Landing below glideslope?

[DrewBlows]

If your book landing distance is 3600 feet, and you have 3900 feet of runway, dipping below glideslope to touch down at 500 feet from the threshold adds 500 feet to the runway available, increasing the margins.

I suppose this is reasonable. I can't relate to this situation though, as I have never had to cut it that close. (Part 121 gives you generous margins, for those of us who slipped though the cracks.)

 

[minitour]

If your book landing distance is 3600 feet, and you have 3900 feet of runway, dipping below glideslope to touch down at 500 feet from the threshold adds 500 feet to the runway available, increasing the margins.

Is that even legal under 121 or 135? Does that meet the 60% (or is it 70%?) requirements? (I always mix the 60%/70% up).

-mini

 

[avbug]

§ 91.129 Operations in Class D airspace.

(e) Minimum Altitudes. When operating to an airport in Class D airspace, each pilot of -

(2) A large or turbine-powered airplane approaching to land on a runway served by an instrument landing system (ILS), if the airplane is ILS equipped, shall fly that airplane at an altitude at or above the glide slope between the outer marker (or point of interception of glide slope, if compliance with the applicable distance from clouds criteria requires interception closer in) and the middle marker; and

(3) An airplane approaching to land on a runway served by a visual approach slope indicator shall maintain an altitude at or above the glide slope until a lower altitude is necessary for a safe landing.

Remember that operations under Parts 121 and 135 are also beholden to Part 91. Parts 119, 121, and 135 merely add additional restrictions to the general operating regulations.

 

[MauleSkinner]

Is that even legal under 121 or 135? Does that meet the 60% (or is it 70%?) requirements? (I always mix the 60%/70% up).

-mini

I don't know about 121, but the 60% rule under 135.385 is only a "takeoff" requirement, not a "landing" requirement. In other words, if things change enroute, you can still land.

It can also be pretty much disregarded under paragraph (e), provided you have an appropriate alternate:

A turbojet airplane that would be prohibited from being taken off because it could not meet paragraph (b)(2) of this section (the 60% rule) may be taken off if an alternate airport is selected that meets all of paragraph (b) of this section.

Fly safe!

David

 

[THE Flying Ace]

Based out of FCM (Flying Cloud in Minneapolis) where the runway is only 3900 feet, it is common to dip below and aim for the numbers. Everytime we come home, it is like doing a short field approach. I wish MAC would just do this runway extention that they have been talking about for many years.

 

[minitour]

I don't know about 121, but the 60% rule under 135.385 is only a "takeoff" requirement, not a "landing" requirement. In other words, if things change enroute, you can still land.

It can also be pretty much disregarded under paragraph (e), provided you have an appropriate alternate:

Fly safe!

David

ooooooh...now I get it.

Ya the gleim ATP test prep doesn't really do that reg justice. I get it tho...so I can legally land in that amount of distance...I just can't takeoff in the first place unless my performance numbers (taking into account normal fuel/oil consumption) allow for a landing in 60% of the available (or is it "usable"?) runway.

Very good.

Thanks...dang that clears a lot up...

Back to the question though...
If your numbers show you can land in X feet (3,000 as an example) and the runway is Y (3200) feet long... you should be plenty good to go. Doesn't the landing performance data include crossing the threshold at 50' and touching down on GS?

-mini

 

[MauleSkinner]

Back to the question though...
If your numbers show you can land in X feet (3,000 as an example) and the runway is Y (3200) feet long... you should be plenty good to go. Doesn't the landing performance data include crossing the threshold at 50' and touching down on GS?

-mini

Yes, you are, and yes, it does...BUT...have you ever stopped 200 feet short of the end of the runway with max braking? It's not fun...I'll take every advantage I can get.

Fly safe!

David

 

[minitour]

Yes, you are, and yes, it does...BUT...have you ever stopped 200 feet short of the end of the runway with max braking? It's not fun...I'll take every advantage I can get.

Fly safe!

David

LOL actually....this one time flying my first SE Approach in a Duchess (damn prop wouldn't unfeather)...I was just....a LITTLE fast and uh...

Runway 3 at OUN never seemed so short...we did finally make Bravo though...I had the instructor almost crapping

True...not fun and yes you're right...take every single advantage.

-mini

 

[MauleSkinner]

LOL actually....this one time flying my first SE Approach in a Duchess (dang prop wouldn't unfeather)...I was just....a LITTLE fast and uh...

Runway 3 at OUN never seemed so short...we did finally make Bravo though...I had the instructor almost crapping

True...not fun and yes you're right...take every single advantage.

-mini

You can tell it's a guy's first real engine-out landing in a twin just by watching...almost everybody does it that way

 

[avbug]

Back to the question though...
If your numbers show you can land in X feet (3,000 as an example) and the runway is Y (3200) feet long... you should be plenty good to go. Doesn't the landing performance data include crossing the threshold at 50' and touching down on GS?

That was a joke, right??