Exceeding Rate One turns

[Bucket]

Dear All

Need help...

When is it permissible to excced at rate one turn. The scenario is the inbound turn into NDB QDM or interception of ILS localiser.

I was always taught never to crank it over but continue the turn and re-intercept. Now that I am doing the teaching I want to get this right from the start.

Pans Ops 8168 in a bit thin on this and only mentions the 25 degrees or 3 degrees per second etc limt.

Is there a concrete restriction or not?

Ta:confused:

[DFC]

The procedures are based on a minimum rate of turn. They expect that you will turn at a minimum rate of 3deg per second (rate 1) up to the point where this requires 25 degrees of bank (airspeed 180Kt aprox). At higher speeds, the turn is calculated based on a constant bank angle of 25 degrees which of course will give less than rate 1.

There is no specified maximum rate of turn that one can use just the same as there is no specified maximum rate of turn for visual turns onto final.

However since we teach VFR pilots not to tighten the turn onto final if they are going through the centerline (danger of low speed, high angle of attack, ball not in the middle, distraction, spin etc) it is entirely logical to teach that same safe practice when flying a turn on instruments especially considdering the posibilities of disorientation and the inherrent errors that can affect the gyro instruments after a steep turn.

Think back to your own IR training and how you positioned the aircraft in the hold or on the outbound leg.

Regards,

DFC

[aces low]

My own opinion...there will always be some circumstances that tempt an IMC student to want to tighten up the turn beyond rate 1. I always suggest to them that turning at rate one involves minimum workload (i.e. your already busy with the procedure, so up your scan rate further while having to increase back pressure to remain level whilst turning). Nine time sout of ten, busy IMC students lose altitude when they overbank when busy with procedures.

If it is obvious that the wind will cause an aircraft (in the standard rate one turn) to blow through the inbound track then I teach them to be aware of this fact before it happens. The needles will tell you at least 30s beforehand in a hold, prompting you to continue the turn to a positive intecept angle...remembering they will be into wind as they do this. This should result in a swift recapture of the desired track. Usually the student rolls out on heading. Ponders a while, then takes up a tiddly intercept angle to go get a track that is rapidly disappearing to one side.



Bottom line is....it shouldn't be a surprise when it happens, and correct procedure should recover the situation rapidly. Exceeding rate one? Shouldn't be necessary for a competent IMC student.

[pilotbear]

If I have a reasonably confident IR student, then I will let them turn up to AOB of 30deg, after all rate one should be flown on AOB 20deg with the TC as a guide.

If you teach them not to exceed rate one ever then if it happens unexpectedly I find they panic, I like to get them used to it on the understanding that is not the norm.

IMC student? well it depends on their attitude and reason for doing the IMC, because I believe it is really only to get out of trouble as rarely does anyone stay current.

[BraceBrace]

It's rate 1 or 25° (faster aircraft like jets), with an absolute maximum of 30°. In certain circumstances you never overshoot, ie intercepting localizer in IMC. I feel it is far more dangerous to overshoot than to increase bank up to 30°. One day he might be intercepting a LOC on parallel runways, I'd rather not have him overshoot the LOC then.

[nosehair]

BraceBrace, brace yourself for this one. I undrstand your thinking on trying to emphasize not overshooting the localizer, but truthfully, in my experience, pilots will get into more trouble overbanking than overshooting. I teach never overbank. And I don't think an ATC controller is ever going to have an aircraft vectored at an intercept angle that would result in a collision with another aircraft on a parallel ILS.

[alphaalpha]

Bucket was talking about turns as part of approach procedures. Going beyond this, I will go to a minimum of 30 degrees of bank, and maybe up to 45 degrees, if issued with an 'avoiding action, pop-up traffic, turn......' type advisory.

In this situation (in IMC), scanning is not a particular problem, as your mind is concentrated on just the one thing, turning.

However, more than 45 degrees in IMC is asking for trouble.

AA.