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Bottom speed brakes


Yetti

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4 hours ago, Yetti said:

For those of you who think you need speed brakes, just remember Al provided you with some on the bottom of the plane.   If you can't slow down to land, your gear may not be down.

 

As I recall, the DC-7 had a speed brake handle that dropped the main gear.

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I admit it’s tough to do this in practice, but here’s a rebuttal to the above “complaints” about low gear speeds.  Said with complete respect for what you said...

The point of speed brakes isn’t to get rid of speed, but energy.  Both kinetic (speed) and potential (altitude).  Find yourself too high in a decent?  Try slowing down, getting gear, full flaps down and flying minimum speed... say 75mph at idle. Yes, initially you level off, but then your decent gradient is very steep.  Like scary steep if you’re low.

My poh doesn’t have an emergency decent profile, but most of them have you slow to gear speed, drop gear and then fly just below gear speed to descend rapidly (which will put you at lower altitude faster, but at a higher airspeed).

Edited by Ragsf15e
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1 hour ago, Jerry 5TJ said:

The short body planes I owned have a max gear speed of 120 mph, so if I needed to slow down I was usually going too fast to drop the gear.  

I've only had speed trouble twice:  my first curving GPS approach into KECP for a Mooney Summit, in actual [I could stay on slope but not on speed, or on speed but kept drifting high], and once going into RDU when Tower sent me almost 20nm out before turning me final at 7500 msl. Go rid of altitude with Takeoff Flaps, but had a hard time staying inside the white stripe [125 mph] and drifting high. Caught the gear up at KECP after breaking out, and caught it up at Raleigh about 1/2nm from the numbers. Check, check and recheck, but I don't do enough straight-ins of any length [much less 20nm!] to have the locations down other than when the ground starts getting close.

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6 minutes ago, Ragsf15e said:

I admit it’s tough to do this in practice, but here’s a rebuttal to the above “complaints” about low gear speeds.  Said with complete respect for what you said...

The point of speed brakes isn’t to get rid of speed, but energy.  Both kinetic (speed) and potential (altitude).  Find yourself too high in a decent?  Try slowing down, getting gear, full flaps down and flying minimum speed... say 75mph at idle. Yes, initially you level off, but then your decent gradient is very steep.  Like scary steep if you’re low.

My poh doesn’t have an emergency decent profile, but most of them have you slow to gear speed, drop gear and then fly just below gear speed to descend rapidly (which will put you at lower altitude faster, but at a higher airspeed).

my landings are all about energy management.  Gear and flaps are used to best manage the energy.

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8 minutes ago, Yetti said:

my landings are all about energy management.  Gear and flaps are used to best manage the energy.

Definitely.

One more thing I should have mentioned about speed brakes that they can do but the gear maybe not... reduce energy quickly even with the power still above idle.  Nice to not just rip it to idle to slow to gear speed.

All this being said, I don’t have speed brakes on my F. I plan for full power descents at 500fpm and speed well into the yellow (smooth air).  I can usually fly that right down to pattern altitude about 3 miles out, pull to 15”mp and drop the gear at 120mph abeam the runway. Usually.  So I don’t see the need for speed brakes, but then I don’t have a J or other slick model.

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Speed brakes in the O, are good for deployment at or below Vne...

But that ruins my explanation to the fine officer...  it’s not my fault, I was going too fast to be able to slow down....   :)

If above Vne... pulling the throttle out and pushing the prop in.. are pretty effective.... at slowing down when needed...

PP thoughts only not a CFI...

Best regards,

-a-

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22 minutes ago, Yetti said:

my landings are all about energy management.  Gear and flaps are used to best manage the energy.

The non-GPS approach into SMO had you with gear and flaps out in a full slip on the last step of the approach in the clouds. Something like 1,200 feet to lose in under a mile. No planning makes that easy. Speed brakes do though.

 

-Robert

Edited by RobertGary1
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When traveling 1.5 nm per minute... 90kias...

1.5 X 1200 = 1800fpm...

hard to slow down while descending that hard...

Gear down, brakes out, throttle out, prop forwards is pretty good at burning altitude at Vle....

The VSI will be pegged with the actual descent rate near 5kfpm...?

This comes from emergency descent procedures using speed brakes as discussed in the POH for the LB...

Not a strong memory of mine... if I had a strong memory...

Best regards,

-a-

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2 hours ago, carusoam said:

When traveling 1.5 nm per minute... 90kias...

1.5 X 1200 = 1800fpm...

hard to slow down while descending that hard...

Gear down, brakes out, throttle out, prop forwards is pretty good at burning altitude at Vle....

The VSI will be pegged with the actual descent rate near 5kfpm...?

This comes from emergency descent procedures using speed brakes as discussed in the POH for the LB...

Not a strong memory of mine... if I had a strong memory...

Best regards,

-a-

The best I've seen in my C is 2000-2500 fpm, Takeoff flaps, 45° left-banking spiral descent. Don't recall gear position, probably up due to speed. No speed brakes . . . .

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Is the max gear speed higher for younger C models? I think this was discussed here recently. When was the last model year the manual gear was sold? Did those have higher gear speeds?


Sent from my iPhone using Tapatalk

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1 minute ago, tigers2007 said:

Is the max gear speed higher for younger C models? I think this was discussed here recently. When was the last model year the manual gear was sold? Did those have higher gear speeds?


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I"m not sure the last year of manual but I know some F's actually have manual. I think there was a couple of decades of overlap of both electric and manual.

 

-Robert

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4 hours ago, Ragsf15e said:

My poh doesn’t have an emergency decent profile, but most of them have you slow to gear speed, drop gear and then fly just below gear speed to descend rapidly (which will put you at lower altitude faster, but at a higher airspeed).

My J POH notes the above procedure for emergency descents, but also makes the comment that you get an equivalent descent rate at 195 KIAS, gear up, cowl flaps closed.

That would be exciting :) 

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18 minutes ago, jaylw314 said:

My J POH notes the above procedure for emergency descents, but also makes the comment that you get an equivalent descent rate at 195 KIAS, gear up, cowl flaps closed.

That would be exciting :) 

If its a real emergency I don't think you'd cause structural damage by putting the gear down. Might tear off gear doors or overwork your motor but might be better than whatever else is happening. If I'm on fire and want to get down I don't think I'm wasting time slowing down. Dump the nose and drop the gear and worry about the POH later.

-Robert

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Definitely.
One more thing I should have mentioned about speed brakes that they can do but the gear maybe not... reduce energy quickly even with the power still above idle.  Nice to not just rip it to idle to slow to gear speed.
All this being said, I don’t have speed brakes on my F. I plan for full power descents at 500fpm and speed well into the yellow (smooth air).  I can usually fly that right down to pattern altitude about 3 miles out, pull to 15”mp and drop the gear at 120mph abeam the runway. Usually.  So I don’t see the need for speed brakes, but then I don’t have a J or other slick model.

If you’re flying IFR:
You can’t control your descents.
You don’t want to do any of the normal tricks like pull throttle and climb to slow to gear speed, or go into a slip in IMC (at least I wouldn’t).
You’re straight in, so no extra pattern time to lose energy.
Because of limitations (for most us) with MP & RPM, you can only pull the throttle so much.

Yea, VFR you probably don’t need them.


Tom
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1 hour ago, RobertGary1 said:

I"m not sure the last year of manual but I know some F's actually have manual. I think there was a couple of decades of overlap of both electric and manual.

 

-Robert

Last year of the manual gear was 1968.  Gear speed = 104 kts.

John Breda

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19 minutes ago, ArtVandelay said:


You don’t want to do any of the normal tricks like pull throttle and climb to slow to gear speed, or go into a slip in IMC (at least I wouldn’t).
 

Why couldn't you pull throttle and climb to slow while IFR?  While you're enroute or transitioning into the approach, ATC may ask you to hold a specific altitude, sure.  Most approaches, though, just have a minimum altitude for each segment, not a maximum altitude restriction, and you really should be cleared for the approach before you hit the IAF. 

OK, maybe you don't want to do that while your on the ILS glideslope, but you're expected to use the segment before crossing the GS to slow down

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2 hours ago, tigers2007 said:

Is the max gear speed higher for younger C models? I think this was discussed here recently. When was the last model year the manual gear was sold? Did those have higher gear speeds?


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I think the gear speed on all the Cs is 120mph right?  The J bar disappeared in 1969.  The mechanical gear on these planes is very stout and can take deployment much higher speeds. Not sure what the electrical actuators can handle. The gear doors may be susceptible to damage, but the time my C's J bar unlatched accidentally at >150mph, they escaped unscathed as well.  The violent swing of the J bar does get your attention.  In a real life emergency descent, I would not hesitate to deploy the gear and also descend at well above  Vle/lo.

Edited by DXB
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27 minutes ago, DXB said:

I think the gear speed on all the Cs is 120mph right?  The J bar disappeared in 1969.  . . . Not sure what the electrical actuators can handle. 

Electric Cs have 120mph Vg also, but higher Flap speed than the hydraulic ones (125 mph).

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In short body Mooney with 120 mph gear limit the tricky time for me was in IMC approaches when ATC didn’t provide any “level off interval” where I could slow down enough.  Seems most common on a non-precision approach.  

Sure,  @DXB in a true emergency I’d drop the gear at any speed.  

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35 minutes ago, Hank said:

Electric Cs have 120mph Vg also, but higher Flap speed than the hydraulic ones (125 mph).

Actually the higher flap speed appeared in 1968, when hydraulic flaps were still standard.   So mine has the 125mph Vfe.

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