any real world heavy metal flyers out there if my assumptions on flying technique for airliners on the ILS are incorrect!

Bill