Max glideslope Cat 1 apr

[abovethebelow]

hey guys anyone got an idea of max glipeslope for cat 1 apr? or where i could find it?

cheers

[TyroPicard]

This is what wiki says... usual health warning applies.
The centerline of the glideslope signal is arranged to define a glideslope of approximately 3° above horizontal (ground level). The beam is 1.4° deep; 0.7° below the glideslope centerline and 0.7° above the glideslope centerline.

[renard]

London City glideslope is CATI and is 5.5deg.

Minima are higher than for a normal 3deg.

For an BA146/RJ they are it

RW09 360' and 1000m RVR
RW27 460' and 900m RVR

[Flexi]

@ Tyropicard: Probably not what initial poster was looking for...

I guess he is looking for the maximum permissible GS-deviation during approach (right?!)!

I was recently discussing the same issue with my captain. Our manual states the maximum allowed discrepancies for CAT II/III, but nothing mentioned about CAT I!

My pov: if you stay within the limitations, obey SOPs and are established according to the books, no problem to deviate from the glideslope (to fly above, NOT below the GS) in fair weather. Different thing under "real" Cat I conditions with RVR less than 800m...:}

Sorry - but i can´t give you a more precise answer, but looking forward to other comments!

Cheers

[kijangnim]

Greetings,

In the cockpit we have behaviors, acquired during training, then after training, the brain remains in the learning mode for a while, so if at that stage you start doing "things your own way" then you replace the behavior acquired during training by this new one.:hmm:
In other words, my advice fly the ILS CAT I as if the weather is bad, although it is CAVOK.:ok:

One dot below is max.:}

[abovethebelow]

Thanks for the response seems city is highest around so at 5.5deg

[finncapt]

Probably digressing a bit but I seem to recall that the space shuttle flies a g/s of 12deg.

Not sure if it can do cat1 though.

The go around may be interesting!!!!

[BOAC]

Type dependent

[safetypee]

The maximum ILS glide-slope angle is probably defined by an aircraft’s aerodynamic capability – e.g. shuttle; for commercial aircraft a steep approach certification.
The original LCY glideslope was 7.5 deg (for noise reasons), and because the only aircraft planned to use the airport was the Dash 7. This aircraft was certificated in the STOL category.
LCY was reduced to 5.5 deg to accommodate the limit of BAe146 / Avro RJ steep approach capabilities (although some 146/RJ’s have a 6 deg clearance)

With increasing angle at constant beam-width, the apparent GS sensitivity decreases (greater altitude deviation for the same GS indication), thus the beam-width may have to be narrowed. If so, then as far as the crew is concerned, they continue to fly within the normal limits to provide adequate obstacle clearance. However, crews should be aware that they may less time to response to a deviation due to the higher descent rate, i.e. with a GS deviation you have less time to recover back to the beam centre. Similar adjustments may be made to LOC instalations on short runways.

IIRC, planning for LCY jet operations considered the use of a Cat 2 quality glideslope installation (beam accuracy, stability, etc) so that a smaller obstacle clearance margin could be claimed to ease some for the problems of close in obstacles.

Also, with failing memory, Plymouth (UK) had a test / trial ILS installation at 7.5 deg, as a switchable alternative to the normal 3 deg beam.

[TopBunk]

FinnCapt

I think the space shuttle uses a 21deg g/s rather than 12deg:eek:

[lalbak]

Why are the minima at LCY lower for the BA146/RJ than for even CAT A aircraft? Looking at the chart and assuming the same climb gradient the Avro is still below CAT A, B, and C.

[JW411]

Some 20 years or so ago, I spent two days with the FAA (on loan) in the Hatfield BAe146 simulator flying lots and lots of approaches into the likes of Aspen, Colorado and Casper, Wyoming. The object of the exercise was to establish the steepest safe approach possible.

If we got everything exactly right at the beginning of the approach, a 7 degree glideslope with everything hanging out at glideslope capture was possible but if you got high or fast then there was absolutely nothing you could do to correct.

It was decided that using a 7 degree slope on an everyday basis could be fraught with disaster.

I believe that was one of the reasons that a slope of 5.5 degrees was decided upon at LCY.

[finncapt]

Top bunk

I defer to you.

I at least got the 2 and 1 right!!!

[SIAMW]

The max descent angle for ILS CAT 1 is 3.5 deg.
(ICAO DOC 8168):ok:

Cheers

[BOAC]

Siam - you may want to look at http://www.pcpages.com/njanjua/gs_angles.htm

[SIAMW]

Precision approach glide path angle:

1) minimum: 2.5°
2) optimum: 3.0°
3) maximum: 3.5° (3.0° for cat II/III operations).

Procedures involving non-standard glide path angles

Procedures involving glide paths greater than 3.5° or any angle when the nominal rate of descent exceeds 5 m/sec (1000 ft/min), are non-standard and subject to restrictions ("Height loss/altimeter margins"). They are normally restricted to specifically approved operators and aircraft, and are promulgated with appropriate aircraft and crew restrictions annotated on the approach chart.

[411A]

One dot below is max


This could well be unsuitable for large widebody aircraft.
Remembering that most of these have minimum threshold crossing heights to avoid the main landing gear becoming rather close to the frangible bits of the approach lights....:ooh:

[latetonite]

Looks like some fellows are confusing degrees with percentages though..:bored:

[kijangnim]

Greetings
This is why stabilization criteria kicks in, and that you go around :ok: