Atr 42-500 No Go Items

[pilotsaab]

after going through the fcom1 and fcom2 and consulting even senior copilots ive hit rockbottom ,,,can anyone please tell me WAT ARE THE NO GO ITEMS for this plane!!! please dont say engine failure before v1..

And yes,somebody asked me this question abt the atrz hotstart,, - 1.What is hot start ?

2- During hot start why does the ITT first drop and then rise?

heres' my answer ,,please shed some light,,hot start is when ure operating in high temperatures and ure itt is beyond 200,,so u wanna start the engine but dont want the itt to burst 900degress,,which calls for the memory item,,so wat u do is u turn off the bleeds and let the engine cool down first when starting the engine coz of more air hitting the internal part of the engines and its not being bled,,and then ofcourse the fuel cooled oil cooler,,which when u start the engine the itt drops right??this is wat i get ,,the cool fuel introduced cools down the engine oil which transfers the heat to the fuel,,this lowers the itt so that when temp is 160 u can start ,,after starting engine u wait for the itt to drop,,,

[Mach E Avelli]

The no-go items are *anything NOT mentioned in the MEL plus items that are in the MEL but with conditions that can't be met on the particular flight.
An example could be something allowed under the MEL for flight by day only - therefore is a no-go at night.
*Let's say an ITT gauge is NOT mentioned. It means it is a no-go.

MEL does not apply to minor stuff like seat covers - there will be a statement in the preamble about that.

If an engine has been running recently the residual ITT drops initially as engine is cranked due to cooler air blowing through it.

[no-hoper]

Hotstart is when the amber light on the ITT indicator comes on(815°).
During an engine start with ITT above 200° you should give fuel at 20%Nh
instead of 12% with cold engine.
The fuel/oil heater/cooler has nothing to do with the ITT during startup.
Bleeds are normaly in off,but i don`t think it will make a difference because the bleed valves are springloaded closed and a certain pressure is needed to open them.On 72 and 42-500 the MFC has a time delay to open function to keep the bleed valves closed for some seconds after engine start.The drop of ITT on the first seconds was explained earlier.The drop in ITT after lightup and the second peak are related to the opening of the
secondary fuel nozzles.
Normal reasons for a hotstart are:fingertrouble,EEC u/s,bat start,tail wind,
propbrake on,worn fuel nozzles,GPU cut out.

[pilotsaab]

so ure saying that the FCOC has nothing to do with the itt of the engine,,

[no-hoper]

complete correct

[pilotsaab]

i was sitting on the observers' seat and noticed that the itt was past 200c and the fuel temp was relatively more than it should have,,the pilot mentioned that the fuel temp is high because of the fcoc,,what is that:confused:?and then they performed the hotstart,,

[pilotsaab]

he specifically pointed at the fuel temperature indicator,and then said it was coz of FCOC?

[GoDirect]

The FCOC is the Fuel Cooled Oil Cooler - the fuel cools the oil and the warmer oil warms the fuel - quite ingenious really. 2 jobs at the same time.

[no-hoper]

On all ATR:
Fuel filter/heater assy upstream of HP fuel pump/HMU to prevent icing of the fuel.Engine oil is used for fuel warming,the sensor for fuel temp is located here as well.
With a stopped engine the temp indication is rising due to no more flow.
Often problems with the thermostat inside the assy,will lead to move the pointer out of the limit.Still nothing to do with Hotstart !

On ATR with newer PW 124 and all PW 127 engines there is an
additional Fuel cooled oil cooler (FCOC) installed.
It is downstream of HP fuel pump/HMU using high pressure fuel (metered)
to cool the oil going to the Reduction gearbox.(Higher loads from the
stronger engines).
No temperature indication from this assy.

[pilotsaab]

so what ure saying is that those fuel temperature indicator are basically to indentify whehter the fcoc is working and the fuel heater /filter are doing their job or else there are chances of fuel ice ,,and this has nothing to do with the hot start,,that a completely differnt thingy,,,okay,,,

[FLEXPWR]

No offense, but a lot is answered in the FCOM1 Ch.17.

You should have a look, the FCOC is (although briefly) explained, and on the ground with engines recently shut down, the fuel line temp indicators (not the fuel tank temperature) will rise to max value. This is normal, and further reading should make you realise it has nothing to do with a hot start... The "hot" fuel will vaporise even better on the next start.

As a rule of thumb, the max 200c residual temperature can be seen as the limit for a normal start up, where the CL goes from FSO to FTR (fuel opening) at 10% NH. If the residual temperature is higher, you have 2 options: If on GPU, there is absolutely no harm in performing a dry crank to cool off the hot section. If you are on battery, you can open the fuel at 19%, as recommended by the manufacturer.

I also have seen airlines opening at 20% NH in hot/high conditions, it works just fine.

Now about the bleeds: they are not used during the start sequence and forced closed. Only the monitoring of the bleed position is using power (lack of electricity or air pressure will also close the bleed valve), which is minimal, but the bleed Pb's need not be in the OFF position. They re-open 30 sec after the start sequence is complete.

There is however something useful to be done with the bleed valves, but it is before engine shut down. If you switch OFF the bleeds about 1 or 2 minutes before shutting down the engine, the hot section core of the engine will have a much less residual temperature, thus less turnaround time or risk of an overtemp... if your turnaround is less than 30 minutes, don't bother shutting down #2, and keep hotel mode.

Flex

PS: Chapter 7 of AFM gives a list of the MEL items that shall not be combined, otherwise they become a NOGO. Maybe that was what you were looking for?

[pilotsaab]

thanks flex,, machevelli,,no hoper,,and godirect:ok:,,so can u then explain me what makes the itt lower then 200 degrees when the starter pushbutton is pressed and the fuel opening is delayed till nh 20%,,,isnt it the delaying for combustion,,@flex,,there isnt any chapter 17 in my fcom1,,its atr42-500,,:E

[Mach E Avelli]

When you have high residual ITT from a previous flight, it is always good practice to let the engine crank to the limit of the starter motor's capability before introducing fuel. If it will go to 20% Nh, let it get there before introducing fuel; if it won't crank past 15%, too bad, run it to its time limit then put the fuel in.
Or consider a 'dry motor' first to pull the ITT down, let the starter cool off for a couple of minutes, then start. Don't worry about reducing starter motor life by such abuse. Starters go for a long time, so if you reduce one's life by say 100 hours it won't be much in dollars per hour. However engine hot section overhauls are much more expensive if the engine suffers too many hot starts or has to be removed before its TBO.

[FLEXPWR]

Yeah, whatever chapter says "powerplant" on it...I am sure you're big enough to find it. I've flown the ATR all variants for more than 8 years, and on 4 continents, but not recently, so my memory of TOC numbering may not be up to date. :ouch: ATR made a point not to follow ATA chaptering for the FCOMs, not to mention the "great" books they pull out for Normal ops...even more confusing! :}

[speedsalive]

Hi. any ATR driver get me an MEL for the 42/500

thanks