When can you descend from circling MDA?

[poadeleted20]

From your quote about seeing someone coming in fast and that pilot needing remedial training, it gave that impression.

To you, perhaps, but your perception of things is often significantly different than most anyone else I know, so I don't feel any need to explain further.

 

[EdFred]

Yeah, I believe the PTS is a starting point, not an ending point and instruct well beyond it. I'm also not a self appointed authority on other pilot's capabilities.

 

[dtuuri]

You make it sound like we're talking about only a small increase in approach path angle. We're not.

Perhaps if you would have quoted my complete statement you wouldn't have misunderstood. Here's the rest of the story:

At night, obstructions that penetrate a 3° slope in the visual portion of the final approach course are supposed to be lighted. Since the visual portion is only 8° to 9° left or right of centerline, that's where you'd normally be starting a rollout on final. Staying at MDA until rolling out on final at an unfamiliar airport and making a steeper than normal approach should protect against unknown obstacles, but introduces other potential risks, like landing too long. At some airports, like you say, it can't be done at all. Aspen or Eagle come to mind. Tred carefully when it comes to night circling approaches at unfamiliar fields.

dtuuri

 

[peerlesscowboy]

On the contrary, if I see someone flying a 172 clean at 90 knots to 200 AGL and then trying to deploy full flaps and slow to normal landing speed, I think that pilot needs remedial training on basic airmanship, focusing on the critical importance of a stabilized approach. And I guarantee the FAA agrees with me about the importance of making a stabilized approach to landing at an appropriate speed (and 90 KIAS does not fit the PTS definition of that that in a 172) or they wouldn't have made it part of the PTS.
[/LEFT]

OK let's crunch the numbers; Cessna 170B stalling speed at full gross weight, zero degree bank, foreward CG, normal catagory, 10* flaps---56 mph. Convert that to 48.5 knots X 1.3 = 63.05 knots. So you're flying the approach at 63 knots.................

 

[Captain]

Crappy instructors = crappy pilots.

Odd how some of us know more crappy pilots than others. Also sounds like some flight instructors are only doing what's needed to have the student pass the PTS. I always go a few notches further.

Well, you could start by using specific terms with your students instead of vague undefined terms that may have different meanings to different people. That right there would raise your game at least a 'notch'.

 

[poadeleted20]

OK let's crunch the numbers; Cessna 170B stalling speed at full gross weight, zero degree bank, foreward CG, normal catagory, 10* flaps---56 mph. Convert that to 48.5 knots X 1.3 = 63.05 knots. So you're flying the approach at 63 knots.................

From about 400 feet down, yes. From the FAF? Of course not, and I never said otherwise. But I will keep those 10 flaps out there to get that big initial trim change out of the way.

 

[peerlesscowboy]

From about 400 feet down, yes. From the FAF? Of course not, and I never said otherwise. But I will keep those 10 flaps out there to get that big initial trim change out of the way.

Assuming "400 feet down" means 400' HAT, are you advocating slowing from 90 knots to 65 knots with it's resultant trim change 200 feet above DH on the ILS, still in the clag?

 

[poadeleted20]

Assuming "400 feet down" means 400' HAT, are you advocating slowing from 90 knots to 65 knots with it's resultant trim change 200 feet above DH on the ILS, still in the clag?

No. And there's not that much trim change if you have already pulled the first notch of flaps. But y'all are missing the point completely (and I think one or two may be doing that deliberately). What really buggers people is when they come screaming down the ILS at Vfe+20, break out at 200 AGL, and then try to get it slowed, configured, and on the ground safely. And if you try flying 90 knots clean in a light single, it's darn easy to have that speed get away from you.

 

[peerlesscowboy]

No. ........................

So, what do you mean by "400 feet down" ...down from where?

 

[peerlesscowboy]

I guess Ron isn't going to explain what "400 feet down" means

 

[gismo]

So, what do you mean by "400 feet down" ...down from where?

I'm pretty certain the "No" was a reply to the question asked:

"are you advocating slowing from 90 knots to 65 knots with it's resultant trim change 200 feet above DH on the ILS, still in the clag?"

... rather than the assumption about the reference height which was correct AFaIK.

 

[peerlesscowboy]

I'm pretty certain the "No" was a reply to the question asked:

"are you advocating slowing from 90 knots to 65 knots with it's resultant trim change 200 feet above DH on the ILS, still in the clag?"

... rather than the assumption about the reference height which was correct AFaIK.

That's the impression I had also, I'm trying to visualize where Ron advocates slowing down for landing but he seems to have gone missing. He said upthread "from the FAF? Of course not, and I never said otherwise." OK so if it's not 400' HAT then it must be "400 down" from the FAF Either way he's got a trim change associated with a significant speed reduction somewhere between the FAF and DH. Personally I find it easier to slow my 170 to the top of the white arc, flaps at zero, trimmed out prior to the FAF and at GS intercept just reduce power and she'll slide on down the slope. Delay flap extension until I break out and I don't have to deal with pitch trim changes while I'm trying to maintain the glideslope. Once I break out visual just reduce power and when the nose starts getting heavy drop the first 10* of flap.
FWIW, I suspect lowering 10* of flap and trimming up prior to the FAF would work as well except then you're limiting yourself to a maximum of 90 knots all the way down final when ATC might be trying to fit you in with faster traffic plus it occurs to me if you're expecting picking up ice on the approach deploying flaps might not be such a good idea?

 

[gismo]

That's the impression I had also, I'm trying to visualize where Ron advocates slowing down for landing but he seems to have gone missing. He said upthread "from the FAF? Of course not, and I never said otherwise." OK so if it's not 400' HAT then it must be "400 down" from the FAF Either way he's got a trim change associated with a significant speed reduction somewhere between the FAF and DH. Personally I find it easier to slow my 170 to the top of the white arc, flaps at zero, trimmed out prior to the FAF and at GS intercept just reduce power and she'll slide on down the slope. Delay flap extension until I break out and I don't have to deal with pitch trim changes while I'm trying to maintain the glideslope. Once I break out visual just reduce power and when the nose starts getting heavy drop the first 10* of flap.
FWIW, I suspect lowering 10* of flap and trimming up prior to the FAF would work as well except then you're limiting yourself to a maximum of 90 knots all the way down final when ATC might be trying to fit you in with faster traffic plus it occurs to me if you're expecting picking up ice on the approach deploying flaps might not be such a good idea?

Well, I can't speak for Ron but getting the speed inside the white arc and flying the approach at 90 KIAS from somepoint prior to the FAF in a 170 makes sense to me, especially for someone learning to fly instruments.

But your point about fast traffic is valid as well, especially at a major airport. That's certainly something an experienced pilot ought to have in their playbook but also noticeably more difficult to pull off.

And FWIW, making a significant configuration (flaps) and speed change once the runway or environment is in sight is more difficult to do safely when the visibility is low. In many airplanes it's possible to pitch up enough to lose all the lights long enough to cause trouble if you're not real smooth in the transition. I usually just leave my flaps at the approach setting and speed at 100 KIAS (Vyse) until I'm close to the ground if it's murky (e.g. < 1 mile vis).

 

[Jaybird180]

No. And there's not that much trim change if you have already pulled the first notch of flaps. But y'all are missing the point completely (and I think one or two may be doing that deliberately). What really buggers people is when they come screaming down the ILS at Vfe+20, break out at 200 AGL, and then try to get it slowed, configured, and on the ground safely. And if you try flying 90 knots clean in a light single, it's darn easy to have that speed get away from you.

I read this thread staccato so forgive if this question has been asked/answered (doubt it though)

I reasoned that it would pay dividends by flying prec and non-p approaches at flaps 10, 90KIAS in that it satisfies a stable approach, the timing is worked out for you on dive and drive, you have all known settings that are the same regardless and no worries about major changes.

Issues?

 

[Palmpilot]

On the contrary, if I see someone flying a 172 clean at 90 knots to 200 AGL and then trying to deploy full flaps and slow to normal landing speed, I think that pilot needs remedial training on basic airmanship, focusing on the critical importance of a stabilized approach.

That's the way I was taught to do it. Never had a problem with it.

And I guarantee the FAA agrees with me about the importance of making a stabilized approach to landing at an appropriate speed (and 90 KIAS does not fit the PTS definition of that that in a 172) or they wouldn't have made it part of the PTS.

Maintains a stabilized approach and recommended
airspeed, or in its absence, not more than 1.3 Vs0,
+10/-5 knots, with wind gust factor applied.

I'm not finding that quote in the instrument PTS. What did find is the following:

Maintains a stabilized final approach, from the Final Approach Fix to DA/DH allowing no more than ¾-scale deflection of either the glideslope or localizer indications and maintains the desired airspeed within ±10 knots.​

 

[Palmpilot]

No. And there's not that much trim change if you have already pulled the first notch of flaps. But y'all are missing the point completely (and I think one or two may be doing that deliberately). What really buggers people is when they come screaming down the ILS at Vfe+20, break out at 200 AGL, and then try to get it slowed, configured, and on the ground safely. And if you try flying 90 knots clean in a light single, it's darn easy to have that speed get away from you.

I checked POHs for the 172N and 172S, and 90 knots is only Vfe+5, not Vfe+20.

 

[poadeleted20]

I read this thread staccato so forgive if this question has been asked/answered (doubt it though)

I reasoned that it would pay dividends by flying prec and non-p approaches at flaps 10, 90KIAS in that it satisfies a stable approach, the timing is worked out for you on dive and drive, you have all known settings that are the same regardless and no worries about major changes.

Issues?

Works for me, although the specific flap setting and speed would vary with aircraft type.

 

[poadeleted20]

I checked POHs for the 172N and 172S, and 90 knots is only Vfe+5, not Vfe+20.

Now you know why I say 90 knots to the "commit to land" point is fine in a 172. However, I do see/hear pilots trying to fly well over 100 knots just because they might some day want to fly into O'Hare between a couple of airliners doing 150 or more, and that is really making instrument approaches to landings much harder.

 

[poadeleted20]

I'm not finding that quote in the instrument PTS. What did find is the following:

Maintains a stabilized final approach, from the Final Approach Fix to DA/DH allowing no more than ¾-scale deflection of either the glideslope or localizer indications and maintains the desired airspeed within ±10 knots.​

That's part of the approach task, not the landing (Task E) in the IR PTS:

Transitions at the DA/DH, MDA, or VDP to a visual flight

condition, allowing for safe visual maneuvering and a​

normal landing.

That last part will be judged per the AFH, which discusses the Stabilized VFR approach concept in detail, including recommended speeds which are echoed in the Private/Commercial PTS from which I extracted that item above. And if you come down the final segment at 120 knots in your 172 all the way to DA/DH, you aren't going to be able to do that.

 

[peerlesscowboy]

That's part of the approach task, not the landing (Task E) in the IR PTS:
That last part will be judged per the AFH, which discusses the Stabilized VFR approach concept in detail, including recommended speeds which are echoed in the Private/Commercial PTS from which I extracted that item above. And if you come down the final segment at 120 knots in your 172 all the way to DA/DH, you aren't going to be able to do that.

Nobody's suggesting making a practice of flying the final segment at 120 knots in a 172, Ron. You're just setting up a strawman.........again
BTW, welcome back. Now could you please answer my question........what you referred to by "400 feet down"........."down" from where? At some point in the approach you appear to advocate slowing from 90 knots to 65 knots "400 feet down" from somewhere.......leaving you with a pretty significant speed reduction at some point between the FAF and DH (I must assume?). Hardly a "stabilized approach" I'd say