Max Torque Allowances at Different Speeds
Вставка
- Опубліковано 17 вер 2024
- In most helicopters the pilot can pull more torque at a lower speed and needs to reduce the torque above a certain speed.
Click Subscribe to be notified of future EuroSafety Videos
www.eurosafety.us
training@eurosafety.us
Another really informative video Glen. Your video's offer so many valuable nuggets of information that often aren't covered in any great detail in the flight manual. The real value in these forums you offer comes from understanding why a limitation exists; That greater level of knowledge reinforces the importance of the limitation and what the possible consequences are if the limitation is exceeded.
Much appreciated
Thanks eurosafety for making such interesting videos you are number one congratulations!
Thank you very much!
Nop I expressed myself wrong. So sorry...english is not my native language. I will try again: TOP limitation: 5 or 30 minutes and no more than 40 KIAS applies to TRQ, NG and TOT ...I do not understand why the 40 KIAS limit applies to NG and TOT as it applies to TRQ. It would have more sense to stablish the 40 KIAS limit just to TRQ and not the other two. Why AIRBUS applies the 40 KIAS limit in TOP to NG and TOT? Again...apologizes for my english!
Thank you for the explanation. I was told it was because of aerodynamic limitations on various components of the rotor head. Never made any sense. Your explanation makes total sense
Crystal clear answer! Brilliant instructor! Question: Why the TOP limitation of 40 KIAS equally apply to N1 and TOT and not only to TRQ? Guessing....just to simplify?
If I understand your question correctly... Torque is a transmission limitation whereas N1 (NG) and TOT (T4) are engine limitations.
thanks for producing this video, I believe I asked you this very question. Cheers
Yes you did! I made it after your question. Good idea
So good! Thank you.
Our pleasure
Thank you for your short but very informative videos! Can you elaborate on the claim that the tail rotor is completely off-loaded at 40 KIAS? Or is rather that at 40 KIAS and above the tail rotor is increasingly off-loaded? And for simplicity the Tq limitiation is limited to 94% instead of it being depended on several ranges of airspeed? The reason I am asking is that I have previously requested Airbus for an airspeed at which the vertical fin complety off-loads the tail rotor to aid me in the case of tail rotor drive failure. Their response were that it depended on too many variables such as weight, density altitude, configuration, etc. I further requested a recommened flight speed that would allow relatively coordinated flight characteristics to which they responeded to maintain Vy or higher (optimum climb speed = 55 KIAS). Could you shed further light on this matter? Thank you
Ok we are really going into the weeds here. First Airbus/Eurocopter/Aerospatial does not share engineering data for the most part. When we have information like, the vertical fin off loads the tail rotor, the engineers have simply given us that number. They dont show a graph showing, for instance, off load amount for 0-60 kts. Engineering, also, is often not an exact science, there are many variables at different conditions and they find a happy medium for alot of limits. At the end of the day its about aerodynamic performance and TBO. When looking at the transmission limit of 94%, they found that aerodynamically it works and time on component is achieved. As an example if you only need 2 minutes on that transmission to save your life, you can pull the guts out of it and it will work, but now TBO may be 3 minutes. Im sorry if this is not definite answer you were looking for. But the best I can do is engineering is a pursuit of averages and variables that come together to create a mechanism that works. There are no exact numbers in reality.
What happens when the torque limitations are exceeded?
For 1 or 2 seconds above 104% what is the maintenance required?
Yes, any limitation that is exceed a maintenance action is required. Regarding the specific action required will be dependent on the amount and time the over limit was exceeded. For a light over limit an inspection is required. If sever enough the transmission has to be overhauled.
Love these videos!
Can you shed some light as to why the TRQ transient in the regular B2 is 10 seconds, but in the B2 with a VEMD, the TRQ transient is 5 seconds? Thanks
This is a very good question, one that I only have a guess on as the engineers at Airbus have never told us why. This is Glen Whites guess... on the B2 VEMD they wanted to make all the transient times the same to make it easier. Since the lowest transient value is 5 seconds, they made everything 5 sec for that model
@@EUROSAFETYTRAINING Thanks for the insight!
Glenn can you describe a torque turn in the Astar?
This is not a term I am familiar with. Its not a term we use with AS350s. I am assuming you are referring to the nose rotating when collective is applied without pedal input. If you were not to manipulate the pedals when you raise collective the nose will rotate to the left.
Question Off topic.. What is the reason for the Strake on the B2 and why did they remove it from the B3/B3e modle Aircraft? Cheeers
Short and Long Answer.... Short: it was installed on AS350B2/AS355N to assist with tail rotor loads but it was apparent that it made the helicopter unstable, so they removed it from future models. Long answer: The strake works by creating a low pressure on the left side of the tail boom and a high pressure on right from the down flow of main rotor wind. If the controls are not moved it improves tail rotor performance by 5%. But when the controls are moved, including the pedals, the attitude of the helicopter will roll more or less as tail rotor thrust is applied (see pick up/set video we made). When this occurs the strake changes position in the down flow making its assistance variable and then causes more inputs to be made.
Hello again. I have a few more questions concerning the operation of the BA,B2,B3e Aircraft would you like me to ask them here, or do you have an emial I can send them too. Cheers
No problem.... glen@eurosafety.us
i like it
So as pilot when we transition from hover to forward flight we modify rudder or it happens automatically?
yes as you transition into forward flight the pedals are adjusted
@@EUROSAFETYTRAINING thx
I guess “as a pilot” it happens automatically. But maybe you ask this question “as a student pilot” (asking for a friend…😂)? Then the answer yes, it takes all available brain power to consciously and continuously adjust the pedals though-out the phases of flight.
@@TimToussaintokay captain! I was asking out of curiosity. I never flown anything except paper plan.