Question on getting down

LowHrsMan

LowHrsMan

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LowHrsMan
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IFR student here with another question. This is a thought exercise and has not happened to me ; I'm just wondering "what if".

Let's say you're flying IFR south on V495 to KCVO at 8000 at 120 TAS.
ATC is super busy with airliner traffic.
Then you hear "N1234, you are 4 miles north of SKIVE. Cross SKIVE at or above 4500, cleared straight-in for the ILS 17 approach to Corvallis."

Now you have 4 miles to lose 3500 feet (yes, it's "at or above", but you need to get down). That's a very steep decent.
Obviously diving at over 1000 FPM is not a good plan.

What's the best thing do?
-ask ATC for delay vectors to descend?
-ask ATC to fly the hold at SKIVE and use the hold to get down?
Or would this scenario just neve happen in real flying?

Plate attached for reference.

LHM
 

Attachments

I'm not instrument rated, but 8000' is above 4500', so I think you're good there. I also don't think there's anything wrong with a 1,000 fpm descent. I assume you'll be slowing down, too.
 
LowHrsMan said:
IFR student here with another question. This is a thought exercise and has not happened to me ; I'm just wondering "what if".

Let's say you're flying IFR south on V495 to KCVO at 8000 at 120 TAS.
ATC is super busy with airliner traffic.
Then you hear "N1234, you are 4 miles north of SKIVE. Cross SKIVE at or above 4500, cleared straight-in for the ILS 17 approach to Corvallis."

Now you have 4 miles to lose 3500 feet (yes, it's "at or above", but you need to get down). That's a very steep decent.
Obviously diving at over 1000 FPM is not a good plan.

What's the best thing do?
-ask ATC for delay vectors to descend?
-ask ATC to fly the hold at SKIVE and use the hold to get down?
Or would this scenario just neve happen in real flying?

Plate attached for reference.

LHM
Click to expand...
“Cascade Approach, 123AB unable straight in ILS one seven, expecting full procedure for descent”.
 
Your descent is marginal needing ~1750 ft descent, and I recall the IFR standard is 500-1500. I agree though, I do not like horseplay in clouds. I'd ask for a vector or a published hold for a more gentlemanly descent. One turn should do it.

And it absolutely does happen. Seattle Center in that area are particularly thin stretched I feel lately.
 
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LowHrsMan said:
Then you hear "N1234, you are 4 miles north of SKIVE. Cross SKIVE at or above 4500, cleared straight-in for the ILS 17 approach to Corvallis."

Now you have 4 miles to lose 3500 feet (yes, it's "at or above", but you need to get down)..

Or would this scenario just neve happen in real flying?
Click to expand...
It happens. Occasionally ATC gets behind, has a trainee or simply forgets about you. I try to give them a pass as I've caused ATC more grief than they have ever caused me.
 
The hold at skive is part of the approach, so I think you are expected to fly it unless ATC says "cleared straight in." Also, since skive is eight degrees off of V495, I think there should be a "fly direct skive" in that clearance. (I haven't flown IFR in several years, so if I'm wrong, hopefully someone will correct me.)

In a plane that cruises at 120 knots, I would reduce the descent rate required by slowing down to about 90 knots.
 
Bad clearance. V495 doesn't intersect with SKIVE (or any part of the localizer). If they tell you to go direct SKIVE, then you'd have to do the hold-in-loo unless they told you proceed straight in. If they had vectored you to the localizer, then you can go straight in.
 
You can pull the power and do a steep, but CONTROLLED, descent. Or just tell them you may need a turn at SKIVE for your descent if you don't want to go down that fast.
 
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Like already said, it’s an incomplete clearance. It doesn’t have a route to get you to SKIVE. You’d need a vector to join the Localizer or Direct if you have RNAV. Once that problem is resolved you can refuse the straight in and tell them you need the hold. But it’s still gonna be steep. 4700 is the Maximum Hold altitude. You could always just accept the straight in clearance and then if you can’t get down just execute the Missed Approach. Might be fun, they may take you out to MUFFE for another try and you can play DME ARC.
 
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flyingron said:
Bad clearance. V495 doesn't intersect with SKIVE (or any part of the localizer). If they tell you to go direct SKIVE, then you'd have to do the hold-in-loo unless they told you proceed straight in. If they had vectored you to the localizer, then you can go straight in.
Click to expand...
Hmm. If they vector you join the Localizer outside of SKIVE you are not on a published segment out there. I think they still must say ‘straight in’ if they don’t want you to do HILPT.
 
luvflyin said:
Hmm. If they vector you join the Localizer outside of SKIVE you are not on a published segment out there. I think they still must say ‘straight in’ if they don’t want you to do HILPT.
Click to expand...
The rules don't say you have to be vectored to a published segment, just to the final approach course (not segment).
 
Say "we're too high to make that" and let the controller decide what do to
 
bbchien said:
Super common. Agree with reduce airspeed and request delay vector.
Click to expand...
Yep, you can do that too. The IAP in the scenario is for an uncontrolled airport, the airspace for the approach has been assigned and the hold is a super easy option for a busy ATC.
 
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M20K said:
You can pull the power and do a steep, but CONTOLLED, descent. Or just tell them you may need a turn at SKIVE for your descent if you don't want to go down that fast.
Click to expand...
CONTOLLED must be a Mooney procedure.
 
Clip4 said:
CONTOLLED must be a Mooney procedure.
Click to expand...
It is! Very special procedure just for us!

So for those less fortunate that can't do it, I've updated my original post to make sure the rest of you do a "CONTROLLED" descent! (Rather than pull the power, do a dive with the VSI swinging irratically and then are still all over the place trying to end up with a stable approach.)

Thx for the heads up...:cheerswine:
 
Tell ATC you are too high to fly straight in. If you have an option that you prefer, request it.

ATC expects pilots to tell them when they are unable to fly the clearance they are given. They don't know your airplane's capabilities.

BTW, I don't fly 120 TAS, I fly 120 KIAS.
 
Larry in TN said:
Tell ATC you are too high to fly straight in. If you have an option that you prefer, request it.

ATC expects pilots to tell them when they are unable to fly the clearance they are given. They don't know your airplane's capabilities.

BTW, I don't fly 120 TAS, I fly 120 KIAS.
Click to expand...
Which results in what Ground Speed? Which you need to know if you’re gonna get the angle of descent you’re going to need make it
 
LowHrsMan said:
What's the best thing do?
-ask ATC for delay vectors to descend?
-ask ATC to fly the hold at SKIVE and use the hold to get down?
Or would this scenario just neve happen in real flying?
Click to expand...
I don’t know their MVA but since the MSA is 5300, I suspect the MVA is lower and they’ll be able to get you down. But never say never.

If they couldn’t or didn’t, I would ask for whatever made sense based on my direction of travel and the conditions that day.
 
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