Comparing vertical climb capabilities...
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Comparing vertical climb capabilities...
Im trying to compare vertical climb capabilities of various helicopters.
Anyone know where I might find a combined list of specs? Specifically looking for power loading values, or even transmission horsepower limits on various models.
Thank you.
Anyone know where I might find a combined list of specs? Specifically looking for power loading values, or even transmission horsepower limits on various models.
Thank you.
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The vertical climb capability of a helicopter is not a figure you'll come by easily, I don't recall a performance chart that gave such information in any flight manual. Climb charts were available for climb at normal climb speed however, usually in the order of 60 or 75 knots for the helos I flew. The parameter you may be looking for which would give a similar answer is the helicopters out of ground effect hover capability (OGE), or the in ground effect hover capability (IGE). Go to the relevant manufacturers web site and they will give the relevant figures, plus the other info you seek.
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You have not posted the reason for your inquiry, however, there are several companies that are in the comparison business. Conklin and de Decker Associates, Inc is one I have used reliably in the past.
Conklin & de Decker - Aircraft Operating Costs & Aviation Services
Conklin & de Decker - Aircraft Operating Costs & Aviation Services
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I am trying to make comparisons for a thesis paper. Comparing hover ceiling numbers of various helicopters does not give an easily comparable indication of vertical climb performance. I realize its a tough number to come by, but the biggest issue I have been encountering in my research is that operators who do a lot of max performance takeoffs (i.e. vertical) along with OGE hover, desire a greater power margin in the aircraft they are flying. Aside from suggesting that they lower their mission gross weight, I was looking for a way to compare that performance requirement between airframes.
I browsed the link you sent me, doesn't sound like they show much more than any other spec sheet. Just looking for a way to extract the necessary answers. Thanks.
I browsed the link you sent me, doesn't sound like they show much more than any other spec sheet. Just looking for a way to extract the necessary answers. Thanks.
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There are theoretical ways to do it, but it would involve a lot of studying of textbooks, and accurate knowledge of power required and power available. One of the other problems is that the vertical climb performance is going to be slightly better than the prediction due to some complex aerodynamics.
Vertical Climb performance is not published and probably not even tested because it is unnecessary. I cannot think of any vertical manoeuvre that has to be completed within a certain time, both civil and military.
The only unofficial example I can think of was in Borneo with the Whirlwind HAR 10. With the Gnome engine installed the transmission limits meant that you were restricted on how much power you could put into it. This was indicated by a red line on the fuel flow gauge. Periodically we would ballast it to MAW and climb it vertically with the fuel flow at Max Permissible. It had to climb 200 ft. in one minute. If it failed then the red line marker would be adjusted until it did.
This was to make sure that you got out of a vertical entry clearing in the jungle up to 200ft. high.
The only unofficial example I can think of was in Borneo with the Whirlwind HAR 10. With the Gnome engine installed the transmission limits meant that you were restricted on how much power you could put into it. This was indicated by a red line on the fuel flow gauge. Periodically we would ballast it to MAW and climb it vertically with the fuel flow at Max Permissible. It had to climb 200 ft. in one minute. If it failed then the red line marker would be adjusted until it did.
This was to make sure that you got out of a vertical entry clearing in the jungle up to 200ft. high.
I think that where FED mentions 200ft/min ROC OGE probably refers to the `standards of the day` from AvP 970,BCARs, and MilSpecs;a lot of what was written in them was rather vague,but changing, and test methods/instrumentation as well. WIWO WW10s,we didn`t have a performance manual,as such,that came much later,(I think !) and one had to rely on fuel-flow as an indicator of power.Digging out my old notes, even though one had an idea of what one could lift,we would do a power-check,at 50kts,level flight ,near the LZ,check power available,either f/f,ptit,or Ng and then decide either the type of approach and landing,ie OGE,OGE+ 2.5% thrust margin,10-15ft-roping,low hover,or a run-on landing,if taking troops/freight in,or the amount of t/frt one could lift out.
Later, the`rules-of -thumb` were combined on the kneepad checklist when torquemeters became standard,to give one both t/o and landing performance data.
Does anyone use a similar method these days,or is FADEC/HUMS your friend ?
Later, the`rules-of -thumb` were combined on the kneepad checklist when torquemeters became standard,to give one both t/o and landing performance data.
Does anyone use a similar method these days,or is FADEC/HUMS your friend ?
