View Full Version : BUMPS
cabbage
2nd Nov 2001, 23:00
ok - heres the deal - been flying the scarebus 320/321/330 for a few years now. starting new job shortly - but still on the same types - (granted not an ideal time to be moving employer!!) been browsing their ops manual - checklists etc - and have come across the term BUMPS in the after start checks.In 5 years on the airbus ive never come across this. please someone shed some light for me.
Pengineer
4th Nov 2001, 16:47
From what I remember it refers to a thrust bump option which was available. I specifically recall the 'Denver Bump' option which was available for aircrft operating out of Denver airport.
I think it was a sort of preset derate option but I'll have to check with Malcolm tonight as he told me he knows everything!
I seem to recall 'bump' switches on the throttles of some of the A320s I've worked on in the past (they had V2500s).
The ones I see now have CFMs and I haven't seen anything about bumps for a few years now.
http://www.stopstart.fsnet.co.uk/aircraft2/a320.gif
http://www.stopstart.fsnet.co.uk/mica/FarSKid.gif
Pengineer
cabbage
4th Nov 2001, 21:03
Thanks Peng
My new operator uses v2500 on their 320s which explains why ive not come across it before.
Gents
Basically, "Thrust Bump" is a system fitted to the IAE V2500-A1 engine, and it is used to obtain an additional thrust capability during takeoff. It is selected by 2 guarded red pushbuttons on the thrust levers, and activates when the thrust levers are advanced to the TOGA detent after selection via the pushbuttons. It corresponds to an approximate 10% increase in thrust. There are various other engagement and disengagement conditions which I can't be arsed to type out. I'm sure you get the idea! It can be used in two engine or single engine operation.
It is not fitted to the later versions of the V2500 (eg the A5 version) due to their increased thrust.
If you need any further info on the above - please feel free to email.
Hope this helps :cool:
Enjoy your new job!!
[ 04 November 2001: Message edited by: SLT ]
Pengineer
5th Nov 2001, 15:59
Thats what I nearly said!
http://www.stopstart.fsnet.co.uk/mica/FarSgoof.gif
Pengineer.
GotTheTshirt
8th Nov 2001, 21:37
L1011 used Thrust Bump which did exacly what SLT and Pen. said but without the fancy Airbus switches !! :rolleyes:
It was done manually to provide additional thrust under certain limiting take off conditions conditions, basically setting a higher EPR than normal.
Like all goodies nothing is free and there were life considerations if used a lot!
O\ZON
10th Nov 2001, 07:20
hi.
re bump on V2500.
if u need that extra bit of thrust "bump" for a go around. u must first select it for takeoff
O\Z
The L10, instead of fancy red buttons, used that very useful option for setting bumped takeoff thrust.....and was known as...the Flight Engineer. Also has been known as very useful for the external checks in the rain....and for keeping the F/O awake on long sectors...