Veetail88
Well Known Member
Seeking knowledge and wisdom regarding the importance of indicated airspeed accuracy.
I recently installed a heated pitot on my 8 having flown it for the past year and a half with the standard Vans bent aluminum tube. During phase I testing, I verified it?s accuracy with the usual GPS triangulation method and established stall speeds and whatnot.
I fly airspeed in the pattern and my normal speeds have been 90 downwind, 80 crosswind and 70 on final and this has been working out fine, although probably a bit faster than required, but I?m good with that. I also have AOA, and in the pattern I check it here and there if I feel I?m getting a bit slow or if I?m cranking a turn to final to avoid overshooting, a scenario I keep a close eye on. The AOA (AFS flavor) is calibrated a bit conservative, so I don?t get the aural warning ?angle angle push push? in normal patterns until I?m actually right about in the flare. Of course the chevrons give me visual feedback along the entire range but the aural part comes in when I still have maybe 4 red chevrons left.
Due to the length of the pitot mast I have, the distance from the bottom of the wing to the center of the pitot inlet is shorter, like around 4 inches, and if I recall the standard one is 6 or more. I figured I?d install it with what I had, fly it to see how things were and adjust as required. Feeling safe with this approach since the AOA is present.
I?ve only had time to make a couple of flights with it so far, but those had purpose and I didn?t have time to run it through a stall sequence. It appears the pitot reads accurately at higher speeds, but when the angle of attack increases I?m pretty certain it?s reading higher than the old one, probably quite a bit. On downwind at 90 knots, I?m getting the AOA aural warning, so of course I carried quite a bit extra indicated air speed to keep her quiet and me safe. I?ve been using the AOA as a backup check so I never actually tracked its indications during normal pattern work otherwise.
I?ll do more testing when I can get to it, but my real question here is, does it really matter if it?s actually right? If it?s consistent and I fly the new numbers instead I don?t really see a problem with it, other than when I let another RV guy fly the airplane and he might expect the more normal numbers.
With multiple GPS units on board, I really don?t see any use for IAS en route. I get ground speed and time to waypoint and that?s what really matters for trip and fuel planning. Am I missing some point as to the need for accuracy here other than just to be correct? Like I said, I?ll likely order a new mast and redo the installation, I?m just pondering?..
I recently installed a heated pitot on my 8 having flown it for the past year and a half with the standard Vans bent aluminum tube. During phase I testing, I verified it?s accuracy with the usual GPS triangulation method and established stall speeds and whatnot.
I fly airspeed in the pattern and my normal speeds have been 90 downwind, 80 crosswind and 70 on final and this has been working out fine, although probably a bit faster than required, but I?m good with that. I also have AOA, and in the pattern I check it here and there if I feel I?m getting a bit slow or if I?m cranking a turn to final to avoid overshooting, a scenario I keep a close eye on. The AOA (AFS flavor) is calibrated a bit conservative, so I don?t get the aural warning ?angle angle push push? in normal patterns until I?m actually right about in the flare. Of course the chevrons give me visual feedback along the entire range but the aural part comes in when I still have maybe 4 red chevrons left.
Due to the length of the pitot mast I have, the distance from the bottom of the wing to the center of the pitot inlet is shorter, like around 4 inches, and if I recall the standard one is 6 or more. I figured I?d install it with what I had, fly it to see how things were and adjust as required. Feeling safe with this approach since the AOA is present.
I?ve only had time to make a couple of flights with it so far, but those had purpose and I didn?t have time to run it through a stall sequence. It appears the pitot reads accurately at higher speeds, but when the angle of attack increases I?m pretty certain it?s reading higher than the old one, probably quite a bit. On downwind at 90 knots, I?m getting the AOA aural warning, so of course I carried quite a bit extra indicated air speed to keep her quiet and me safe. I?ve been using the AOA as a backup check so I never actually tracked its indications during normal pattern work otherwise.
I?ll do more testing when I can get to it, but my real question here is, does it really matter if it?s actually right? If it?s consistent and I fly the new numbers instead I don?t really see a problem with it, other than when I let another RV guy fly the airplane and he might expect the more normal numbers.
With multiple GPS units on board, I really don?t see any use for IAS en route. I get ground speed and time to waypoint and that?s what really matters for trip and fuel planning. Am I missing some point as to the need for accuracy here other than just to be correct? Like I said, I?ll likely order a new mast and redo the installation, I?m just pondering?..