Talked with Sam again last night. After getting
the aircraft back to hangar and FAA investigator had done his thing, Sam asked
the investigator whether he wanted him to fire up the engine. The
investigator told Sam that was up to him. So Sam turned on all the
switches and the engine fired right up and ran smoothly - the investigator
commented he was amazed at how smooth the rotary ran. So the engine and
it subsystem (at least initially) appears to function normally.
It appears the nose gear did not fold when Sam
encountered the fence - but apparently the one nose gear rod retaining bolt in
the motor mount may have sheared and permitted the rod and nose gear to fold
side ways. Spinner and prop apparently incurred some damage - which may
(or may not) be minor and fixable. The right wing spar is bent so that
wing is toast, fuselage appears OK and left wing with some trailing edge
damage (probably fixable).
Further discussion with Sam leads me to believe that the
highest probably cause was a "vapor lock" of some type in the fuel line. Sam
stated the engine never stopped running (correction to my earlier report
- where I stated it had quit), but just continued to sputter and failed
to produce power.
The ignition checked out OK as did the rest of the
system back in the hangar. The symptom of sputtering engine and no power
would put a fuel system problem high on my list of suspects and given the high
ambient temps (98F) and the run up before take off -- would leave me to
believe those conditions could have lead to diminished fuel
flow.
Sam is going to inspect his coarse filter to ensure it
was not partially obstructed.
One item of note is that Sam does not have any sort of
boost pump between tanks and his EFI pumps. In my early days of testing
while doing power-on stalls (high power low cooling airflow) on a hot day, my
engine started to sputter (unlike Sam I had plenty of altitude when it
happened) and I noticed my fuel pressure fluctuating between 20 - 35
psi. I turned on my Facet boost pump (puts out approx 6 psi pressure)
and it immediately squelch the problem. So I now take off/land with
boost pump on and have never since had that problem.
We know that any obstruction in a fuel line produces at
least a small pressure drop down stream - Given the suction of the EFI pumps
and even minor restriction of the coarse filter - a lower pressure region
would exist between filter and EFI pumps - elevated temperatures could be
enough to cause some of the fuel in this area to flash into a gaseous
state - which of course is not pumped very well. Its my opinion that a
boost pump is a worthwhile addition in keep pressure in the low pressure part
of the fuel system sufficiently high to prevent the fuel from percolating -
particularly on HOT ambient days. However, make certain that the boost
pump is of a type that does not obstruct fuel flow during a malfuction or when
off.
Will provide any further details as Sam provides
them.
As we all know engine failure right after take off is
probably the most difficult and challenging situation you will face.
Unless you immediately lower the nose, your airspeed will bleed off almost
immedately and a stall will occur. So Sam certain is to be commended for
his quick and effective action responding to the event.
Ed
Sent: Tuesday, August 09, 2011 7:49 AM
Subject: [FlyRotary] Re: Sam Hodges Force landing - All
OK
Hmmm, two forced landings in one week … I hope the trend
stops here!
Good job Sam for getting down safely from such a critical
point … 200-300’ on take-off is about as bad as it
gets.
Let’s hope we get an answer soon as to the
cause.
Jeff
|
|
|
Sam Hodges just called
me to tell me about his forced landing after take off at Paducha on 7
August. Ed K had notified me the day before of the incident but I
wanted to get more details from Sam before reporting.
Engine sputtered and
quit approx 200-300 ft after take off - Sam stated he had time to
switch from A to B controller - but it made no difference. It was
a hot 97F day. Sam had performed runup before take off and all
appeared OK.
Sam made it to a dirt
road after the engine quit, but the nose gear failed and the aircraft
also incurred some damage to the wing tips. He and his spouse Rose
were shaken up a bit but bascially OK except for sore muscles,
etc.
Sam is meeting FAA guy
to go over the aircraft - back at the hangar- today.
As those of you who make
it to the Paducha flyin last fall know - Sam and Rose have a beautifuly
Renesis installation in an RV-7A - a really nice looking package.
Sam has been working out
the bugs of his installation - wrestling with temperatures primarily and
this flight was to check out the effectiveness of some of his recent
changes.
I'm sure Sam will let us
know whatever is uncovered pertinent to the incident.
Just great that no one
was seriously injured or worst
Ed |
Jeff
Whaley
Manager,
Test and Repair
International Datacasting
Corp.
Tele: 613-596-4120
(ext: 2295)
Fax: 613-596-9208
www.datacast.com
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