Starters Flashcards
cause of hot start?
weak battery
_____ _____ is when the engine fails to accelerate during a start.
hung start
2 common starters used today:
electric and pneumatic
If not used for starting ____ ____ are being driven by the engine to produce electricity for aircraft system use.
Starter-Generators
TBO for starter generators?
1000 Hour
ATA chapter for Starter generator.
ATA 80 (starting) ATA 24 (Electrical Power)
If looking for cracks on starter generator, where is the weakest area?
Splines
always inspect brushes for proper ______.
length
percentage of brush length for maintenance decision?
25%
Safety:
- battery disconnected
- pull cb and put warning flag
- make sure to mark all terminals and wire when you disconnect
Once v-band is removed dont let the weight of the starter generator hang off of the drive shaft.
to prevent the shear from breaking
Where do you get energy for starting large starter generators?
APU
Where do you get air for Pneumatic starters?
- APU
- crossfeed from running engine
- Ground start supply
This type of starter is a low pressure, axial flow air motor that has a very high power to weight ratio.
Pneumatic starters
Prior to Boeing 787 Dreamliner, what kind of starter do they equipped?
pneumatic air turbine starters
For an electric starter to have the same power output as a pneumatic starter, it would be approximately ____ heavier.
5 times
How much air required to run a pneumatic starter?
45psi at flow rates 50-100pounds per minute
654 to 1308 cubic per minute
The turbine in the starter rotates at ____ - ______ rpm and is geared down by a ratio of 20-30 times to provide the high torque that the engine requires to rotate.
60k to 80k rpm and geared dow by a ratio of 20-30 times
These type of starters may have their ___ ______ oil system that requires between 4 to 12 ounces of oil for proper operation. They may also be connected to the main engine oil supply system.
own independent
Pneumatic starters will have a _____ _____ _____ and a ____ ____ to monitor the condition of the oil passing through the starter.
MAGNETIC DRAIN PLUG and a CHIP DETECTOR
-must be frequently inspected
(1st safety feature) Pneumatic Starters also have a ____ _____ which will break a predetermined gear train induced torque force to prevent damage to the engine.
Shear point
(2nd safety feature)
If the starter valve malfunctions and stays open, the air passing through the ______ ______ can only be accelerated up to the point of SUPERSONIC FLOW.
At this point a shock wave forms across the nozzle vane and slows down air to sub-sonic speeds.
Choked (Convergent) nozzles
Once the turbine is no longer providing power to the starter and engine reached a preset speed, centrifugal force overcomes the leaf springs and the pawls are thrown outward.
driveshaft is now disengaged from the pneumatic starter.
PAWLS are forced inwards by small leaf springs to engage the SPRAG CLUTCH RATCHET
Engine starting conditions:
Check the ____. Prior to starting any aircraft engine, make sure that there is ____ in the engine
oil, oil
