I ran across a picture that reminded me of an interesting experience in Tanker 65 following a flight out of Porterville in 1982.This particular picture is at Alamogordo in 1980 and features Tanker 68,but that doesn't really matter.Here's the picture:
Tanker 65 was N5237V,a PB-1W that's now in the R.A.F. Museum in London.For the 1982 fire season,my co-pilot,Gerry Glenn and I were based in Porterville on the CDF contract.One day in August,we were dispatched to a grass fire on the nearby Tule Indian Reservation.As it turned out,the Hotshot Crew was able to corral the fire without our help.We had to jettison half of our load of retardant to get down to landing weight.
That's an interesting point in itself.When Aero Union operated B-17's as tankers,nobody had ever seen a document that stated a maximum landing weight for the B-17.The published Gross Weight was 59,000 lbs,so that's what everyone used as a landing weight.Once Aero Union replaced their B-17's with C-54's,they "found" a document from the Air Force that was dated in 1956,I think.This listed a landing weight for the few B-17's that were still in the USAF inventory at that time as 54,000 lbs.This gave the C-54 a new advantage over the B-17 because we would now have to jettison $300-$400 worth of retardant to get down to the reduced landing weight and the C-54 could land loaded.This made a big difference with the CDF because they use tankers like fire engines and send them almost automatically when a smoke is reported and,as often as not, cancel the tankers a couple of minutes into a flight.
Back to the story.We dropped half of the load and Gerry landed the airplane on Porterville's Runway 30.Everything went normally until Gerry started to brake for the turn off at the end of the runway,which is a 120 degree right turn to the taxiway.Braking began about 1500 ft from the end of the runway.Two things happened fairly quickly.First,a warning light lit up on my subpanel below the instrument panel.For a couple of seconds,I tried to think what the light was for,as I'd only seen it light up once before.Then,Gerry said "I've got no Brakes!".
That's when I remembered the last time that I saw that light come on.That time it was taxi-ing into the pits at McCall when a metering valve in one of the brake master cylinders stuck open and started bypassing hydraulic fluid to the point that the pressue dropped to zero.I had a guarded switch for the electric hydraulic pump next to the warning light.
Back at Porterville,I held the pump switch in the manual position and hydraulic pressure started climbing to the point that we had brakes again.We figured that the pressure switch to restart the pump automatically must have failed.I unlocked the tailwheel and Gerry stated around the corner at the end of the runway when the hydraulic pressure dropped to zero again.
As we started into the grass between the runway and the taxiway,I took over and managed to get onto the taxiway by using differential power and a bit of rudder and aileron.The last two weren't a lot of help,as we were moving at a walking pace.I got back to the center of the taxiway and locked the tailwheel while Gerry went down into the nose where the airplane hydraulic system was located.He verified that the tank was empty and that we didn't have any spare fluid in the nose.
I shut down the inboards and the airplane slowed to around 5 mph with the outboards at idle.I figured that we'd better just stop where we were and regroup,so I shut down the outboards.I'd once read about a Liberian oil tanker that ran over a sailboat and took 7-8 miles to get stopped.That came to mind in Tanker 65 as it was down to walking speed,but,even with the tailwheel locked,it was drifting to the left side of the taxiway.I had full rudder and aileron in,but it did no good at that speed.
I had to fire up the outboards again and get back to the middle of the taxiway.Gerry had found a few quarts of hydraulic fluid back in the radio room where there was a completely indepenent hydraulic system for the retardant tank.He poured thev fluid in the main system tank and I tried building pressure,but it didn't work.Gerry found a wheel chock somewhere in the airplane and took it down into the nose walkway.I shut down the outboads again and Gerry tossed the chock out the nose hatch and it landed in about the same position as the chock in the picture.That did the trick.We stopped when the wheel hit the chock.
We got out and looked around for the source of the hydraulic leak.It turned out to be the flex line for the brake at the top of the right main gear strut.It had blown out.I found out later that this wasn't uncommon,although it was the first time that I'd heard about it.Apparently,somebody had one fail in flight and the fluid caught fire as it passed the turbo.
As I mentioned earlier,Tanker 65 had a completely separate hydraulic system for the retardant tank.The main pressure line for that system was exactly the right size to replace the blown brake line.We had an idea that we ran past Kenny Stubbs,our Director of Maintenance,in a phone call.We still had half a load of retardant on board,but,assuming the doors were over center in the tank,they should stay closed without any hydraulic pressure.Kenny agreed with that.We'd install the pressure line from the tank system in place of the blown brake line long enough to taxi to the tanker base and Kenny would make up a new line and replace the bad line permanently before we came on duty the next morning.In the meantime,Jim Baughman brought us several gallons of spare hydraulic fluid from the tanker base.
The first thing that we did was to build up full system pressure to be sure that the doors were closed.After that,Gerry bled off the tank hydraulic pressure to see what happened.We'd done this before with the tank loaded to change a line.We waited 10 minutes and everything looked fine,so Gerry pulled the pressure line off of the tank system.It was a tight fit and slimy with fluid.At about he time that got the replacement line installed,the two left retardant doors began to slowly creep open.There was a mad scramble to reinstall that line back onto the tank system and build up hydraulic pressure before all the doors and the remaining 900 gallons of retardant ended up all over the taxiway.Somehow,Laurel and Hardy came to mind at about this time.
The two empty doors were wide open by the time we got pressure built up.We got them closed and decided to cut our losses and leave the airplane where it was for the night.That was also a problem,as the taxiway was unlighted and Porterville is an uncontrolled field.We checked in at the airport office and the solution was to have the water department bring out a couple of sawhorses with blinking lights that we could place to the front and rear of T65 for the night.
Kenny came over the next morning and replaced the line,serviced the hydraulic ststem and even taxied 65 to the tanker base for us.Thinking back,it's unlikely that the two tank doors for the full tanks would have opened.The two that were jettisoned must not have locked overcenter,although we built up full system pressure prior to bleeding it off to remove the tank system line.65 had huge tank doors that often wouldn't close if you were above 140 mph after dropping.It wasn't unusual to look back and see the actuating cylinder for the forward tank door fully extended after a drop.In that case,I'd have to slow down to 120 mph and kick in a lot of rudder to get the air load to start the door closed.
One thing that got my attention for the next few weeks after losing the brakes was that it could have been a much more serious situation.There were a number of places that we went to that could easily have had us either run into another airplane or into a building or vehicle.There was always the possibility of hitting someone on the ramp.That almost happened that time at McCall as Bob Franklin,the tanker base manager was right in front of us leading us in.I was c/p then and remember Ralph Rensink (my pilot) yelling at Bob to get out of the way while he swung around out of the pit with differential power.I even tried to get TBM to rig a squat switch over-ride in a guarded switch,just in case retracting the gear might prevent a disaster,such as running into the fuel farm or Air Force One.Kenny was going to do it for me,but that was the last year that TBM flew B-17's as tankers.
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