Compass EMB Options

[SpauldingSmails]

Try again.

Northwest Airlink, operated by Compass is pleased to serve crow as breakfast to our first class a**holes this morning.

 

[profit]

Honestly, it depends a lot on the weight and speed of course.

Typically were looking at around 3200lb/hr (+/- 100) total at long range cruise (around M.73-.75) in the mid-thirties. At M.76 it's in the realm of 3600-3700lb/hr. for the mid-thirties.

The -900 burns around the same. Low 3000s total/hr in the mid 30s at M.77

So it doesn't sound like one plane is "killing" the other w.r.t. fuel

 

[skid]

The -900 burns around the same. Low 3000s total/hr in the mid 30s at M.77

So it doesn't sound like one plane is "killing" the other w.r.t. fuel

I would have to agree that the burns are probably 200-300 lbs/hr better with the 900. No I have not flown the 900 but I have spoken to several 700 operators.

(Yes slightly different aerodynamics (winglets and such), but still much lighter than a 900.)

They have mentioned similar burns as we get on a 175.

One problem I have heard of with the 175 is crews that refuse to climb to the most efficent altitudes. Seems strange but I had an FO that said the last captain he flew with refused to climb above 320 because he was afraid of the dreaded coffin corner.

Almost fully loaded book numbers allow you to climb straight to 330 at .76. At 370-390 heavy you will still see 50+ knots of an operating window before worrying about that. Yes the book numbers are crazy conservative. (if you want to look at LRC numbers in the book most show G ranges of about 1.5 g's at 350 - 370 at a large range of weights.

My point is the way we are operating the 175 is killing us just as much or more than the straight efficiency of a 900 vs 175. Yes our heavier weights give us a large disadvantage to that.

Finally what will happen in the long run....NO ONE HAS A CLUE!!! Management will get the airplane they want... It may or may not be what we want or the what the pax want to see. We are all just along for the ride.

 

[Ridgeback]

The -900 burns around the same. Low 3000s total/hr in the mid 30s at M.77

So it doesn't sound like one plane is "killing" the other w.r.t. fuel

One must not forget even if the 900 is buring the same (which it is not) than the 175, the 900's are flying a faster cruise at .77 the 175's have to cruise at @.70 to acheive even a burn close to the 900's. More time in the air buring more gas equals much more fuel for the same mission.

The 900's are burning 300/side less than the 175, flying faster = less time in the air, times 36 aircraft= yes the 900's are killing the 175's

 

[SpauldingSmails]

One problem I have heard of with the 175 is crews that refuse to climb to the most efficent altitudes. Seems strange but I had an FO that said the last captain he flew with refused to climb above 320 because he was afraid of the dreaded coffin corner.

I have to say I'm very surprised. It seems contrary to the actions of almost every captain I've flown with.

Coffin corner in the 175... sheesh, if the LRC tables, the PLI and the yellow snake weren't enough to tell you when you're getting close.

 

[Hollywood82]

If NWA doesn't want any more EMBs would they ever get any other type of RJ? or T-Prop? Or, is 36 EMBs as big as Compass gets?

 

[Airline Driver]

In all practical Terms, The 170 is good to FL350. The 175 in the 86 seat configuration is good to FL330. Now Let me clarify that I am speaking in terms of a fully loaded plane. Fuel, Bags and PAX. Yes The plane will go to FL410, I have done it, it took a while and we were very light.

Compass to my understanding has a 76 seat configuration so it should be good to FL330-350 fully loaded. If that Compass Captain was worried about coffin corner at 320, then he either does not have the experience to know better or does not have the experience in the airplane to understand what it can do at various altitudes.

 

[DrewBlows]

-900 Pilot: "Mine's longer."

-175 Pilot: "Mine's wider."

...and the debate continues.

 

[G2T]

So much hate...
How about we all go fly our respectively better airplanes, maybe throw a head nod to the other guys once in a while in the terminal, and hope for the best. Despite our best predictions, we have no idea what's going to happen, other than someone will get screwed, we just don't know who or how yet.

 

[labbats]

I've been keeping track to put some numbers into fltplan.com.

Keep in mind that these are cruise #'s, taken over the course of a 4 day trip. It would be nice to have one flight where I could make a stop at every FL above 300 to get a reading as that would be most accurate.

I'll just have to keep taking "readings" on every leg and average them out.

FL360: M.78 (462KTAS) 3650lbs/hr (around 72K lbs)
FL340: M.78 (458KTAS) 4000lbs/hr (around 74K lbs)
FL330: M.78 (459KTAS) 3900lbs/hr (around 73K lbs)
FL320: M.80 (463KTAS) 3900lbs/hr (around 71K lbs)

I'm surprised how much more fuel the 170 burns compared to the 145.

I don't have specifics, but I know that a full weight 145 at around M.74 is roughly 2400lbs/hr at FL360.

How many seats are on the Compass planes? Is it the 76 seat config?

 

[AvroGuy]

I'm surprised how much more fuel the 170 burns compared to the 145.

I don't have specifics, but I know that a full weight 145 at around M.74 is roughly 2400lbs/hr at FL360.

How many seats are on the Compass planes? Is it the 76 seat config?

You are kidding right?? The 170 is nearly twice as heavey with larger engines. I would also imagine more drag causing specific range/Nautical mile per poud to go down. Even empty with just the two pilots the CRJ7 probably burns more than the EMB 145. Couple of weeks ago @FL410 we were still burning a little over 3000/ hr.

On a side note, when I was an FE on the E-3 AWCS we were happy with 12,000/hr. If I remember right, been almost 6 yr, in cruise @ FL310 .72M we would burn in the range of 18,000-20,000/hr.

 

[labbats]

No I'm not kidding. That's 50% more fuel for 50% more seats and 50% more weight. I guess it makes sense, but it wasn't what I had in my head as far as a guess.

I've ridden on a few 170s and they are great planes, but I'm just surprised at the fuel differences regardless of the different engine mounting, etc. It wasn't meant to be any kind of a put down, just an expression of my surprise.

 

[SpauldingSmails]

Hey no offense or compliment taken. I didn't design the thing, I just fly it.

Sure it's only 26 more seats, but twelve of those seats are first class, which bring in more money than the average coach seat. (i know, i know, not all the time) But it's also only one extra person (+1 FA) to move 76 people instead of 50. Even if fuel costs per seat are equal, the economics are superior.

 

[DoinTime]

Hey no offense or compliment taken. I didn't design the thing, I just fly it.

Sure it's only 26 more seats, but twelve of those seats are first class, which bring in more money than the average coach seat. (i know, i know, not all the time) But it's also only one extra person (+1 FA) to move 76 people instead of 50. Even if fuel costs per seat are equal, the economics are superior.

By that theory everyone should be flying A-380s, right? The most economical aircraft for the mission is mission specific.