A330 T.O. thrust
 

Are there any laid down limitations for an instance of where the engine(s) do not reach T.O. thrust. Our S.O.P. states "Check T.O. N1: Check that the actual N1 of the individual engines has reached the N1 rating limit before the aircraft reaches 80 knots. Check EGT." So if one engine is, say, 0.5% below the N1 limit, is that a stop call???

The only limit I have found relating to T.O. thrust is that, if there is 1% difference between the engines, record the difference in the Tech log.

TSFC
 

Thrust of an engine - i.e. takeoff power (or cruise) - can also be determined by the fuel flow, provided you know the thrust specific fuel consumption of the engine. Some Air Florida 737 pilots (DCA accident) failed to look at their fuel flow, as their EPR PT2 gages (JT8D) were frozen by ice, and probably never knew of that fact.
xxx
On 747 - JT9D-7Q engines, a FF of approximately 9000 KG would indicate a normal T/O thrust at sea level.
:ok:
Happy contrails

TOT
 

Thanks Bel. I understand and agree with your point, but I was after more specific details. If anyone has an idea please chip in.

Hola NoJoke -
xxx
Dont know your A-330 engines...
Give me your engine SFC (tell me KG or LBS)
Likely to be a number like .35...
Tell me your T/O rated thrust (in KG or LBS)
I will give your FF/ENG for MSL at 15ºC...
xxx
:ok:
Happy contrails

BelArg

I agree that knowledge of your type is very important. Interestingly, the profession is being dumbed down. Even Boeing, in its wisdom, suggests that there is no need for the lower EICAS display to be used routinely. This display, when selected to display engine data would include fuel flow. So, on the 747-400, you take off with only EPR, N1 and EGT displayed on the upper screen.:rolleyes:

Let us cry, TopBunk -
xxx
Ot should we...? - Our salaries are decreased anyway.
As they are proportional to the required airmanship levels of today.
xxx
Soon your F/O will be a Rottweiler or Doberman...
Captain's duty will be to feed the dog. Dog food might remain SCD.
And the dog duty will be to bite hard if you dare touching any switch.
Cave canem...
xxx
:E
Happy contrails

NoJoke
 

Your company SOP are mirror like my Airbus FCOM 4.3.12, which says :

• Before reching 80 knots :

- TAKE OFF EPR.....................................CHK
Check that the actual EPR of the individual engines has reached the EPR rating limit, before raching 80 knots. Check EGT.

No reference to any other powerplant parameter(s).
I consider yes.
If engine(s) do not reach TO thrust within 80Kts in all likelihood the risk not to meet all performance requirements is high. So, better to RTO before reaching 100Kts or above, when a RTO becomes "a much more serious matter".

Our company SOPs only allow for an EPR shortfall of 0.01, if greater than this reject, obviously prior to 80kts.

Hola HenryVIII -
xxx
Your SOPs are inspired by Air Florida, I assume.
Even if FF too much to understand - how about having a look at N1...?
Frozen EPR PT2 - Your EPR will be... perfect
xxx
:D
Happy contrails

May I submit a modest proposal, watch FF during a few take-offs and note it. It will give you a ballpark (your choice of ball :}) idea of what FF to look for. Then, make it a habit to check FF as power is set to the approximate take-off setting. FF will increase quickly and should be at the right flow before the engine has reached EPR or N1. I used it all the time on GE CF6s, worked well.

GF

SMOC
 

Is that just a local perception of the limitations, or is it based on Airbus recommendations? If you can point me in the right direction I would be grateful.

NoJoke, you pointed out the right item.

Despite the doubtful humor espressed by BelArgUSA, the text I reported is an OFFICIAL AIRBUS PROCEDURE, not my point of view or my company SOP (I stated that, pls verify before voice comments...).
In case of complaint please refer to Toulose and offer them your operational consulting.

Any other way to check the thrust setting based neither on Airbus nor company SOP, regardless its technical validity, is to intend as "just a local perception".

Fly safe.

Despite "my doubtful humor"...
 

To all concerned here... -
xxx
I believe in crosscheck of more than one parameter i.e. for engine power.
EPR is quite unreliable, compared to N1, as an example.
I am surprised at Airbus using only the EPR values to set power.
And that they do not use N1 as alternate power setting values.
In that case, with a failed EPR... your A-330 is grounded. No MEL deviation.
xxx
That your company SOP goes along with Airbus policy, surprises me.
Or are your instructor and check pilot staff replaced by computer CBT...?
For many years, I saw technically informed pilots improving/changing SOPs.
And this is not directed against Airbus only. Boeing needed some as well.
xxx
HenryVIII - I love your humor as well about your spelling of Toulouse.
You write Toulose... (to lose) - Appropriate, is it...?
Suggest you read the engine manufacturer's own operations manual.
Certainly, your engineering office has one. Or is it a prohibited publication...?
xxx
You gentlemen have ONE parameter for power settings.
For "Jurassic" 747s, we had 3 - EPR, N1, FF... EPR/N1 were published in AOM.
Our FF values were from P&W published data, and subject of classroom briefing.
xxx
HenryVIII - You sign "Fly safe" - I wrote my lines with ideas of "safer" yet.
xxx
:ok:
Happy contrails

Henry
 

I did not mean to doubt your word, and I didn't mean to imply that you are 'making things up'. Sorry if I offended.

NoJoke
 

NoJoke, I was not relating to you :ok: and when I highlighted your sentence was to agree with you ;).
I wrote my last post to reinforce the concept that we should all avoid "personal interpretations" but refer to official docs.

Luckily nothing is prohibited by us :), but I believe the pilots behaviour has to be ruled by the docs available as standard from the company to ALL of them. Such as AOM/FCOM or company SOP.
The pilots referring to engeneering or maintenance docs places themself out of the standard level of knowledge, sometimes creating problems rather then solving.

FF Trent 700
 

Hi There,

the FF parameter discussion interested me so I thought I would observe what happened on a take off. Tha parameters were:

EDDM 08R,
OAT 22C
W/V LV
PA 1500'
Q1021
TOW 197T
Flex 47
Conf 1+F

FF at EPR reaching target started at 8300 Kg/h per engine and steadily climbed throughout the take-off run to 8900 Kg/h. At no time did the FF stabilise at a particular figure. This may be a function of the MAESTO on the Trent, but I doubt it since the fan instability is below the EPR target. With that first (brief) look I am inclined to consider a FF target as being unhelpful in establishing whether the engine has achieved the correct thrust. Maybe the GE and Pratts are more stable on their FF during the T/O run.

Regards

TOD

[QUOTE]In that case, with a failed EPR... your A-330 is grounded. No MEL deviation.[QUOTE]
DEAR BEL
This not correct so: In case of inop EPR you can go on RR Engines in N1 Control mode for 10 days.(MEL 73-25-01-C)

EPR Mode is only an Indication for Thrust. Every Engine has a "in house" different EPR for a special thrust. To make it easier for pilots, the Engines get a EPR Trim, so that for example ENG1 and 2 have EPR 1,4 for FLEX TO, Thrust is the same, but differrent N1 and also EGT(but also here is a trim/equalisation).

Other Engines get a N1 Trim to indicate the same N1 for the thrust set.

The A330 gives You different warnings in Case of EPR malfunctions and/or Thrust diagree during TO, but there is no specific limit for that, only one FADEC selects a different EPR.
This failure is normally an indication for a broken EEC.You will get a different Warning before You will see a uneven EPR, because one parameter and/or control will run out of cycle.


rgds