ERJ-145....

Cherokee_Cruiser

Well-Known Member
Hi, I could use some insight here from anyone (esp. you Kingairer !)


I've heard (uncofirmed) that several US carriers operating the Embraer Regional Jets have a STANDARD policy to NOT use the reverse thrust on runways greater than 7000 feet. Supposedly, this is because the spoilers and the carbon-made brakes can do the trick, and fuel is saved.

Is that really true?!?!?!? I mean can an airline really require that???? It's almost a safety issue just to save some money on gas.


All keeping this in mind with *a certain airlilne* pilots 'spooling' the engines up and back down (once on the ground) as a way to revolt having to pay for their own Pepsi onboard... the airline found out they were losing much more money on the fuel this way, and so stopped charging for a drink!
 

pilot602

If specified, this will replace the title that
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Is that really true?!?!?!? I mean can an airline really require that???? It's almost a safety issue just to save some money on gas.

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Yes. If the aircraft can be stopped using brakes/spoiler safely why use the reversers? There are a lot of maintenance and noise issues involved with reversers. It's cheaper to buy new brakes than overhaul or replace the engine(s).

That 7,000ft. clause is due to safety. If the airline came along and said the use of reversers is prohibited ALWAYS - that'd be a different story.
 

sorrygottarunway

Well-Known Member
"and the workers threw their shoes 'sabot' into the machines in protest, so they would stop working... thus came the expression, sabotage"
 

Kingairer

'Tiger Team' Member
You are correct sir! At my company we have thrust reversers on all of our aircraft, not all companies do. The thrust reversers arent even manufactured by the same company (Rolls Royce). There was a study done, and a company down in Brazil was getting longer use out of their brakes and they didnt even have reversers...This led to some head scratchin. The outcome, as you suggested, was due to teh make up of the brake and the fact that when heated it actually leads to a longer brake life.
We however do not have a 7000ft requirement or any number for that matter, and we are not looked down upon if we do use the reverses, but typically we open the buckets but do not use reverse thrust. Some folks still use them all the time anyways. Going into places like KeyWest, or using one of the shorter runways at PHL, its defintly a good idea to use them. They really dont do all that much and our numbers are figured without their use, so its just icin on the cake.
 

Cherokee_Cruiser

Well-Known Member
If I was on the 16000 foot runway in Denver, then fine, I dont think there is a reason to use it...

However, I always stick with the 'better safe than sorry' philosophy, and would much rather engage reverse upon landing rather than having to use them at the last second cause I'm running out of runway now...

Ah hell what do I know... I fly a Cherokee

So if it is a company policy to not use the thrust reversers on runways longer than 7000 feet, and a pilot uses them with every landing, can (s)he get in trouble??? (reprimands, etc)
 

Kingairer

'Tiger Team' Member
It should never come down to, oh no im runing of the runway, type situation. You should touchdown in the touchdown zone, and if you do, it really is a non event on a runway of any real size. Ive landed on the short runway in PHL that is 5000 feet or so. A runway like this we most certianly use reverse.
 
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If I was on the 16000 foot runway in Denver, then fine, I dont think there is a reason to use it...

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If I was landing on a 16,000 ft. rwy ina ERJ or CRJ it'd be a maybe if I used thrust reversers as the PF.

Now same situation but flying an MD-88/90 or 737-800 or 757. It'd be thrust reversers everytime when landing on a rwy 11,000 ft. or 16,000ft even if I landed on the "numbers" each time.


Matthew
 

Mr_Creepy

Well-Known Member
You are never required to use thrust reversers in any jet transport aircraft. They are always optional. Airport analysis is always figured with both reversers inop.

Besides, they really don't do as much as you think. The brakes are what stop the plane. I interviewed a guy once who thought reversers would stop a plane if the brakes failed. Yeah I suppose, but it would be a long way down the runway!
 

Derg

Cap, Roci
Staff member
Thrust reversers in most jet aircraft are more or less 'fun noise makers'.

They don't do a heck of a lot, but if the NTSB finds them stowed if you run off the edge of the runway, it'll show up in the report.

A real catch-22.
 

IrishSheepdog

Sitting in the median
I don't always use reverse, even at MDW. Ground idle works fine if you land in the touchdown zone. I do use reverse fairly often when it's windy and gusty. The rapid change between forward and reverse thrust helps quickly dispell lift should the airplane want to try and go airborne again.

Landing on speed, in the touchdown zone, you can stop in 3000 feet using only ground idle and brakes below 60 knots in the Saab. Like said above... noisemakers!

Remember: Chicks dig beta.
 

Tim06

New Member
I never use the reverse thrusters in th C152
You just make a hard 3 wheel landing and you stop in your tracks
 
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Thrust reversers in most jet aircraft are more or less 'fun noise makers'.

They don't do a heck of a lot, but if the NTSB finds them stowed if you run off the edge of the runway, it'll show up in the report.

A real catch-22.

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Yes,yes but very kool noise makers. In TUS I lived 5 miles from the airport and you could hear the noise from airliners doing reverse thrust that far away more especially in the morning when all the cargo planes come in to sit all day.

Hands down best airplen for loud reverse thrust MD-80 series aircraft next prolly a 727.

These new high bypass engines on the 737, 757,767,777 and Airbus aircraft are wimps.


Matthew
 
Also when piloting a commerical airliner and you flying over the "numbers" on final do you airline pilots pull the thrust levels all the way back to idle like we beginners do in our 152's & 172's to get the airplane into "ground effect" and float the rest of the way until the wheels make contact with the runway?

And what is the procedure for reverse thrust? Are the thrust levels all the way back to idle when you select reverse thrust or do you maybe inch then forward some to have a higher thrust on reverse so when you do reverse you have greater stopping power vs. being all the way on idle when reverse thrust is selected?


Matthew
 

chperplt

New Member
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I don't always use reverse, even at MDW. Ground idle works fine if you land in the touchdown zone

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Matt,

You can't compare the effect of beta range in a turboprop with the effect of reverse in a jet. That's comparing apples to oranges. Beta range provides much more stopping ability in the turboprop than reverse does on a jet.
 

Baronman

Well-Known Member
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And what is the procedure for reverse thrust? Are the thrust levels all the way back to idle when you select reverse thrust or do you maybe inch then forward some to have a higher thrust on reverse so when you do reverse you have greater stopping power vs. being all the way on idle when reverse thrust is selected?


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Depends on the aircraft/engine/TR manufacturer....

In the King Air 200 you can bring the throttles back to idle. You can lift the throttles over a gate and get the props to begin changing pitch or "reverse." *Note the engine doesn't reverse it's direction, nor does the prop, just the pitch changes.
If you pull back further, the engine increases it's output thus getting more thrust than just idle. As FLYchicago said, alot of times especially in a turboprop just changine the pitch of the prop is enough to slow you down and keep you on the ground.

In the jet I've flown (Lear24) there is an additional 2 levers just forward of the throttles which you can "pull up and backwards" to activate the reverse thrust. Again, sometimes you can just pop them open so that on roll out you don't have any forward thrust (essentially thrust attenuation) or you can pop them and add thrust by increasing the engine speed.

If all else fails and end of runway is coming......DRAG CHUTE next to co-pilots left leg!!! PULL ON IT!
 

IrishSheepdog

Sitting in the median
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I don't always use reverse, even at MDW. Ground idle works fine if you land in the touchdown zone

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Matt,

You can't compare the effect of beta range in a turboprop with the effect of reverse in a jet. That's comparing apples to oranges. Beta range provides much more stopping ability in the turboprop than reverse does on a jet.

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I know. I was just saying that reverse isn't always what it's cracked up to be, or always needed. I should edit my post to reflect that. Thanks for pointing it out though.
 

IrishSheepdog

Sitting in the median
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Also when piloting a commerical airliner and you flying over the "numbers" on final do you airline pilots pull the thrust levels all the way back to idle like we beginners do in our 152's & 172's to get the airplane into "ground effect" and float the rest of the way until the wheels make contact with the runway?

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First of all let me say my experience is in the Saab 340 and in the B-737-200/300/500 sims.

When we cross the numbers, we are working the power levers back to flight idle (or idle thrust in the jet). You flare as you would in any airplane, however the flare is somewhat different in a airliner. Instead of flaring and holding it off until stall, we flare, hold a specific pitch attitude (+/- a few degrees... we try for 4 or 5 in the Saab) and touchdown in the touchdown zone hopefully at Vref -5ish. Holding the yoke back and trying to work for a smooth landing will only get you A) landing long and B) a tail strike. A tail strike in the Saab happens at 13 degrees when the wheels are on the ground (struts compressed). Can't remember the angle in the 737. I think it was around 15 degrees. So basically, we are flying speeds down final while holding the glideslope, then reduce power in the flare, and touchdown on speed in the touchdown zone. A smooth landing comes from reducing power and flaring at the right time.

As for ground effect, we don't hang in there, we try to bust through it. We want to get on the ground and not float down the runway. Ideally, you want to land 1000 feet down the runway, and no more than 1000 feet past that. Any farther down the runway, go-around is a consideration.

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And what is the procedure for reverse thrust? Are the thrust levels all the way back to idle when you select reverse thrust or do you maybe inch then forward some to have a higher thrust on reverse so when you do reverse you have greater stopping power vs. being all the way on idle when reverse thrust is selected?

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In the Saab, going to reverse means lifting two power lever "locks" over "gates" that prevent going into beta range or reverse without wanting to. From idle, keep going back, you'll go into reverse.

On the 737, going into reverse means bringing the thrust levers back to idle, then reaching up on the two reverse levers forward and attached to the thrust levers. Pulling back slightly opens the reversers, and keep pulling back for more reverse thrust. Normally you don't pull them back all the way. Just about halfway, to 40% N1. If I remember correctly going all the way back on the reversers is around 60% N1.
 
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