CRJ-200 - spoilers or flaps for speed restricted descent?

Re: CRJ-200 - spoilers or flaps for speed restricted descent

PCL_128:


You guys have flaps 5 on the 717? Is that via dial-a-flap or is that normal detent? We only had detents for 0, 11, 15, 28, and 40... dial-a-flap was avail for most in between positions... 18 and 5 were utilized for various situations, but I only used 11 during my quick tenure on the doggy.
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

PeanuckleCRJ said:
PCL_128:


You guys have flaps 5 on the 717? Is that via dial-a-flap or is that normal detent? We only had detents for 0, 11, 15, 28, and 40... dial-a-flap was avail for most in between positions... 18 and 5 were utilized for various situations, but I only used 11 during my quick tenure on the doggy.
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Eh, "dial-a-flap"? :confused:
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

PeanuckleCRJ said:
PCL_128:


You guys have flaps 5 on the 717? Is that via dial-a-flap or is that normal detent? We only had detents for 0, 11, 15, 28, and 40... dial-a-flap was avail for most in between positions... 18 and 5 were utilized for various situations, but I only used 11 during my quick tenure on the doggy.
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That's dial-a-flap. I didn't realize that the -88 had dial-a-flap. We use it for virtually every takeoff. Aerodata will calculate to give the absolute best flap setting, so sometimes you'll see weird settings like flaps 6, flaps 19, etc... The usual setting that it turns out is flaps 5, though, and that's dial-a-flap. The only fixed detents on the 717 are 0, 13, 18, 25, and 40.
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

Maximillian_Jenius said:
Eh, "dial-a-flap"? :confused:
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Yeah, kind of unusual, but it's a great thing. You can set any flap setting between 0 and 20 with a "dial-a-flap" wheel next to the flap handle. It controls a variable detent in the flap control. Also makes it nice when you extend the flaps. Since there's techically no fixed settings between 0 and 13, you can slowly move the handle to 13 when you extend them and the flaps go out nice and slow and don't cause a pitching moment. Big difference from the CRJ where the flaps would drop out to 20 real quick and cause a big pitching moment if you weren't at minimum speed before extending them.
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

Heh, it'll still pitch like a bronco if you're AT minimum speed. :)

If they put something like dial-a-flap on the CRJ, the flaps would probably fail even more often. We took off outta CLE today. No flex again. Why? Flex temp was a whopping 10 degrees more than the ambient temp. That was in a flaps 20 bird. If it were flaps 8, we woulda still had to go 20 anyway since it was off 6C. Day before outta CLE, we were so heavy would couldn't flex even at flaps 20.

Sometimes when it starts getting hotter, you won't be able to flex at flaps 8 b/c the ground roll is just gonna be too long. But, then again, I see the heat a lot more since I'm not DTW based....
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

kellwolf said:
No flex again. Why? Flex temp was a whopping 10 degrees more than the ambient temp.
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OK I'll admit it, this went right over my head. Why couldn't you flex if the flex temp was higher than ambient? I'm lost.
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

Blackhawk said:
Why not just use the boards??? They were put there for a reason.
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kellwolf said:
If you need to get slow and down fast, gear is a good option. Like, say, if ATC leaves you out to dry and clears you for the approach 10 miles out at 9000 ft.

Now, if you're not gonna be landing in the immediate (like next two minutes) future, I'd go with the boards.
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What he said. I try not to use the mistake brakes if at all possible. If I get slam dunked close to the airport I'll use the gear to help me get down. If I'm far out I'll use the boards.

I'm also a big fan of flex (reduced thrust) takeoffs. The chances of having an engine failure on takeoff are greatly reduced, that alone is reason enough for me.
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

Ahh, the dial-a-flap!

Flaps 5 was like "is this damned thing EVER going to takeoff!?"

We did flex flaps t/o's in the -90, but I'm not sure if it ever got to the -88.
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

There are some days with a 48 degree flex and flaps 8 on the CRJ where we use 7000 or 8000 feet of runway before rotating. Nothing like doing 149 knots and having all 6 wheels on the ground still.
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

wheelsup said:
OK I'll admit it, this went right over my head. Why couldn't you flex if the flex temp was higher than ambient? I'm lost.
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We could flex, there just wasn't much point to it. It was only a MINOR reduction in N1.
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

kellwolf said:
We could flex, there just wasn't much point to it. It was only a MINOR reduction in N1.
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Any flex is worth while. Even reducing the takeoff N1 by a small amount will help reduce engine wear and reduce the possibility of an engine failure on takeoff. A study at USAir years ago using FOQA data showed that using flex and derated takeoffs reduced chances of an engine failure by 50%.
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

Maximillian_Jenius said:
And what is a flex takeoff? :confused:
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De-rated thrust. Basically, a lot of variables are taken into account: winds, temperature, weight, runway length, etc. Take those variables, mix them up, and you come out with a different thrust setting that allows you to take off at a lower N1 setting than what would be required under full thrust.

PCL_128, wasn't aware of the US Air FOQA data. I'm normally all about the flex if we can under normal circumstances. The CLE thing was the CA's leg, so he made that call. MSP has gotten so crazy lately, it almost seems like a good idea to get off the ground ASAP, though.
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

kellwolf said:
The CLE thing was the CA's leg, so he made that call.
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Yeah, there are way too many Captains at Pinnacle that just don't understand this stuff. It's hard to blame them, too, since the company's training department is so pathetic and doesn't teach it. Half of the checkairmen don't even understand the Worldflight and CFM PERF data correctly.

MSP has gotten so crazy lately, it almost seems like a good idea to get off the ground ASAP, though.
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Haven't been to MSP lately. So far I've been able to avoid all of the NWA hubs. :)
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

Kellwolf, I like the Icanhazcheeseburger avatar. Pretty funny website to look at.
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

The only time I wouldn't flex in the CRJ was when the computer just wouldn't take the number it gave me (when the flex temp was too close to the OAT the perf computer just wouldn't take it sometimes). Any reduction in takeoff power can save your butt later- or your fellow pilots' butts.

Respect the machines you fly and in turn you are taking care of yourself and your fellow pilots.
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

Van_Hoolio said:
It's something that sounds like work in the CRJ, but is pretty much done for us in the Jungle Jet!
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It's not really work at Skywest--unless we're at a non-ACARS outstation, we get performance numbers off the ACARS that give us a flex temp. Punching it in the FMS takes 2 seconds.

For us, though, there's a number of situations where flex takeoffs aren't allowed even if environmental and runway conditions allow it (takeoff behind a heavy, windshear, etc). It sucks having to rush to get speeds reset and the flex removed when tower puts a heavy in front of you at the last minute.
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

We have some conditions that prevent flex, but they are all weather related. The aircraft in front of us makes no no difference.

Actually getting the number (even without ACARS) is pretty easy. Either it comes up on the ACARS data, or if we are minus ACARS we just look at the TLR and the FLEX data is listed by weight. Know your TOW, know your flex. Pretty easy.
 
Re: CRJ-200 - spoilers or flaps for speed restricted descent

zmiller4 said:
It's not really work at Skywest--unless we're at a non-ACARS outstation, we get performance numbers off the ACARS that give us a flex temp. Punching it in the FMS takes 2 seconds.

For us, though, there's a number of situations where flex takeoffs aren't allowed even if environmental and runway conditions allow it (takeoff behind a heavy, windshear, etc). It sucks having to rush to get speeds reset and the flex removed when tower puts a heavy in front of you at the last minute.
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ACARS, wussies!!!!!!!!:sarcasm:
 
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