Flight Rules of Thumb - ONLY...!!!
Thread Starter
Practical Flight Tips, Advise & Rules of Thumb - ONLY...!!!
What flying Rules of Thumb do use in your everyday flying...?
Been searching the site and came up with a few from various threads, which started out as possitive and ended as
.
Irrespective of what machine you're flying, where you're flying, or what job you're flying.
Oh, and try not post any useless information or comments. This would be a great resource to all pilots if everyone shared their experience instead of turning it into a joke/comment/cheque's in the mail/trust me I'm a Dr... 
thread...!
Been searching the site and came up with a few from various threads, which started out as possitive and ended as
.Irrespective of what machine you're flying, where you're flying, or what job you're flying.
Oh, and try not post any useless information or
comments. This would be a great resource to all pilots if everyone shared their experience instead of turning it into a joke/comment/cheque's in the mail/trust me I'm a Dr... thread...!
Last edited by Flyting; 20th Jan 2010 at 09:02.
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AS350: For training we use 5ft hover power as the reference for take-offs.If simulated max pwr is the same as hover pwr, a cushion creep is possible. For an IGE towering take off 5-10% over hvr pwr is required. For an OGE take off, a minimum of 10% over hvr pwr is needed. A figure of 10% less than hvr pwr is a suitable figure to use as a max for teaching limited pwr running landings - it ensures that the run on speed is not excessive.
Hovering AND talking
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Always use the search function ....
http://www.pprune.org/rotorheads/334...les-thumb.html
Cheers
Whirls
http://www.pprune.org/rotorheads/334...les-thumb.html
Cheers
Whirls
What is a "Cushion Creep"?
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Rule of thumb
When flying a 3 degree glideslope, the target rate of decent is 50% of ground speed times 10. For example: 90Kts GS / half = 45 x 10 = 450 fpm. Take the GS by half and add a zero is the easy way to think of it.
This will get you very close to dead on target.
Another rule of thumb: If you are all thumbs that day, it is a bad day to fly!
This will get you very close to dead on target.
Another rule of thumb: If you are all thumbs that day, it is a bad day to fly!
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Some pretty remedial ones for the R22/R44:
On approach, check 3-2-1 to avoid settling with power: Rate of descent less than 300 fpm whenever using >20% power and below 10 KIAS. It's not perfect and a bit conservative, but it's a good pre-landing check. (And for better or worse, this or some variation is drilled into most students' heads.)
The fuel gages show your endurance: a full main tank is good for 2 hours and a full auxiliary is good for an hour.
For hover autos...well, this isn't a rule of thumb really, but throttle-pedal, settle-pull. It's just a good way to break that maneuver down.
I think this is a good thread...the other one was more tongue-in-cheek (and already 6 pages!).
On approach, check 3-2-1 to avoid settling with power: Rate of descent less than 300 fpm whenever using >20% power and below 10 KIAS. It's not perfect and a bit conservative, but it's a good pre-landing check. (And for better or worse, this or some variation is drilled into most students' heads.)
The fuel gages show your endurance: a full main tank is good for 2 hours and a full auxiliary is good for an hour.
For hover autos...well, this isn't a rule of thumb really, but throttle-pedal, settle-pull. It's just a good way to break that maneuver down.
I think this is a good thread...the other one was more tongue-in-cheek (and already 6 pages!).
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Errr...won't that depend on the size of the tank and your fuel burn?
One I use everyday....
True airspeed is 105% of that indicated for every 3,000' DA.
GP
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So at 6,000 the true airspeed is 210% of that indicated.. or did I get that wrong..?
My apologies. I normally put more thought into what I write.
This should leave you in no doubt:
For true airspeed: Add 5% of your indicated airspreed to your indicated airspeed for every 3,000' of DA.
So, 100kts IAS, 3,000'...105kts true. 120kts IAS, 9,000'.... 138kts true.
Hope this clarifies
A couple of others...
If in doubt, chicken out.
You're only gonna crash when you're near the ground.
If you can't hover, don't bother (landings at altitude).
If you think you're trying too hard, you probably are.
GP
Thread Starter
Updates... New in Bold Italics
General
Confined Landing:
Do the P.A.W.S. check:
Power
Draw a horizontal line across the graph from point B (IGE Hover) to point C, which is X speed in straight and level flight. Point B and point C both use the same power. The trick is to know what the speed at point C is. To find this, when lifting off, stabilize into an IGE hover and read what power is being used. Now, using that same power, establish a S&L flight +-500’ above your IGE hover alt. Read what speed that particular aircraft gives at that IGE power setting.
Now when you come to land at a different LZ, reverse the process. Fly at the speed you obtained earlier, as you are approaching the LZ at +-500’ agl, and check what power you are using. This will give you an idea for what you will be using for an IGE hover at that LZ.
Obviously, the graph shifts according to altitude, temperature, etc, but it is an easy way of figuring it out instead of having to add/subtract Tq/MAP to give an IGE power required.
Area
Wind
Wires
Way in/Way out
Size
Shape
Sun
Surroundings
Slope
Surface
Rough rule of thumb to get you going. Every ten pounds you want to lift will require one horsepower.
When flying a 3 degree glide slope, the target rate of decent is 50% of ground speed times 10. For example: 90Kts GS / half = 45 x 10 = 450 fpm. Take the GS by half and add a zero is the easy way to think of it.
This will get you very close to dead on target.
or:
which translates into ' 5 times GS '
120KTS= 2 miles a minute
At 1500' you can see the legs of horses
At 1000' you can see the legs of cows
At 500' you can see the legs of sheep
Fuel consumption of an aircraft engine is equal to 1/2 the Hp divided by 10. (160 hp engine. 1/2 the hp = 80 divided by 10 = 8 gph)
Never believe your fuel gauge-Always trust your Low Fuel Light
For true airspeed: Add 5% of your indicated airspeed to your indicated airspeed for every 3,000' of DA.
So, 100kts IAS, 3,000'... 105kts true. 120kts IAS, 9,000'... 138kts true.
70% Tq does not give you "VNE", I was just saying in the 14 different airframes I have flown, a rule of thumb I have found that much above 70% Tq gives you high fuel flow without a whole lot of airspeed increase.
A formula to work out a rate of turn (degrees per sec
for a given airspeed and angle of bank)
Use 10% of IAS +7 e.g.: 100kts = 17 AOB e.g.: 80kts = 15 AOB
this is a std rate one turn 360 degree in 2 min.
A 3-degree glide slope is a decent of 318 feet per nautical mile. A good rule of thumb to determine the rate of decent required to maintain a 3 degree glide slope is:
AS/2 x10= ROD, example: 120knots/2 x0= 600 ft per min.
You need 100 ft to accelerate 10 Kts in auto. Therefore, to accelerate to 50 Kts you need approx 500 ft.
NVG
The dusk period and resultant sky glow issues are so variable as to defy any attempt at ANOTHER prescriptive restriction or rule. One outcome based rule of thumb that we are going to trial as an SOP is as follows:
"IF the NVG image is washed out AND you feel you have to go in unaided AND you want to turn on the searchlight to help - then you should postpone the landing until dark enough for NVG"
Secondly we have a rule of thumb to deal with reduced vis or very poor contrast conditions....if you are down to 400' and 60kts then abort and turn back seek alternative method (such as IFR).
Humidity Factor/Performance
0% humidity = baseline
25% humidity = +100 feet DA, and minus 1% power (therefore -1% gross weight to hover.)
50% humidity = 200 feet DA, and minus 2% power
75% humidity = +300 feet DA and -3% power
100% humidity = +400 feet DA and -4% power.
So, for each 25% humidity above 0, subtract 1% from your hover weight.
206:
+- 10% power is needed for OGE than IGE
You lose +-3% Tq for every 1000’ gained
+- 1% Tq is lost with every 1.5 deg OAT gained
Never pull the collective faster than the Tq needle can move
33lbs per 1% of torque. Obviously any tot or n1 limitations would have to be taken into account.
Check what power (torque) it uses to maintain level flight at 80KIAS about 500' above your intended landing site. Add 20% (torque) to that figure to give you a IGE hover. To climb back out of the landing site add another 10% and if you have picked up some freight or Pax add 1% for every 15Kg.
The advantage of this method is it automatically takes into account the altitude you are operating at.
Fuel consumption:
206B = 25 US gals/Hr
A119
Will cruise at 145 kts @ 90% TQ at 2720 kg but burn a lot of fuel.
We normally fly at 68-70% TQ again at MAUM and accepted 123 - 125 Kts, giving a range of 450 nm
UH1H/205:
1 inch of TQ is about 400lbs of payload.
Fuel consumption:
Bell 205 100Lbs = 10Mins
AS350:
For training we use 5ft hover power as the reference for take-offs. If simulated max power is the same as hover power, a cushion creep is possible. For an IGE towering take off 5-10% over hover power is required. For an OGE take off, a minimum of 10% over hover power is needed. A figure of 10% less than hover power is a suitable figure to use as a max for teaching limited power running landings - it ensures that the run on speed is not excessive.
Fuel consumption:
AS350 is easy 10% = 20mins
R22/R44
You lose about 1" MAP off the Max and must add 0.5" MAP to the IGE for every 1000' alt gained to get your power available for T/Off & Landings
The fuel gages show your endurance: a full main tank is good for 2 hours and a full auxiliary is good for an hour.
Confined Landing:
Do the P.A.W.S. check:
Power
Draw a horizontal line across the graph from point B (IGE Hover) to point C, which is X speed in straight and level flight. Point B and point C both use the same power. The trick is to know what the speed at point C is. To find this, when lifting off, stabilize into an IGE hover and read what power is being used. Now, using that same power, establish a S&L flight +-500’ above your IGE hover alt. Read what speed that particular aircraft gives at that IGE power setting.
Now when you come to land at a different LZ, reverse the process. Fly at the speed you obtained earlier, as you are approaching the LZ at +-500’ agl, and check what power you are using. This will give you an idea for what you will be using for an IGE hover at that LZ.
Obviously, the graph shifts according to altitude, temperature, etc, but it is an easy way of figuring it out instead of having to add/subtract Tq/MAP to give an IGE power required.
Area
Wind
Wires
Way in/Way out
Size
Shape
Sun
Surroundings
Slope
Surface
Rough rule of thumb to get you going. Every ten pounds you want to lift will require one horsepower.
When flying a 3 degree glide slope, the target rate of decent is 50% of ground speed times 10. For example: 90Kts GS / half = 45 x 10 = 450 fpm. Take the GS by half and add a zero is the easy way to think of it.
This will get you very close to dead on target.
or:
which translates into ' 5 times GS '
120KTS= 2 miles a minute
At 1500' you can see the legs of horses
At 1000' you can see the legs of cows
At 500' you can see the legs of sheep
Fuel consumption of an aircraft engine is equal to 1/2 the Hp divided by 10. (160 hp engine. 1/2 the hp = 80 divided by 10 = 8 gph)
Never believe your fuel gauge-Always trust your Low Fuel Light
For true airspeed: Add 5% of your indicated airspeed to your indicated airspeed for every 3,000' of DA.
So, 100kts IAS, 3,000'... 105kts true. 120kts IAS, 9,000'... 138kts true.
70% Tq does not give you "VNE", I was just saying in the 14 different airframes I have flown, a rule of thumb I have found that much above 70% Tq gives you high fuel flow without a whole lot of airspeed increase.
A formula to work out a rate of turn (degrees per sec
for a given airspeed and angle of bank)
Use 10% of IAS +7 e.g.: 100kts = 17 AOB e.g.: 80kts = 15 AOB
this is a std rate one turn 360 degree in 2 min.
A 3-degree glide slope is a decent of 318 feet per nautical mile. A good rule of thumb to determine the rate of decent required to maintain a 3 degree glide slope is:
AS/2 x10= ROD, example: 120knots/2 x0= 600 ft per min.
You need 100 ft to accelerate 10 Kts in auto. Therefore, to accelerate to 50 Kts you need approx 500 ft.
NVG
The dusk period and resultant sky glow issues are so variable as to defy any attempt at ANOTHER prescriptive restriction or rule. One outcome based rule of thumb that we are going to trial as an SOP is as follows:
"IF the NVG image is washed out AND you feel you have to go in unaided AND you want to turn on the searchlight to help - then you should postpone the landing until dark enough for NVG"
Secondly we have a rule of thumb to deal with reduced vis or very poor contrast conditions....if you are down to 400' and 60kts then abort and turn back seek alternative method (such as IFR).
Humidity Factor/Performance
0% humidity = baseline
25% humidity = +100 feet DA, and minus 1% power (therefore -1% gross weight to hover.)
50% humidity = 200 feet DA, and minus 2% power
75% humidity = +300 feet DA and -3% power
100% humidity = +400 feet DA and -4% power.
So, for each 25% humidity above 0, subtract 1% from your hover weight.
206:
+- 10% power is needed for OGE than IGE
You lose +-3% Tq for every 1000’ gained
+- 1% Tq is lost with every 1.5 deg OAT gained
Never pull the collective faster than the Tq needle can move
33lbs per 1% of torque. Obviously any tot or n1 limitations would have to be taken into account.
Check what power (torque) it uses to maintain level flight at 80KIAS about 500' above your intended landing site. Add 20% (torque) to that figure to give you a IGE hover. To climb back out of the landing site add another 10% and if you have picked up some freight or Pax add 1% for every 15Kg.
The advantage of this method is it automatically takes into account the altitude you are operating at.
Fuel consumption:
206B = 25 US gals/Hr
A119
Will cruise at 145 kts @ 90% TQ at 2720 kg but burn a lot of fuel.
We normally fly at 68-70% TQ again at MAUM and accepted 123 - 125 Kts, giving a range of 450 nm
UH1H/205:
1 inch of TQ is about 400lbs of payload.
Fuel consumption:
Bell 205 100Lbs = 10Mins
AS350:
For training we use 5ft hover power as the reference for take-offs. If simulated max power is the same as hover power, a cushion creep is possible. For an IGE towering take off 5-10% over hover power is required. For an OGE take off, a minimum of 10% over hover power is needed. A figure of 10% less than hover power is a suitable figure to use as a max for teaching limited power running landings - it ensures that the run on speed is not excessive.
Fuel consumption:
AS350 is easy 10% = 20mins
R22/R44
You lose about 1" MAP off the Max and must add 0.5" MAP to the IGE for every 1000' alt gained to get your power available for T/Off & Landings
The fuel gages show your endurance: a full main tank is good for 2 hours and a full auxiliary is good for an hour.