REFLECTOR: N4PE flies but not so good at the end
Scott Derrick
scott at tnstaafl.net
Mon Mar 30 20:08:26 CDT 2009
Yeah,it sure sounds like it could have been fuel starvation.
Were the engine parameters recorded? Can you check what the fuel flow was?
Scott
Chuck Jensen wrote:
> Brian,
>
> I can guess with the best of them, even if my guesses aren't very good. One clue is the low sump level. Any chance that the sump and/or fuel system wasn't venting properly and it was either creating a vacuum or otherwise not allowing fuel to flow to the sump and/or engine.
>
> I've saw more than a couple motorboats setting dead in the water. They said they'd switched to a fresh portable fuel for the outboard and it ran for a few minutes, then lost power. After waiting a while, the motor would start, but then slowly die.
>
> After suggesting they open the vent on the portable fuel tank...the outboard ran a lot better. It's a long shot, but another thing to check out.
>
> Chuck Jensen
>
>
> -----Original Message-----
> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org]On
> Behalf Of Brian Michalk
> Sent: Monday, March 30, 2009 5:09 PM
> To: Velocity Aircraft Owners and Builders list
> Subject: Re: REFLECTOR: N4PE flies but not so good at the end
>
>
> Dennis,
>
> Thanks. I went out to the airport with the FAA inspector to determine
> if it's an accident or incident today.
>
> I think electronic is the way to go, it's just more difficult to set
> up. I'll pull off the tables, and certainly go over them. Now I've got
> to get over this feeling of depression and get back to work.
>
> Dennis Martin wrote:
>
>> I went to Cincinnati and left my laptop behind. What a shock to see
>> this email. Your preflight preparations are impressive and remind all
>> of us how critical it is to cover all the bases. I'm close to 12 years
>> on my project and can't imagine how disappointed you feel, but I'm so
>> glad that you're in one piece.
>>
>> I've also got electronic ignition/fuel injection. I'll do all I can to
>> make it perfect before rotating, but there's no guarantee that ground
>> testing is the same as flying. All the best in your Phoenix project.
>>
>> Dennis
>>
>> 2009/3/29 Brian Michalk <michalk at awpi.com <mailto:michalk at awpi.com>>
>>
>> Group,
>>
>> Today was my first day to fly. Unfortunately it resulted in an off
>> airfield landing. It's been a long day, and I wanted to get this out
>> there before the FAA notice was posted.
>>
>> I have several theories at this point as to what happened, and I'll go
>> through each one trying to identify the smoking gun.
>>
>> First, the flight. Approximately 12:30 pm with a 5 knot southern
>> wind,
>> I prepared for takeoff. Some people think I am a bit cautious, and
>> maybe so in many cases, but today was a good day to be cautious.
>> I had
>> the local fire department notified, and they were standing by. Pretty
>> nice folks, and I think they liked having something interesting to do.
>> Dean Norris with a sharp eyed passenger took off in his Velocity
>> to fly
>> chase. I had maps made, and distributed to everyone with big
>> letters to
>> help direct ground crews in a bad event. Dean took off, and I waited
>> for him to get on downwind before starting my roll. Previous to
>> today,
>> I had been doing a bit of fast taxiing, and nothing abnormal ever
>> showed
>> up. I rotated several times during fast taxi tests at about 65mph.
>> Today, as I accelerated through 70, I remember thinking how odd it was
>> that I had not yet rotated, but this was the first time under power.
>> Rotation speed is lower without the power vector pushing the nose
>> down.
>>
>> I accelerated, and lifted off about 75kts. The plan was to climb to
>> 1000'AGL at 90kts. I reached my 90kts very quickly, and kept pulling
>> nose up a little bit more. Man, there was a lot of power. The plane
>> flew straight. No major stick forces that I can recall. I reached
>> about 900 feet, and the engine began losing power. I immediately
>> turned
>> crosswind to downwind. I wish I could say I was maintaining optimal
>> airspeed, but I don't recall any airspeeds after that point, and
>> looking
>> back would have been the absolute best thing to maintain. I
>> pulled out
>> some throttle, and regained some engine power, but not enough to
>> arrest
>> the descent. I was still on downwind, and picked out a field north of
>> the field to put down in. Then I changed my mind. With the bit of
>> power I had, I decided to turn south into the find to reduce my ground
>> speed. I picked out a field, and turned to it. I ended up about 600
>> yards north from the end of the runway facing south.
>>
>> I will remember this day forever, and will play back the choices into
>> eternity.
>>
>> The plane contacted ground, and came to a stop within 47 yards. I
>> stepped it off. The ground was quite soft. The gear all had been
>> sheared off. The right tip of the canard dug into the ground, and
>> when
>> it did, caused compression crumpling on the right side of the
>> fuselage.
>> Next, the plane wanted to move left, and that's when the main gear
>> really dug in and sheared off, which was quite a jolt.
>>
>> Nothing broken for me except my ego. I literally have a minor scratch
>> on my left hand, that's all. Amazing. I'm not even sore ... yet.
>>
>> Going back to the causes, I have a few theories that need to be
>> researched. As I taxied over to the fuel pumps, I saw the low fuel
>> light was on. After taking on five gallons each side, I noticed the
>> warning light had turned off. When the engine lost power after
>> takeoff,
>> the light was on. However, I'm not sure fuel starvation is the reason
>> for the power failure. There's 4.9 gallons in that sump. That's
>> a lot
>> of time, and there is no way I could have emptied it. The other
>> theory
>> is that I was running too rich. The electronic injection system was
>> tuned out to 2250 RPM's, because that's the limit I could do in ground
>> testing. I then extrapolated out to 3000 RPM's (red line at
>> 2800), and
>> then richened up the whole table to be on the safe side. One thing I
>> wish I had done during high power testing was to see how much more
>> rich
>> I could go before killing the engine. I pulled the spark plugs,
>> and the
>> plugs closest to the firewall were very sooty. The other four plugs
>> looked very good.
>>
>> After 12 years of building, it looks like I have a little bit more to
>> go. The belly of the plane looks good. The compression buckling
>> worries me as to how I will fix that. The wings are also showing
>> compression buckling just outboard of the spar attach bolts.
>>
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>>
>>
>> --
>> All the best,
>> Dennis
>> ------------------------------------------------------------------------
>>
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