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- Mar 15, 2016
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Ari
If the crash happened at 5:30 a.m. and they were flying for 2 hours, that means they preflighted around 3:00 a.m. and flew the entire trip in the dark. It's easy to imagine missing something during preflight or in flight. Forgot to lean, didn't see water in an aux tank sump, etc. It's hard to read a checklist if you have an emergency in the dark. Also, losing an engine in night VMC is something most pilots don't directly train for the way we do with day VMC and simulated IMC engine failures. Thankfully, with the outcome of this mishap, there's a decent chance the pilot can eventually tell us exactly what went wrong.
I offer some data points to help with the speculation. I fly a 310R, which has VGs but a stock airspeed indicator. If you re-mark the ASI, the VGs give you lower Vmc, lower stall speeds, and an increased gross weight. A 310R's useful load can lap at the shores of 2,000 lbs. I don't know the configuration of the mishap plane, but it's hard to overload a 310R.
Going partly from memory, at gross weight at sea level, the stock Vmc is 80 KIAS and with VGs it's 71 KIAS, despite the increased gross weight. Clean stall speed at gross is 72 stock and 70 with VGs. Vyse is 106 either way. A healthy 310R that started at gross and burned off 50 gallons of gas by flying for 2 hours would weigh 5200 lbs. Based on the single-engine charts in the POH, it should have a service ceiling around 8,000 feet and the rate of climb out of 1,000 MSL should be 200 or 300 ft/min.
There are anywhere from two up to six fuel tanks, but the system isn't as complicated as it sounds. The tip tanks are the mains and hold 50 gallons each. I think all 310R's have aux wing tanks, which can be 20 or 31.5 gallons each. There are optional wing locker tanks, which are usually found on only one side so you can still use the whole other wing locker. Wing locker tanks get pumped into another tank (main or aux, I'm not sure since I don't have a locker tank) by a pilot-controlled electric pump. There are not as many fuel sumps as a new 172, but more than a PA-28. My plane has 8 sumps: main, aux, engine, and crossfeed valve on each side.
Crossfeed is only from the main tank. Excess fuel not used by the engine gets pumped back to the main tank. The boost pumps are hooked up to the main tanks. So you take off and land on the mains, but your goal is to keep them full since aux fuel can be trapped if you lose an engine driven fuel pump (boost pump can only draw from main) or an an engine (crossfeed can only draw from main). If you start with full tanks, you fly 60 or 90 minutes (for the 20 or 31.5 gallon aux tanks, respectively) on the mains to make room for the returned excess fuel, switch to the auxes and run them dry, then switch back to a mostly-full main tank. I flight plan 175 KTAS, 28 gallons in the first hour, and 24 gallons an hour after that.
I offer some data points to help with the speculation. I fly a 310R, which has VGs but a stock airspeed indicator. If you re-mark the ASI, the VGs give you lower Vmc, lower stall speeds, and an increased gross weight. A 310R's useful load can lap at the shores of 2,000 lbs. I don't know the configuration of the mishap plane, but it's hard to overload a 310R.
Going partly from memory, at gross weight at sea level, the stock Vmc is 80 KIAS and with VGs it's 71 KIAS, despite the increased gross weight. Clean stall speed at gross is 72 stock and 70 with VGs. Vyse is 106 either way. A healthy 310R that started at gross and burned off 50 gallons of gas by flying for 2 hours would weigh 5200 lbs. Based on the single-engine charts in the POH, it should have a service ceiling around 8,000 feet and the rate of climb out of 1,000 MSL should be 200 or 300 ft/min.
There are anywhere from two up to six fuel tanks, but the system isn't as complicated as it sounds. The tip tanks are the mains and hold 50 gallons each. I think all 310R's have aux wing tanks, which can be 20 or 31.5 gallons each. There are optional wing locker tanks, which are usually found on only one side so you can still use the whole other wing locker. Wing locker tanks get pumped into another tank (main or aux, I'm not sure since I don't have a locker tank) by a pilot-controlled electric pump. There are not as many fuel sumps as a new 172, but more than a PA-28. My plane has 8 sumps: main, aux, engine, and crossfeed valve on each side.
Crossfeed is only from the main tank. Excess fuel not used by the engine gets pumped back to the main tank. The boost pumps are hooked up to the main tanks. So you take off and land on the mains, but your goal is to keep them full since aux fuel can be trapped if you lose an engine driven fuel pump (boost pump can only draw from main) or an an engine (crossfeed can only draw from main). If you start with full tanks, you fly 60 or 90 minutes (for the 20 or 31.5 gallon aux tanks, respectively) on the mains to make room for the returned excess fuel, switch to the auxes and run them dry, then switch back to a mostly-full main tank. I flight plan 175 KTAS, 28 gallons in the first hour, and 24 gallons an hour after that.