Delta goes off runway in Atlanta

Cass said:
Ha I'm wondering the same thing. Maybe didn't not have enough time? If it was pulled up right next to the drop off, things would have happened quick.
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Ok, I was kidding, that's funny. I don't know the 737, basically don't use them below 40kts? You need forward speed so you take air from in front of you vs off the ground. When you go into beta you have a lot of dirt and debris kicked up, and you don't want it to go into the engine. Different aircraft have different min beta speeds, but I'm sure the 737 is above 10 kts.
 
ProudPilot said:
Ok, I was kidding, that's funny. I don't know the 737, basically don't use them below 40kts? You need forward speed so you take air from in front of you vs off the ground. When you go into beta you have a lot of dirt and debris kicked up, and you don't want it to go into the engine. Different aircraft have different min beta speeds, but I'm sure the 737 is above 10 kts.
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Would that have to do with the cascade design? Seems like I'v seen a DC-9 "push back" from the gate using TR. Granted they use the bucket type and have the motors up high in the back.
 
ProudPilot said:
Different aircraft have different min beta speeds, but I'm sure the 737 is above 10 kts.
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Beta? There is no beta on a jet. The fan angle is fixed, so you can't get it to a beta angle. Reverse is achieved either through buckets or cascade reversers. Most jet manufacturers recommend having the reversers stowed below 40-60 knots, depending on type. However, many types are authorized for powerback under certain circumstances. In an emergency, like when your airplane is about to go off a hill and sustain major damage, you wouldn't be paying much attention to minimum recommended reverse speed, of course. That said, I'm not criticizing the mechanics. Maybe they just didn't have enough time to get the reversers out.
 
With those type of reversers, they're largely just noisemakers.

Now the mighty venerable DC-9 series of jets, oh yes.
 
Cass said:
Would that have to do with the clamshell design? Seems like I'v seen a DC-9 "push back" from the gate using TR. Granted they use the bucket type and have the motors up high in the back.
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Yeah, we're authorized for powerback with the 717. The whole DC-9 series is. We were also authorized for it on the CRJ at Pinnacle, although I don't remember ever doing it.
 
@Everyone , Before it flames up, I meant reversers. I was looking through my king air manual and my mind was on beta. My apologies, whip me down good.

However, yes, the DC9 is different because the engines are up higher and they aren't "thrust diffusers." Most jet engines you're basically just blowing the bypass air out the sides. If it goes forward, so much the better. It dramatically reduces your forward thrust, helps to kill lift and therefore combined really help the brakes work better. Even with a prop aircraft, beta doesn't necessarily cause reverse thrust, just nil thrust. If stopped, yes they can go backwards in certain circumstances. Not every aircraft can do it because of the gear. If the main gear are too far forward, going reverse will just cause a tail stand. Due to the DC9 bucket reversers, high mounting and heavy nose, it can go backwards at the cost of significant FOD that can damage the aircraft and ground crew. I know the C130 can if OK'd, but it causes damage and can damage the engine due to reduced intake air and higher EGT.

I hope that makes up for saying BETA when I was too tired to know. I have to start realizing I shouldn't type late.
 
TRs are funny animals.

Lear 55 w/ translating cowls - SUPER DUPER effective
Hawker 800 w/ clamshells - makes a bunch of noise and nothing more
Challenger w/ translating cowls - somewhat effective, but not really
 
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