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2B37 checkout

Attitude gyro
The vertical gyro system is powered by the AC power bus and is located in the aft cockpit behind the left console. The vertical gyro system is to provide the pilot with visual indications of aircraft pitch and roll attitudes on the attitude indicators in both the forward and aft cockpits. The gyroscope develops, through synchros, pitch and roll signals representative of the aircraft attitude through 360 degrees roll and +82 degrees pitch.

The erection system incorporates separate systems for pitch and roll. Vertical reference is established by two gravity-sensitive switches that control a torque motor for each gyro axis. High or low erection rate of the gyro is accomplished by applying high or low voltage to the respective torque motor. A panel-mounted switch placarded FAST ERECT provides fast erection. Pressing the switch will erect the gyro to within 1.0 deg of pitch and roll within 60 seconds of power application and erect to within 0.5 deg within 2 minutes.

A power failure flag in the gyro will be visible whenever input power is lost. For training purposes, the aft cockpit attitude indicator may be disabled from the forward cockpit avionics panel with a switch placarded AFT CKPT, ATTD GYRO, ON and OFF.

The attitude gyro provides the pilot with constant visual indication of aircraft pitch and roll. The attitude gyro is your primary attitude instrument. There are several reasons for this which must be emphasized:

It is the only direct reading instrument. In other words, it shows exactly the amount of bank or nose pitch being utilized.
It shows attitude change immediately. There is no lag in this instrument.
It directly displays two primary components of aircraft attitude, nose and wing. Crosscheck instruments include turn needle (rate gyro precession), balance ball (yaw), RMI, VSI, and airspeed indicator.

The attitude gyro is set on the ground by aligning the arrow on the adjustment knob with the white mark on the face of the instrument. When airborne, if it is necessary to reset the instrument, do so only in straight and level flight at normal cruise (150 kts).

Instrument lag
All pressure instruments have an inherent lag (i.e., altimeter, VSI, airspeed indicator). Additionally, the magnetic standby compass tends to either lag or lead the aircraft’s heading during turns and swings unpredictably in turbulent air. Only in straight and level flight in smooth air can the magnetic standby compass be relied upon.

Instrument scan/attitude crosschecks
Good instrument flight is attained by smooth “attitude control.” Attitude control is attained by:

Visualizing and setting a desired power and attitude combination while studying and controlling the miniature aircraft attitude on the attitude gyro.
rimming the new attitude
Confirming this attitude by scanning attitude crosscheck instruments.

All attitude changes must be accomplished on the attitude gyro. This means that you must look at the gyro while you make your adjustments, trim for the change and continue looking long enough to ensure that the aircraft will remain in its new position. A common error is to move the scan too rapidly to a crosscheck instrument before an attitude is actually “set.” After stabilizing the gyro, then crosscheck other instruments. Remember, all other instruments “lag” behind gyro movement. So use that “lag” time to your advantage for setting gyro attitude.
It is mandatory that the student memorize the scan patterns in the FTI, pages 2-7 and 2-8.

Cockpit lighting
The interior lighting system consists of individual instruments post lights, utility lights, console lights, glareshield floodlights, and console floodlights.

All instruments are lighted by post lights and glareshield floodlights with intensity controlled by two rheostats on the right console. The post-light and glareshield-light rheostats are located adjacent to each other under a group placarded INST. The rheostats are placarded LTS (post) and FLDT (floodlights) and control lighting from OFF through INC to BRT. When the INST LTS rheostat is turned on, the red WHEELS light, the yellow MASTER CAUTION light, the annunciator panel lights, and the AOA indexer are dimmed.

The left and right console panels in both cockpits are lighted by individual panel edge lights and a left and right console floodlight. The edge lighting is controlled by a rheostat that is placarded LTS under the CONSOLE placard, and the floodlights are controlled by the rheostat that is placarded FLDT.

Each cockpit is provided with a special multipurpose utility light. These lights are designed to provide either red or white illumination utilizing a narrow spotlight beam or a wider floodlight beam. There are portable lights with a snap-in permanent mounting base and may be detached by simply pulling the light straight out of the base. Selection of white spot, white flood, red flood or red spot can be made instantly by turning the front section. The color may be changed by depressing a button on top of the light while turning the front section.

The circuit breaker panel edge lights are controlled with a two-position circuit breaker-type toggle switch placarded PANEL LTS on the circuit breaker panel in each cockpit. These lights are constant brilliance.

Instrument checklist
Prior to each flight, it is essential that all instruments and equipment be checked for proper operation. Prior to the runup area, the student will have completed the instrument checklist below and will report to the instructor:

“Instrument checklist complete, oxygen 100%, blinker operating normally, altimeter error less (or more) than 75 feet. Radios and navaids tuned and set.”

Bring any difficulty in completing the checklist to your instructor’s attention at once.

Hood installed and operating properly.
Rudder pedals and seat adjusted.
Airspeed indicator reading zero.
Altimeter set (alignment knob set to white tick)
RMI aligned with magnetic compass.
Clock set and running.
Attitude gyro erect and adjusted.
Vertical-speed indicator reading zero.
Oxygen equipment checked and blinker operating.
Battery switch ON.
Inverter switch to #1 inverter.
Attitude gyro remains erect in turns.
RMI tracking properly in turns.
Turn needle indicating turn in proper direction.
Balance ball moving freely; liquid damping fluid full.
Radios and navaids turned on and set.

Radios tuned (peculiar to 2B37)

Unintentional instrument flight
Instrument conditions are to be avoided at all times FAMs. If actual instrument flight is encountered, immediately level you wings on the attitude gyro and time for 30 seconds. If not VFR at the end of 30 seconds, attempt to regain visual flight conditions by making a shallow turn (15 degrees AOB) for 180 degrees to return to the airspace previously in.

Any time the horizon is not distinguishable, in accordance with OPNAVINST 3710.7, you are in IMC. Additionally, if the existing weather conditions are less than that specified for VMC you are also in IMC. As a result, if for some reason you find yourself in the above situation “unintentionally” you must request an IFR clearance so that you’ll be under positive control. If you don’t, you’ll increase the probability of a midair collision which makes for a very bad day. IFR shall be conducted to the maximum extent possible.

New Maneuvers for this event:

Straight and level flight
For straight and level flight it is necessary that airspeed, heading, and altitude be maintained. Again, the power primarily controls the airspeed while maintaining altitude. It is important in maintaining straight and level flight based on airspeed to set the correct level flight attitude and support it with the proper scan pattern. For instrument flight, the attitude gyro is the basic attitude indicator for nose and wing position. The nose position is crosschecked with the altimeter and VSI, and the wing position is crosschecked with the RMI. The airspeed instrument is the performance instrument. Whenever an error in either heading or altitude is noted, first stop the error and stabilize, then correct back to proper heading or altitude.

If off airspeed and on altitude:
If your scan indicates that altitude is being maintained but your airspeed is slow or fast, you know that a power adjustment is necessary. Remember, each torque setting given in this manual is a suggested starting point.

On airspeed and off altitude:
If you note your altimeter is reading 100’ high, yet the airspeed is correct, you should correct to altitude by reducing power and allow the trim to lower the nose slightly so as to return to altitude with no increase in airspeed. Once returned to altitude; reset normal cruise power setting and retrim.

Off altitude and off airspeed:
If your scan detects a fast airspeed and a small loss of altitude or a slow airspeed and a gain in altitude, it is obviously due to improper nose attitude. Stabilize using the attitude gyro; then, correct by trading excess airspeed for altitude, following by a power increase as necessary to maintain airspeed; retrim.

Precise heading control:
The RMI is your primary reference for heading. In order to maintain a constant heading, the aircraft should be trimmed for wings level balanced flight. If a gradual drift of the RMI is detected, level the wings using the attitude gyro to stop the movement of the RMI. Once the drift is stopped, return to heading by using a shallow AOB, never a greater AOB than the number of degrees off heading. Use opposite rudder on rollout.

CABT
All considerations for turning flight in the instrument stage are the same as in FAMs. Establish an AOB on the attitude gyro and maintain that AOB throughout the turn. Crosscheck the nose position with the altimeter and VSI. Corrections to maintain altitude are made in the same manner as in straight and level flight.
To prevent turning beyond the desired heading, it is necessary to anticipate or lead the new heading. A reasonably accurate rule of thumb is to lead with the 1/3 rule.
If, for example, the AOB is 30 degrees, the rollout should be started 10 degrees before reaching the desired heading. In this example, when you pass 10 degrees prior to your specified heading, shift your scan completely to the gyro and roll out on the gyro. This rule will be used during all turns to specified headings.

Common errors:

Over rotating the nose as the AOB is established, resulting in a climb.

Looking away from the attitude gyro before the AOB is set, resulting in over banking as the wings continue to roll.

Failure to maintain a level flight scan as the turn progresses, allowing the nose to fall, resulting in a loss of altitude.

Failure to roll out on the desired heading due to slow or improper scan (not looking at the RMI for turn performance and not applying the 1/3 rule).

Not rolling out on the gyro. The most common error is to watch the RMI during rollout. Thus, the wings do not level and the nose is raised or lowered.

Rolling too fast. This prevents proper coordination between nose and wing attitudes.

Constant airspeed climbs and descents
Nearly all climbs and descents are performed at a constant airspeed or at least some climb schedule. These particular maneuvers are performed in Vertical Performance Speed (VPS) during initial instruction and are used as a basis for rate climbs and descents. The purpose of these maneuvers is to emphasize that nose attitude controls airspeed in climbs and descents. These descents and climbs are continued for 1000’ of altitude change, followed by a transition to a Level off and a constant heading is maintained throughout the maneuver. The nose crosscheck is the airspeed indicator and RMI is the wing attitude crosscheck. Altimeter and VSI show performance. Use PAT for all transitions.

Configuration: Enter VPS from normal cruise by reducing power to 300 ft-lbs. Trim right and up as the aircraft decelerates in order to maintain attitude and heading throughout the transition. Approaching 130 kts, adjust power to maintain 130 kts, and retrim. The VPS power setting is approximately 550 ft-lbs; the VPS level flight nose attitude is approximately 1 degree nose up.

Climbs:

850 ft-lbs, right rudder. Use peripheral vision to set power.
As power is added, raise nose to VPS: 4° nose up.
Trim right rudder, slightly nose down.
Start attitude scan, IGO report.

Level off from climb:

50' prior to desired altitude, power to 550 ft-lbs, left rudder.
As power is reduced, lower nose to level VPS: 0° nose.
Trim left rudder, nose up.
Reset power.
Start attitude scan, IGO report.

Descents:

250 ft-lbs, left rudder.
As power is reduced, lower nose to VPS: 2° nose down.
Trim left rudder, slightly nose up.
Reset power.
Start attitude scan, IGO report.

Level off from descent:

50' prior to Level off altitude, power to 550 ft-lbs.
As power is added, raise nose to VPS: 0° nose.
Trim right rudder, nose down.
Reset power.
Start level flight scan.
When directed by your instructor, return to normal cruise by setting 1015 ft-lbs torque (695 ITT max). 2-3 kts prior to 150 kts set approximately 650-700 ft-lbs and retrim, IGO report.

Common errors:

Not transitioning to VPS

Not accomplishing entire sequence on the attitude gyro-shifting scan to attitude crosscheck instruments before transition is complete and trimmed.

Over correcting the nose attitude for airspeed or making corrections too rapidly before airspeed has a chance to settle down. Remember the airspeed indicator lags behind nose movement and it will not react immediately after a gyro change is made. Retrim.

Not trimming the rudder, resulting in heading drift.

Fixating on the torque gauge.

DISCLAIMER: The information provided on this page is to be used only to assist Student Naval, Marine, Coast Guard Aviators and U.S. Air Force Student Pilots. It is by no means meant to replace or supercede the knowledge presented in NATOPS, OPNAV 3710.7T, Flight Training Instructions, FLIPS, or any other official Navy, Marine, Coast Guard or U.S. Air Force publication. Knowledge of these documents is considered paramount to flight safety. Any unauthorized use of the information on this page in an actual flight (without reference to the official publication) is strictly prohibited. Viewing web pages listed above constitutes acceptance of all responsibility for flight safety by you, the user. The author of this page assumes no responsibility for the completeness of these documents or their use in Aviation training.

If you find discrepencies in the information here, please contact me. This is NOT an official Navy web site. All opinions and statements are exclusively those of the authors and do not reflect the views of the Department of Defense, The United States Navy, The United States Marine Corps, The United States Coast Guard or the The United States Air Force.