Jump to content
Aero Precision provides OEM part support for military aircraft operators across more than 20 aircraft

Bleed effect on max power

Recommended Posts

Hello dear herc crew! can some one kindly guide me about the following, please:-

As per graph of bleed effect on max power, with all bleed on the torque at sea level is lesser as compared to that for 2000 feet and 4000 feet and higher pressure altitudes. Lets say we start with 15000 thousand inch pounds, and see torque against sea level, then 4000 feet then 8000 feet; the torque keeps rising? why the effect of drawing all bleed (air conditioning, pressurization & anti-icing) is more pronounced at sea level aa compared to higher pressure altitudes?


Link to post
Share on other sites

In which publication is this chart located? There are many calculations you can make on this chart and it is not one I am familiar with (in this configuration). There should also be an "explanation" paragraph that precedes the chart if you could post that as well. I would like to see how this chart is utilized.


Link to post
Share on other sites

Thanks for sparing your valuable time. Well the explanation paragraph just tells to use this graph for the effect of drawing all bleed (including anti icing) on the torque at max power static with 1077 TIT. If you observe the graph, first help we can seek from it is to calculate the effect of drawing all bleed at various aerodrome elevations. In that, lets say my torque with normal bleed was 15000; the corrected torque at sea level comes out to be 10500 inch lbs and that at 4000 field elevation comes out to be 10900. Similarly, at 8000 feet field elev it comes out to be 11150 inch lbs against same 15000 inch lbs torque we started with. What i cant understand is that why am i getting greater torque at a higher field elevation when i take all bleed? As per the graph, the lower the field elevation, greater the torque loss due to switching the anti icing systems run by bleed air system i.e. wing and empannage anti icing. If we closely observe the chart, there are temp deviation lines as well. As per my understanding they can be used once you know the field elevation and you start with the torque with only air conditioning and pressurization bleed ON (normal bleed); you can calculate reduced torque at various temperature deviations and yes its a manual for E and H models with A-15 engines and 54H60-91 props. Kindly guide.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...