Sometimes I have a min clean of 245-255. I just leave the slats out until 10,000 or if the route is pretty much straight ahead.

So tell me this, what if you have a minimum climb gradient or better yet a failed engine (which we plan for every takeoff). How would you calculate maximum takeoff gross weight limited by climb gradient with slats hanging? There are no charts for that since the procedures have you clean up on schedule.You only have clean charts. So how do you ensure you meet the published gradient? Also, you are heavy and lose an engine, so you are going to go against procedure and leave slats hanging again? As the pilot in command, you are ultimately responsible for safety in operation of the aircraft. That's why the procedure have you clean up so that you maximize the performance of the aircraft. The whole goal in the takeoff condition is to reach safe altitude and safe speed.

 

Keep in mind that climb gradient charts only come in two flavors. One is the takeoff configuration, this gives you climb capability in the takeoff configuration up to accel height. These charts normally top out at 1500ft agl. The other is in the clean configuration. These charts pick up at 1500agl and go on to cruise.

 

Another question, why would a aviation authority certify an aircraft that has procedures to clean up and accel to clean speeds above 250kts if it wanted them to stay below this speed? The authority certifys the AFM/FM that tells you to clean up and accel to speeds higher than 250. If this wasn't wanted, wouldn't the authority have the manufacture provide procedures and charts to remain below 250? Just keep in mind that heavy is attached to the call sign for a reason. 

To answer your question you fly it differently depending on what happens. Two engine you leave the flaps/slats out. If you loose an engine then climb to Engine out altitude, retract the slats at the 0/RET speed then climb at 0/RET+20. However you are limited to a 15 degree bank. Now you ask, "What if you have to turn due terrain?" Normally that airport will contain an engine out chart with a specified procedure to follow.

To answer your question you fly it differently depending on what happens. Two engine you leave the flaps/slats out. If you loose an engine then climb to Engine out altitude, retract the slats at the 0/RET speed then climb at 0/RET+20. However you are limited to a 15 degree bank. Now you ask, "What if you have to turn due terrain?" Normally that airport will contain an engine out chart with a specified procedure to follow.

Obviously you missed the whole point of the question. There is no performance data for what you are saying.

I'm speaking real world, How do you calculate/verify the climb capability of the aircraft? How would you calculate your max weight for climb gradient? It's nice to be able to read a airport chart for a specified procedure, but you are also required to meet the minimums for that procedure. So how will you do that in your non standard configuration? Would you go at max takeoff? or calculate it based on climb capability and AFM procedure as I do in the real world?

It's been a while since I was in the Gulfstream but I will try to point out the differences between it and a transport with slats.

 

I still remember a statement from one of the instructors, "What everyone else does with flaps and slats, Gulfstream does with power."

 

Since I have been working for the airline(s), lately, the performance manual is loaded in to the airlines flight planning computer.  Depending on the airport, ambient conditions and obstacles, and other factors, the computer spits out a weight number. That weight number guarantees that if you lost an engine at V1, you will meet all the climb segments.

 

In you training, when you lost an engine at V1, you rotate, climb at V2 to the engine out altitude.  I know on the G2 it was 400' AGL.  Nowadays most people have moved it to 800 AGL.  At that altitude you accelerate to (varies on plane VCL, V2+15, 0/RET).  In your Gulfstream on attaining that speed you retract the flaps.  On mine I retract the flaps and then have to wait an additional 10 knots to retract the slats.  We both then climb clean at a final segment speed to the minimum altitude.

 

Now if I'm on any departure, and I lose an engine, I must hold altitude and clean the plane up.

 

Now for hanging the slats on a departure.  If I'm at max gross weight my min clean speed is 260.  Most RNAV departures require a 30 degree bank.  Well, due to the discussion here I can't accelerate to that until 10000.  So I have some choices: 

 

1.  I can leave the flaps out and wait till I'm faster than V2+15 and then execute a 30 degree bank but I will have to climb with the flaps out.

 

2.  Accerate to Flap retraction speed and execute a 30 degree bank but the slats will still be out.

 

On most departures before the turn, I can accomplish #2.  Sometimes I have to use #1.

 

While I was writing this, I dug a GIV reference manual out of my closet.  The highest VSE speed is 180.  My plane usually has a min clean of 220.

It's been a while since I was in the Gulfstream but I will try to point out the differences between it and a transport with slats.

 

 

 

I still remember a statement from one of the instructors, "What everyone else does with flaps and slats, Gulfstream does with power."

My friend, you are missing the point again. Yet you explain the procedures that I'm very familiar with. I started flying heavies(real world) with the C-141B, many wouldn't even know what that is. After a few years I went to the mighty KC-10A. After years in that i moved on to the DC-10-30ER. The DC-10 has slats if you didn't know. I still have all of my manuals so I will use them as a last attempt to show you my point and I'm done with it.

 

You stated that you fly with slats out to stay below 250 prior to 10,000. This goes outside of the manufactures recommendation and burns a lot of fuel. When required to turn up to 30 degrees, the best option is to accel to flap retract speed, stay configured and then retract flaps and slats after the turn. This gives you the tightest turn radius. To accel to flap retract speed maintain it and then suck up the flaps don't make any sense to me. Plus in the heavies I've flown, you can't bank greater than 15 degrees when ever below min maneuver for existing configuration. In your description, you would be below slat extended min maneuver, which would prevent 30 degrees since you sucked up the flaps. That wouldn't fly in any of the heavy jets I've flown. You would just go to flap retract stay configured, turn, then clean up. But anyways, back to my point that you are missing. You said that the computer does the performance for you, same in my ops but you are still required to know how to calculate performance in my ops. You should have a thorough working knowledge of the aircraft's performance. Also, guess what that computer performance is based? The manufactures approved manual.

 

Lets start with climb out flight path, which is governed by the FAR part 25. This is the reg that governs the certification and the reg that manufacturers base their manuals on. Performance flight paths are not normally created with turns in mind. This is why operators will have engine out procedures created. Lets see what my old DC10 manual has to say about flight paths.

  https://www.dropbox.com/s/f6ev1xapjcazctc/climboutflightpath.jpg?dl=0

 

Note that there are no procedures for leaving slats or flaps out. The manufacturers procedure has you clean up. It even cautions about performance loss during turns. That's why turning while configured is a technique to turn away from terrain and then clean up. Also, if you can't comply with a particular SID, you don't fly it. That simple. Now lets look at my climb gradient chart and profile that I used religiously.

https://www.dropbox.com/s/7oq79kgmz3zxeqk/Climboutflightpathchart.jpg?dl=0

 

Note the solid line at 1500ft. This is the 1500ft accel that the FAR 25 denotes. You climb, level, clean up, and continue the climb towards the obstacle. Again, no alternate procedures here like leaving slats hanging. No charts for that. All of the charts are based on this profile. If you don't lose an engine, same profile, just a low rate of climb till you clean up and reach climb speed.

 

Here is the graphical representation of the chart. Again, no mention of slats hanging and alternate procedures.

https://www.dropbox.com/s/at4onwwcpx0bxm4/standardflightprofile.jpg?dl=0

 

 

So now you see what I mean about charts/data to ensure that you are safe at gross weights while dealing with climb gradients and obstacles. You don't just gas and go like in flight sim. You have to analyze the data to figure out your maximum weight for climb restrictions. If you are limited by a climb gradient and you are choosing to leave slats out while your obstacle clearance data is based on you being clean above 1500ft, you are asking for it. Here is some info about all engine climb gradient charts. These are not used for obstacle gradients, but ATC gradients. Take note of the aircraft's configuration.

https://www.dropbox.com/s/571bdhsw9bberhg/allenginegradients.jpg?dl=0

 

Again, no alternate charts, data or procedures for climbing with slats out. You would be in no mans land with no data to prove you are safe to do so. Even your computer program is based on the same data. You said your clean was 260, mine was higher in the DC10. Lets have a look.

https://www.dropbox.com/s/ysnf8b5g6huv0x9/speedsbelow10000.jpg?dl=0

 

Notice at 440,000 pounds, speed is higher than 250. no mention of leaving slats out. Here are my clean up speeds.

https://www.dropbox.com/s/h7vd6gq6fcwuhaw/minman.jpg?dl=0

 

Notice again, no mention of alternate procedures. In fact, if i did on a whelm leave my slats hanging, I would still be above 250 at higher weights. Here is my actual speed schedule

https://www.dropbox.com/s/yhttibqs0hq1xfj/Speedschedule.jpg?dl=0

 

Note that it says that this schedule achieves the climb performance provided. Why would you stray from it? I thought airlines were all about saving money in all aspects, apparently not yours. Also note that it says 250 or min maneuver, which ever highest. Here is an example of a climb chart. This is distance to climb chart.

https://www.dropbox.com/s/te7zsak3a7wz8iu/climbchart.jpg?dl=0

 

Notice the note at the top says clean configuration. How could i calculate time, distance and fuel to climb if i left slats out up to 10,000 ft. There are no alternate procedures here to validate doing so. Maybe you would share your own manuals demonstrating what you are saying.

 

Also, you proceeded to give me a lesson in the take-off procedures as if i don't hold a type. Well here is the procedure from "Big Sexy", I do miss flying this jet. My all time favorite.

https://www.dropbox.com/s/y3mnku7fq57vdfs/procedure.jpg?dl=0

https://www.dropbox.com/s/6y7ckk1bz195z5e/procedure1.jpg?dl=0

https://www.dropbox.com/s/l7ircjqbxc8yi40/procedure2.jpg?dl=0

 

Read through those carefully, notice there are no procedures outside of clean up in this jet. I hit my hard cleanup limit at 3000 AGL only if there are no obstacles. I still know the procedures like the back of my hand. I still do call flaps 22 every blue moon in the G5/550 when calling for flaps 20. Again, my point is that there are no procedures for leaving things hanging up to 10,000ft. To do so is a waste of gas and potential climb problems when trying to clear obstacles above accel height. This manual is FAA certified to part 25 of the FAR, along with its climb profile. If that was the intention of the authority, they would have made the manufacturer change the procedures to ensure you stay at 250 below 10,000. You will probably miss the point I made, but never the less, someone will hear what I'm saying. As Kyle stated, it's hard to get some to understand a concept if they are not in the actual bizz.

 

 

When required to turn up to 30 degrees, the best option is to accel to flap retract speed, stay configured and then retract flaps and slats after the turn.

 

I think we are saying the same thing. 

 

My manual:

https://www.dropbox.com/s/rj7dk3at28ze371/file%20apr%2012%2C%202%2023%2045%20pm.png?dl=0

Hopefully this will help in this forum:

 

I just got off the phone with my friend who has flown both the B747-400 and the MD-11.  He is currently flying the MD-11 for a "Brown" cargo company.

 

Normal:  He said in the continental US, he can takeoff and accelerate to Min clean (Flaps, slats up) with a courtesy call to ATC even if its 300kts.

 

If a speed is published on the SID:  He must comply leaving the aircraft dirty.  He then must ask for relief.  He mentioned certain SIDs out of LAX where controllers gauge aircraft climb rate before turning them.

 

Where he says he must ask for relief is on a descent.  It is assumed you will slow.

 

International:  He mentioned several countries where is doesn't have to ask on climbout.  Others he does.  The company publishes the speed rules along with the airport diagrams.  To cover themselves, the company says, "Ask for high speed departure."  Some of the non ask countries are Korea, Hong Kong and Japan.

 

He did mention a coffin corner on the MD11.  Leaving the slats out to too high an altitude will cause the min clean speed to be too high to retract them.