250 Below 10

[westwind driver]

Interesting ASRS report here:

http://asrs.arc.nasa.gov/docs/cb/cb_249.pdf

 

[Singlecoil]

Where do you get your numbers?

MD80 series (reference the -83 here) If you look at the charts, assuming MGTOW of 149,500#, using the 150,000# chart, 33 degress C at sea level, Altimeter 30.06, dry runway, no wind, Flaps 15

Here are your speeds:

V1: 143
VR: 147
V2: 154
Flap Retract: 169
Slat Retract: 202
Final Segment: 223
Clean Maneuver: 252

The airplane will fly just fine cleaned up at 250 and climb no problem. Once you hit 10k push the nose over for a 300-320kt climb.

I don't think the Maddog is like a true heavy that has to have the slats out up till around 280. Comming out of Charlotte, ATC has to cancel a 280 speed restriction.

As for the 250/10k rule, well... Been into North Dakota airports and had controllers tell us no speed restriction below 10,000, and this was on the descent. Ultimately, if this question went to court, I would think the PIC is required to adhere to FAR/AIM regardless of what ATC tells you. Just MHO.

I get my numbers from memory from over 4 years ago, so I'm not surprised if they aren't super accurate. I do remember that the clean maneuver speed was sometimes over 250 knots, so section d of the FAR's applied. The point is, you are allowed to fly 252 knots in your example.

 

[westwind driver]

I get my numbers from memory from over 4 years ago, so I'm not surprised if they aren't super accurate. I do remember that the clean maneuver speed was sometimes over 250 knots, so section d of the FAR's applied. The point is, you are allowed to fly 252 knots in your example.

Pretty good memory to be that close Of course you would probably agree most aircraft of the MD80 size are pretty close in numbers?

I went back a read my post, and sorry if it sounded a$$holish. Didn't mean to come across like that. I was more though questioning if slat retract speed is say, 200 kts, and clean maneuver speed is say 250 kts, what is there to say that you couldn't fly at 230 kts. Not that you would, but can you?

I have performance charts for several aircraft I do not fly, and have never flown. So my experience with this is somewhat new.

If someone could explain why pilots want to fly at clean maneuvering speed (other than having to keep slats/flaps extended) maybe I could get a better understanding.

My experience has been limited to V2+20 flaps up, climb at 250/.65

Does any of this have to do with say exceeding 15 degrees bank flaps/slats retracted? Because of VSL?

Good discussion here I think.

 

[stupidpilot]

CMS(Clean Maneuvering Speed) allows the aircraft to meet the final segment climb gradient. If you lose an engine the extra drag could really hurt your performance and get you in a whole lot of trouble.

 

[milky]

As a military pointy nose pilot, you are expected to operate at a speed that is reasonable for maneuverability and visibility over the nose. For the Hornet, 300-350 knots is defensible. It is true that we cannot be violated by the FAA. Only by the CNO.

 

[Singlecoil]

Pretty good memory to be that close Of course you would probably agree most aircraft of the MD80 size are pretty close in numbers?

I went back a read my post, and sorry if it sounded a$$holish. Didn't mean to come across like that. I was more though questioning if slat retract speed is say, 200 kts, and clean maneuver speed is say 250 kts, what is there to say that you couldn't fly at 230 kts. Not that you would, but can you?

I have performance charts for several aircraft I do not fly, and have never flown. So my experience with this is somewhat new.

If someone could explain why pilots want to fly at clean maneuvering speed (other than having to keep slats/flaps extended) maybe I could get a better understanding.

My experience has been limited to V2+20 flaps up, climb at 250/.65

Does any of this have to do with say exceeding 15 degrees bank flaps/slats retracted? Because of VSL?

Good discussion here I think.

No worries, mate
In the MD you were limited to 15 degrees of bank until you reached clean maneuver speed, so yes you could fly 230 clean.
Also, have you ever noticed that the flap retraction speeds on takeoff (when you are heavy) are lower than the flap extension speeds when you are landing and lighter? In a 737 you are retracting the flaps at about 190 heavy, then 3 hours later you have to extend the first notch before 200 or so. So yes, you can definitely fly slower than the published speeds. In the 737NG, the flap extension speed might be 200, but you are good to 40 degrees of bank (25 plus a 15 degree overshoot) to the top of the yellow arc, which is much slower.

 

[GCD]

The IAH Class B high speed climb experiment was contested by ALPA for a safety issue. Most bird strikes occur below 10,000' and most windscreens are tested and certified for bird strikes at 250 KIAS or less.

The B747, however, has a three inch thick windscreen because of the operational need to climb clean at 278 KIAS during the final segment climb, which is well below 10,000'.

 

[GittinFatter]

Some of you folks are only thinking about desending and some are only thinking about climbing. Both groups need to think about both climbing and decending to carry on an intelligent argument.
A 747 that is carrying any weight at all will usually have a clean speed above 250 on T/O. A max gross clean speed will be about 280kts on take-off. I have had controllers waive the Speed when they want an altitude first on a desent. Controllers are a represenative of the "administrator".

 

[Say Again Over]

We authorize heavies all the time

Sorry MK you don't have the authority to waive this regulation, the PIC does by applying the reg.

 

[ultrarunner]

Where do you get your numbers?

MD80 series (reference the -83 here) If you look at the charts, assuming MGTOW of 149,500#, using the 150,000# chart, 33 degress C at sea level, Altimeter 30.06, dry runway, no wind, Flaps 15

Here are your speeds:

V1: 143
VR: 147
V2: 154
Flap Retract: 169
Slat Retract: 202
Final Segment: 223
Clean Maneuver: 252

On the -80's the faster speeds down low after takeoff are typically in a -88 version with forward and aft aux tanks. With these, and loaded for LAX or SFO or SEA you'd approach 170,000 lbs for take-off, if I recall.