Landing with speed brakes deployed

[A64Pilot]

I just figured out how to link to a search, by accident.

Will that link work for everyone or just Apple things?

[Hank]

2 minutes ago, ArtVandelay said:

Yes, when landing at low power and low speeds, but if you’re descending on approach at high speeds I think is a different story.

Push the prop all the way forward if you're a little fast. I can hear and feel the deceleration in my little C with Hartzell 3-blade. Usually around pattern entry, much later there's not enough MP for it to make a difference. 

[donkaye]

49 minutes ago, Brandt said:

OK I’ll play. Why in the world would I want to add any stress to my prop governor or engine to serve as a brake when I have a purpose built device that adds to drag and allows me to keep my cht’s up in a 1000 fpm descent? And how is a prop a “more efficient” source of drag?

Adding either speed brakes or reducing the prop rpm (remember 300 rpm is approximately 10% power) when it's not necessary is inefficient.  I want to go as fast as I can for as long as I can and reduce the speed in such a manner that the least amount of drag is added over time during the slow down.  So my slow down method is, at the appropriate time from my experience of when to do it, I'll bring the MP back first to 25" then to 20" while watching the maximum cooling cylinder, then reduce the prop rpm from 2400 slowly to 2000, then bring the MP down to 15".  At that point I'll be below 140 and put the gear down.  Below 110 I'll add approach flaps to get me down to 90, add full flaps when turning base, slow to 80; turn final and slow to whatever approach speed is appropriate of the landing weight. I believe this method uses the least amount of fuel and provides the least amount of drag over time for a smooth transition to a landing.

Drag is drag.  A prop isn't any more efficient than the speed brakes.  It's just how and when you use them.

[toomany]

wait a minute, Isabel Goyer isn't Roberts daughter? Haa! no wonder she looks just like him.


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[Brandt]

23 minutes ago, donkaye said:

Adding either speed brakes or reducing the prop rpm (remember 300 rpm is approximately 10% power) when it's not necessary is inefficient.  I want to go as fast as I can for as long as I can and reduce the speed in such a manner that the least amount of drag is added over time during the slow down.  So my slow down method is, at the appropriate time from my experience of when to do it, I'll bring the MP back first to 25" then to 20" while watching the maximum cooling cylinder, then reduce the prop rpm from 2400 slowly to 2000, then bring the MP down to 15".  At that point I'll be below 140 and put the gear down.  Below 110 I'll add approach flaps to get me down to 90, add full flaps when turning base, slow to 80; turn final and slow to whatever approach speed is appropriate of the landing weight. I believe this method uses the least amount of fuel and provides the least amount of drag over time for a smooth transition to a landing.

Drag is drag.  A prop isn't any more efficient than the speed brakes.  It's just how and when you use them.

1.  RE inefficiency. So when do you believe speed brakes are necessary?

2. If you can pull back the throttle to 20” and descend at 1100 fpm from 17,000 to 1,500 without decreasing cylinder temp below the green then you are a wizard.

3. Putting the gear down before it’s necessary is inefficient and no different than speed brakes.

4. Using the least amount of fuel is far less important to me than engine and prop governor stress, so I guess it depends on what you consider important.  

 

 

[kortopates]

1.  RE inefficiency. So when do you believe speed brakes are necessary?
2. If you can pull back the throttle to 20” and descend at 1100 fpm from 17,000 to 1,500 without decreasing cylinder temp below the green then you are a wizard.
3. Putting the gear down before it’s necessary is inefficient and no different than speed brakes.
4. Using the least amount of fuel is far less important to me than engine and prop governor stress, so I guess it depends on what you consider important.  
 
 

Needing to come down at 1100 fpm is why you’re needing your speed brakes.
Hopefully that should be very rare and only when the controller insists on keeping you high.
My standard IFR descent is 500 FPM and when i can get a descent at pilot discretion it’s only 2-300 fpm - then i am truly taking advantage of the energy from altitude without adding inefficient drag while descending at cruise power. (At 500 fpm power does come back.)

Frequently though i need to be assertive with requesting a descent to avoid getting held high. But very rarely i will use the brakes when traffic has the controller keeping me high - but it’s certainly not the norm. My typical descents will frequently start 100+ miles from the destination. Even in busy SOCAL airspace i more than not get what i ask for.


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[Brandt]

14 minutes ago, kortopates said:

Needing to come down at 1100 fpm is why you’re needing your speed brakes.
Hopefully that should be very rare and only when the controller insists on keeping you high.
My standard IFR descent is 500 FPM and when i can get a descent at pilot discretion it’s only 2-300 fpm - then i am truly taking advantage of the energy from altitude without adding inefficient drag while descending at cruise power. (At 500 fpm power does come back.)

Frequently though i need to be assertive with requesting a descent to avoid getting held high. But very rarely i will use the brakes when traffic has the controller keeping me high - but it’s certainly not the norm. My typical descents will frequently start 100+ miles from the destination. Even in busy SOCAL airspace i more than not get what i ask for.


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I agree with everything you posted.  In this case it a combo of the handover from Washington Center, IAD traffic and the mountains.  I just find the idea that preferring using the prop or gear as a drag device over speed brakes when needed is without merit.

[donkaye]

4 hours ago, Brandt said:

2. If you can pull back the throttle to 20” and descend at 1100 fpm from 17,000 to 1,500 without decreasing cylinder temp below the green then you are a wizard.

I made a mistake.  By now I should have learned, you can't flight instruct on the internet.  There are too many variables that influence a particular flight.  I knew I shouldn't have answered your last posting, but fell for it anyway.  No more.  You didn't get how I do it at all.  Reduce the throttle to 20" at 17,000 feet 50 miles out?  No way.  I don't reduce the power at all.  Just lower the nose to 500 ft/min, pick up speed that I lost in the climb, and wait to do any other configuration changes until the appropriate time on final.  Coming into San Jose in instrument conditions once on final I fly 160 to 170 until 5 miles from touchdown, then use what I have at my disposal to slow the plane to 75 knots on touchdown.  Take off 1" per minute and ATC will have you flying in circles until all the jets behind you come in.  Fly your airplane the way you want to.  I'm on my 3rd engine and with 31 years of experience with the Bravos, I'll be teaching my students the best way they should be flown and all the other models from that experience.

[Brandt]

4 hours ago, donkaye said:

I made a mistake.  By now I should have learned, you can't flight instruct on the internet.  There are too many variables that influence a particular flight.  I knew I shouldn't have answered your last posting, but fell for it anyway.  No more.  You didn't get how I do it at all.  Reduce the throttle to 20" at 17,000 feet 50 miles out?  No way.  I don't reduce the power at all.  Just lower the nose to 500 ft/min, pick up speed that I lost in the climb, and wait to do any other configuration changes until the appropriate time on final.  Coming into San Jose in instrument conditions once on final I fly 160 to 170 until 5 miles from touchdown, then use what I have at my disposal to slow the plane to 75 knots on touchdown.  Take off 1" per minute and ATC will have you flying in circles until all the jets behind you come in.  Fly your airplane the way you want to.  I'm on my 3rd engine and with 31 years of experience with the Bravos, I'll be teaching my students the best way they should be flown and all the other models from that experience.

Yes, you clearly fell for my dastardly plan of asking you legitimate questions.

And yes, I do get how you do it.  While I also prefer a 500 fpm descent with little to no power reduction, that was not possible under the circumstances I described. It is clearly inefficient to fly fast only to throw out drag devices in a slam dunk descent in the end.  But you stated that using the prop as a drag device is preferable to speed brakes, which also was not practical in the scenario I described.   I told you we disagreed. Your response was smug.

But hey, I’ve been wrong before.  I’m not only willing to factually defend my views but I’m also willing to admit when I am wrong if presented with relevant facts.  So I posed some questions. It wasn’t an evil plan, it was an attempt at dialogue, even if spirited. I am not angry, just disappointed that you ignored most of them.  

[Tx_Aggie]

Speed brakes help me to be a non-issue with controllers when I’m “in line” with the jet traffic on an approach. I obviously use them when slam dunked also. 
 

I don’t see them as a crutch but ‘part of the tool bag’ as others have stated. However if I deploy them on final approach I don’t retract them until after touchdown. I think they smooth out the landing really. 
 

folks in other planes are not flying airframes as smooth as ours so there’s really no equal/fair comparison in my opinion.  Don’t be ashamed to use them. 

[Danb]

6 hours ago, donkaye said:

I made a mistake.  By now I should have learned, you can't flight instruct on the internet.  There are too many variables that influence a particular flight.  I knew I shouldn't have answered your last posting, but fell for it anyway.  No more.  You didn't get how I do it at all.  Reduce the throttle to 20" at 17,000 feet 50 miles out?  No way.  I don't reduce the power at all.  Just lower the nose to 500 ft/min, pick up speed that I lost in the climb, and wait to do any other configuration changes until the appropriate time on final.  Coming into San Jose in instrument conditions once on final I fly 160 to 170 until 5 miles from touchdown, then use what I have at my disposal to slow the plane to 75 knots on touchdown.  Take off 1" per minute and ATC will have you flying in circles until all the jets behind you come in.  Fly your airplane the way you want to.  I'm on my 3rd engine and with 31 years of experience with the Bravos, I'll be teaching my students the best way they should be flown and all the other models from that experience.

I recently read your article on speed brakes use, which was very helpful to me even a 4000 hour 35 years flyin Moonies, I’d suggest you all read his article which is quite informative 

D

[Pinecone]

12 hours ago, donkaye said:

That's a lot of unnecessary work.  Both Lycoming and Continental both permit a 50°/min cooling rate on a cylinder.  At cruise a cylinder will conservatively run at 350° at cruise and 250° at idle.  So in a worst case scenario (of course you wouldn't go below 15"MP in descent) that would take 2 minutes.  So what instructor recommended 1"/minute?

Another OWT that presists.

[toomany]

i usually get held high until the last min coming from the south over iad and bwi or from the west if mdt is busy. i dont throttle back until the airspeed goes yellow and i normally descend at 1000fpm or more. i'll use speed brakes if i need them but have learned to fly the bravo w/o them for the most part. i dont subscribe to the "cool the engine super slowly" but rather am comfortable cooling it down at about half the rate, or less, than it heats up in climb out - usually 2" a min, or less, when i'm at 5-10 miles out. i usually enter the pattern around 165-175 and slow w power reduction and gear - i dont use flaps until final and cross the fence around 80. i will say that you have to have the wind in your face in the mooney or it seems to float forever.
im not saying this is the best way to fly and really dont care if anyone agrees with it - i just learned from a very seasoned pilot and my own experience that its easier to lose energy (ie fast and high) than it is to get it back. i try to make every approach one i could do from 5 miles out if the fan stopped - because it has and i did.


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[Fly Boomer]

11 hours ago, donkaye said:

Adding either speed brakes or reducing the prop rpm (remember 300 rpm is approximately 10% power) when it's not necessary is inefficient.  I want to go as fast as I can for as long as I can and reduce the speed in such a manner that the least amount of drag is added over time during the slow down.  So my slow down method is, at the appropriate time from my experience of when to do it, I'll bring the MP back first to 25" then to 20" while watching the maximum cooling cylinder, then reduce the prop rpm from 2400 slowly to 2000, then bring the MP down to 15".  At that point I'll be below 140 and put the gear down.  Below 110 I'll add approach flaps to get me down to 90, add full flaps when turning base, slow to 80; turn final and slow to whatever approach speed is appropriate of the landing weight. I believe this method uses the least amount of fuel and provides the least amount of drag over time for a smooth transition to a landing.

Drag is drag.  A prop isn't any more efficient than the speed brakes.  It's just how and when you use them.

When and where do you get concerned about the prop driving the engine?

[dkkim73]

15 minutes ago, toomany said:

i just learned from a very seasoned pilot and my own experience that its easier to lose energy (ie fast and high) than it is to get it back. i try to make every approach one i could do from 5 miles out if the fan stopped - because it has and i did.
 

That's a new and orthogonal point. I can see the idea, keep speed instead of height for contingencies. Kind of like some single jets accelerating hard on takeoff to preserve options. 

Sounds fast but also that you don't have a problem showing down... A lot of folks warn me these are hard to slow down. 

Thanks for the thought provoking point! 

[affricate]

On 1/5/2024 at 1:41 PM, Fly Boomer said:

I like this plan.  I'm still learning how to keep my size 14 clodhoppers off the brakes.

Same, same 

[Schllc]

1 hour ago, dkkim73 said:

That's a new and orthogonal point. I can see the idea, keep speed instead of height for contingencies. Kind of like some single jets accelerating hard on takeoff to preserve options. 

Sounds fast but also that you don't have a problem showing down... A lot of folks warn me these are hard to slow down. 

Thanks for the thought provoking point! 

I think a lot of times it is described as hard to slow down, and I have been guilty of that in the past for sure. 
But perhaps a better way to describe this would be that losing airspeed in a descent in a Mooney will not likely happen without intentional acts, it must be intentional because it is a slippery airframe. The singles I have flown are a diamond, cirrus, Cessna, pipers, as well as some warbirds and none of them gather speed in a descent the way a Mooney does. 
If you are at 17k and directed to descend to 5,000 ft in 10 miles, it’s just about impossible to do without picking up speed.
Low drag has its own characteristics, and the mooney’s flap speeds are so low, it’s nice to have speed brakes. 

[Hank]

1 hour ago, Schllc said:

I think a lot of times it is described as hard to slow down, and I have been guilty of that in the past for sure. 
But perhaps a better way to describe this would be that losing airspeed in a descent in a Mooney will not likely happen without intentional acts, it must be intentional because it is a slippery airframe. The singles I have flown are a diamond, cirrus, Cessna, pipers, as well as some warbirds and none of them gather speed in a descent the way a Mooney does. 
If you are at 17k and directed to descend to 5,000 ft in 10 miles, it’s just about impossible to do without picking up speed.

In a simple 500fpm descent, I generally pick up ~25mph indicated, putting me just below the yellow arc. 1000fpm puts me just above the midpoint of the yellow arc.

[Brandt]

4 minutes ago, Hank said:

In a simple 500fpm descent, I generally pick up ~25mph indicated, putting me just below the yellow arc. 1000fpm puts me just above the midpoint of the yellow arc.

1000 fpm clean puts me at Mach .82

[dkkim73]

27 minutes ago, Brandt said:

1000 fpm clean puts me at Mach .82

Alright, I couldn't resist. .82 mach at 17K ISA works out to 405KCAS...

Man, I should've held out for the Ultra...

[Brandt]

8 minutes ago, dkkim73 said:

Alright, I couldn't resist. .82 mach at 17K ISA works out to 405KCAS...

Man, I should've held out for the Ultra...

Damn new math. Never want to exaggerate.  I meant .81. 

[PT20J]

Whether you agree with Don @donkaye or not, I've found that his techniques always come after experimentation to determine what he considers the best or most efficient way to achieve his aim, and he can explain why he considers his technique superior.

The speed brakes increase drag and thus will reduce speed if you hold altitude or increase descent rate if you hold speed constant. If you can't get the speed or descent you need in the distance available, they are a great tool. You have other tools: reducing power, lowering the landing gear, changing the flight path. 

I cannot think of a good reason to land a  Mooney with the speed brakes deployed. Float is caused by excessive speed, not too little drag. In a gusty crosswind, you what less drag, not more, in case you encounter wind shear.

[Pinecone]

2 hours ago, Schllc said:

If you are at 17k and directed to descend to 5,000 ft in 10 miles, it’s just about impossible to do without picking up speed.
Low drag has its own characteristics, and the mooney’s flap speeds are so low, it’s nice to have speed brakes. 

I had this going to Mooney Summit.  They kept me high then wanted me at 5,000 (from 17,000) in 12 minutes or less.

Pushed the nose over and let the speed build, then they amended my clearance at or below 5,000 by a certain point. I guess my increased speed threw them off.

 

[Hank]

7 minutes ago, Pinecone said:

I had this going to Mooney Summit.  They kept me high then wanted me at 5,000 (from 17,000) in 12 minutes or less.

Pushed the nose over and let the speed build, then they amended my clearance at or below 5,000 by a certain point. I guess my increased speed threw them off.

 

Tower turned me downwind at EPC about 6 nm out, then asked me to expedite my approach. Raised flaps and gear, advanced throttle and slowed down as I turned base, dropped gear on final, turned off a the 2nd exit, taxied forever to the FBO, and was halfway through unloading bags when the jet they were worried about became visible to me. Tower asked, I complied.   You think they'd learn, there were 40+ Mooneys there that weekend.

[Will.iam]

I find most towers that want me to keep my speed up for jet traffic also have a runway that’s at least triple the landing distance i require (with some being up to 6 times) to land. I can still be gear up over the threshold at cruise speed and still slow down get the gear down and land as long as tower approves a long landing which gets me to one of the high speed turn offs sooner. Good time to do a no flap landing as well.