Reverse Thrust!!!!

[ipilot]

hey!! guys,
recently I travelled with an airline on a DC-9 30 series. the pilot used reverse thrust for push back. i'm a kid pilot and what i'd heard that u can't use reverse thrust untill at a certain speed and certainly not standing still in a jet. another thing was that he had to move forward a bit before he could deploy the reverse thrust. any insight on this will be of great help. thanks in advance to everyone....
Happy new year.

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[banned username 2]

Some aircraft are certified to use reverse thrust for backing up.... Some are not....

The Falcon 20 I used to fly recommended stowing the reversers by 60 kts on landing... The Falcon 900EX I fly now has no such liimitation, and is actually certified for backing the airplane....

Each airplane is different....

Hope this helps...

 

[ifly4food]

It's called a powerback and it's fairly common in the DC9 series as well as 717s and 727s. The roll forward is to get the flat spots off the tires and to spool up the engines. The roll back is by reverse thrust.
With most a/c you wouldn't want to go into reverse below a certain speed, especially those with wing mounted engines due to ingestion of debris. However, the aircraft I mentioned are approved for this maneuver.

 

[ipilot]

thanks to you guys. i knew that i'd read somewhere about the speed thing. but ya it has to do with the airplane. i think the engines being on the tail helpes resolve the debrie issue. can i add another question, does it has to do anything about the reverse mechanism being used or its just the certification? i think different aircrafts use different types of reverse mechanism? thanks again...


_____________________
Check that its three greens.....

 

[banned username 2]

Both.....

 

[avbug]

We used to back the Herc all the time with reverse. There are limitations, among them the application of brakes while in reverse. Some airplanes will squat right down and fall on their tail if braked in reverse, and the herc was no exception. There are usually specific limitations on time, temperature, etc, when operating reverse thrust below a certain airspeed.

 

[enigma]

DC9

You can use reverse in the DC9 series to back up as long as you don't exceed a certain level of power. My company does not allow powerbacks, so I'm not totally certain, but I believe that 1.2 EPR is the max power setting for powerback. 1.2 EPR is essentially high idle.
regards