Stick Monkey Slang for Moles - Prop Issues

Question 1

What does VMC stand for and what does it mean?

Answer 1

Minimum Control Speed and it is the lowest airspeed at which directional control of the aircraft can be maintained following an unexpected engine failure.

Question 2

For 20 degree and 30 degree flap settings with 20 degree rudder authority available, what is the Hawkeye’s VMC?

Answer 2

102 KIAS

Question 3

For 10 degree flap settings with 20 degree rudder authority what is the Hawkeye’s VMC?

Answer 3

For a 46.5K LB a/c, VMC will be around 114 KIAS; However rudder shakers will be reached before VMC is acheived *at approx 112 KIAS.

Question 4

With Flaps fully retracted and 6 degrees of rudder authority available what is the Hawkeye’s VMC?

Answer 4

169 KIAS

Question 5

If VMC is attained, is it guaranteed that aircrew can expect to see a positive rate of climb?

Answer 5

No, NATOPS WARNING states airspeed above VMC does not ensure flying speed or positive climb rate. Aircrew can consult the appropriate stall speed and single-engine rate-of-climb charts to determine required airspeeds.

Question 6

What factors affect VMC?

Answer 6

Operating engines HP (5100 HP is the assumption), non-operating engines condition (FX, Windmilling, etc), Amount of rudder authority available, which engine has failed.

Question 7

Generally what affect does increased rudder authority have on VMC?

Answer 7

Higher rudder authorities decreases VMC. (Which is a good thing as slower airspeeds allow for the Hawkeye to handle appropriately during approaches)

Question 8

Higher drag on a failed engine has what affect on VMC?

Answer 8

Higher drags increases VMC.

Question 9

Will the engine failed increase or decrease VMC?

Answer 9

It depends, the affect of prop wash on control surfaces is different for the right and left engine.

Question 10

Expalin what it means to be the critical enigne.

Answer 10

The critical engine is that engine, that when failed, produces a higher VMC. IN the Hawkeye the critical engine is the left engine.

Question 11

Explain the differences between VMC and Single Engine Rate-of-climb (SERC).

Answer 11

Achieving VMC allows the aircrew to maintain controllability of the aircraft while SERC allows for a positive rate of climb with a failed engine. It is possible to be at SERC but not be able to maintain control of the a/c depending on aircraft configuration.

Question 12

What factors affect SERC?

Answer 12

Gross weight, altitude, temperature and blade angle.

Question 13

Decreases in altitude will have what affect on the Hawkeye’s SERC?

Answer 13

Will improve SERC performance.

Question 14

Decreasing a/c gross weight will have what affect on SERC?

Answer 14

For 1K LBS of weight reduced SERC will improve by 50 ft/min

Question 15

Although SERC airspeed varies, what is the gouge airspeed to fly with maximum power on the operating engine that SHOULD yield the climb performance at or near the best possible given most windmilling prop situations?

Answer 15

125 KIAS.

Question 16

With a failed engine and a high drag prop at/or below what altitude is it critical to assess controllability and make a determination to Ditch, Land, or Bailout?

Answer 16

5,000 AGL

Question 17

Is it possible to have a VMC that is higher than SERC? And if so what is the significance of that fact?

Answer 17

Yes, the a/c maybe controllable but not achieving a positive rate of climb or remain in level flight. In this case the crew needs to prioritize their options and quickly determine if they can land, bailout or ditch.

Question 18

Should turns be made into the operating engine or the non operating engine when one has failed and the prop is windmilling?

Answer 18

Turns into the inoperative engine reduces teh margin of directional control and should only be done if required.

Question 19

Loss of prop hydraulic fluid may initiate what safety feature of the prop system?

Answer 19

Pitch Rate Delay mode (see The Prop System card deck for details on PRD).

Question 20

Will Pitch Rate Delay always be initiated with a loss of prop hyd fuid?

Answer 20

No. Some situations that result in loss of prop hyd fluid will not initiate PRD. THe reason is due to where the prop hyd leak occurs in relation to the PCA.

Question 21

If a loss of prop hyd fluid does not initiate PRD what will likely happen to the prop blades?

Answer 21

The counterweights will rapidly drive the blade angle towards feather.

Question 22

In ditching with a failed to feather prop situation list, in order of importance, the factors that increase the chance of a successful ditch maneuver.

Answer 22

1) A/C under control to assure proper a/c attitude upon impact with water (wings level, nose slightly above horiozon, fuselage aligned with flight path), 2) minimal rate of descent while maintaining control, 3) Minimal forward speed consistent with maintaining control and minimal rate of descent.

Question 23

What is the NATOPS WARNING with descending below VMC in an attempt to minimize VSI/forward airspeed?

Answer 23

It may result in a potentially fatal uncontrolled ditch impact.

Question 24

What is the NATOPS WARNING concerning holding an optimum SERC attitude and airspeed until impact?

Answer 24

May result in a potentially fatal nose high, operating engine wing down attitude on impact.

Question 25

Describe the different pros and cons for conducting a power off and a power on ditch manuever with one engine windmilling.

Answer 25

Power on - will provide the most time for the crew to prepare for impact and provide the best opportunity to impact with a minimized rate of descent and stabilized attitude when the impact point can be determined visually. There is a higher risk of losing directional control close to impact if the aircraft slows below VMC during the final flare.
Power off - reduces the risk of a loss of directional control and therefore may allow impact at lower airspeed, but this requires more altitude and energy for the flare than the power on ditch.

Question 26

When ditching with a prop that is windmilling what flap settings does NATOPS recommend and why?

Answer 26

10 degree, it provides a greater margin of directional control and a reduced rate of descent.