If anything it is not a very well written section of the regulations... Not surprising if you look at the history that caused this regulation and the arguing of it by both sides.

 

It's part of the Code of Federal Regulations. It's written primarily in the language of lawyers. The way it is written is to avoid ambiguity, and unintentional loopholes.

 

As a side note, there has been a long-standing system for aircraft seperation that has proven to be fail-safe: stay on the ground. One of the accidents cited in your post states that 2 IFR aircraft were on seperate courses with acceptable seperation from each other. You can regulate all you want, create routes, etc. A plane doesn't fly on a rail, and if it deviates from it's intended path an accident is far more likely to occur. If there is more than one plane in the air, there exists a chance that they may collide.

 

Thanks for the post, though. It was a fun read! (I'm not sure who Amanda is though.)

on our country airspace, you may request to maintain high speed at 280 knot even below FL100 especially if you are directed for the number one approach.

 

 

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I don't see the problem with that reg, really. If anything, it's one of the most clear. If you're searching for the definition of the word "night" however, have fun. Regulations around that definition vary depending on what you're referring to. Some of the regs actually require me to draw out a flow chart just to see how it would apply in certain circumstances because there are so many exceptions in other parts.

 

Not sure how much clearer you can get:

 

Don't bust 250 under 10,000', unless:

Your minimum clean maneuvering speed is above 250.

You have a waiver from the FAA.

Not just me that's sees a problem with it.... Just do an Internet search!

 

The problem is part D, because it does not say minimum clean speed it uses different wording to the controllers manual.

 

It does not really give an authorization via part D to exceed 250 knots just to be clean (even though everyone uses it as that)

 

Anyway, I have sent an email to the person that deals with our 129 and other international certificates to as the FSDO for clarification.

 

Carter,

 

As for Amanda yu can thank Apple and my language not being in English... As much as I love Apple their auto / type / correct really comes up with some funny things

If you're searching for the definition of the word "night" however, have fun.

 

Amen to that!

 

Carter,

 

As for Amanda yu can thank Apple and my language not being in English... As much as I love Apple their auto / type / correct really comes up with some funny things

 

So do I get to know what you were trying to say? :-)

Sorry...

 

What I was trying to say is that part D does not talk about minimum clean speed, we all use part D to exceed 250 and accelerate to minimum clean. (when in actual fact that regulation does not explicitly authorize you to do so - you could very well fly at 250 or less with flaps out, you would just burn more fuel)

 

However, when we refer to the FAA controllers manual that specifically talks about mimumun speed required.

 

This brings me on to the point I made that the regulation is not as well written as it could be, and the two sources of documents don't actually align fully.

 

FAR 91.117(D) If the minimum safe airspeed for any particular operation is greater than the maximum speed prescribed in this section, the aircraft may be operated at that minimum speed.

 

 

 

FAA 7010.65

 

a. If traffic conditions permit, approve a pilot’s request to cross Class C or Class D surface areas or exceed the Class C or Class D airspace speed limit.

Do not, however, approve a speed in excess of 250 knots (288 mph) unless the pilot informs you a higher minimum speed is required.

 

 

NOTE−

14 CFR Section 91.117 permits speeds in excess of 250 knots (288 mph) when so required or recommended in the airplane flight manual or required by normal military operating procedures.

 

So as we can see the FAA uses at least 3 terms when talking about speed in excess of 250 below 10,000 feet - none of them actually state minimum clean speed - one says you may fly a speed higher than 250 if it recomended in the flight manual - recomended for what? To get to your destination faster? To save fuel - it does not say the regulation is unclear and open to various views and opinions.

Ok.... Just found something else.. It actually would seem that maybe we are all wrong. Acording to the FAA letter to Continental Airlines, FAR 91.117(d) does not refer to the aircraft in clean state, and as such if the aircraft can use flaps to fly at the speed required - then it must do so.

 

So that means day in day out just about every heavy is not following the rule? See what you make of this....

 

http://www.faa.gov/about/office_org/headquarters_offices/agc/pol_adjudication/agc200/interpretations/data/interps/2010/Seltzer.pdf

It's a very interesting find, for sure.

 

The focus of the scenario they are dicussing is part (B) of the reg, regarding the speed limit of 200 kias with 4nm less than 2500 feet above field elevation, and they are discussing a B739. This is why both parts (a) and (d) are relevant to our discussion. The assumption I make is that operators of heavy aircraft have a waiver in the form of their FAA approved Operations Specifications. That would bring the operation into compliance through part (a). The letter is about a large aircraft, not a heavy. I would find it highly unlikely that their B739 op-specs permit them to operate outside the normal speed restrictions.

 

Also, within 5nm and less than 2500 AFE, it is highly likely that a plane is in a dirty configuration, but most aircraft/operators have a strong and reasonable desire to clean up prior to 10000 MSL. They aren't quite the same thing.

 

The letter does suggest that part (d) would not protect someone flying a clean and heavy aircraft at greater than 250 kias below 10,000 MSL unless no configuration could bring the min safe speed under 250 kias. It appears that part (a) is the part that is being exercised by carriers.

We shall soon find out! I have made contact with the person who wrote that letter at the FAA and made the specific request for our question!

 

Seems it was not so cut and dry after all... I have a feeling our manual may have some "arse covering" built into it for situations such as this!

The focus of the scenario they are dicussing is part (B) of the reg,

 

That's great that Avsim thought that should be a smiley face... it's SUPPOSED to be part b.

However, when we refer to the FAA controllers manual that specifically talks about mimumun speed required.

 

The JO7110.65 is not fully regulatory in nature, especially when referring to what aircraft are permitted to do. It only has standing when referring to what controllers are and are not allowed to do. Furthermore, you'll find a lot of "should, may, suggested," and other passive statements, whereas the FARs are more restrictive with "shall, must," and so on.

 

Since very few pilots know the 7110.65 exists, and therefore don't read it, trying to glean restrictions on the flying side from that manual is incorrect. It's there to say what controllers are and are not allowed to do, and set standards of control.

 

The fact that it uses different terminology is simply because a controller could care less what the speed is called. It's summarizing the technicalities so that the controller simply knows that in some cases, the AFM specifies a higher speed. What it's called and in what flight condition it's achieved is irrelevant to the controller. They can't see the plane (assuming the radar environment).

 

 

As Charles mentioned, the above letter is invalid to your case because a B739 is not a heavy, it's a large, which is not specifically exempted by .117(d.). Furthermore, references to the terminal chapter of the 7110.65 are also invalid because you're really never going to see aircraft operating that low, that close, that fast. The reason that language is there is to, as you mentioned, play CYA (cover your arse). It's there to cover the area closer to the tower environment where it's more visual (instead of radar), where other aircraft are operating in dirty configs, flying a lot slower.

 

It's not speed that kills. It's the differences in speeds that kill.

Kyle, you need to back and read that letter again. What that letter does it set out in writing the FAA position with regard to part D of the regulation, specifically that it does not relate to an aircrafts configuration and as such if slats and or flaps can be used to meet a speed restriction then they should be used.

 

If that FAA interpretation does not stand to the application of 250 below 10,000 then the FAA need to rewrite the FAR because it would mean they have contradicted themselves, as they have issued guidance in that letter specifically stating the part D does not refer to and aircraft being "clean"

 

Let's not forget the importance of the controllers information being consistent with the FAR's this is how miss communication happens, that at best leads to reports at worst something more serious - it is especially important in this case as this section of the FARs is not in accordance with ICAO (so even more room for miss communication) *source United States AIP.

 

When I was talking about CYA I was referring to our company manuals and guides instructing us to ask ATC for the speed - as can be seen it is not clear what they mean by these regulations as they have set them out different to ICAO and your own airlines are not such of the exact meaning without seeking review from the FAA Legal Council.

 

The FAA with regard to this regulation make no mention of a HEAVY aircraft, the only one mentioning that is yourself Kyle.

Kyle, you need to back and read that letter again. What that letter does it set out in writing the FAA position with regard to part D of the regulation, specifically that it does not relate to an aircrafts configuration and as such if slats and or flaps can be used to meet a speed restriction then they should be used.

 

Where? Every time I see them making a statement on the reg, they say "in the scenario you described," meaning, they're applying the interpretation based on the fact that his scenario used a B739. Furthermore, again, you're never going to be in that airspace they're referring to.

Section 91.117 does not distinguish requirements based on the aircraft's configuration during different portions of the operation. Under the scenario you describe, the aircraft can in fact be configured to operate in accordance with the speed restrictions of paragraph (B). Therefore, the pilot must operate the aircraft in the configuration to meet the requirements unless the minimum safe airspeed for that operation is greater than 200 knots. If so, then the aircraft can be operated at the minimum safe airspeed, in accordance with paragraph (d).

 

Do you not see how this directly offers guidence? Yes Continental asked the question because of an issue that came up with the 739 but the legal view that the FAA have issued is on FAR 91.117 and the fact that part D is not talking about the aircraft in any specific config - just the fact that if flaps and slats will allow the aircraft to operate below the maximum airspeed as per FAR 91.117 then it must do so.

 

Just have to see how long it takes the FAA to put that in writting in relation to my question I asked them this afternoon.

 

Carter,

 

From your reply I think you see the point I'm making.. Can you think of another way to word it that might be more clear?

DEFINITION OF TERMS

CLIMB SPEED SCHEDULE

The climb speed schedule is defined as the speed

schedule used to achieve the climb performance

provided in this section. The climb speeds below

10,000 feet are shown versus gross weight in

Figure 4-1 and are based on 250 KIAS or the

minimum manuever speed, whichever is higher.

The climb speeds above 10,000 feet are as

follows:

Three engine climb - 330 KIAS up to 27,402

feet, then at Mach = 0.82

Two engine climb - 300 KIAS up to 27,993 feet,

then at Mach = 0.76

SERVICE CEILING

The service ceiling is defined as

 

This is out of my FAA approved performance manual which was certified during aircraft certification. I tried to post some images but avsim won't allow direct pics and the host sites shrinks your uploads grrrrr.

One thing to keep in mind is that whether you lose a engine or not, you will fly your FAA approved takeoff profile and clean up schedule every time. These profiles and schedules are approved and certified during certification. The FAA can't expect you to to stay dirty to maintain a speed below 250. This will invalidate your obstacle clearance during your takeoff profile, which is what the performance is based on. Choosing to fly your profile dirty, engine out or not, will surely effect your calculated climb gradient/obstacle capability when heavy. In the DC10's case, you will also get into slat vibe at higher speeds, which causes stress. This is the reason we don't use them until you are ready to slow further. Also you will create more wake turbs flying dirty, slow and heavy. Minimum maneuver speed provides at least full maneuver capability for terminal area maneuvering. It is the slowest safe speed that you can fly and ensure you can make standard rate turns or more. Anytime I'm below min man, I am limited to 15 degrees of bank. I will stay at flap retract speed & configured if i need to make a tight sid turn or meet a turn speed limit. Once clear I'm back on schedule to clean up. Arrival is a different story. I did have a slat problem after takeoff and had to fly above 250, even in the holding pattern. I had to until i burned/dumped enough gas(200,000) to get slow enough to land with flaps 22 without slats. Approach speed was 180. Landing flaps gave me a -10 pitch which i didn't like compared to the 4.5 I'm used too. plus the difference in flaps was only 5kts.