Morning dawned crisp and clear in Houston, and the forecast along my route to Minnesota was for the clear weather to hold for the day. This wonderful cool weather was, of course, courtesy of a northerly flow from Canada, which meant that I?d be flying into the wind all the way. But the trip was necessary, and on short notice - so I loaded a bag with necessities; another with my goose down expedition clothes and heavyweight sleeping bag; rolled the Valkyrie out on the pad; and fired up for a two-leg flight to Anoka County Airport. Weathermeister showed headwinds increasing with altitude, but averaging better than 20 knots the whole way, so a true mid-point refueling was called for, and Fort Scott (Kansas) filled the bill with relatively cheap gas to boot.
Climbing out from Polly Ranch and heading north it became clear very quickly that I was going to face that unique torture of a zero-sum wind/altitude game. As we all know, for a given horsepower, True Airspeed increases with altitude due to thinner air and the resultant lower drag. If you use 75% power as a high limit for cruise, then you can get about 140 knots True out of a typical two-place RV (with an O-360) at low altitudes if that same airplane will top out around 170 knots at 8,000?. On what I call a ?zero-sum day?, the headwind increases at about the same rate as the TAS increases as you climb, so the ground speed is essentially the same no matter what altitude you pick. Sure, at lower altitudes, you have the choice of running more than 75% power, but the fuel burn will be considerably higher, so you will probably end up losing on range. And if you climb above 8,000?, you will be generating less than 75%, so while your fuel burn will decrease, so will your TAS. High altitudes work with tailwinds to give you a good groundspeed, but if it is calm aloft, you don?t gain much above that magic 8,000? level.
Closely examining the winds aloft forecasts for today, it looked like I could go to 8K for the first half of the trip and not lose anything while gaining smooth air. Farther north, the penalty with altitude was worse, so lower would be better for the second half of the trip. The no-wind time is generally about five plus thirty, but today was looking more like six plus forty-five. Throw in a fuel stop and you get a full crew day out of it. Sure enough, that?s just about how it turned out, except I lost an additional thirty minutes up front stopping for an initial fuel load at Anahuac, one of cheap local options (since we have no fuel at our air park). The weather remained clear most of the trip, except for an interesting layer of cumulous over most of Iowa that was somewhere between scattered and broken, but showed up on none of the METARS for the area. ?Clear? prevailed on all of the sequence reports, as if all of the AWOS machines were conspiring together to paint a better picture than was actually out there. Of course, it was bumpy below and the headwinds increasing steeply above, so it was a day to pick your poison. I elected to stay just above them and take the headwind ? bumps for an hour get very old.
Resigned to ground speeds in the 140?s (my only real consolation the fact that the SPAM Cans were going that much slower still?), all that was left was tp pick a way to stay awake. Fortunately, Sirius/XM replays ?Car Talk?, Prairie Home Companion?, and a few other weekend shows that actually engage your mind more than just listening to music, so sanity was easily maintained. Playing with new EFIS software was also fun, although straight and level is a tough way to evaluate new features ? at least I could remind myself what obscure buttons do. With multiple flight-planning systems on board, it pays to play with them all when you get the chance, or the syntax differences can easily slip from memory. And with outside Air Temperatures dropping to a frigid 10 degrees F by the end of the trip, I needed a few distractions in the rapidly cooling cockpit ? a high layer of clouds was blocking the sun which provides most of the heat in the RV-8 cockpit. Thank goodness for the solar collector bubble, ?cause the heat muff doesn?t do much! Thermal underwear and a flight suit kept my teeth from chattering ? but just barely.
Closing in on Anoka County Airport, a place where I earned my wings well over three decades ago, I was number two for the runway following a Mooney on short final. I wagged the tail back and forth to urge life back into my lower extremities, but rapid rudder action turned out not to be necessary. The AWOS was warning of potentially poor breaking due to loose snow, but the runway proved to be clear and dry. The same couldn?t be said for the taxiway alleys, and I was a bit nervous for the young line boy wanding me in to parking, so I just so I just took it slow to end the day with close to seven more hours on the clock. With temperatures predicted to be mostly below zero for the couple of days I?ll be here, paying for a warm toasty hangar seems like a bargain, considering that most of the cracked RV-8 canopies I have heard about happened with very cold temperatures.
Another mission completed through the magic of the RV! I probably save more than half of what I would have paid for a non-notice airline ticket, and while the airliner would have beat me today, I expect my return trip will be a lot quicker ? at least the odds in the winter are with me. I?m pretty sure the back seat would have been a pretty miserable place as the temperatures dropped, so it was a good day to be solo. But other than that limitation, the RV-8 once again proved itself to be an outstanding traveling machine!
Paul
Climbing out from Polly Ranch and heading north it became clear very quickly that I was going to face that unique torture of a zero-sum wind/altitude game. As we all know, for a given horsepower, True Airspeed increases with altitude due to thinner air and the resultant lower drag. If you use 75% power as a high limit for cruise, then you can get about 140 knots True out of a typical two-place RV (with an O-360) at low altitudes if that same airplane will top out around 170 knots at 8,000?. On what I call a ?zero-sum day?, the headwind increases at about the same rate as the TAS increases as you climb, so the ground speed is essentially the same no matter what altitude you pick. Sure, at lower altitudes, you have the choice of running more than 75% power, but the fuel burn will be considerably higher, so you will probably end up losing on range. And if you climb above 8,000?, you will be generating less than 75%, so while your fuel burn will decrease, so will your TAS. High altitudes work with tailwinds to give you a good groundspeed, but if it is calm aloft, you don?t gain much above that magic 8,000? level.
Closely examining the winds aloft forecasts for today, it looked like I could go to 8K for the first half of the trip and not lose anything while gaining smooth air. Farther north, the penalty with altitude was worse, so lower would be better for the second half of the trip. The no-wind time is generally about five plus thirty, but today was looking more like six plus forty-five. Throw in a fuel stop and you get a full crew day out of it. Sure enough, that?s just about how it turned out, except I lost an additional thirty minutes up front stopping for an initial fuel load at Anahuac, one of cheap local options (since we have no fuel at our air park). The weather remained clear most of the trip, except for an interesting layer of cumulous over most of Iowa that was somewhere between scattered and broken, but showed up on none of the METARS for the area. ?Clear? prevailed on all of the sequence reports, as if all of the AWOS machines were conspiring together to paint a better picture than was actually out there. Of course, it was bumpy below and the headwinds increasing steeply above, so it was a day to pick your poison. I elected to stay just above them and take the headwind ? bumps for an hour get very old.
Resigned to ground speeds in the 140?s (my only real consolation the fact that the SPAM Cans were going that much slower still?), all that was left was tp pick a way to stay awake. Fortunately, Sirius/XM replays ?Car Talk?, Prairie Home Companion?, and a few other weekend shows that actually engage your mind more than just listening to music, so sanity was easily maintained. Playing with new EFIS software was also fun, although straight and level is a tough way to evaluate new features ? at least I could remind myself what obscure buttons do. With multiple flight-planning systems on board, it pays to play with them all when you get the chance, or the syntax differences can easily slip from memory. And with outside Air Temperatures dropping to a frigid 10 degrees F by the end of the trip, I needed a few distractions in the rapidly cooling cockpit ? a high layer of clouds was blocking the sun which provides most of the heat in the RV-8 cockpit. Thank goodness for the solar collector bubble, ?cause the heat muff doesn?t do much! Thermal underwear and a flight suit kept my teeth from chattering ? but just barely.
Closing in on Anoka County Airport, a place where I earned my wings well over three decades ago, I was number two for the runway following a Mooney on short final. I wagged the tail back and forth to urge life back into my lower extremities, but rapid rudder action turned out not to be necessary. The AWOS was warning of potentially poor breaking due to loose snow, but the runway proved to be clear and dry. The same couldn?t be said for the taxiway alleys, and I was a bit nervous for the young line boy wanding me in to parking, so I just so I just took it slow to end the day with close to seven more hours on the clock. With temperatures predicted to be mostly below zero for the couple of days I?ll be here, paying for a warm toasty hangar seems like a bargain, considering that most of the cracked RV-8 canopies I have heard about happened with very cold temperatures.
Another mission completed through the magic of the RV! I probably save more than half of what I would have paid for a non-notice airline ticket, and while the airliner would have beat me today, I expect my return trip will be a lot quicker ? at least the odds in the winter are with me. I?m pretty sure the back seat would have been a pretty miserable place as the temperatures dropped, so it was a good day to be solo. But other than that limitation, the RV-8 once again proved itself to be an outstanding traveling machine!
Paul
