Getting low and slow on short short final

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DaveInPA

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Dave
I’m IFR rated but still practicing a lot of approaches and I’m finding that even my most stable approaches I end up getting low and too slow at about 300 ft agl part of the approach. I add power but then I end up coming in fast and have to adjust. So not very stable.

I’m flying a Seneca and at 95 kt on the approach after the final fix with one notch flaps and about 18in on manifold and cruise props. I start getting low and slow before I extend more flaps and put props full forward. Yes I need some power once I add flaps and power but I shouldn’t need to go from 18 to 22” right to compensate for those.

curious if others flying similar performance planes find they need to add power as they descend from the final fix. Some adjustment needed of course and will depend on headwind reduction as you descend. The adjustments I’m making to compensate seem to be too much and I’m over correcting .
 
my suggestion...go up in the plane and get your pitch/power settings nailed down for each phase of flight. get those nailed down so u never have to think about them (I'm sure you can find a template of a document with what power settings are recommended for your make/model). you get those power settings finalized so at whatever phase of flight you're in, you just set it and forget it monitor it, with some minor fine tuning if necessary. I only have a coupl'a hours in a seneca and don't recall the power settings. also, definitely don't get low and slow on short final.
 
My opinion: Seneca 2 flyer 4000 in type. My approach setting is 2250 and 22”. Gear out at FAF. aim flying 95 kts down the GS. You also have 10 deg flaps out…so VERY DRAGGY by comparison. IOW you do need to carry just a tad more power with the gear hanging and 10 flaps out…..the gear is very draggy…..Flaps amplify the problem.

But I eschew flaps on the GS. No flaps out until the runway is made…it’s one less thing to do when you lose a fan BEFORE that moment.


CFII-MEI
 
DaveInPA said:
I’m IFR rated but still practicing a lot of approaches and I’m finding that even my most stable approaches I end up getting low and too slow at about 300 ft agl part of the approach. I add power but then I end up coming in fast and have to adjust. So not very stable.

I’m flying a Seneca and at 95 kt on the approach after the final fix with one notch flaps and about 18in on manifold and cruise props. I start getting low and slow before I extend more flaps and put props full forward. Yes I need some power once I add flaps and power but I shouldn’t need to go from 18 to 22” right to compensate for those.

curious if others flying similar performance planes find they need to add power as they descend from the final fix. Some adjustment needed of course and will depend on headwind reduction as you descend. The adjustments I’m making to compensate seem to be too much and I’m over correcting .
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A minor off-topic suggestion. Please make the sentences a bit more readable and grammatically correct so that people don't have to read several times to try and figure out what you are really saying.
 
sarangan said:
A minor off-topic suggestion. Please make the sentences a bit more readable and grammatically correct so that people don't have to read several times to try and figure out what you are really saying.
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I was able to understand the OP’s post without difficulty.
 
105mph (blue line) in the old Seneca has always been my preference, until landing is committed. It sure doesn’t take much effort to slow to 90-95 when you put the flaps in..
 
ja_user said:
105mph (blue line) in the old Seneca has always been my preference, until landing is committed.
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My Seneca II also uses MPH units. Similar to @ja_user, I target Blue Line (105 mph) from glideslope intercept at FAF to short final. On short final (for me about 1 mile from threshold), I slow to 95 mph. My target is 85 mph over the threshold with either 2nd or full flaps and assuming no wind gust adjustments.

This Seneca has Micro Vortex Generators installed so landings with excessive speed can get some serious float down the runway.

I prepare for landing at GS intercept which for me includes extending first notch of flaps, mixture and props full forward, dropping the gear, lights on. If I have not already properly managed power prior to GS intercept than it is going to be difficult if not impossible (for me) to obtain a stabilized approach at that point.
 
I am trying to figure out what "I shouldn’t need to go from 18 to 22” right to compensate" means. I don't think the pilot can change the amount of drag the gear and flaps produce.
 
robin ardoin said:
Ah, I see.
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I was also scratching my head about the grammar/readable comment but now see it’s a typo. I meant “props” and not “power”. But yea it’s not super clear but I was just saying I know I need some extra power when I add more flaps and push the props full forward.
 
dmspilot said:
I am trying to figure out what "I shouldn’t need to go from 18 to 22” right to compensate" means. I don't think the pilot can change the amount of drag the gear and flaps produce.
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Going from 18” of manifold to 22” of manifold seems like a big power change on a stable approach. On short short final around 300 agl I add full flaps and full prop forward. Both add drag of course so I may need more power but that seems like a lot of power. Plus I end up a bit fast once I make that correction.
 
If low and slow
Add more power
Adjust your trim
Focus on your sight picture (aim to land between the start of the runway and the 1000’ markers - your flare will bring you to the 1000’ markers)
 
DaveInPA said:
Going from 18” of manifold to 22” of manifold seems like a big power change on a stable approach. On short short final around 300 agl I add full flaps and full prop forward. Both add drag of course so I may need more power but that seems like a lot of power. Plus I end up a bit fast once I make that correction.
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I push props forward at GS intercept. The full props and gear drop make a big difference. That gives me plenty of time to make small power adjustments. I go full flaps @ ~ 500 AGL.

imho, making changes at 300 AGL like props and flaps would give little to no time to react.

@DaveInPA - Which model Seneca? (I am wondering Turbos or not).
 
Is this on a precision approach??? If so, you should not do anything and you will land about 1000 feet down the runway.
 
In my Seneca I find a big difference in drag between leaving the props at 2500 cruise setting vs advancing to 2800 on short final. So maybe that is part of it? Not saying which is correct just maybe an explanation to why you are having to add that much more power after breaking out. But I also like to fly my approaches on the faster side at 110 or so and find it easy to drop more flaps, bring the throttle back, and slow down to hit the blocks.
 
Man...there is a hell of a lot of thinking going on here. If you need more power...add more power...
 
@jesse - The throttles on my Seneca are sensitive and have delay due to the turbos. If I add power on short final, I am likely to end up coming in too fast. Without a long runway, I can easily float and use up the runway. Better for me to just do a go-around and come back at it with my energy better managed and a stabilized approach.

I have no doubt that more experienced Seneca pilots can salvage approaches which are beyond my skill level.

At my experience and skill, if my approach is not stabilized within 500’ AGL then my safest course of action is a go-around.
 
jesse said:
Man...there is a hell of a lot of thinking going on here.
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Yeah, it strikes me as rather poor thinking too. For starters, blue line is a takeoff reference speed, not for landing. On takeoff, you're going uphill and trying to get over obstacles. Flaps are up or minimal, gear is up, too, raising the optimum reference speed, as is the gross weight. Landing, on the other hand, has you well above the obstacles with a lot of excess power available from gravity just by pointing the nose down and the plane is dirtier, thus reducing the most aerodynamically clean airspeed for reference, as well as being at less weight. When you push the props forward, you should be slow enough that no change occurs in sound level or RPM or drag because the blades are on the low pitch stops already. YMMV, depending on the specific light twin or operating procedure for a specific job, but that's how I remember it.
 
dtuuri said:
When you push the props forward, you should be slow enough that no change occurs in sound level or RPM or drag because the blades are on the low pitch stops already.
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I can tell you 100% this is NOT how my Seneca II operates.
 
Yep, get stable earlier and then monitor, monitor, monitor …. with small adjustments if needed. Cheers.
 
Pitch for airspeed, power for altitude

I know it's a cliche but it really is as simple as that. As soon as people have that click in their heads all of a sudden every landing is a greaser and they're touching down exactly on their touchdown point
 
DaveInPA said:
I was also scratching my head about the grammar/readable comment but now see it’s a typo. I meant “props” and not “power”. But yea it’s not super clear but I was just saying I know I need some extra power when I add more flaps and push the props full forward.
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Funny how some readers thought the post was very clear.
 
sarangan said:
Funny how some readers thought the post was very clear.
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It’s kind of like those visual games where every 3rd letter in a paragraph is misspelled but you’ve been around long enough that you can interpret/understand the intent.
 
Mongoose Aviator said:
I can tell you 100% this is NOT how my Seneca II operates.
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IN what way?

If you reduce throttle until the RPM changes without touching the props, advancing the props will not increase the RPM.

The other reason to do this is the sound of a rapid RPM change is annoying to our airport neighbors, who want to shut us down.
 
Mongoose Aviator said:
I can tell you 100% this is NOT how my Seneca II operates.
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I'm going to go out on a limb here as a CFI and recommend you find a CFI preferably with Seneca or similar experience and get some additional training. The issues you are raising don't sound like the kind of thing somebody on the internet is going to help you fix.
 
dtuuri said:
Yeah, it strikes me as rather poor thinking too. For starters, blue line is a takeoff reference speed, not for landing. On takeoff, you're going uphill and trying to get over obstacles. Flaps are up or minimal, gear is up, too, raising the optimum reference speed, as is the gross weight. Landing, on the other hand, has you well above the obstacles with a lot of excess power available from gravity just by pointing the nose down and the plane is dirtier, thus reducing the most aerodynamically clean airspeed for reference, as well as being at less weight. When you push the props forward, you should be slow enough that no change occurs in sound level or RPM or drag because the blades are on the low pitch stops already. YMMV, depending on the specific light twin or operating procedure for a specific job, but that's how I remember it.
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Not in any twin I've flown.. props definitely rev right up. Also, always over blue line. You lose an engine with a dirty plane and you're not going to speed up to blue line and have train clearance in time!
 
Tantalum said:
Not in any twin I've flown.. props definitely rev right up. Also, always over blue line. You lose an engine with a dirty plane and you're not going to speed up to blue line and have train clearance in time!
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That is my experience and training in high performance twins as well. The only time we are below blue line is a few seconds after takeoff, and the few seconds after landing is assured. In a twin, speed is life, and low, slow, and dirty is no way to go.
 
midwestpa24 said:
That is my experience and training in high performance twins as well. The only time we are below blue line is a few seconds after takeoff, and the few seconds after landing is assured. In a twin, speed is life, and low, slow, and dirty is no way to go.
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Youse guys are victims of the "Blue Line Mania". My condolences. :p
 
Tantalum said:
Not in any twin I've flown.. props definitely rev right up.
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HUH. You are saying you have a power setting of say 2300 RPM. You reduce the throttle until the props drop to 2100 RPM and if you push the props levers forward the RPM increases? That cannot happen unless something is really screwed up.
 
midwestpa24 said:
The issues you are raising don't sound like the kind of thing somebody on the internet is going to help you fix.
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I am not clear which issues you feel that I am raising.

I have suggested to prepare for landing at glide slope intercept and to be on a stabilized approach no later than 500’ AGL.
 
Power plus attitude equals performance. I guess that could be considered to simplistic?

Of course ‘ballpark’ known power settings are good, there will always be variations, weight, atmospheric conditions etc.. Look at comparisons of a 25 kt headwind to zero headwind on final, even with the same VASI picture, higher power setting with the headwind.

I like ‘whatever it takes, added to the mix too.
 
midwestpa24 said:
I've had some pretty highly regarded instructors and examiners that would disagree with you.
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The Blue Line Mania is an inherited disease. Once the gene is passed to enough offspring there remain few healthy specimens for comparison. But you can be saved with logic serum! Here's my remarks again, parsed sentence by sentence for your convenience. Note they are all true — there's nothing for the "highly regarded " to quibble with:
  1. For starters, blue line is a takeoff reference speed, not for landing.
  2. On takeoff, you're going uphill and trying to get over obstacles.
  3. Flaps are up or minimal, gear is up, too, raising the optimum reference speed, as is the gross weight.
  4. Landing, on the other hand, has you well above the obstacles with a lot of excess power available from gravity just by pointing the nose down and the plane is dirtier, thus reducing the most aerodynamically clean airspeed for reference, as well as being at less weight.
  5. When you push the props forward, you should be slow enough that no change occurs in sound level or RPM or drag because the blades are on the low pitch stops already.
 
Mongoose Aviator said:
Nothing wrong with having your own opinion.
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Not just MY own, have you read the Maneuver Guide I linked to? Seems like there's a lot there for an aircraft owner to consider that would help lower your operating costs in addition to improving passenger comfort.
 
dtuuri said:
The Blue Line Mania is an inherited disease. Once the gene is passed to enough offspring there remain few healthy specimens for comparison.
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Mongoose Aviator said:
Nothing wrong with having your own opinion.
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I tend to discount personal opinions from those who sound a bit off the beaten track. However, again, I respect your right to your own opinion.
 
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