Fuel leakage during in-flight refueling

On 24 Mar 2005 09:36:13 -0800, "John" wrote:

I am stretching here, but I seem to recall this is the reason that the
AAR probe on the A-4 Skyhawk was revised from a straight design to one
that incorporated a "dog leg." If I recall correctly, when the
Scooter backed away from the basket, a valve in the end of the probe
would sometimes allow a puff of fuel to escape. In the original
straight design, the puff would then be promptly ingested down the
starboard engine intake. This occasionally would do bad things to the
engine and create a bad day for the pilot. The "dog leg" design
moved the path of the fuel puff far enough away from the inlet to
prevent ingestion.

If I am wrong, I hope someone will correct me on this.

Blue skies . . .

Never tried to put my broad butt in a Scooter, but other aircraft with
the dog leg in the probe, such as the F-100, did it to move the
refueling point into quieter air out of boundary layer or to improve
pilot visibility for hook up.

The very small amount of fuel that sprayed at disconnect either from a
drogue or off the boom from a receptacle surely wouldn't do much to an
engine under normal conditions. In the F-105, the spray of mist would
fog the windscreen and then blow off in two seconds. Any fuel that
went down the intake could be sniffed in a second or two as it came
through the pressurization system--which is why the checklist for
refueling specified 100% oxygen.

Ed Rasimus
Fighter Pilot (USAF-Ret)
"When Thunder Rolled"
www.thunderchief.org
www.thundertales.blogspot.com