Combat Radius for Early Jets

Discussion in 'Aviation' started by Piper106, Oct 2, 2016.

  1. Piper106

    Piper106 Member

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    Wondering what the combat radius was for the early jets like the P-80, Me 262, and Gloster Meteor using internal fuel only.??

    Also interest on the mission profile used to calculate the combat radius for theses jets. I saw a post on another site, that indicated that combat radius for piston engine fighters was calculated flying to the mid-point at 15000 to 20000 feet, using combat power for 15 minutes, war emergency power for 5 minutes, than returning to base, and having enough fuel left for 30 minutes at most economical cruise power.
     
  2. GregP

    GregP Well-Known Member

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    We are restoring a Bell YP-59A Airacomet to flight status. It has two GE-I16 engines in it and the operating characteristics are "interesting," to say the least. The I16 became the J31. It had enormous wings and had a very good glide ratio.

    I can tell you this: The engine makes abysmal power below 12,500 rpm and the max rpm is 16,500, with normal operating limit at 16,000 rpm. The thrust at 12,500 rpm is low, about ground idle, and the thrust builds rapidly from 14,500 rpm on up to 16,500. At low altitudes, say under 5,000 feet, fuel consumption was 570 US gallons per hour! That isn't pounds, that is gallons.

    So, with a nominal 285 internal gallons aboard a Bell YP-59A, we figure auxiliary tanks are a necessary item even though they weren't fitted to the YP-59A series. They came later in production. The fuel consumption can get as good as 120 GPH, but you have to be up around 30,000 feet to GET that consumption, and with 280 gals internal fuel, once you got to 30,000 feet, you weren't staying up there long!

    Fortunately, the Bell YP-59A had enormous wings and a very good glide ratio, so when it ran out of fuel way up high, the landing options were usually many.

    The Lockheed P-80A-1 POH states some interesting things.

    Leading edge and outboard wing tanks = 153 gallons. Inboard wing tanks = 144 gals. Fuselage tank = 207 gals. Drop tanks = 320 gals total.

    So full internal fuel was 504 gals, but is figured at 470 gals after allowance for takeoff and climb.

    At 10,000 feet, range was 225 miles at max continuous power with a 200 gallon reserve. Range was 450 miles with no reserve. At 40,000 feet range was 325 miles with 200 gallon reserve and 850 miles with no reserve. Att at 12,000 pounds. Everything else was in between these, all at max continuous power condition. The numbers improved 50 to 75 miles at max range condition. Either way, the legs were short.

    At 14,000 pounds range was almost doubled since the extra 2,000 pounds was all fuel.

    It didn't glide nearly was well as the Airacomet, which could flit about for a long while in an unpowered state. So you had better plan to be down and parked under power in P-80A-1 aircraft.

    Check the manual out at: Pilot’s Flight Operating Instructions For Army Model P- 80 .

    Not too sure about the Me 262.

    Regards, - Greg
     
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  3. BiffF15

    BiffF15 Well-Known Member

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    The instrument approaches designed for those early jets were started at higher altitudes and flown almost completely in idle. All designed to get them from the high flight structure to on the ground with minimal use of fuel.

    Cheers,
    Biff
     
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  4. Piper106

    Piper106 Member

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    Boy... for ground support these early jets leave a lot to be desired. You might be able to give the enemy heck for a few minutes, but then its time to head home for more fuel. Definitely not much ability to keep orbiting the target to remind the enemy to hold their position with their heads down.

    From what I think I know, Korea was pretty much the same. Jets had too short of 'legs' to hang around long supporting ground troops. And as far as I know, still pretty much the same in Vietnam. Has any jet powered aircraft ever had the ability to 'sit' on a target area for a hour or more??? .
     
  5. Shortround6

    Shortround6 Well-Known Member

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    Depends on the jet (think turbofan/s) and load carried and radius from base. Lots of drop tanks and few bombs/rockets?
    A-10s can :)
     
  6. XBe02Drvr

    XBe02Drvr Active Member

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    Back in the 50s NAS Memphis and NAS Key West both had high altitude TACAN penetration approaches that came from FL200 down to the surface in a single teardrop turn. In the 70s at Boca Chica I remember watching a four-plane flight (two student F-4s and two A-4 aggressors) fly that (no longer published) approach in a tight finger four "for old times sake". The students peeled off into the break pattern and the aggressors continued to touchdown in tight formation. Hotdoggin' it with the taxpayers toys. It was all so quiet and distant I never would have been aware of it until the last second if I hadn't run into one of my Air Controller drinking buddies just coming off shift, who pointed it out. Awesome!
     
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  7. pbehn

    pbehn Well-Known Member

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    From another forum poster name A2QFI

    I have just come across a review of a book called "Meteor - Eject" by Nick Carter. The book contains statistics about loss rates, can anybody who served in the 50/60s confirm these - they seem horrendous?

    1. 150 total losses in 1952
    2. 68 lost after running out of fuel
    3. 23 lost doing official low level aeros displays
    4. 890 lost in total
    5. 436 fatal accidents between 1944 and 1986.

    Other posters confirmed those were about par for the course
     
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  8. XBe02Drvr

    XBe02Drvr Active Member

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    Can't confirm the numbers, but I can believe them for sure. Early jets had many pitfalls for pilots weaned on WWII piston fighters to fall into: anemic thrust (especially at low airspeeds), slow throttle response, unfamiliar and startling accelerated stall behavior, roll divergence, flameouts with any fluctuation in the intake airflow, huge variations in fuel consumption with altitude, primitive ejection seats with a narrow survival envelope (and spine-crushing G-loads), and the real killer; the backside of the power curve. You get just a little low and slow on the approach with thrust at a low setting ('cause you started a little high andand fast) and you suddenly realize you've developed a high sink rate, which has increased your angle of attack. "Power, Power! POWER!!" Your power levers are bent around the stops, the engines whine, slowly the revs rise as angle of attack reduces the intake ram effect, and Mother Earth (or King Neptune) beckons you home. You are on the backside of the power curve and all the thrust your puny blowtorches can aspire to will not arrest your descent. Time to step out of the jet. As you feel your vertebrae collapse, you realize that the 37MM shell that kicked you out didn't give you enough upward velocity to counter the downward velocity of your launchpad. Like it or not, you and your mount are going to arrive more or less together.
     
  9. GrauGeist

    GrauGeist Well-Known Member

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    During the war, unless you were flying the He162, you had no ejection seat.
     
  10. BiffF15

    BiffF15 Well-Known Member

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    Grau,
    Didn't the He-219 have ejection seats?
    Cheers,
    Biff
     
  11. GrauGeist

    GrauGeist Well-Known Member

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    It did indeed, Biff, so did the Do335...but they were piston aircraft.

    Of the jets that had ejection seats, only the He280 and the He162 were equipped - the He162 being the only type put into service.
     
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  12. drgondog

    drgondog Well-Known Member

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    As an anecdotal, non statistical, recount of losses in the 50's - I was a Brat at Eglin AFB Air Proving Ground from early 1951 through mid 1954. The losses including specifically the F-100 were horrendous. I'm sure it wasn't 'one a week' but it seemed like it. A lot of my friends/acquaintances fathers were KIFA and virtually disappeared as the widows went somewhere else. The strangeness of the variety of actions, including an F-86D (flown by a good friend of my father) shooting down a B-17 Mother ship (flown by a real good friend) instead of the QB-17 in trail was just another day.
     
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  13. drgondog

    drgondog Well-Known Member

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    Combat Radius was a calculated mission profile - which varied considerably between USN and AAF as the escort/fighter bomber radius were built around different missions.

    Combat radius for AAF escort profile was calculated at 30000, 25, 20, 15, 10 and 5000 feet for full internal fuel, plus combinations of combat external fuel tanks, 500 pound bombs, and clean (but with bomb racks). Each of the combinations are referenced to Take off Gross Weight. It included warm up, takeoff and climb to cruise, cruise to limit of external fuel, drop tanks/fight at 5 min WEp, 15 min MP, cruise back and let down/land with 30 minutes reserve.

    USN fighter combat radius calculations except the calculations were for 1500 and 15000 feet cruise altitude.

    USN
     
  14. fastmongrel

    fastmongrel Well-Known Member

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    They werent known as the Meatbox for nothing.

    My Dad worked on an RAF Auxillary Sqadron and the pilots were part timers often WWII veterans who had fairly low annual hours. When the Sqd changed from Spitfire F22s to Meteor F4s the pilots who were used to the Spitfires fairly pathetic range were crashing like flies because they were running out of fuel a go round or a diversion because of weather often meant a smoking hole in the scenery. F4s didnt have ejection seats, were not easy to jump out of and there were no T7 two seaters to convert on. Poor sods had to learn on the job.
     
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