Weight and Balance | Does it Matter???

[Laughter] [Music] hey guys what is up john and steph here from fly8mcalpha.com here today to answer the question exactly how much does it change the performance of your airplane particularly this bear hawk patrol flying it light versus heavy how much does it change the performance of an airplane significantly when you add weight to it it changes it significantly some arbitrary amount so we're gonna fly this thing nice and light we're going to fly it nice and heavy we're going to find out exactly how much that changes the takeoff roll the climb rate the crew speed the stall speed all of that stuff we're gonna find that out right now we're going to do this as short as we can expecting the pretty short takeoff not necessarily the shortest landing because we are at a very far forward cg right now we are as light as we can get this thing i got my flip-flops on right now we are at about 1440 on our weight as we sit right now fully loaded with fuel and everything in here 1440 and this airplane has a gross weight of 2000 pounds let's go ahead and taxi up to this line over here we'll see how short we can get this thing off i'm hoping for under 100 feet now in addition to this takeoff we're also going to be timing our time to climb so how long does it take from us to get from the ground on up to 1 000 feet from the time we throw the power forward until we are at 1000 feet we will see here in just one moment go ahead and bring in a little bit of power 10 flat for our best possible takeoff performance i'm actually going to pull flap to gank us off the ground here add in power tail is already up oh we are light and here we go and three so now we're picking up speed we're kind of still hanging around effect there and there is our v y let's raise that nose on up nice climb angle about 20 degrees maybe 25 degrees even well looks like about 22 is going to be real happy for us there and we are climbing and close to 2000 feet a minute is what we're pegged at right now we'll keep full power in there as we're coming up and we'll throttle back once we hit 1000 feet showing us the flight time now 30 seconds so far and 1 000. all right now it is time to come in for the landing this landing is probably not going to be that short because we are awful nose heavy so i'm not going to be able to use the brakes quite as much as i'd like to if i was really doing this for a soul competition my best possible takeoff and landing performance combined would actually be to put about 30 to 50 pounds of lead right on that tail wheel spring right in the very aft part of the airplane there to get my cg moved to a more middle stance a more happy place and the further after your cg the better your i guess your stole takeoff and landing performance might be at least your landing performance anyways but with this airplane it's made to have a lot of weight back obviously you're meant to have a passenger you're meant to have some gear and back so just one person flying it empty although it's great takeoff performance like you just saw we're not gonna be able to land real short and it's pretty far forward on the cg all right there's our line now it's also important to mention that we're doing this without any exterior cameras so i know you guys are used to seeing some cameras on the outside of the airplane for some cool views we're doing this without any exterior cameras because we don't want any of our camera gear or any of our mounts out there to affect the performance of the airplane so we're trying to do this as clean as possible start slowing her down here a little bit boy we are really on the forward edge of that cg is not the most fun to fly with that forward cg there at least there's better visibility over the nose and let's see what we're able to do here wow all right and next up is the time to climb from zero on up to 3500 feet agl both light and heavy all right our flight time counter is reset realistically for a normal takeoff no flaps because flaps are nothing but drag really they will pop you off the ground sooner they're not going to help you climb crazy so let's go ahead and get this tail up bring some power in and let's go so on the left hand side of the screen you see the airplane weighing in at 1440 pounds and then on the right hand side of the screen you see the airplane weighing in at 2000 pounds that was after we flew it over to homer picked up some freight field all the way up and this is the time lapse of it going on up to 3500 feet agl homer is about 100 feet elevation where we started so we'll go up to 3600 on the right side of the screen for the left side for the light side what we saw was two minutes and 50 seconds to get up to 3500 feet agl an average of 1235 feet per minute climb rate from sea level all the way up to 3500 feet agl and for a heavy test we saw four minutes and 35 seconds for an average of 765 feet per minute about a 40 reduction in climb rate all right so first priority up here is going to be to find the wind we need to find the wind and we're going to do our slow flight first that's going to give us a nice chance to cool down this engine after that long climb up here to 3 500 feet right now my little computer screen is telling me it's coming down to 230 let's go ahead and try heading over that direction and see if it's correct the computer screen is bigger in the wind direction based on the ground speed based on our heading based on what it's getting for the pedo static system no pedo static system is perfect and peter stack errors lead to this guy not being super accurate so we're going to do a little bit of testing here ourselves to figure out what our slowest ground speed really is just getting a rough idea here it appears to me actually what this thing's really telling me here is no there's not much of a headwind out here at all that keeps changing his mind like that there's very little wind aloft here at 3500 because it certainly is not swinging around like that give it a moment here to catch up all right so we got that guy set for 280. we can see very little in the way of winds aloft we're gonna go ahead and start slowing this guy down right here at about 3500 and see what the slowest speed we can possibly fly really is and now of course it's showing a tailwind that's because well our pedo tube is not very accurate these crazy angles back no we are not doing 20 miles per hour through the air we can see a ground speed of 40 miles per hour that's a lot more accurate there so we can see 40 miles per hour gonna bring in a little bit of power here about 13 inches that's a reasonable amount of power to have coming into land with a normal cg anyways you can see 37 miles per hour and there's the break so 37 miles per hour is the break let's go ahead and flip around 180 degrees ignore whatever this guy says because it's totally inaccurate because it's getting bad information from our beetle tube again we're not doing 20 miles we're not doing zero we're not a helicopter right so there we are 39 not much wind up here at all today although i do need to take some power off there get a little excited with that come back to a normal power setting for approach about 13 inches i have to lower the nose to accommodate for that a little bit picking up some speed there now we can raise our nose right up to the stall 40 miles per hour 39 all right there's the break at 39 so broke at 37 broke at 39 we'll call that 38 mile per hour stall speed with full flap 13 inch demand full pressure outer ground effect up here 3538 mile per hour stall speed super lightweight like that all right there we are about 13 inches manifold pressure 40 flat nice approach power setting and we're coming down here we're at 260 degrees you see 43 miles per hour 41 miles per hour over the ground it's pretty mushy here and there's the buffet and break at 41. go ahead and spin her around here and see what she does going the other direction come back to 13 inches manifold pressure let that nose come down 13 inches manifold pressure 49 miles per hour going this direction get mushy and there's the break at 49. now let's go ahead and clean this guy up and try that same thing we're going to use that 100 heading and we're going to use the 280 heading and we're going to see how fast this guy goes here at 3500 feet so what is our top speed remember we don't have any pretty views for you today because we took all the cameras off of the outside of the airplane no camera mounts out there just cameras inside the airplane so there's no extra drag out there affecting our wings all right what are we seeing we're seeing 131 miles per hour here a little bit of a decent there so let's try to level off 35.80 level 132 2400 rpm 24 inches manifold pressure 11 and a half gallons per hour 131. let's go ahead and see what we do at more of a reasonable power setting like 23 squared or even yeah 22 inches 2300 rpm 10 gallons per hour let's see what we're getting here for a cruise speed we saw about 131 132 there on the 100 heading now we're seeing about 125 i'd say about 125 is pretty steady there right 125. let's go ahead and flip this guy around clear left clear right coming right all right and very little wind up here today we can see we're getting now about 122. that's 22 inches of manifold pressure 2300 rpm 10 gallons per hour warren level flight right about 3500 feet seeing about 122. back there to 132 miles per hour so pretty solid 132 mile per hour airplane we're at 3500 it's a pretty average cruise altitude for the airplane all right we're going to plug our heading here of zero eight zero and this is where we're going to go ahead throttle up here to 22 inches 2300 rpm see what kind of speed we get out of the airplane just like we were doing that before 22 inches 2300 rpm nice level flight here showing that we have a little bit of a tailwind and we're seeing about 120 322 miles per hour there so 122 123 miles per hour let's call it 123. let's spin around 180 degrees here check it clear left clear right all right we're on that 260 heading now 180 degrees opposite come back to 22 inches 2 300 rpm about 10 gallons per hour there nice normal crew setting and we're seeing 120 miles per hour going this direction other direction we were seeing about 122 ish now we're going to be up there at about 11 and a half gallons per hour so we're cruising along here 11 and a half gallons per hour seeing about 127 over the ground 127 miles over the ground 125 somewhere in there 125 to 127 let's just average out call it about 126. we'll call 126 over the ground at 3500 feet at and a half gallons per hour let's go ahead and spin her around and we'll do that same test going the other direction 20 400 rpm 24 inches manifold pressure about 11 and a half gallons per hour here right around 3 500 feet and what are we getting for a speed settling in here to about oh we see 132 133 leveling out here all right 11.6 gallons per hour 135 miles per hour and the other direction we're doing about 126 125 let's just call it about 130 miles per hour 131 about the same so really adding all that weight adding 500 pounds of weight plus to the airplane did not change our crew speed that much really our top end speeds that much at all all right here's our gross weight takeoff we're taxing up to the line we'll see if we can even get our tail off the ground get our flight counter preset and this will be time to climb to 1 000 feet can we get our tail up almost and the tail's back down come on tail get up they'll get up tail get up and we're going back down and now we're climbing almost 2 000 feet 50 seconds into play here and there we are that is one thousand sixty seconds into flight coming back around let's do this landing sold over traffic red bear hawk left beast final three four sloping oh a little swirly on the wings there okay so summary here right when we were light we're 1440 pounds when we were heavy we're 2000 pounds we added 560 pounds to the airplane what do we see taking off from zero to a thousand feet so we saw a sixteen hundred foot per minute climb rate from zero to a thousand feet and then we were heavy at two thousand pounds we saw a thousand foot per minute average now when somebody tells me oh my airplane climbs at 2500 feet per minute i'm like yeah whatever i just don't care about that spec you just told me or somebody shows me a spec sheet that says this airplane climbs at 2000 feet per minute i'm like yeah no what i want to see is what's the average climb rate from sea level to a thousand feet i want to see real numbers and by the way what was in the airplane when they did that test was it that gross weight was it just one average guy flying it with half tanks how did they do that actual test sure i saw him take off 2000 feet a minute for a moment there but really my average when i was light was 1620 feet per minute when i was as light as you could possibly make this airplane the airplane is 12 30 empty it has no insulation it has one radio simple panel really no interior so it's as light as it's going to get it does have a starting system of course it has a battery an alternator it has a starter you could take that stuff out but i don't really want to hand prop it so we have that earth x battery that's nice and light in there you're not going to be able to really pull 100 pounds of weight out of this airplane and make it much lighter so really flying with 10 gallons of gas and basically nothing else and tiny me in there i'd say that's about as light as you're gonna get the airplane now for actual takeoff and landing numbers we saw a 155-foot landing on the first go-around when we were light and 85-foot takeoff when we were nice and light once we got a little heavier there we saw a 280 foot takeoff about a 330 increase and then we saw a 175 foot landing really hitting those brakes tires spread out a little bit as they kind of skidded a little bit there definitely heavy um definitely 2 000 pound landing and that's as slow as you can come in we saw a 38 mile per hour stall speed when we were light up high there we saw a 45 mile per hour stall speed of 7 mile per hour increase in stall speed by adding that 560 pounds it's gonna happen within the airplane that is why we do not fly indicated air speeds on approach when we're flying in the back country because our weight changes based on how much fuel we have we have a person with us cargo etc so we fly power and pitch settings right so power and pitch certain attitudes is what we fly on approach we don't worry about our airspeed obviously i'm not going to be able to really ballpark a 20 to zero mile per hour indicator speed anyways you can see that indicated airspeed at these angles of attack really not that reliable anyways so the other thing we saw besides that 1600 foot per minute climb when we were light and a thousand foot per minute climb when we were heavy about a 40 reduction in climb rate well same thing from zero to 3 500 feet so somebody says oh my clean cleanse is 2500 feet a minute i doubt it does that all the way up to 3500 feet what does it actually do from zero to four thousand feet or zero to two thousand feet or zero to ten thousand feet how long does it take you to get there can you even use climb power settings without overheating your engine one thing about the bear hawk it has a nice tight cowling really efficient it climbs really well and cools really well when you're in cruise flight going fast we noticed in florida new mexico utah arizona at the higher hotter altitudes and just in florida at sea level but when it was warm out in april that yeah we couldn't even climb 2500 feet without getting cylinder head temps up over 400 degrees approaching 440 450. we had actually come back off 25 squared level off and let the engine cool down now it works fine up here in alaska and it's totally gonna work fine in january but something to consider does your airplane really climb that fast if you can't actually use that power because your engine cowling is pretty tight or because your engine is producing so much heat and you can't get rid of it so you can make some mods to the cowling to allow for better airflow for the most part it works just fine especially up here in alaska where we're at sea level we have pretty cool air year-round and we are able to climb pretty well above any obstacle most of our flying doesn't involve jumping over top mountains having to climb five or ten thousand feet a lot of our stuff is drainage flying flying down low where we don't really see ourselves climbing above 3000 feet anyways so ultimately from zero to 3500 feet we saw about 1235 feet per minute when we were light average and we saw an average about 765 feet per minute when we were pretty heavy there are two thousand pounds once again does my airplane climb at a thousand feet per minute i would tell you all day long my airplane climbs at a thousand feet per minute if not more but does it climb at a thousand feet per minute at gross from zero to three thousand five hundred no it doesn't it doesn't do that at all does it take off in 250 feet well not at gross because we saw a 280 foot takeoff with about six to eight knots of wind on the nose coming down the runway at that point and our 175 foot landing across was with some wind blowing down the runway again 45 mile per hour stall speed when we were heavy at 2 000 pounds 38 miles per hour stall speed when we were light so what's our realistic landing speed you're going to probably want to add a mile or two or three over that for a wheel touching speed no you're not going to be stalling the airplane in right there every single time with power on at 13 inches of manifold pressure to get those same numbers that we saw up high when we were using 13 inches of manifold pressure to kind of hang it on the prop a little bit to find those stall speeds no you're going to be a few miles per hour over that when your wheels are actually touching and those are really three-point attitude landings with the tail wheel touching first or really close to touching first not much forward visibility so if you want to consider doing a wheel landing or something with a little bit better forward visibility we're coming in at 10 12 degree deck angle and possibly pitching up to about 15 degrees right there as we're touching kind of stalling the airplane onto the ground if you're going to be coming in say at five degrees nose up five degree pitch attitude well you're going to be coming in a lot faster all right so figure a realistic touchdown speed in this bear hawk patrol of being oh somewhere in the mid 40s ish when you're really light and probably in the high 40s low 50s when you're heavy possibly a little more especially if there's any swirly winds you might be adding a little bit realistically 50 low 50s is what you're gonna be seeing when you're at full gross weight coming in there we were seeing a little bit slower but again 6-8 knots of wind blowing down the runway so that really helped us out there overall what is the idea here spec sheets develop more questions than they do answers whenever i look at a spec sheet for a bear hawk a kit fox a cub crafters aircraft just aircraft rans any of those manufacturers out there they're all great airplanes but spec sheets raise more questions in my mind than it really does answers ever spec sheets are not actually how your airplane is going to perform how it's going to perform is how it does in real life when you do comparison videos like this and that's what i really wish there was more out there so if you want to pick between a carbon cub or a kit fox or a bear hawk or a maul or a husky well you need to see real world numbers not just a spec sheet because there's a lot of asterisks or there should be a lot of asterisks with any spec sheet the spec sheet that you'll find on the bear hawk website for the patrol is not the same specs that we see in our patrol no not really so is it wrong maybe maybe not i don't know how they came up with those numbers but it's certainly not the numbers that we see flying ours around finally on the top end cruising at 10 gallons per hour an econ crew setting of 22 inches and 2300 rpm at 3 500 feet we saw an average ground speed there of about 123.5 miles per hour and then spooling it up to 24 squared 24 inches manifold pressure 2400 rpm 11.5 gallons per hour that's 75 power we saw about 131 132 miles per hour when we were light when we were heavy we saw those numbers come down to about 121 and a half and about 130 and a half so what does that really mean well when we're heavy we only lost about a mile or two per hour and the airplane realistically cruises about 131 miles per hour so at 3 500 feet density altitude and this was a pretty standard day about as close as standard as you could get here in alaska 59 degrees at the surface about 299 or 2 on the altimeter so these are the realistic numbers if you bring the airplane down to sea level yeah it's going to cruise a little bit slower if you bring it up to 8500 feet yeah add a few miles per hour it's gonna go a little faster we do have stall speed vgs across our wings we took off all the camera mounts so there's no extra drag we do have bush tires we got those little 26 inch goodyears small bush tires but bush tires so it causes a little bit more drag than say a six by six tire so maybe that's how they come up with some of those numbers but certainly if you're gonna be flying around on 31-inch bush wheels with stall speed bg's maybe put a gopro out there and fly around a gross weight you're going to be seeing slower numbers right so overall about 131 mile per hour airplane is what i would say cruises at 75 power and what's a stall speed well probably reasonably about 40 some miles per hour i would call it maybe 45 at gross weight for sure what's a realistic landing speed oh in the high 40s low 50s ish somewhere in there perhaps if you want some better forward visibility it'll definitely be in the low 50s those are the specs that we're seeing on our bear hawk patrol if you guys have a bear hawk patrol definitely make a video about it if you have a bear hot four place or a copper green cub or a husky or a kit fox or anything put together a speck video on it let everybody else see what it really does when you load it empty when you load it heavy and so on that's the real numbers that's what's kind of cool to really compare all these airplanes and figure out what airplane is right for you because the barrack patrol is an awesome airplane and i'm really happy with it and it fits our mission pretty well there's other missions that a kickbox might fit better or that a carbon cub might fit better and the bear hawk may not be the right fit for that mission so every airplane is mission specific decide what your mission is before you spend three years of your life building an airplane for an airplane that you think fits your mission and then turns out that spec sheet wasn't a hundred percent don't waste three years building an airplane until you actually verify all those specs that's it for this video guys if you have any questions leave it in the comments below stay tuned for more videos coming from alaska flying the bear hawk around here this summer epic summer definitely hit that subscribe button hit that little bell so you get notified when we post those latest videos and as always guys if you cannot fly every day fly at mykelp.com be safe out there

Channel: FLY8MA.com Flight Training

Views: 17,079

Rating: 4.8994198 out of 5

Keywords: fly8ma, bearhawk, bearhawk patrol, gross weight, light vs heavy, empty weight, piper cub, bushplane, comparison, weight and balance, aircraft, airplane, does it matter, aircraft loading, written test, private pilot, private pilot checkride, aircraft weight and balance, aircraft weight and balance explained

Id: odoGYOmg1Pc

Length: 23min 16sec (1396 seconds)

Published: Wed Sep 30 2020