3* Glideslope

Jaybird180

Jaybird180

Final Approach
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Jaybird180
This seems a bit shallow for my taste. Is this common in Jetliners? Relevant material starts at 6m42s

 
looks perfectly normal to me, standard glide path angle and crossing the threshold at roughly 50 feet.
 
Looked fine to me. Although letting the nosewheel go right over the centerline lights like that bugs the crap out of me.:lol:
 
I think I Have flown 2 straight in approaches EVER. Otherwise I Am always clearing an obstacle in final, which explains why that looked scary. And in the Airbus I suppose there is no worry about losing the engine on short-final.

Edit- make that 3. Even when I landed at KATL it didn't look like that. Different technique...
 
A 3 deg glide slope is nominal for a precision approach (ie ILS) and GPS approaches with vertical guidance (eg LPV) regardless of aircraft type
 
Jaybird180 said:
Hadn't considered that.
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I've linked to this before, but in the below video I attempted to fly identical approaches, with three different camera settings - and I think the difference in perspective is readily apparent:


In my estimation the last one with the narrowest field-of-view most closely corresponds with reality.
 
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FastEddieB said:
I've linked to this before, but in the below video I attempted to fly identical approaches, with three different camera settings - and I think the difference in perspective is readily apparent:


In my estimation the last one with the narrowest field-of-view most closely corresponds with reality.
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Certainly a difference between those!
 
tsts4 said:
A 3 deg glide slope is nominal for a precision approach (ie ILS) and GPS approaches with vertical guidance (eg LPV) regardless of aircraft type
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Not exactly. At some locations Cat D is excluded, which make use of a 3.6 degree GS possible. This has been done at quite a few locations where obstacles are a problem.
 
FastEddieB said:
I've linked to this before, but in the below video I attempted to fly identical approaches, with three different camera settings - and I think the difference in perspective is readily apparent:

In my estimation the last one with the narrowest field-of-view most closely corresponds with reality.
Click to expand...

Next, you need to do them with 3 cameras mounted atop your head. :D Thanks for posting that.:yes:
 
Slower airplanes typically comfortably fly steeper approaches.

At 70kts GS it will take about 350fpm to fly a 3deg GS.

At 140kts it will take about 700fpm.

At 180kts it will take about 900fpm.

Jets are typically fly 170-180kts until the final approach point then slow to a target speed which can be anywhere in the 120kts-160kts range depending on aircraft, weight, and conditions. At those speeds a 3deg GS is very comfortable.
 
Jaybird180 said:
Next, you need to do them with 3 cameras mounted atop your head. :D Thanks for posting that.:yes:
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I should try that! I'm going for max dorkiness!

Let me again reiterate that a 3° glidepath virtually guarantees an off-airport landing if a single engine pilot loses power on final.

I like to be well above that, conditions permitting.
 
FastEddieB said:
I should try that! I'm going for max dorkiness!

Let me again reiterate that a 3° glidepath virtually guarantees an off-airport landing if a single engine pilot loses power on final.

I like to be well above that, conditions permitting.
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You mean most SE airplanes can't maintain a 19:1 glide ratio? I suppose you'd have to have quite a bit of excess airspeed during the approach to be able to make the runway. The other option is to fly a 6 degree approach at normal speeds.
 
I'm not so much concerned about the engine quitting (why is it going to die on approach rather than any other time in the flight), but other than being on a surveyed and charted glide path, it's safer to maintain a bit of altitude until you're closer in. Less chance of things rearing up suddenly in your way. Even some instrument approaches aren't quite clear of these challenges.
 
flyingron said:
I'm not so much concerned about the engine quitting (why is it going to die on approach rather than any other time in the flight), but other than being on a surveyed and charted glide path, it's safer to maintain a bit of altitude until you're closer in. Less chance of things rearing up suddenly in your way. Even some instrument approaches aren't quite clear of these challenges.
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Aside from running out of fuel, I would think that you've got a pretty low percentage chance of the engine quitting on approach at low power.
 
Somedudeintn said:
Aside from running out of fuel, I would think that you've got a pretty low percentage chance of the engine quitting on approach at low power.
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Amusingly, I remember reading this accident report. A pilot flying I think a Navaho, put down on the flight plan that he had 7hours of fuel on board. 7 hours and 10 minutes into the flight he ran out of fuel. Unfortunately he was still on downwind when it occurred and didn't quite make the field. I gave him credit for nailing the fuel burn time (if not the time to destination).
 
Somedudeintn said:
Aside from running out of fuel, I would think that you've got a pretty low percentage chance of the engine quitting on approach at low power.
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It apparently happened in Oakland last week. PA32 crashed while on the ILS in warm IMC. Wreckage found on a hillside in Sunol.
 
Somedudeintn said:
You mean most SE airplanes can't maintain a 19:1 glide ratio? I suppose you'd have to have quite a bit of excess airspeed during the approach to be able to make the runway. The other option is to fly a 6 degree approach at normal speeds.
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I personally don't like dragging a plane in on the backside of the power curve. I think it's bad technique.
 
The fix where the ILS starts is usually about 5 miles out and 2000' up. In a 172 or Cherokee, fly 70-90 indicated and 500-600fpm. Usually takes some throttle. Level out just above the runway and land on a stripe about 1000' down the runway. Planes big and little follow the same path although at different speeds.
 
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Jaybird180 said:
I personally don't like dragging a plane in on the backside of the power curve. I think it's bad technique.
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I'm just curious, bad technique for what? Day VFR? Runway type?
 
Jaybird180 said:
I personally don't like dragging a plane in on the backside of the power curve. I think it's bad technique.
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A three degree glide slope doesn't mandate the "back side of the power curve." There's a difference between having to carry power and being on the back side of the power curve.
 
flyingron said:
A three degree glide slope doesn't mandate the "back side of the power curve." There's a difference between having to carry power and being on the back side of the power curve.
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Yes. You're not on the back side of the power curve at 90 KIAS in a typical light single. It's not synonymous with having power. The back side means the controls are "reversed." That is, pulling back on the yoke loses (more) altitude. You'll have to be below 60 KIAS in a 172 to do that.
 
Airliner approach speed is twice if not a bit more than yours. Twice the speed = double the VS down to stay on G/S.
 
flyingron said:
A three degree glide slope doesn't mandate the "back side of the power curve." There's a difference between having to carry power and being on the back side of the power curve.
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MAKG1 said:
Yes. You're not on the back side of the power curve at 90 KIAS in a typical light single. It's not synonymous with having power. The back side means the controls are "reversed." That is, pulling back on the yoke loses (more) altitude. You'll have to be below 60 KIAS in a 172 to do that.
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Thank you for the correction.
 
flyingron said:
I'm not so much concerned about the engine quitting (why is it going to die on approach rather than any other time in the flight), but other than being on a surveyed and charted glide path, it's safer to maintain a bit of altitude until you're closer in. Less chance of things rearing up suddenly in your way. Even some instrument approaches aren't quite clear of these challenges.
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Especially those that state "NA at Night." The only NPAs that you can really trust below MDA are those with the 34:1-clear stipple on FAA charts.
 
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