Climb Profile

papanovember · 04-22-2008, 01:19 PM

Hey Eagle guy here. We have a big discussion on this going on at the lounge.

Just wanted to compare our climb profile vs yours. Our AOM recommends climbing at 270/.56 (FLC) when practical and 290/.65 other times. We have almost completed modifying all our 145s to allow a MGTOW of 49,823. Since the modifications nothing has been changed regarding our profiles. They remain the same for all our aircraft (135, 140, 145) Some people have been seeing the PLI come down when climbing at .56 up high and heavy.

I was just curious to see what your profiles are. Do you have an econo climb and a fast climb? Are they different in different types (135, 145, XR)? Is your FLC programed for 270/.56 or something diffent? I have heard some operators have FLC programed for 290/.65. Finally, do you guys climb in speed mode or VS? At least on our aircraft speed mode causes uncomfortable pitch movements so I along with everyone I fly with use vs.

juice · 04-22-2008, 01:38 PM

290/.65 is the planned climb for all aircraft except the XR which is 290/.60. There is no "econ" climb on the paperwork, and no climbs at .56M. they experimented with some different climb profiles a couple years back, like a 220 kt. all the way up, ect. but nothing has officially come out different from the 290/.65 or .60.... not yet anyway.

MKFlying7 · 04-22-2008, 02:04 PM

Quote:

Originally Posted by papanovember

Finally, do you guys climb in speed mode or VS? At least on our aircraft speed mode causes uncomfortable pitch movements so I along with everyone I fly with use vs.

Reference the other thread going on right now on aversion to pitch mode...to give you the gyst though, some people like using each of the modes.

Like the other guy said though, we have our XR profile and our "everything else" profile. I'm not really sure how much of that is based on fitting into the airspace system at our hubs vs. economy, but that's what they say to fly at least.

Someone else called the climb in the XR in the 30s the "death climb"...the extra few knots make it a lot more comfortable for me at least...

mszluka · 04-22-2008, 02:06 PM

I wonder if Embraer used some sort of mathematical formula to come up with these climb profiles, or were they based on flight testing? I've used a few different climb profiles due to various conditions, and I've found there are much more fuel efficient profiles than the ones we use. I don't mean doing 220 KIAS all the way up, either.

UncleJesse · 04-22-2008, 02:06 PM

That's SSI we cannot divulge under federal law. Now go back and tend to your For Sale sign.

UncleJesse · 04-22-2008, 02:07 PM

Quote:

Originally Posted by mszluka

I wonder if Embraer used some sort of mathematical formula to come up with these climb profiles, or were they based on flight testing? I've used a few different climb profiles due to various conditions, and I've found there are much more fuel efficient profiles than the ones we use. I don't mean doing 220 KIAS all the way up, either.

You know you really aren't a test pilot and should be flying the way they tell you to fly. The EMB is not your personal testbed.

kidicarus5897 · 04-22-2008, 05:04 PM

Quote:

Originally Posted by UncleJesse

You know you really aren't a test pilot and should be flying the way they tell you to fly. The EMB is not your personal testbed.

That's a lot of big words coming from someone who gets all his flight time on flight-sim 98. Don't you have burgers that need flipping or pipe that needs fluffing?

lonestarwings · 04-24-2008, 01:46 AM

Quote:

Originally Posted by papanovember

Hey Eagle guy here. We have a big discussion on this going on at the lounge.

Just wanted to compare our climb profile vs yours. Our AOM recommends climbing at 270/.56 (FLC) when practical and 290/.65 other times. We have almost completed modifying all our 145s to allow a MGTOW of 49,823. Since the modifications nothing has been changed regarding our profiles. They remain the same for all our aircraft (135, 140, 145) Some people have been seeing the PLI come down when climbing at .56 up high and heavy.

I was just curious to see what your profiles are. Do you have an econo climb and a fast climb? Are they different in different types (135, 145, XR)? Is your FLC programed for 270/.56 or something diffent? I have heard some operators have FLC programed for 290/.65. Finally, do you guys climb in speed mode or VS? At least on our aircraft speed mode causes uncomfortable pitch movements so I along with everyone I fly with use vs.

The vast majority of pilots here uses vertical speed mode to climb and descend, but most use that mode to maintain a (somewhat) constant airspeed/mach number, not a constant vertical speed. Like someone said earlier, we are pretty standardized in using 290/.65 in the EP/LR and 290/.60 in the XR. The XR's mgtow is about 53,000 lbs. If you takeoff weighing about 50,000 lbs you will fall below the low speed buffet margin if you attempt to climb straight to FL370 at .60 mach (meaning you could potentially stall the airplane if you encountered a significant bank angle). Accelerating to .65-.70 mach once you get into the mid 30's usually prevents this problem. The same thing would undoubtedly happen in an LR or EP if you tried climbing it at .56-.60 at weights close to MGTOW.

You should have low speed buffet margin charts somewhere in your CFM or performance manuals. Keep the speed at or above what the chart specifies. Allowing the speed to accelerate to .65-.70 when you pass FL300 is a good policy when you're operating a heavily loaded EMB-145. That should keep you above the low speed buffet margin and free from the PLI in most scenarios.

Our FLC modes in the EP/ER/LR's are the same as yours, 270/.56, but they are rarely used. The XR FLC modes holds 290/.60, but VS is still used by most pilots because of the autopilot's erratic pitch corrections in FLC mode.

Hope things are going well for you at eagle, fly safe.

D-Luv · 04-24-2008, 02:11 AM

Quote:

Originally Posted by lonestarwings

The vast majority of pilots here uses vertical speed mode to climb and descend, but most use that mode to maintain a (somewhat) constant airspeed/mach number, not a constant vertical speed. Like someone said earlier, we are pretty standardized in using 290/.65 in the EP/LR and 290/.60 in the XR. The XR's mgtow is about 53,000 lbs. If you takeoff off weighing about 50,000 lbs you will fall below the low speed buffet margin if you attempt to climb straight to FL370 at .60 mach (meaning you could potentially stall the airplane if you encountered a significant bank angle). Accelerating to .65-.70 mach once you get into the mid 30's usually prevents this problem. The same thing would undoubtedly happen in an LR or EP if you tried climbing it at .56-.60 at weights close to MGTOW.

You should have low speed buffet margin charts somewhere in your CFM or performance manuals. Keep the speed at or above what the chart specifies. Allowing the speed to accelerate to .65-.70 when you pass FL300 is a good policy when you're operating a heavily loaded EMB-145. That should keep you above the low speed buffet margin and free from the PLI in most scenarios.

Our FLC modes in the EP/ER/LR's are the same as yours, 270/.56, but they are rarely used. The XR FLC modes holds 290/.60, but VS is still used by most pilots because of the autopilot's erratic pitch corrections in FLC mode.

Hope things are going well for you at eagle, fly safe.

There isn't any data in our buffet margin charts for anything above FL350 at more than 46K...

The book says up there to not exceed 15 degrees of bank untill you're below 46K.

I think the highest low speed in the chart is .63 M so in the XR if I'm doing .60 I'll switch to .65 above FL300. Normally though I just use 290/.65M...

lonestarwings · 04-24-2008, 03:17 AM

Quote:

Originally Posted by D-Luv

There isn't any data in our buffet margin charts for anything above FL350 at more than 46K...

Sure, but that certainly doesn't mean we are prohibited from operating at altitudes above FL350 at weights over 46k. You can extrapolate from the data the chart does provide and get a good idea of where you need to be in terms of speed to operate safely in those situations. In my experience you can still usually get 600-800 fpm out of the plane at those altitudes and weights with a high ISA if you keep your speed up. Your technique sounds like a good one.