737 CAT II
 

737NG is approved for CAT II dual/single autopilot and F/D approach under some requirments mentioned in the AFM (2 HYD system, 2 Elec. power sources, 2 ADIRU's, both engines...etc)

So after the stabilization 1000ft AGL stabilization gate and before the Alert height, you got a failure in one of those equipments, and you can control the A/C. My question here is you wait until the minima and decide.. or just iniate a G/A?

Go-around except if you decide the safest course of action is to get on the ground ASAP.

Mind that the aircraft will not fall apart if you will fly on only 1 hydraulic system / 1 generator / 1 engine...

Thanks flyingstone.. But at this point if a visual reference is made and the a/c is controlled then a landing should be made, correct?

Also when AFM says that F/D is accepted for manual cat II approach, does it mean ONLY when visual reference is made?

Depending on your SOP's, if the a/c is no longer CAT 2 capable, and you've passed 1000'agl, and the RVR is >CAT 1 you could continue to CAT 1 minima and then decide as normal. This is called CAT 1 reversion from an LVO approach.

As RAT5 says, if you are visual and can maintain visual contact simply revert to CAT I and continue. For that reason we always bug the CAT I minimum for LVO approaches, simply turn the minimum selector back to BARO and fly as normal.

Denti: I was quite saying that. If you are visual then there are no minimums. You land. If the a/c becomes unable for CAT 2, and you are still IMC, you might be able to continue to CAT 1 minima and then decide.

thanks guys

Answer:---NO you don't wait. ( unless visual reference is established. )

In our mob ( A330 2 A/P's )
Any equipment degradation ( Aircraft or Ground ) the approach may not commence OR continue ( even if below 1000' ) unless the weather conditions are suitable for the new degraded approach capability.

So, using your Cat 2 if something required fails on a Cat 2 approach and the Vis is not suitable for Cat 1 then you MUST go around now unless already visual.


To quote our books----

Equipment Deterioration---
If an aircraft or airport systems failure necessitates a reversion to a degraded approach category, the approach may not commence (i.e. descend below 1,000 FT AAL) or continue, if already below 1,000 FT AAL, unless the reported RVR readings are at, or above, the minima for the degraded approach category

Nitpicker330, maybe your reported vis was greater than the Cat I min to start with..
Then what ICAO says and your company SOP's provide, may be different.

Well then it depends on when ATC advised the updated RVR's, what type of approach you were planning, were LVP's in force if the RVR was above Cat 1? etc

it's all in the timing......

But it's still simple. If while conducting an LVP approach to Cat 3B/3/2 and you suffer an equipment failure the approach can ONLY continue or commence IF the reporter RVR's are at or above the new degraded capability at the time of the failure. If in your case the RVR's were above Cat 1 to start with then I'd suggest you don't get an update on the RVR's because you may not like what you hear!!

Quite honestly, it depends on the operator you fly for. Some are as permissive as possible, others lay their safety case on being uber safe to the regulators. There are merits in both approaches.

However, it doesn't matter what we say here, it just matters what is written in YOUR ops manual. Nitpicker330 has his rules, others have theirs... Read em, use them, and if there is any doubt then go around...

Wonding if you got an equipment failure above 1000ft and decide not to continue CAT II approach (due to unstablilized approach) will you just perform a Go-around or just discontinue the approach?

Only you knowing your company requirements and type of approach you are conducting can answer that question.

Mind you that on a dual channel approach at 400 feet the aircraft will trim nose up. Reverting to manual flight to attempt a landing after this point can be quite a challenge and you are better of going around even when visual.

On a single channel approach you dont have this problem, but single channel autopilot minimum use height is 158ft AGL so still above your 100ft RA. Although its a bit academic you would need to fly the last 58ft to your minimums manually, which is not prohibited. However my outfit does not allow manually flown CATII approaches.

Anyway a system failure on a CATII or III approach will most of the time lead to a go-around.

A go around for a bit of trim up in visual condition?you are taught to trim nah?
Its good to know what to expect(nose up) but going around?you are not even unstable yet:E

Go around? Not on the A330 anyway. If you are doing a CAT 2 approach followed by a manual landing ( for some reason, quite common ) then you only have to disconnect by 80' minimum.

If everything is working you would have had CAT 3 DUAL annunciated and thus 2 A/P' engaged up to that point.

To Ditched: A manual GA after dual AP approach, below the 350 ft nose up trim in the 737 is a non event.

Latetonite,
No, it is NOT a non- event.
Due to the up trim, a manual go-around on B737 below 350' will require a significant downwards force on the yoke by the PF.
You need to know what you are doing or you WILL stall and burn.

Despegue: of course you need to know what you are doing. Don't we all have to?
And then, even in a manual GA resulting from a single channel approach, or manual approach for that matter, can result in a crash and burn situation with some individuals.

Sure, however anyone who had a halfway competent trainer will know how to deal with that. However, for those too afraid of their job to hand fly every now and then it might be a challenge. But lately it seems that it is too much to expect from a professional pilot that he is able to actually fly. Same as boeing expects every pilot to deal with the sudden onset of rudder force when the rudder servo quits during every single engine auto go-around.