Juan Posted March 3, 2011 Share Posted March 3, 2011 Hello ! I have this un-answered question, if any can help: How much do you add to Vmca for safe turns if you've lost one or two engines? thx Juan Quote Link to comment Share on other sites More sharing options...
NATOPS1 Posted March 3, 2011 Share Posted March 3, 2011 Depends on Bank angle and direction of turn Quote Link to comment Share on other sites More sharing options...
Juan Posted March 3, 2011 Author Share Posted March 3, 2011 Thanks, i was looking for a general safe addition to Vmca. I can´t remember if it was like Vmca + 20 Kts. Because if you remember, Vmca can increase as much as 18 Kt if you don´t raise the engine-off wing. But I can´t find the correct figure. Maybe is just a non-written tradition in my Squad. Thanks ! Juan Argentina AF Quote Link to comment Share on other sites More sharing options...
NATOPS1 Posted March 3, 2011 Share Posted March 3, 2011 It is a range and takes gross weight into account as well... your Squadron my have numbers they use. Quote Link to comment Share on other sites More sharing options...
victorp1 Posted March 3, 2011 Share Posted March 3, 2011 The following is from the Lockheed "Slow Flight" handout. "The Flight Manual air minimum control speed data are for a 5-degree favorable bank angle. An increase in airspeed is necessary to control the airplane if the favorable bank angle is reduced to a wings-level or adverse (into the failed engine) bank angle. The accompanying figures show the influence of bank angle on VMCA. For models with T56-A-15 engines, a 9-to-12-knot increase in minimum control speed above the Flight Manual value is necessary to maintain controllability with wings level. Air minimum control speed is increased 20 knots with 5 degrees of adverse bank at minimum flying weight and increases even more as gross weight increases. Similar increases are shown for models with T-56-A-7 engines. Banking into the failed engine will cause the airplane to "slide off" to that side, increasing adverse sideslip which increases drag, reduces performance, and increases the risk of losing heading control." Quote Link to comment Share on other sites More sharing options...
tenten Posted March 4, 2011 Share Posted March 4, 2011 We are using a minimum of 160 notes as a safe speed to turn towards the dead engine. Quote Link to comment Share on other sites More sharing options...
Fred Posted March 5, 2011 Share Posted March 5, 2011 Hello ! I have this un-answered question, if any can help: How much do you add to Vmca for safe turns if you've lost one or two engines? thx Juan "Used to be" 20 and 25 knots..so many flight manuals floating around out there nowadays...use whatever yours says in the emergency procedures chapter regarding flight under partial power or with one or two engines inoperative....if it just says not recommended; well that's what it is. My guess: yours still says 20 and 25 knots... My $0.02 Quote Link to comment Share on other sites More sharing options...
Juan Posted March 5, 2011 Author Share Posted March 5, 2011 Thanks for your help ! I'm a Chancha's Capt now ! Juan *Chancha=C130 Quote Link to comment Share on other sites More sharing options...
bobdaley Posted March 6, 2011 Share Posted March 6, 2011 Juan If you can please check the inventory in thye files and documents section and see if we should make any changes for the Argentine Chanchas Gracias Bob Quote Link to comment Share on other sites More sharing options...
tenten Posted March 11, 2011 Share Posted March 11, 2011 Quoting: FM 382C-14E Turns into inoperative engine(s) are not recommended due to…..etc. A 5-degree adverse bank angle (into the inoperative engine) requires an increase of 20 KIAS above the charted value at the lightest gross weight, increasing significantly with gross weight (37 KIAS at 140,000 pounds)…… Quoting: SMP777 (Flight Manual Performance Data) Because of the powerful influence of bank angle on minimum control speed, it is important to maintain a bank angle away from the failed engine. So: 1- It is not recommended to turn into inoperative engine(s). 2- If situation necessitate to turn to avoid (obstacle, fire/active zone, etc.. ) the 20 to 37 range above air minimum control speed is your target speed; the higher the GW. the higher the speed required to control the airplane) (Note: air minimum speed based on 50% flaps= hi rudder boost pressure). 3- We are using 160 notes (50% flaps) as a minimum safe speed to turn towards the inoperative engine, this speed is compensating for the possibility of losing the other engine on the effected side during the turn. Quote Link to comment Share on other sites More sharing options...
US Herk Posted March 11, 2011 Share Posted March 11, 2011 Remember also that if you don't have max power on all remaining engines, your Vmca is much, much lower and safe turns into the inoperative engines are easily executed even at pattern speeds. We do it in training every day... Quote Link to comment Share on other sites More sharing options...
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