Zoom climb

Performance history

Zoom climbs have been used to test new aircraft designs and conduct research in different flight regimes.

An NF-104A fitted with an additional rocket engine was regularly used in zoom-climb research for future spaceflight. On 7 May 1958, the aircraft reached an altitude of 27812 m in a zoom climb at Edwards Air Force Base, setting a new altitude record. The Mach 2 mission took the airplane so high that the standard F-104's engine routinely exceeded its temperature limit and had to be shut down. Sometimes the engine simply flamed out for lack of air. Then the pilot steered the aircraft like a returning spaceship to a lower altitude, where he would restart the engine. An NF-104 set an unofficial altitude record of 120800 ft on 6 December 1963.

NASA tested a reaction control system on the JF-104, derived from a YF-104A, to give the jet maneuverability over 80000 ft in the thin air where normal control surfaces have little effect.

On 4 September 1959, a specially modified Sukhoi Su-9 (designated T-431) set a record of 28852 m using a zoom climb.

On 6 December 1959, during the proving phase of the McDonnell Douglas F-4 Phantom II, an early version of the aircraft (the XF4H-1) performed a zoom climb to 98557 ft as part of Operation "Top Flight". Commander Lawrence E. Flint Jr. accelerated his aircraft to 14330 m at Mach 2.5 and climbed to 27430 m at a 45-degree angle. He then shut down the engines and glided to the peak altitude. As the aircraft fell through 21300 m, Flint restarted the engines and resumed normal flight.

On 10 December 1963, flight test pilot Chuck Yeager was nearly killed flying a heavily modified F-104.

On 25 July 1973, Aleksandr Fedotov reached 35230 m in a Mikoyan-Gurevich MiG-25M with a 1000 kg payload, and 36240 m with no load (an absolute world record). In the thin air, the engines flamed out and the aircraft coasted in a ballistic trajectory by inertia alone. At the apex, the indicated airspeed (IAS) had dropped to 75 km/h. On 31 August 1977, Fedotov broke his own record by reaching 37650 m, which remains the record for highest crewed jet aircraft and highest self-launched planes .

Without engine power, the cockpit would depressurize on these missions. Above 43000 ft, the standard oxygen system cannot provide blood oxygen saturation enough for the pilot to function, so a full-body pressure suit must be used.

In a 1984 demonstration of their performance, an English Electric Lightning fighter aircraft used a zoom climb to intercept a Lockheed U-2 cruising at 66000 ft, above the Lightning's service ceiling of 60000 ft. Shortly before this, it had even reached 88000 ft.

References

References

1. White, J. Terry. (2018-12-06). "NF-104A Zoom Climb Record".
2. Lowery, John. (February 2005). "Zoom Climb".
3. (1961). "F-104 E-6595: JF-104 ground testing reaction control system (RCS) jets". NASA.
4. (July 1, 2015). "The Crash of Chuck Yeager's NF-104A".
5. Belyakov, Rostislav Apolossovitch. (1994). "MiG: Fifty Years of Secret Aircraft Design". Airlife.
6. link. (2016-09-11 .)
7. Belyakov, Rostislav Apolossovitch. (1994). "MiG: Fifty Years of Secret Aircraft Design". Airlife.
8. Ross, Charles. (October 2004). "Lightning vs Concorde".