Crew Communications

RADIO INSTRUMENTS

CHAPTER THREE

4. Perform wind analysis and groundspeed checks. A 36 second groundspeed check at T-2C

cruising speeds is a rough estimate at best, and will be rendered even less accurate by the

difficulty in accurately reading the T-2C DME indicator.

5. Calculate lead turnpoints. Lead turn procedures may be universally applied among

different aircraft, because the laws of aerodynamics rather than aircraft characteristics determine

aircraft turning performance. Thus, any of several methods of determining leadpoints for turns

to intercept arcs and radials will work in the T-2C. The most common one is the "rule" that the

turning radius of an aircraft is equal to about 1% of aircraft groundspeed (the turning radius

would be the lead distance required to intercept an arc or radial at a 90 angle). This rule is

based on a one-half standard rate turn, which will require an angle of bank of about 10% of the

aircraft's true airspeed. Note that the calculation to estimate the radius of turn requires

consideration of wind (for groundspeed), indicated airspeed, altitude (for estimating true

airspeed), and angle of bank. The companion "rule" that the turning radius is 1/2 of 1% of the

groundspeed for a standard rate turn can be helpful at slower airspeeds (such as in the landing

configuration).

6. If the intercept angle between the old and new courses is 60, use one-half of a

90 lead distance. If the angle is 45, use one-third of a 90 lead distance. If the angle is 30 or

less, don't lead the turn. Due to the variables involved, it is not uncommon for turn estimates to

be somewhat inaccurate. As the aircraft completes an intercept turn, a request to "roll out of the

turn" or "continue the turn to a heading of ____", is often necessary for good course control.

Turn procedures for intercepting new courses over NAVAIDs is included in the Enroute Section.

Use the sequence "Aviate, Navigate, Communicate, Checklists" whenever the correct

priority of these activities is in question.

302. CREW COMMUNICATIONS

Standard Procedure

The ICS system in the T-2C is activated by the Power Control Lever (PCL) Microphone Switch

or the Microphone Select Switch on the ICS Control Panel. Activation of the PCL Microphone

Switch opens microphones in both crewmembers' oxygen masks, producing unwanted noise in

the ICS system. Accordingly, VT-86 policy is that (whenever possible) students will activate the

ICS by placing the Microphone Select Switch ("MIC SEL") on the ICS Control Panel to the

"HOT" position to talk, then reposition the switch back to the "COLD" position when finished.

Student use of the PCL Microphone Switch is permitted only during flight conditions (such as

Basic Fighter Maneuvering: BFM) wherein the student is unable to reach the Microphone Select

Switch. The ICS system in the T-39 is a voice-activated (VOX) system, requiring no switch

movement for activation. Because of their recent experience in the T-39 cockpit, T-2C students

are frequently unprepared for the T-2C requirement to activate a switch in order to talk on the

ICS. During 2F101 RI and SUA events, the 2F101 is flown by the Simulator Instructor (SI)

from the console ("NFO Mode") and the student will use the Microphone Select Switch on the

ICS Control Panel to activate the ICS system.

RADIO INSTRUMENTS

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