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10/23 Raptor Video

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bmcj

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Fresno, California
Early landing would be back to 17. But he went around again for 6 minutes.
But why land in the opposite direction of takeoff? I can think of a few reasons...

  • Windshift.
  • Traffic pattern preferred runway change at the airport.
  • Took off downwind to avoid overflying the town of for favorable terrain.
  • Forced landing due to deteriorating circumstances.
I guess we’ll have to wait for the YouTube video to find out.
 
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lelievre12

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N252TD Second Flight.JPG

Looks to me like he climbed to about 750ft after takeoff on 17. He then immediately started a descent intending to land on 17.

Looking at the pattern I think he probably found he was too high/close on base for 17 (panic?) so turned it into a crosswind for 35 then climbed back up to 625 ft for an unconventional downwind (upwind?) 35. Then descended 500-600ft/min as he turned base for 35 for a landing the wrong way downwind. Not ideal at all and obviously trying to get back down in a hurry rather than make a full circuit for 17. If we can get ATC then will know for sure.

Postscript: Looks like I was wrong. The new video shows a slight downwind takeoff then a normal pattern to resume downwind 35. Aside from a slightly elevated oil temperature, looked like a pretty good flight. No panic landing here at all.
 
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Oct 1, 2020
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LiveATC at this airport is basically useless, it only archives 2.5 minutes out of every half hour period. There is some discussion with Rescue 7 headed out somewhere on the runway/taxiway area during the 1300-1330Z archive, but that's all.
 

rbarnes

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Texas
The constant up deflection of the left aileron while turning right and going straight has me puzzled. How can that even happen ?
 
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rv6ejguy

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Calgary, Alberta, Canada
The gear is down of course but the fuel flows are pretty prodigious- roughly 13-14 gph to maintain 110 kts, 16-17 for around 120 kts and around 8 gph in ground effect during landing at 90 kts. Lots of drag and/or the engine mapping is WAY off and the turbo layout is suffocating it. An RV-10 burns less than half the amount of fuel at these speeds with fixed gear and climbs at almost triple Raptor's ROC with such a light load at these temps.

With the gear retracted, no way this airplane will true 230 KTAS on 7 GPH at 25,000 feet, as was predicted. A couple years back, I predicted closer to 13-16 gph. May even be higher than that. Will have to see how much difference the gear retraction makes.

Of note, the oil and coolants temps didn't stabilize until power was reduced to about 55%. With OAT at around 40F, that doesn't bode well for a 90F day at gross at climb power. Much work to do on the thermal side of things.

On the plus side, it looked much more stable during this flight.
 

Deuelly

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Marshall, MN
What made me nervous was his comment about trying to decide what he wanted to do as he's already flying around.

When you're test flying you should have a plan before you ever leave the ground. You should have emergency procedures ready for every point of that flight. You should also talk to the control tower about your plan for the flight. This goes for any aircraft, even a proven design like the RV.

Brandon
 

Kyle Boatright

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Marietta, GA
Much less "interesting" flight than the first one. Glad he got it back on the ground safely again.

The 40F temperatures and the cooling kludges he's installed delivered 5 minutes (?) before the engine exceeded thermal limits. As Ross said, lots of work to do there. If he'd spend a month working on fixing the cooling issues, rather than applying duct tape over the band-aids, he'd get to a point where he can do more than a partial (or full) lap around the pattern. He's not going to get any real flight testing done with 5 minute hops.
 

lelievre12

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The constant up deflection of the left aileron while turning right and going straight has me puzzled. How can that even happen ?
He put a large tab on the outer trailing edge to correct a port low wing. Looks like he overdid it hence the new up deflection of the aileron to counteract. If he backs off the trim tab (or removes) the aileron should level.
 

Scheny

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Vienna, Austria
Will have to see how much difference the gear retraction makes.
I took some notes in the DA42 (old Thielert model) about power settings for landing. Now I can fly them by feeling and don't need the values in the NG anymore. Note: the aircraft has FADEC and these values correspond roughly to thrust, hence drag.

Pattern speed (120kt), const. ALT:
  • Clean config: 55%
  • Flaps full: 68%
  • Flaps+LDG gear: 86%
Drag factor gear 86%-68%=18%. Percentual increase 1+(18%/55%)=1,327. Possible speed of the Raptor with retracted gear (1,327)²*110kt=194kt
 

flywheel1935

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Downham Market, Norfolk, UK.
In the Audi cars that this engine is used in surely the fuel flow at max speed 155 mph wouldn't be anywhere close to 21 gallons /hour, guessing at 20 mpg so 7-8 gph ??? Is he using the vehicles pumps and is the fuel system/injectors actually capable of handling 20+ gph ? Also the maingear wheel stopped pretty quickly on T/O I bet the brakes are still an issue.???
12 gallons of fuel onboard !!!! so less than 1/2 hour fuel at full power, is there no limit ref available fuel for a divert/problem/etc ???
 
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rv6ejguy

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21 gph should be around 350hp on a stock Audi engine but we know from the acceleration that it's nowhere near that here. He has different external pumps and fuel system from the car. Engine pump is stock.

12 gallons of fuel on board seems like a poor decision. How much is usable? Was fuel feed/ flow ever checked at climb attitude? I never saw that ground tested.
 
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