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Star engine 1 and 4 problem


Attilio Cardone

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Attilio Cardone

 

Until a few day I had no problem.
Now as a procedure, I first turn on the 3 and then the 2.
During the pushback sept the bleed air panel correctly by opening the crossfeed valves.
When I go to turn on the 4 I do not get any rotation. Equal for the n. 1.
I have to resort to ctrl + E

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Fraser Gale

As posted above, plus if you turn on the air conditioning groups "as you go" then there is reduced air for starting, so even with the ground idle switches at Hi you might need to open the corresponding throttle of the already running engine by about 2% to get the other engine turning. 

It is easier to leave the air con off until everything is running, but more comfortable for the passengers if you switch each group on as each engine is started.  

Frazz

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Attilio Cardone
2 hours ago, Mike Ionas said:

When you try to start 4 & 1, do you have the idle switches to high?

Yes

1 hour ago, Fraser Gale said:

As posted above, plus if you turn on the air conditioning groups "as you go" then there is reduced air for starting, so even with the ground idle switches at Hi you might need to open the corresponding throttle of the already running engine by about 2% to get the other engine turning. 

It is easier to leave the air con off until everything is running, but more comfortable for the passengers if you switch each group on as each engine is started.  

Frazz

When I start the engine, air conditioning groups are OFF

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Kyprianos Biris

If the high idle does not help you just need a bit more. It depends on atmospheric conditions.

In such cases e.g. when I start No1 with crossfeed bleed from No2 I just power up a tiny bit No2.

Once No1 fires up I reduce No2 to idle and close the crossbleed.

While I do the above and, say, No4 is still not started, No3 feeds bleed air to Air Conditioning.

Once No1 is started, No1 & No2 feed Air Conditioning for the cabin while No3 crosfeeds pneumatic pressure for No4 start. If No3 idle is not enough I power up (just a tiny bit) No3 until I get rotation.

You must open and close Air Conditioning switches every time you don't want to suck air from the sources you want available for respective engine starts.

Concorde engine starting is like playing Piano ;-)

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AdrianSmith

Condition valves should be OFF for a cross bleed start.

For the length of time it takes to start 1&4 (literally two minutes) the highly pampered Concorde passengers are not even going to notice any discomfort in that short a space of time.

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Fraser Gale
3 hours ago, AdrianSmith said:

Condition valves should be OFF for a cross bleed start.

For the length of time it takes to start 1&4 (literally two minutes) the highly pampered Concorde passengers are not even going to notice any discomfort in that short a space of time.

Sorry but this is incorrect.  If you watch the ITVV program very carefully during engine start you will see after starting engine 3, he opens the bleed valve followed by the two cross-bleed valves and both the number 3 & 4 conditioning valves.  This means with engines 2 & 3 running all four conditioning groups can be running for the pushback which in a New York summer (originally Bahrain which would have been hotter) would be considered necessary.  

The only use for the engine idle hi/low switches was to boost the N2 in order to assist with starting, they served no other purpose which is why the solenoid holding of the switch to Low was deleted in the early days and the switch remained at low for the rest of the flight.  

Frazz

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