Dallas Bump???
Warning Toxic!
Disgusted of Tunbridge
Disgusted of Tunbridge
Joined: Jan 2005
Posts: 4,011
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From: Hampshire, UK
http://crpit.com/confpapers/CRPITV47Williams.pdf
When an aeroplane climbing rapidly is due to level off below another aeroplane, and causes a nuisance TCAS warning despite there being no danger, but due to the rate of climb and rapid closure, still generates an RA.
When an aeroplane climbing rapidly is due to level off below another aeroplane, and causes a nuisance TCAS warning despite there being no danger, but due to the rate of climb and rapid closure, still generates an RA.
We have a 'Denver Bump' but that was slightly different. 'Twas a EEC 'throttle push' to allow the normally asthmatic GE90 to get out of KDEN
Joined: Feb 2002
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From: The Sandpit
Dallas/Denver or just simply BUMP,
'Tis a term used when a little extra oomph needs to be supplied to get the a/c out of (usually) hot and high airfields. I know it is fitted to GE90, V2500 and I think some operators CFM56's.
What it does is to provide extra cooling to the engine casing via the active turbine clearance control system. This further reduces the tip clearance and thus tip losses, so increasing engine efficiency and power for a given throttle position.
The trouble is that it reduces the clearance to such an extent that tip rub takes place so in the long term it actually degrades the engine efficiency. That is why a bump take off has to be recorded in the log because after a certain number the engine must be removed for inspection/overhaul.
'Tis a term used when a little extra oomph needs to be supplied to get the a/c out of (usually) hot and high airfields. I know it is fitted to GE90, V2500 and I think some operators CFM56's.
What it does is to provide extra cooling to the engine casing via the active turbine clearance control system. This further reduces the tip clearance and thus tip losses, so increasing engine efficiency and power for a given throttle position.
The trouble is that it reduces the clearance to such an extent that tip rub takes place so in the long term it actually degrades the engine efficiency. That is why a bump take off has to be recorded in the log because after a certain number the engine must be removed for inspection/overhaul.
Joined: Aug 2005
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From: fairly close to the colonial capitol
Denver Bump:
Also applies to some JT8 powered MD-80s - manually set the EPR to 2.03 (90 degree day) as opposed to the normal 1.98 max takeoff thrust. Usually only authorized domestically at KDEN, hence the name.
Dallas Bump:
The Bump-Up was also a more common event when the vertical buffers were larger.
Nice bit of reading on this Rainboe.
'Tis a term used when a little extra oomph needs to be supplied to get the a/c out of (usually) hot and high airfields. I know it is fitted to GE90, V2500 and I think some operators CFM56's.
Dallas Bump:
The Bump-Up was also a more common event when the vertical buffers were larger.
Nice bit of reading on this Rainboe.
Joined: Sep 1999
Posts: 5,552
Likes: 25
From: ME
We started off with reference to TCAS and ended up with engines 
We have the option of using a TAKEOFF THRUST BUMP... Its just another rating (TO-B, I believe), i have never heard of it referred to as "airport name-bump"...
Mutt
We have the option of using a TAKEOFF THRUST BUMP... Its just another rating (TO-B, I believe), i have never heard of it referred to as "airport name-bump"...
Mutt
Joined: Mar 2000
Posts: 8,571
Likes: 3
From: Arizona USA
And, let us not forget, as long as RR RB.211 engines have been mentioned, that there is also a bump thrust available for the TriStar, both the -22B and -524B402 models.
The basic -524B02 used at SV, was interesting in that it was a derated engine already, so altho a bump thrust rating would have been useful on some occasions, one was not published...you had to write to Rolls Royce for the data.
I mentioned this to the L10 fleet manager one day and his reply was...'shhhhh, say nothing, please, we have enough problems with some of our pilots as it is.'
The basic -524B02 used at SV, was interesting in that it was a derated engine already, so altho a bump thrust rating would have been useful on some occasions, one was not published...you had to write to Rolls Royce for the data.
I mentioned this to the L10 fleet manager one day and his reply was...'shhhhh, say nothing, please, we have enough problems with some of our pilots as it is.'
Top Dog
Joined: May 2000
Posts: 2,098
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From: Close to FACT
Ah 411A, thats like trying to get an answer out of Boeing for some of their non-sensical/non-mathematical calculations. Typical answer is " we don't have the engineering resources to answer you question " = sod off and leave us alone, like it or lump it.
