3 questions

[number]

I need some clarifications:

-In a standard take off briefing, what's the difference between a rejected t.o. procedure after V1 and the one engine out procedure?
In both cases, are we supposed to follow the procedure in missed approach section of any IFR approach?

-In what condition do we need to use the MAPt in a precision approach?

-Is the DA(H) between parenthesis in a precision approach referred to the radio altimeter, while the normal DA(H) it's referred to the local altimeter setting?

thanks!

[keithl]

More details required! I feel I may be able to answer your DA and MAPt questions, but tell me what "paretheses" you mean. It may be helpful if you say what chart(s) you are looking at. Are we talking Cat II ILS or CAT I? Or are you looking at a Military or joint use aerodrome? Also, you obviously can't follow a Missed App. Procedure if you've rejected the t/o. So please clarify.

For now, I'll limit my reply to the one clear bit, which is that the MAPt has no use in a Precision Approach. It's on the plate in case the GP fails and it becomes a non-precision Approach(LLZ only).

[number]

About my DA question, I'm referring to an ILS precision approach chart, jeppesen. non militar.
But I've noticed that for the same airport for example, if it's CATII ILS there's DA(H) 344'(100') and RA 93' (which is obviously referring to the radio altimeter) , airport elev is 244' but then it also sais TCH displ thresh 49' .... now I'm confused.

about the rejected t.o. sorry I didn't explaim myself, mistaken question.

About the one engine out procedure, in case of engine failure right after V1 during a T.O. are we supposed to follow the directions of a missed approach procedure? Climb on blah blah, then right turn to blah blah and hold...

thank you

[Freddie-M]

DA = Decision Altitude ie. what you see with QNH set. Airport QNH will give you a 344 ft decision in your example and show 244ft at touchdown.
DH = Decision Height ie. What you see with QFE set. Runway QFE will give you zero feet at touchdown and a 100ft decision.
EFATO. Fly straight ahead, follow the SID or emergency turn. It depends on terrain. You do not follow the MAP unless you are going around. However, at some airfields the MAP is similar to the emergency turn and it usually gives a good heads up for terrain problems.

[stellair]

It's also worth remembering that most regional aerodromes have radar and normal procedures for most will be a straight climb to a published altitude followed promptly by priority vectors to intercept the llz

[keithl]

OK, for 'rejected' read 'Engine Failure After T/O'. The 'one engine out' case is the same thing. And Cat II ILS, OK. Now to your original questions:
1. Following engine failure, continue as cleared. After a T/O this will be per SID or departure clearance, or following a go-round it will be as per standard Missed Approach Procedure or as modified by ATC. If the failure means you're unable to comply, tell ATC, declare emergency if necessary, and get a new clearance.
2. MAPt. - already answered.
3. DA(H) refers to Decision Alt or Decision Ht, depending on whether you are using QNH or QFE, as explained by Freddie-M. The Radalt reading is clearly marked 'RA'. TCH is a different thing. It is your height above the ground as you cross the Threshold, in your example 49 ft as you cross a displaced (i.e. inset) threshold. This has nothing to do with instrument minima. It is more for info. in case the back end of the aircraft is a long way below the front end.

Hope this clarifies things for you.