Accident Board Recommendations

The Court of Inquiry issued 62 recommendations, which were all commented upon by the Indian government.  The recommendations can be viewed at the following link:  (Recommendations)

Certain specific recommendations relative to airspeed, autothrust, and use of the flight control unit (FCU) and flight director were made:

Airspeed Related Recommendations

Recommendation # 26. Installation of a conventional airspeed indicator unconnected with any computers with a speed bug which could be manually set at the desired V-app, generating an unmistakable audio warning (again unconnected with any computers) fitted on all aircraft when speed drops more than 5 knots below the bug, which have computer generated display of airspeed to be used as the primary speed display may be considered. A provision should be available to check this warning, during the pilots pre flight check. Such warning should be serviceable, for release of the flight.  Airbus Industrie and Indian Airlines to evaluate retrofit such a feature in place of their present standby airspeed indicator on the A-320.

Gov’t Comment  -  Not acceptable as a conventional airspeed indicator with a provision of speed bug setting is already available in the aircraft. Too many warnings would only tend to confuse the pilots.

Recommendation # 27. Expanded indication of the value of the current (speed) against the lubber line in the PFD is recommended for better appreciation of current speed value.

Gov’t Comment  -  Acceptable. Would be brought to the notice of the Airbus Industrie.

Recommendation # 28. A provision of a low speed warning even under pitch normal law should be examined by the certification authorities at about 1.14 to 1.15 Vsg for this type of FBW aircraft to prevent a similar accident in future.

Gov’t Comment  -  Airbus Industrie has already brought out a modification by which the aircraft will automatically go into speed mode whenever the speed reaches Lowest Selectable Speed (VLS).  As such, this recommendation is not necessary.

Recommendation # 42. Airbus Industrie should immediately amend A-320 FCOM bulletin No.09/2 of June 1990.

Gov't Comment - The FCOM bulletin has already been amended.

(Bulletin Subject - "Assessment of the Aircraft Energy Level". Addressed control and awareness of aircraft energy level, design features to assist in maintaining aircraft energy level (PFD's, FD's, FMA's, etc.), Protections and Low Energy Warning.)

Autothrust Related Recommendations

Recommendation # 29. Due to possibility of mistaking altitude and vertical speed knobs one for the other, a modification is recommended where vertical speed knob would have a wheel to be operated vertically up and down instead of the present clockwise and anticlockwise direction of movement of the knob.

Gov’t Comment  -  This will be referred to Airbus Industrie as it requires a design change.

No A320 design change was made in response to recommendation # 29.

Recommendation # 30. A very serious human factors evaluation is necessary using ordinary line pilots regarding the loss of direct physical and visual cues by the type of sidestick controls in use in A-320 when compared to dual control wheels operating in unison of the earlier aircraft to determine the adverse impact it may have under critical conditions of flight like that of VT-EPN. Human factor evaluation of moving auto throttles giving feel of thrust increase or decrease versus the static thrust levers of the A-320 auto thrust system using line pilots is recommended to establish advantages and disadvantages.

Gov't Comment - Airbus Industrie has informed the Court that in a conference of users of A-320 aircraft held in Cairo early this year, there was an unanimous opinion for not adopting moving thrust levers. The recommendation is, therefore, not acceptable.

Recommendation # 31. Option of moving auto throttles is desirable in all future aircraft if static auto thrust system similar to A- 320 is to be installed in such aircraft.

Gov't Comment - Airbus Industrie has informed the Court that in a conference of users of A-320 aircraft held in Cairo early this year, there was an unanimous opinion for not adopting moving thrust levers. The recommendation is, therefore, not acceptable.

Recommendation # 32. After gear down and below 2000 feet radio altitude it is recommended that idle/open descent mode should be indicated in flashing red on the FMA associated with a single stroke chime.

Gov't Comment - Partly acceptable and Airbus Industrie will be requested to have a different colour for idle/open descent mode display on FMA during final approach.

Recommendation # 33. Airbus Industrie should evaluate the provision of a feature, by which low thrust level occurring, during final approach, even on speed mode due to gusty wind conditions, would attract immediate attention of the pilots; if it occurs every close to the ground it could lead to unsafe situations.

Gov't Comment - Not acceptable technically, as while on approach a pilot has to monitor speed and too many warnings at the critical phase of landing would only cause confusion.

Recommendation # 34. It is recommended that the low range scale of the EPR gauge up to 1.10 should be expanded to give a better indication by the needle of a low thrust condition.

Gov't Comment - Not acceptable as considered not necessary.

Recommendation # 35. Airbus Industrie may look into providing a range in red colour up to 1.02 EPR to attract pilots' attention of a low thrust situation when on final approach.

Gov't Comment - Not acceptable as considered not necessary.

Recommendation # 36. Similar features as above could be evaluated and provided for operation in N1 mode.

Gov't Comment - Not acceptable as considered not necessary.

Recommendation # 53. It is recommended that all pilots in India operating automated aircraft be advised that in case of any malfunction of any auto pilot or auto thrust systems or any engagement of undesired mode occurs at altitudes below 1000 feet above ground level manual control should immediately be taken over and if considered necessary a go around should be carried out. No critical investigation or correction on the automated system should be carried out at critical altitudes. Prohibiting the idle/open descent mode below 1000 feet radio altitude should be seriously considered.

Gov't Comment - Acceptable. A circular will be issued to all pilots.

Recommendation # 54. Indian Airlines should very carefully evaluate with the DGCA and Airbus Industrie the advantages of introducing manual thrust operation when manual flight is being carried out on the A-320.

Gov't Comment - Not acceptable as auto-thrust provides greater safety level.

Recommendation # 55. Indian Airlines should carefully evaluate with Airbus Industrie the auto thrust behavior during gusty wind conditions when speed suddenly increases beyond V-app and decreases at altitudes below 200 feet AGL and adverse implications if any to determine the limits of use of auto thrust system. This may have to be evaluated in both cases of Magenta speed or selected speed.

Gov't Comment - Not acceptable as considered not necessary.

Flight Control Unit (FCU) Related Recommendations

Recommendation # 29. Due to possibility of mistaking altitude and vertical speed knobs one for the other, a modification is recommended where vertical speed knob would have a wheel to be operated vertically up and down instead of the present clockwise and anticlockwise direction of movement of the knob.

Gov't Comment - This will be referred to Airbus Industrie as it requires a design change.

Recommendation # 40. A modification to prevent auto thrust mode change from speed mode to thrust mode during Alt* just by change of altitude selection is highly desirable. The mode change should occur only by pulling the altitude knob after change of altitude selection.

Gov't Comment - Already being incorporated.

Recommendation # 60. DFDR should record the selections made by the pilots in the FCU; at present it is not possible to infer many of the actions taken by the pilots during the last phases of the flight. Practicability of getting DFDR recordings of instrument displays such as speed display also should be considered.

Gov't Comment - Acceptable.

Flight Director (FD) Related Recommendations

Recommendation # 39. Installation of a single master switch conveniently located to switch off both FDs when required is recommended; slave switches could be used to switch them 'on' individually or repositioning of both switches centrally be considered.

Gov't Comment - Acceptable. It will be referred to the manufacturer as it requires a design change.

Recommendation # 41. Airbus Industrie should clearly define in their procedures and flight patterns the position at which they need the flight directors to be put off.

Gov't Comment - Use of flight directors is emphasised during training of pilots and a circular would be issued by the Indian Airlines.

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