Need for Speed brakes

[carusoam]

Ross has been hanging out in the O club...  

-a-

[Shadrach]

Just now, carusoam said:

Ross has been hanging out in the O club...  

-a-

Maybe someday I'll be a member!

[Shadrach]

15 hours ago, peevee said:

Stock 231 I didn't use them much. Now I consider them necessary.

Why?

[Shadrach]

13 hours ago, Mike261 said:

ok...so not to be contrarian, well yes to be contrarian.

they do increase cumulative airspeed...stay fast until closer to your destination and then deploy them and throw the nose over...go down but don't slow down, and no shock cooling if you ascribe to that sort

 of thing.

for efficiency see above, reclaim the energy invested in the climb at a higher airspeed.

mike

 

Yea see, that's the ticket...adding drag inducing devices to your approach profile is more efficient because it helps reclaim the energy used for climb in the decent see...sure...that's the ticket...

There is a principal called the conservation of energy that contradicts what you're suggesting. You have a fixed amount of potential energy at the TOD, any parasitic drag introduced during descent diverts that energy away from the work of getting you to your destination.

That's like putting bigger disc brakes on your car so that you can hold your speed until just before the intersection and brake hard. It is not efficient at all...

Excellent demonstration of how humans can articulate a rationalization that is contrary to well understood principals of physics.  

[ArtVandelay]

I use them occasionally just to exercise them, would never buy them, helps for IFR, I've practiced using them on short field steep approaches.

[Greg_D]

17 hours ago, peevee said:

3 or 4k a minute is really no big deal for a jet. 2k or 2.5k a minute seems pretty standard... Unless you're that dude doing 500fpm or less for no reason and you have an animal on your tail.

FPM is a descent rate.  That's quite a bit different than a crossing restriction.

[peevee]

18 minutes ago, Greg_D said:

FPM is a descent rate.  That's quite a bit different than a crossing restriction.

Oh, I see. Crossing restrictions have absolutely nothing to do with the descent rate required to meet said restriction. Who knew.

This place is becoming P of A at an alarming rate.

[gsengle]

That's my line lol


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[Shadrach]

6 minutes ago, peevee said:

Oh, I see. Crossing restrictions have absolutely nothing to do with the descent rate required to meet said restriction. Who knew.

This place is becoming P of A at an alarming rate.

Wouldn't descent gradient be the key factor?

I am familiar with the phrase "P of A", but not in the context with which you're using it...

[Greg_D]

6 minutes ago, peevee said:

Oh, I see. Crossing restrictions have absolutely nothing to do with the descent rate required to meet said restriction. Who knew.

Jesus Christ you people just want to argue about everything around here.

I was just curious what kind of descent crossing restriction that a jet would be given and could accept that a Mooney wouldn't be able to handle.  Yeah, the jet's descent rate would be 3 times higher, but so would it's groundspeed.  Think about feet per nautical mile in the descent.

If ATC asked me to descend at 3000 FPM in my Mooney, I'd just tell them I was unable.  I'd give the same response if they gave a crossing restriction that required that descent rate in my Mooney.  And I'd tell them the same thing if they asked for a 9000 FPM descent rate or a crossing restriction that required that in the jet I fly for work.

[M20F]

The only time you have too much gas is when you are on fire.  Thus Jose's tanks and speed brakes are on my upgrade list. Flying more on the East Coast you get a lot of slam dunks (always into KBDL), if I want to get down fast from the FL's for hypoxia/fire/etc. they would be great, if you slip with low fuel in the tanks it will cut the motor.  

I don't need an auto-pilot, GPS, and a bunch of other things.  Those things though sure are nice and speedbrakes are one of those things where when you want/need them they are great to have.  

[Shadrach]

Just now, M20F said:

The only time you have too much gas is when you are on fire.  Thus Jose's tanks and speed brakes are on my upgrade list. Flying more on the East Coast you get a lot of slam dunks (always into KBDL), if I want to get down fast from the FL's for hypoxia/fire/etc. they would be great, if you slip with low fuel in the tanks it will cut the motor.  

I don't need an auto-pilot, GPS, and a bunch of other things.  Those things though sure are nice and speedbrakes are one of those things where when you want/need them they are great to have.  

Depends on which tank or the direction of the slip. In a forward slip the trailing wing and higher wing would likely concentrate fuel around the pick up. 

[M20F]

Just now, Shadrach said:

Depends on which tank or the direction of the slip. In a forward slip the trailing wing and higher wing would likely concentrate fuel around the pick up. 

One would think but my experience has been otherwise. 

[Shadrach]

Just now, M20F said:

One would think but my experience has been otherwise. 

Interesting.  We both know where the pickups are located.  Having the engine sputter while cross controlled near the ground would scare S out of M (since we're using letters instead of the full word).

[75_M20F]

My 75 F Model came with them installed when I bought it. I think the speedbrakes are great and it gives one more flexibility for sure. They are also helpful on gusty days for landing. They allow you to fly a steeper approach without an increase in speed which is very helpful in many circumstances. 

I recommend them as have been flying with them for 15 years now. 

 

Edited April 8, 2017 by Mooney_Mike

[M20F]

Just now, Shadrach said:

Interesting.  We both know where the pickups are located.  Having the engine sputter while cross controlled near the ground would scare S out of M (since we're using letters instead of the full word).

Well when you are looking to kill altitude it really isn't a worry too much about crashing.  I don't like it from the cylinders getting cold though.  It is hard even slipping to get down fast without shock cooling.  I know that is a popular debate topic but I prefer to keep my cylinders right around 350-360 consistently (I run ROP). 

[Shadrach]

40 minutes ago, M20F said:

Well when you are looking to kill altitude it really isn't a worry too much about crashing.  I don't like it from the cylinders getting cold though.  It is hard even slipping to get down fast without shock cooling.  I know that is a popular debate topic but I prefer to keep my cylinders right around 350-360 consistently (I run ROP). 

My cylinders rarely see much I've 320 except in climb and even then rarely 350. Hard to shock cool something that's not hot.

[Greg_D]

2 hours ago, M20F said:

Well when you are looking to kill altitude it really isn't a worry too much about crashing.  I don't like it from the cylinders getting cold though.  It is hard even slipping to get down fast without shock cooling.  I know that is a popular debate topic but I prefer to keep my cylinders right around 350-360 consistently (I run ROP). 

Ah, shock cooling.  Are you equally as concerned about "shock heating" on the takeoff roll?

Edited April 9, 2017 by Greg_D

[M20F]

18 minutes ago, Greg_D said:

Ah, shock cooling.  Are you equally as concerned about "shock heating" on the takeoff roll?

Yes.  A stable increase and a stable decrease. 

[75_M20F]

Hell, if you want speedbrakes install them. 

Don't expect a great deal of useful information coming out of half the folks on here.

There is a troll factor on here as with any discussion board.

 

 

Edited April 9, 2017 by Mooney_Mike

[gsxrpilot]

As George Braly says, their data shows that in a dive out of the flight levels at idea power, the only way to shock cool the engine would be to continue the dive all the way into Lake Michigan. 

[gsxrpilot]

BTW... I was in the "no speed brakes" camp as long as I flew an M20C. But now that I have a 252, I gotta say, I love my speed brakes. In fact, I'd have loved to have them in the C, now that I've gotten to know them.

[Greg_D]

13 minutes ago, M20F said:

Yes.  A stable increase and a stable decrease. 

So, how quickly do you advance the throttle on takeoff when going from near idle to full power?  How would reducing the throttle at the same rate and by the same magnitude while at cruise power and altitude be any different?

[gsengle]

Hell, if you want speedbrakes install them. 
Don't expect a great deal of useful information coming out of half the folks on here.
There is a troll factor on here as with any discussion board.
 
 

Disagree. The troll factor has generally been low on mooneyspace. Hopefully it's not climbing.


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[jetdriven]

In a J model you can approach the departure numbers on downwind at 196 knots groundspeed and land on the numbers without abusing the airplane.  That's without speedbrakes. Here's a flight the other day.