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Phantom fighter bomber
The F-4E Phantom II fighter bomber is essentially an F-4D with improved J79-GE-17 engines (900 pounds more static sea level thrust each) and an M61A1 “Vulcan” 20mm cannon.
Operational experience gained in Vietnam had a direct influence on the addition of the cannon. The air-to-air missile fire-to-hit ratios were low and air combat usually degenerated to subsonic “dogfighting” where the F-4 was at a decided disadvantage when flying against more maneuverable enemy aircraft (MiG-17 and MiG-21).
The hydraulically powered wing-folding mechanism and the emergency ram-air turbine were removed to save weight and a seventh fuel cell was added. The addition of self-sealing fuel tanks starting with block 41 aircraft lowered the fuel capacity by 139 gallons but provided much better combat survivability.
McDonnell Douglas produced 5,057 F-4s, of which 1370 were F-4Es.
Hahn Air Base
After completing his flying training, Eric Coloney was selected for the F-4 Phantom and attended the F-4 Replacement Training Unit (RTU) at Luke Air Force Base (AFB), Arizona between May, and December 1976. At the time, the training unit was operating old F-4C models.
Once Eric completed his course at Luke, he received orders to join the 50th Tactical Fighter Wing at Hahn Air Base, West Germany and was assigned to the 10th Tactical Fighter Squadron – the ‘Fighting Tenth.’
Eric’s training with the RTU at Luke was all flown with early F-4C model aircraft. At Hahn, the 50th Tactical Fighter Wing operated the F-4E model aircraft with wing slats.
Arriving at Hahn from Luke Air Force Base in Arizona, Eric had to get used to the European weather.
F-4’s fuel system indicator
He recalls in the bookazine F-4 Phantom Tales from the cockpit;
“The F-4’s fuel system indicator was terrible. The fuel gauge was both digital and analogue. There was an arc across the top that was analogue, we called it a tape, which showed the amount of fuel held in the fuselage. If everything failed, the fuselage would gravity feed into the forwardmost tank as your usable fuel, with some limitations. The counter wasdigital, it looked like an old digital clock. Thenumbers ticked up and down, it showed yourtotal internal fuel, which included fuel in thewing tanks which held 2,000Ib per wing, andthere was 8,000lb in the fuselage tanks. So,when the aircraft was full of fuel, the tapewould be on the number eight, and the counterwas on 12. So, you had eight over 12.
“When you walked around the aeroplane inthe summertime, after the aircraft had beenrefuelled, you could feel if the fuel was cool ornot, provided it had been delivered well, hadn’tsat outside and wasn’t at ambient temperature.If you gave the fuel tank a slap and the noisegenerated was a ‘pong’ it was empty, and if itwent ‘bong’ it had fuel inside.
Wing tanks
“The wing tanks were configured in sections,a forward section, and an aft section, and theymight not fill up because of the baffles inside.So, when a wing tank was filled up with fuel,the fuel had to go in slow enough so that thebaffles don’t stop any fuel and the tank couldfill up. That was an intentional, mechanicallimitation to stop the fuel slopping around andthrowing the centre of gravity off.
“So, assuming the aircraft was just fitted with wing tanks, and not a centreline tank, when you lined-up on the runway you selected ‘Outboard’ on a switch to select the outboard
tanks. The fuel was transferred by air pressure to prevent the tanks from collapsing if you had to make a rapid descent. Two green lights on the tele light panel on the right side would light up to indicate the fuel flow was less than the threshold, one light for the left and one for the right.
Low level F-4E flight
“During climb-out, both the tape and the counter would indicate roughly 1,500lb less total fuel load. The two lights were now off so you had no indication. That told you the fuel was transferring above the threshold. Fifteen minutes after take-off, the lights should go on and after a while flicker based on the fuel transferred into the centreline tanks, but not the wing tanks. At that point you should have had eight over 12 lights blinking, that was a standard call to confirm you didn’t have an issue.
“Eventually those lights would start flashing because they’d transferred fuel into the fuselage, and it was full up. At this point, the fuel consumption might be less than the threshold, therefore the lights flashed on and off. Fifteen minutes after take-off the lights should be steady, so you’d turn the switch off. At this point, the wing tanks started to feed fuel into the fuselage When the tape showed 5,600 over 5,600 you knew the wing tanks were empty and fuel was being fed from just the fuselage. There was a period that correlated to that depending on whether you’d used afterburner which used fuel at a faster
rate than the fuel transfer.
“On a two-ship, low-level flight, one aircraft had three tanks, the other just two. Both jets were out of fuel at the same time toward the end of the mission. The extra weight and the extra drag carried and created by the centreline tank cancelled the advantage of the extra 600 gallons of fuel carried in the centreline tank. In combat or in an emergency, you’d get rid of it.”
Photo credit: U.S. Air Force
