Tankerpilot75
Well Known Member
This year?s trip to AirVenture taught me a valuable lesson about C.G. And weight.
Like (I suspect) several RV owners I became complacent about cg and weight because these planes perform so well. Background: my RV7A is a little heavy to begin with due to a nice panel, oxygen system, lovely interior, pretty paint job and a few extra luxuries I consider important to always carry. In other words the basic empty weight is 1,188 lbs. My empty C.G. is 79.97 which is a good forward cg.
Last year I overloaded the aircraft by about 100 lbs. and had absolutely no problems. This year was different! I?ve personally gained 5 lbs., my passenger was a little lighter than last year?s passenger; so I put about 125 lbs in the cargo area and estimated my total gross weight around 1,950 lbs. Takeoff cg was within limits.
I was part of a two ship arriving Saturday night and when three minutes out of Ripon they closed Oshkosh ten minutes early. We diverted to Appleton. Landing at Appleton was stick sensitive but very controlled.
My lead flew to Oshkosh the next day (3.5 hour flight plus one fuel stop) while I elected to stay at Appleton since it was convenient and my parking fee for that Saturday night was the same as the whole week. I was also told OSH HBP was muddy so staying at Appleton just made sense. I had room reservations at Oshkosh dorms and took the bus to AirVenture.
Like a lot of folks I purchased a few things, picked up a few more ?free goodies? and so did my passenger. Return trip on Friday added another 10 to 20 lbs aft. Our return trip had me stopping at North Central Regional (MO8) for fuel. Unfortunately they ran out of 100LL two planes before my turn (price $3.90 gallon). We still had 18.5 gallons so I flew on to Marshall Memorial (KMHL) an additional 20 minutes air born for fuel. This burned about four gallons more. Airplane felt unusually sensitive with a slightly nose high pitch on this flight.
My first landing at Marshall surprised me with severe PIO (never have I experienced this before) so I went around. My second attempt was even worse. Now I?m shook up! (I?m a 3,800 hour - long retired military instructor pilot - and PIO is something only rookies experience - right?). My passenger (a former Tora Tora pilot and Reno Air Racer calmly suggested I apply full nose down trim - which I did. Thankfully it worked and the third attempt resulted in no PIO and a safe landing.
Lessons learned:
1. Don?t become complacent. Play attention to cg limits and gross weight. While you can be within cg limits on take off, inflight fuel burn will move your cg aft. If already over weight this can get you into serious trouble if your cg at takeoff is near the aft limit.
2. Use FedEx or UPS if you suspect your overweight. Even better - don?t start overweight and expect to not have consequences. It?s cheaper to mail stuff than to damage the aircraft and possibly hurt someone.
3. If you find yourself trying to land your RV outside of aft cg limits - apply full nose down trim! It will keep your nose down and help prevent over controlling the aircraft as you try to make a landing. Remember an aft cg makes these aircraft extremely sensitive to control inputs. Full nose down trim dampens this out a little.
4. Make sure your lighter passenger deplanes first and have him/her hold the nose down while you?re getting out. Fat boys on the rear step will cause the tail to drop. We at least thought of this before deplaning.
I share this with you in the hope that you?ll pay more attention to cg and weight limits when you make a long trip. These airplanes are great little performers but they can make you complacent if you?re not careful. Remember ?full nose down trim? can help reduce PIO when control forces feel too light.
Like (I suspect) several RV owners I became complacent about cg and weight because these planes perform so well. Background: my RV7A is a little heavy to begin with due to a nice panel, oxygen system, lovely interior, pretty paint job and a few extra luxuries I consider important to always carry. In other words the basic empty weight is 1,188 lbs. My empty C.G. is 79.97 which is a good forward cg.
Last year I overloaded the aircraft by about 100 lbs. and had absolutely no problems. This year was different! I?ve personally gained 5 lbs., my passenger was a little lighter than last year?s passenger; so I put about 125 lbs in the cargo area and estimated my total gross weight around 1,950 lbs. Takeoff cg was within limits.
I was part of a two ship arriving Saturday night and when three minutes out of Ripon they closed Oshkosh ten minutes early. We diverted to Appleton. Landing at Appleton was stick sensitive but very controlled.
My lead flew to Oshkosh the next day (3.5 hour flight plus one fuel stop) while I elected to stay at Appleton since it was convenient and my parking fee for that Saturday night was the same as the whole week. I was also told OSH HBP was muddy so staying at Appleton just made sense. I had room reservations at Oshkosh dorms and took the bus to AirVenture.
Like a lot of folks I purchased a few things, picked up a few more ?free goodies? and so did my passenger. Return trip on Friday added another 10 to 20 lbs aft. Our return trip had me stopping at North Central Regional (MO8) for fuel. Unfortunately they ran out of 100LL two planes before my turn (price $3.90 gallon). We still had 18.5 gallons so I flew on to Marshall Memorial (KMHL) an additional 20 minutes air born for fuel. This burned about four gallons more. Airplane felt unusually sensitive with a slightly nose high pitch on this flight.
My first landing at Marshall surprised me with severe PIO (never have I experienced this before) so I went around. My second attempt was even worse. Now I?m shook up! (I?m a 3,800 hour - long retired military instructor pilot - and PIO is something only rookies experience - right?). My passenger (a former Tora Tora pilot and Reno Air Racer calmly suggested I apply full nose down trim - which I did. Thankfully it worked and the third attempt resulted in no PIO and a safe landing.
Lessons learned:
1. Don?t become complacent. Play attention to cg limits and gross weight. While you can be within cg limits on take off, inflight fuel burn will move your cg aft. If already over weight this can get you into serious trouble if your cg at takeoff is near the aft limit.
2. Use FedEx or UPS if you suspect your overweight. Even better - don?t start overweight and expect to not have consequences. It?s cheaper to mail stuff than to damage the aircraft and possibly hurt someone.
3. If you find yourself trying to land your RV outside of aft cg limits - apply full nose down trim! It will keep your nose down and help prevent over controlling the aircraft as you try to make a landing. Remember an aft cg makes these aircraft extremely sensitive to control inputs. Full nose down trim dampens this out a little.
4. Make sure your lighter passenger deplanes first and have him/her hold the nose down while you?re getting out. Fat boys on the rear step will cause the tail to drop. We at least thought of this before deplaning.
I share this with you in the hope that you?ll pay more attention to cg and weight limits when you make a long trip. These airplanes are great little performers but they can make you complacent if you?re not careful. Remember ?full nose down trim? can help reduce PIO when control forces feel too light.