X-15A-2 Specific (Drop Tanks Attached)

Emergency Launch

Revise the "Emergency Launch" procedure as follows:

1. External tanks jettison auto-manual switch [3, fig. 5-6] – MANUAL.

2. Tank jettison circuit breakers [1-2, fig. 5-6] – ON/CLOSED (forward).

3. External tanks jettison safe-arm switch [4, fig. 5-6] – ARM.

On a real mission, use the external tanks jettison full (or partially full) button to release full (or partially full) tanks for successful tank separation. Do not use the external tanks jettison empty button to release a full tank, as serious damage to the tanks and airplane will result.

Note: In the simulator, the tanks will not jettison if the wrong button is used.

To manually release the external tanks, proceed as follows:

• If the two external tanks jettison-ready indicator lights [4, fig. 5-1] are ON and the tanks are empty, press the gray external tanks jettison empty button [7, fig. 5-6] to release the tanks.

Or

• If the two external tanks jettison-ready indicator lights are OFF and the tanks are not empty but not full, press the black external tanks jettison partially full button [6, fig. 5-6] to release the tanks.

Or

• If the two external tanks jettison-ready indicator lights are OFF and the tanks are full, press the red external tanks jettison full button [5, fig. 5-6] to release the tanks.

Caution

• If drop tanks are to be released while full, they must be released after launch at approximately 10 degrees airplane angle of attack and before engine start. Both external tanks release simultaneously and propellant feed transfers automatically to internal tanks.

Engine Fire or Explosion

Revise the "Engine Fire" procedure as follows:

If fire cannot be confirmed, land as soon as possible. If fire cannot be confirmed, or if it goes out, establish controllability, release

external tanks (see above), and jettison propellants en route to the nearest available base where a landing can be made. Obtain assistance from chase pilot if possible. Reconfirm controllability before descent below safe ejection altitude.

Propellant Jettisoning

Captive Flight

Because of placement of the ports in the external tanks, approximately 5500 pounds of propellants will be trapped in the external tanks when the propellants are jettisoned during captive flight. This data applies only for level, unaccelerated flight. If propellant jettison is accomplished at a nose-down attitude, additional propellants will be trapped.

After Launch

In the event of an engine failure, the loss of thrust will result in the external tank propellants being forced to the forward end of the tanks. Under this condition, a large amount of the propellants in the external tanks cannot be jettisoned. Therefore, the external tanks must be released (see above) before an attempt is made to jettison internal system propellants.

See also:

X-15A-2 Drop Tank System