DQ-143 Flashcards
Which avionics may be operated with battery power only?
The No. 1 VHF-FM and UHF radios as well as the associated KY-58 voice security systems may be operated on helicopter battery power.
With an APU generator failure explain how it is possible to engage the engine start system (both engines) without external power available.
I suppose we have an airsource from the APU, and only APU GEN does not work.
Power to the No. 1 engine start control valve is from the DC ESS BUS, which is energized by the battery with BATT switch ON.
Start #1 engine first, advance to fly to get RPM R high enough to utilize the #2 gen, energizing the #2 DC primary bus. This enables the #2 starter. From here, start #2 engine.
(“…utilize #1 gen”. I hope, “…to energizing the #2 DC primary bus” - Martin :)
If the aircraft is struck by lightning in flight, give a reason why an autorotation may be required.
If a lightning strike occurs whereby all helicopter electrical power and electronics subsystems and controls are lost (including the engine 701C 701D/CC DEC/EDECU and the engine-driven alternator), both engines go immediately to maximum power with no temperature limiter or overspeed protection. In addition, the 701C or 701D/CC engine overspeed may result in single or dual-engine shutdown without automatic relight. -> Autorotation
How would a dual generator or dual converter failure affect maximum torque available and fuel flow? If it occurs at night how long should the SLAB battery operate?
18%
SLAB should operate 24 min.
How would a dual generator or dual converter failure affect the ability to jettison an external load, ESSS, or cut a hoist cable?
Run off DC ESS Bus, so it would not be affected, as long as BATT is operational
During a single engine failure (hover) RPM R decrease to 92%, at touch down both main generators drop offline. Why?
Generator Underfrequency Protection is enabled by activation of the WOW switch.
