PPC Flashcards
How is MTA effected by bleed air?
Engine Anti-ice- 20% off the top
Cockpit/Gunner heat- 5% off the top
Will you see the MTA in the cockpit if you have two seperate ETF’s?
No, each engine will go to its respective MTA
If you are hovering at GO/NOGO Q in IGE, what Q will you pull OGE?
MTA
How much weight is equivilent to 1% Q?
200lbs
What is the difference between max rate of climb and max endurance?
Max rate of climb is corrected for >1400fpm climbs
When is Max allowable GWT a structural or environmental limit?
It is an enviromental limit when it is <22000lbs
What is gross weight?
Gross weight is the total weight of the helicopter and all its contents
When would you use max range airspeed?
To produce the greatest flying range with the minimum amount of fuel
What is ATF?
Aircraft Torque Factor
Average of the two seperate ETF’s
Ranges from 0.90-1.00
What does single engine indicated airspeed represent?
The upper and lower limit for single engine straight and level flight at 2.5 min contingency power.
When is MTA a structural limit vs an environmental?
MTA is a structural limit when in coincides with Q limitations, environmental when its lower than Q limitations
Why is MTA higher at cruise than at a hover?
RAM air cooling the engine
What is ETF?
Engine Torque Factor
The performance of an engine at 35degC
Ranges from 0.85 to 1.0
How does beed air effect cruise fuel flow?
Engine Anti-ice -100lbs/hr
Heater- 20lbs/hr
Heater & AUX- 30 lbs/hr
What values must be read when doing dynamic in flight performance?
MTA
Max allowable GWT OGE
Q required to hover at max GWT IGE/OGE
Aircraft GWT
What is critical Torque?
The torque that if you are pulling above and you have an engine failure, you will be unable to maintain straight and level flight
What does max angle coincide with?
Retreating blade stall
When would you use max endurance airspeed?
Whenever you want to remain airborne for the longest duration possible
Least amount of drag effecting the aircraft
What is min/max airspeed?
The minimum and maximum airspeed that you are able to maintain straight and level flight at MTA
When does a PPC need to be recomputed?
Increase of 500lbs
Increase of 5degC
Increase of 1000’PA
Change in +/- 0.05ETF
What is operating weight?
Basic weight + crew and required equipment
What happens if you pull over the MTA?
You droop the rotor
What is torque ratio?
ATF/ETF corrected for planned temperature (the actual performance of the engine)
What hapens if you exceed VNE?
You can get into retreating blade stall, as well as cause damage to the aircraft.
What is basic weight?
The weight of the aircraft with hydraulic/oil systems full, trapped fuel, and mounted equiptment.
What is max continous torque?
The torque that you are able to continuously pull without entering 30 min TGT limitations
What can cause an innacurate predicted hover torque?
Environmental conditions
Ground surface
Inaccurate computation
Aircraft is heavier or lighter than predicted
What is MTA?
Max Torque Available
The amount of torque the engines are
capable of producing without exceeding
TGT limits and drooping the rotor.
When must dynamic in flight updates be made?
With the intent to take off or land within 3,000lbs of max allowable GWT
Increase of 5degC
Increase of 1000’PA
