A-109E Power helicopter hyd. servos leakage rate
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A-109E Power helicopter hyd. servos leakage rate
Please help with the following ambiguity-what is your opinion/experience?
-Airwortiness Check item 16. calls for inspection of bleed holes for leaks from flight control servoactuators. (once a day)
-Maintenance Manual in Ch. 67-31-9 inspection (Fig. 67-59) says that hyd. fluid leakage from bleed holes (16 and 17) is not permitted - it requires replacement of servoactuator and even notification to AgustaWestland if leakage discovered.
-Maintenance Manual in Ch. 29-00-10 Leakage checks in Table 29-1 defines, that body (weep hole) leakage is allowed with 2 drop / 25 full stroke cycles in dynamic conditions, and in S-D conditions(static leakage through dynamic seal) says: "No drops during the first 4 h"
1. What is meant by this limitation? 4 hours after last flight there shall be no leaks, but after a night in the hangar, leak is acceptable? 4 hours after installation of new OH actuator there shall be no leaks????
2. So, what should a maintenance technician do when performing Airworthiness check in the morning and discovers fluid leakage from bleed hole (weep hole) of rotor servoactuator?
-declare helicopter unairworthy and replace actuator?
-perform leakage test with ground power unit, to determine dynamic leakage rate? If yes, when to repeat such check, if first check determines, that leakage is within limits (less than 2 drop per 25 full cycles)?????
I checked with several maintenance engineers, that finished A-109E type rating course at AgustaWestland facility, and they all claimed, that they were instructed, that no leakage is permitted at weep holes of mentioned servoactuators.
Comments / suggestions well appreciated. Please do not point me towards AgustaWestland, as there was no response so far. (one month after inquiry)
-Airwortiness Check item 16. calls for inspection of bleed holes for leaks from flight control servoactuators. (once a day)
-Maintenance Manual in Ch. 67-31-9 inspection (Fig. 67-59) says that hyd. fluid leakage from bleed holes (16 and 17) is not permitted - it requires replacement of servoactuator and even notification to AgustaWestland if leakage discovered.
-Maintenance Manual in Ch. 29-00-10 Leakage checks in Table 29-1 defines, that body (weep hole) leakage is allowed with 2 drop / 25 full stroke cycles in dynamic conditions, and in S-D conditions(static leakage through dynamic seal) says: "No drops during the first 4 h"
1. What is meant by this limitation? 4 hours after last flight there shall be no leaks, but after a night in the hangar, leak is acceptable? 4 hours after installation of new OH actuator there shall be no leaks????
2. So, what should a maintenance technician do when performing Airworthiness check in the morning and discovers fluid leakage from bleed hole (weep hole) of rotor servoactuator?
-declare helicopter unairworthy and replace actuator?
-perform leakage test with ground power unit, to determine dynamic leakage rate? If yes, when to repeat such check, if first check determines, that leakage is within limits (less than 2 drop per 25 full cycles)?????
I checked with several maintenance engineers, that finished A-109E type rating course at AgustaWestland facility, and they all claimed, that they were instructed, that no leakage is permitted at weep holes of mentioned servoactuators.
Comments / suggestions well appreciated. Please do not point me towards AgustaWestland, as there was no response so far. (one month after inquiry)
