Thursday, October 29, 2009

First Impressions



Here’s what we know so far by visually observing the crash of the Ecuadorian Air Force-owned Dhruv ALH at Quito on October 27: of the three Dhruv ALHs flying over an air base during celebrations to mark the 89th anniversary of the air force, one of them apparently swung 90 degrees and started losing altitude. As the video clip of the incident shows, the two-man aircrew who are in all probability highly experienced aviators, instinctively resorted to the autorotation technique (the only available option) to regain control and to their credit it must be said that they did succeed in slowing the rate of descent, although within the available 8 seconds, they could not stabilise the helicopter, which in turn led to a half-controlled descent and touchdown, with the stricken Dhruv ALH coming to rest on its portside, with the two-man aircrew managing to leave the helicopter by themselves after the crash before being taken to Quito's Military Hospital. The video clipping also showed the Dhruv ALH’s main rotor blades and tail rotor blades functioning, but not enough to indicate if the tail-rotor hub and tail-rotor shaft were in a fully functional state. Based purely on the available video clipping, it would seem that:

• The ill-fated Dhruv PROBABLY suffered from a sudden loss of power in either one of its twin Ardiden-1H (Shakti) engines, jointly built by HAL and Turbomeca. But catastrophic failure of both engines or failure of both the LH and RH sides of the main gearbox (MGB) can be ruled out. It is also PROBABLE that either one of the two fuel supply tanks (which supply fuel independently to the two engines) was starved of fuel-flow from the the Dhruv ALH’s three main fuel tanks, which house the pumps required for ensuring the fuel-flow to the fuel supply tanks.

• The above two probabilities PROBABLY contributed to the sudden reduction of supply of power to the tail-rotor gearbox via the tail-rotor drive shaft, resulting in the helicopter veering off to the left while losing altitude at the same time.

The only saving grace then, and the only available option for the aircrew then was to resort to the autorotation technique, which they did and that is probably the only reason they were fortunate enough to survive to fly again in future. Full marks to them!—Prasun K. Sengupta

I am enclosing below all the FAR Part 29standards that the Dhruv ALH complies with. FAR Part 29: Airworthiness Standards: Transport Category Rotorcraft
Federal Aviation Regulations Subpart A - General
o Sec. 29.1 - Applicability.
o Sec. 29.2 - Special retroactive requirements.Subpart B - Flight
o Sec. 29.21 - Proof of compliance.
o Sec. 29.25 - Weight limits.
o Sec. 29.27 - Center of gravity limits.
o Sec. 29.29 - Empty weight and corresponding center of gravity.
o Sec. 29.31 - Removable ballast.
o Sec. 29.33 - Main rotor speed and pitch limits.
o Sec. 29.45 - General.
o Sec. 29.49 - Performance at minimum operating speed.
o Sec. 29.51 - Takeoff data: general.
o Sec. 29.53 - Takeoff: Category A.
o Sec. 29.55 - Takeoff decision point (TDP): Category A.
o Sec. 29.59 - Takeoff path: Category A.
o Sec. 29.60 - Elevated heliport takeoff path: Category A.
o Sec. 29.61 - Takeoff distance: Category A.
o Sec. 29.62 - Rejected takeoff: Category A.
o Sec. 29.63 - Takeoff: Category B.
o Sec. 29.64 - Climb: General.
o Sec. 29.65 - Climb: All engines operating.
o Sec. 29.67 - Climb: One engine inoperative (OEI).
o Sec. 29.71 - Helicopter angle of glide: Category B.
o Sec. 29.75 - Landing: General.
o Sec. 29.77 - Landing Decision Point (LDP): Category A.
o Sec. 29.79 - Landing: Category A.
o Sec. 29.81 - Landing distance: Category A.
o Sec. 29.83 - Landing: Category B.
o Sec. 29.85 - Balked landing: Category A.
o Sec. 29.87 - Height-velocity envelope.
o Sec. 29.141 - General.
o Sec. 29.143 - Controllability and maneuverability.
o Sec. 29.151 - Flight controls.
o Sec. 29.161 - Trim control.
o Sec. 29.171 - Stability: general.
o Sec. 29.173 - Static longitudinal stability.
o Sec. 29.175 - Demonstration of static longitudinal stability.
o Sec. 29.177 - Static directional stability.
o Sec. 29.181 - Dynamic stability: Category A rotorcraft.
o Sec. 29.231 - General. o Sec. 29.235 - Taxiing condition.
o Sec. 29.239 - Spray characteristics.
o Sec. 29.241 - Ground resonance.
o Sec. 29.251 - Vibration.Subpart C - Strength Requirements
o Sec. 29.301 - Loads.
o Sec. 29.303 - Factor of safety.
o Sec. 29.305 - Strength and deformation.
o Sec. 29.307 - Proof of structure.
o Sec. 29.309 - Design limitations.
o Sec. 29.321 - General.
o Sec. 29.337 - Limit maneuvering load factor.
o Sec. 29.339 - Resultant limit maneuvering loads.
o Sec. 29.341 - Gust loads.
o Sec. 29.351 - Yawing conditions.
o Sec. 29.361 - Engine torque.
o Sec. 29.391 - General.
o Sec. 29.395 - Control system.
o Sec. 29.397 - Limit pilot forces and torques.
o Sec. 29.399 - Dual control system.
o Sec. 29.411 - Ground clearance: tail rotor guard.
o Sec. 29.427 - Unsymmetrical loads.
o Sec. 29.471 - General.
o Sec. 29.473 - Ground loading conditions and assumptions.
o Sec. 29.475 - Tires and shock absorbers.
o Sec. 29.477 - Landing gear arrangement.
o Sec. 29.479 - Level landing conditions.
o Sec. 29.481 - Tail-down landing conditions.
o Sec. 29.483 - One-wheel landing conditions.
o Sec. 29.485 - Lateral drift landing conditions.
o Sec. 29.493 - Braked roll conditions.
o Sec. 29.497 - Ground loading conditions: landing gear with tail wheels.
o Sec. 29.501 - Ground loading conditions: landing gear with skids.
o Sec. 29.505 - Ski landing conditions.
o Sec. 29.511 - Ground load: unsymmetrical loads on multiple-wheel units.
o Sec. 29.519 - Hull type rotorcraft: Water-based and amphibian.
o Sec. 29.521 - Float landing conditions.
o Sec. 29.547 - Main and tail rotor structure.
o Sec. 29.549 - Fuselage and rotor pylon structures.
o Sec. 29.551 - Auxiliary lifting surfaces.
o Sec. 29.561 - General.
o Sec. 29.562 - Emergency landing dynamic conditions.
o Sec. 29.563 - Structural ditching provisions.
o Sec. 29.571 - Fatigue evaluation of structure.Subpart D - Design and Construction
o Sec. 29.601 - Design.
o Sec. 29.602 - Critical parts.
o Sec. 29.603 - Materials.
o Sec. 29.605 - Fabrication methods.
o Sec. 29.607 - Fasteners.
o Sec. 29.609 - Protection of structure.
o Sec. 29.610 - Lightning and static electricity protection.
o Sec. 29.611 - Inspection provisions.
o Sec. 29.613 - Material strength properties and design values.
o Sec. 29.619 - Special factors.
o Sec. 29.621 - Casting factors.
o Sec. 29.623 - Bearing factors.
o Sec. 29.625 - Fitting factors.
o Sec. 29.629 - Flutter and divergence.
o Sec. 29.631 - Bird strike.
o Sec. 29.653 - Pressure venting and drainage of rotor blades.
o Sec. 29.659 - Mass balance.
o Sec. 29.661 - Rotor blade clearance.
o Sec. 29.663 - Ground resonance prevention means.
o Sec. 29.671 - General.
o Sec. 29.672 - Stability augmentation, automatic, and power-operated systems.
o Sec. 29.673 - Primary flight controls.
o Sec. 29.674 - Interconnected controls.
o Sec. 29.675 - Stops.
o Sec. 29.679 - Control system locks.
o Sec. 29.681 - Limit load static tests.
o Sec. 29.683 - Operation tests.
o Sec. 29.685 - Control system details.
o Sec. 29.687 - Spring devices.
o Sec. 29.691 - Autorotation control mechanism.
o Sec. 29.695 - Power boost and power-operated control system.
o Sec. 29.723 - Shock absorption tests.
o Sec. 29.725 - Limit drop test.
o Sec. 29.727 - Reserve energy absorption drop test.
o Sec. 29.729 - Retracting mechanism.
o Sec. 29.731 - Wheels.
o Sec. 29.733 - Tires.
o Sec. 29.735 - Brakes.
o Sec. 29.737 - Skis.
o Sec. 29.751 - Main float buoyancy.
o Sec. 29.753 - Main float design.
o Sec. 29.755 - Hull buoyancy.
o Sec. 29.757 - Hull and auxiliary float strength.
o Sec. 29.771 - Pilot compartment.
o Sec. 29.773 - Pilot compartment view.
o Sec. 29.775 - Windshields and windows.
o Sec. 29.777 - Cockpit controls.
o Sec. 29.779 - Motion and effect of cockpit controls.
o Sec. 29.783 - Doors.
o Sec. 29.785 - Seats, berths, litters, safety belts, and harnesses.
o Sec. 29.787 - Cargo and baggage compartments.
o Sec. 29.801 - Ditching.
o Sec. 29.803 - Emergency evacuation.
o Sec. 29.805 - Flight crew emergency exits.
o Sec. 29.807 - Passenger emergency exits.
o Sec. 29.809 - Emergency exit arrangement.
o Sec. 29.811 - Emergency exit marking.
o Sec. 29.812 - Emergency lighting.
o Sec. 29.813 - Emergency exit access.
o Sec. 29.815 - Main aisle width.
o Sec. 29.831 - Ventilation.
o Sec. 29.833 - Heaters.
o Sec. 29.851 - Fire extinguishers.
o Sec. 29.853 - Compartment interiors.
o Sec. 29.855 - Cargo and baggage compartments.
o Sec. 29.859 - Combustion heater fire protection.
o Sec. 29.861 - Fire protection of structure, controls, and other parts.
o Sec. 29.863 - Flammable fluid fire protection.
o Sec. 29.865 - External loads.
o Sec. 29.871 - Leveling marks.
o Sec. 29.873 - Ballast provisions.Subpart E - Powerplant
o Sec. 29.901 - Installation.
o Sec. 29.903 - Engines.
o Sec. 29.907 - Engine vibration.
o Sec. 29.908 - Cooling fans.
o Sec. 29.917 - Design.
o Sec. 29.921 - Rotor brake.
o Sec. 29.923 - Rotor drive system and control mechanism tests.
o Sec. 29.927 - Additional tests.
o Sec. 29.931 - Shafting critical speed.
o Sec. 29.935 - Shafting joints.
o Sec. 29.939 - Turbine engine operating characteristics.
o Sec. 29.951 - General.
o Sec. 29.952 - Fuel system crash resistance.
o Sec. 29.953 - Fuel system independence.
o Sec. 29.954 - Fuel system lightning protection.
o Sec. 29.955 - Fuel flow.
o Sec. 29.957 - Flow between interconnected tanks.
o Sec. 29.959 - Unusable fuel supply.
o Sec. 29.961 - Fuel system hot weather operation.
o Sec. 29.963 - Fuel tanks: general.
o Sec. 29.965 - Fuel tank tests.
o Sec. 29.967 - Fuel tank installation.
o Sec. 29.969 - Fuel tank expansion space.
o Sec. 29.971 - Fuel tank sump.
o Sec. 29.973 - Fuel tank filler connection.
o Sec. 29.975 - Fuel tank vents and carburetor vapor vents.
o Sec. 29.977 - Fuel tank outlet.
o Sec. 29.979 - Pressure refueling and fueling provisions below fuel level.
o Sec. 29.991 - Fuel pumps.
o Sec. 29.993 - Fuel system lines and fittings.
o Sec. 29.995 - Fuel valves.
o Sec. 29.997 - Fuel strainer or filter.
o Sec. 29.999 - Fuel system drains.
o Sec. 29.1001 - Fuel jettisoning.
o Sec. 29.1011 - Engines: general.
o Sec. 29.1013 - Oil tanks.
o Sec. 29.1015 - Oil tank tests.
o Sec. 29.1017 - Oil lines and fittings.
o Sec. 29.1019 - Oil strainer or filter.
o Sec. 29.1021 - Oil system drains.
o Sec. 29.1023 - Oil radiators.
o Sec. 29.1025 - Oil valves.
o Sec. 29.1027 - Transmission and gearboxes: general.
o Sec. 29.1041 - General.
o Sec. 29.1043 - Cooling tests.
o Sec. 29.1045 - Climb cooling test procedures.
o Sec. 29.1047 - Takeoff cooling test procedures.
o Sec. 29.1049 - Hovering cooling test procedures.
o Sec. 29.1091 - Air induction.
o Sec. 29.1093 - Induction system icing protection.
o Sec. 29.1101 - Carburetor air preheater design.
o Sec. 29.1103 - Induction systems ducts and air duct systems.
o Sec. 29.1105 - Induction system screens.
o Sec. 29.1107 - Inter-coolers and after-coolers.
o Sec. 29.1109 - Carburetor air cooling.
o Sec. 29.1121 - General.
o Sec. 29.1123 - Exhaust piping.
o Sec. 29.1125 - Exhaust heat exchangers.
o Sec. 29.1141 - Powerplant controls: general.
o Sec. 29.1142 - Auxiliary power unit controls.
o Sec. 29.1143 - Engine controls.
o Sec. 29.1145 - Ignition switches.
o Sec. 29.1147 - Mixture controls.
o Sec. 29.1151 - Rotor brake controls.
o Sec. 29.1157 - Carburetor air temperature controls.
o Sec. 29.1159 - Supercharger controls.
o Sec. 29.1163 - Powerplant accessories.
o Sec. 29.1165 - Engine ignition systems.
o Sec. 29.1181 - Designated fire zones: regions included.
o Sec. 29.1183 - Lines, fittings, and components.
o Sec. 29.1185 - Flammable fluids.
o Sec. 29.1187 - Drainage and ventilation of fire zones.
o Sec. 29.1189 - Shutoff means.
o Sec. 29.1191 - Firewalls.
o Sec. 29.1193 - Cowling and engine compartment covering.
o Sec. 29.1194 - Other surfaces.
o Sec. 29.1195 - Fire extinguishing systems.
o Sec. 29.1197 - Fire extinguishing agents.
o Sec. 29.1199 - Extinguishing agent containers.
o Sec. 29.1201 - Fire extinguishing system materials.
o Sec. 29.1203 - Fire detector systems.Subpart F - Equipment
o Sec. 29.1301 - Function and installation.
o Sec. 29.1303 - Flight and navigation instruments.
o Sec. 29.1305 - Powerplant instruments.
o Sec. 29.1307 - Miscellaneous equipment.
o Sec. 29.1309 - Equipment, systems, and installations.
o Sec. 29.1321 - Arrangement and visibility.
o Sec. 29.1322 - Warning, caution, and advisory lights.
o Sec. 29.1323 - Airspeed indicating system.
o Sec. 29.1325 - Static pressure and pressure altimeter systems.
o Sec. 29.1327 - Magnetic direction indicator.
o Sec. 29.1329 - Automatic pilot system.
o Sec. 29.1331 - Instruments using a power supply.
o Sec. 29.1333 - Instrument systems.
o Sec. 29.1335 - Flight director systems.
o Sec. 29.1337 - Powerplant instruments.
o Sec. 29.1351 - General.
o Sec. 29.1353 - Electrical equipment and installations.
o Sec. 29.1355 - Distribution system.
o Sec. 29.1357 - Circuit protective devices.
o Sec. 29.1359 - Electrical system fire and smoke protection.
o Sec. 29.1363 - Electrical system tests.
o Sec. 29.1381 - Instrument lights.
o Sec. 29.1383 - Landing lights.
o Sec. 29.1385 - Position light system installation.
o Sec. 29.1387 - Position light system dihedral angles.
o Sec. 29.1389 - Position light distribution and intensities.
o Sec. 29.1391 - Minimum intensities in the horizontal plane of forward and rear position lights.
o Sec. 29.1393 - Minimum intensities in any vertical plane of forward and rear position lights.
o Sec. 29.1395 - Maximum intensities in overlapping beams of forward and rear position lights.
o Sec. 29.1397 - Color specifications.
o Sec. 29.1399 - Riding light.
o Sec. 29.1401 - Anticollision light system.
o Sec. 29.1411 - General.
o Sec. 29.1413 - Safety belts: passenger warning device.
o Sec. 29.1415 - Ditching equipment.
o Sec. 29.1419 - Ice protection.
o Sec. 29.1431 - Electronic equipment.
o Sec. 29.1433 - Vacuum systems.
o Sec. 29.1435 - Hydraulic systems.
o Sec. 29.1439 - Protective breathing equipment.
o Sec. 29.1457 - Cockpit voice recorders.
o Sec. 29.1459 - Flight recorders.
o Sec. 29.1461 - Equipment containing high energy rotors.Subpart G-Operating Limitations and Information
o Sec. 29.1501 - General.
o Sec. 29.1503 - Airspeed limitations: general.
o Sec. 29.1505 - Never-exceed speed.
o Sec. 29.1509 - Rotor speed.
o Sec. 29.1517 - Limiting height-speed envelope.
o Sec. 29.1519 - Weight and center of gravity.
o Sec. 29.1521 - Powerplant limitations.
o Sec. 29.1522 - Auxiliary power unit limitations.
o Sec. 29.1523 - Minimum flight crew.
o Sec. 29.1525 - Kinds of operations.
o Sec. 29.1527 - Maximum operating altitude.
o Sec. 29.1529 - Instructions for Continued Airworthiness.
o Sec. 29.1541 - General.
o Sec. 29.1543 - Instrument markings: general.
o Sec. 29.1545 - Airspeed indicator.
o Sec. 29.1547 - Magnetic direction indicator.
o Sec. 29.1549 - Powerplant instruments.
o Sec. 29.1551 - Oil quantity indicator.
o Sec. 29.1553 - Fuel quantity indicator. o Sec. 29.1555 - Control markings.
o Sec. 29.1557 - Miscellaneous markings and placards.
o Sec. 29.1559 - Limitations placard.
o Sec. 29.1561 - Safety equipment.
o Sec. 29.1565 - Tail rotor.
o Sec. 29.1581 - General.
o Sec. 29.1583 - Operating limitations.
o Sec. 29.1585 - Operating procedures. o Sec. 29.1587 - Performance information.
o Sec. 29.1589 - Loading information.Appendices• Appendix A to Part 29 - Instructions for Continued Airworthiness • Appendix B to Part 29 - Airworthiness Criteria for Helicopter Instrument Flight • Appendix C to Part 29 - Icing Certification • Appendix D to Part 29 - Criteria for Demonstration of Emergency Evacuation Procedures Under §29.803

The military variants of the Dhruv ALH adhere to the following FAR/MILSPEC standards:
US Army Aeronautical Design Standard-33E (ADS-33E)Flaw-Tolerant Rotor System: FAR/JAR 29.571,
AM 29-28Crashworthy Fuel System: FAR/JAR 29.952,
AM 29-35Flaw-Tolerant Drive Train with Over Torque Certification: FAR/JAR 29.952, AM 29-28
Turbine Burst Protection: FAR/JAR 29.901, AM 29-36
Composite Spar Main & Tail Rotor Blades with Lightning Strike Protection: FAR/JAR 1309(h), AM 29-40
Engine Compartment Fire Protection: FAR/JAR 29.1193
Redundant Hydraulics & Flaw Tolerant Flight Controls: FAR/JAR 29.571, AM 29-28
Aircraft-Wide Bird Strike Protection: FAR/JAR 29.631, AM 29-40
Crashworthiness Standard: FAR/JAR 29.561, AM 29-38
Crashworthy Seats Conforming to MIL-STD-1472B
Cockpit Instrumentation Lighting Conforming to MIL-STD-85762A
Avionics Databus: MIL-STD-1553B or ARINC-429
Autopilot Accuracy: MIL-F-9490D
Embedded MIL-STD-188-141B ALE Link Protection
Embedded MIL-STD-188-110B data modem

33 comments:

li hung said...

another stat of art product from india,all indigiously produced stuff is next generation technology.but shit happens like arjun,tejas,well i dont follow much but there must be other indigiously produced junk as well which stat of art but doesnt work.
i really feel bad for equadorians but they gonna learn.

Anonymous said...

Li,

I think its because of idiots like you that free speech is not allowed in China.
In china even if a million equipments fuck up - no body knows.
If you think you are so smart, why dont you start a blog of your own about the cheap chinese products.

While we freely discuss our issues - failures as well as success.
In short - just get lost!!!

su30 said...

To Li,
China is good enough in reversed eng anything, but india is trying its own tech . dont compare cheap low class chinese products with indian products.
India ordered 124 arjuns
Tejas -40 nos
Already in production ALH
so don't worry about us , take care of Chinese spying work on others products ( US/UK/Russia/Israel /fra/ger/and even fiji island

Anonymous said...

Let's stop all Hal bashing. Dhruv is performing well and it is really sad that a mishap had taken place. The possibility of pilot error looks good as the other 2 helis had smoother turns as the video shows while the crashed one had a steep turn that defied safety. The equadorian press seems to have their knives out. Seems that Hal has not factored the wining and dinning of managing the PR.Hal must take all necessary steps to ensure and assure the roboustness of the Dhruv-Himalayas King/Thar desert Rover/Relief operations rescue friend/etc. I have confidence in Hal products.

Anonymous said...

prasun, no report is even out on the enquiry but you've already got a theory just from seeing a youtube video, and can attribute the catastrophe to the engine / fuel supply system which isnt even visible. wow, you're great! whatta waste of time for HAL to send a team to Quito when you're not far away. air forces around the world should employ you. or probably even intelligence agencies.

thusspakerono said...

I am extremely impressed by the detailed information...are you a professional?

Anonymous said...

Mr.Pee Dung,

If you are so sad for the Ecuadorians, why don't you send over a couple of your reverse-engineered flying craps to them? We have heard a lot about China's manufacturing prowess -- selling toxic toys to the world's children, you sick baby killers!

Anonymous said...

Mr. Prasun,

With all the kindness and respect, instead of qualifying my comment as ignorant, you stand to gain by pointing out to your beloved readers and visitors of your blog what you feel in that article as 'most objective' and 'brilliantly exposing'. By responding here I simply like to register my response and pls accept my response to your comment.

My retort, "and all the information discussed are just open source and just repeated from the AEC website., is in response to sentence which you choose to describe as "brilliantly exposed the organisational deficiencies prevailing within the AEC."

Irony is that by trying to pick sentences verbatim from AEC website Capt. Subbarao implies symbolically his views are subservient to AEC rather than exposing the deficiencies of AEC as you try to put it. I rather fit to address that as plagiarism rather than 'cogent' and 'coherent' as you prefer to see it.

Regarding your much valuable opinion on Amb. Dean addressing of the Naval officer as Capt., i like to point out that he expressed his shock wondering he could be a double agent so he could have thought the person was still in service and addressed as Capt.

Doctor, Prof., Eng., General are used more as qualifier. We are regularly addressing Sundarji as Gen. K. Sundarji as you see in various news articles. So addressing a person as Capt. doesn't necessarily mean he is still in service.

While adding further rejoinder on this, i like to point out several facts,

1. Amb. Dean talk about the Naval Officer arrested in Bombay Intl. airport. Capt. Subbarao was arrested in Bombay Intl. airport. Amb. left India by Nov 1988. Capt. Subbarao was arrested in May 1988.

2. Capt. Subbarao took voluntary retirement in Oct 1987. Charlie Sub was leased on Jan 1988. Before the lease happened, our officers/sailors had 4 yrs (i.e. from 1984) of training and it did involve the design transfer. Deal for the lease was finalized in 1983. It involved design transfer. As per various documents and per Amb. Dean memoirs, the vessel contracted meant mainly for training. From the design transfer, DAE/DRDO/Naval Bureau were entrusted in building the N Sub, implying design transfer had happened much before the lease.

3. Capt. Subbarao invariable worked on N sub design. He submitted the thesis in 1985. He was reportedly working on the thesis from 1982.

4. After 6 months from his retirement, within few days before he was scheduled for a flight to US, there was a surprise offer from the then Prime Minister out of the blue. He was asked to stay put here in India and continue his service. He declined the offer politely. He was arrested while he was about to aboard a flight on May 1998.

5. Charlie-I lease was over by Jan 1991. Collapse of SU started by Aug 1991. Capt. Subbarao was acquitted by Nov 1991. SU was dissolved by Dec 1991. Is it could just be a mere coincidence? Is the offer from PM is meant to stop Capt. Subbaroa from going US ? While there were many doubts in whole conduct, Amb. Dean memoirs comes as a solution to all these questionnaire.

Anonymous said...

Hi Prasun,

According to press, Ecuadorian Air Chief says that it went down due to pilot error. But you say that crash happened due to failure and pilot did handle it well. From the video, it looks what you say is true. But why did Air Chief say that ?

Anonymous said...

Troll again

When you talk about Indian systems tehn you do a good job bacuse you access to Indian officials. However when you talk about Pakistani and Chinese weapons, you do not have same level of access.

Anonymous said...

Prasun,

I find the 'troll's' comments very disturbing and since he has hinted that you don't have access, I would like to offer you my company's access card. Do what you want with it but just make sure you swipe it for 8 hours or my manager will sack me!

Li Hing said...

we are not talking about democracy we are talking about why that heli fell.I think their might be some design error.thats why indian airforce doesnt like to use state of art Dhruv and tejas.
by the way why ia just acquiring 140 of next generation arjun andthousands of this generation t-90

Anonymous said...

Good eve, Prasun always looking forward 2 ur posts. well taking into acct ur profound knowledge on geopolitics what really is the the SCO, what is its purpose? it seems to have started as security cooperation between Russia and china .especially since russia feared revolutions in its neighbourhood and such a treaty put the other soviet republics away from washington's reach.but russia is weary of china's rise and really is concerned abt chinese growth.they seem to want to have a pan european security architecture rahter than an asian one .they copoperate in air defence(linking up their sys).so why would moscow want to have a security coopn with beijing(cause noobody trains with them?).sco also seems to be abt securing energy routes as well as resources from faling into western hands. but how long is it going to last especially if the US succeeds in color revlns there citing dictatorial govts though russia will do its utmost tonot let things go out of hands and to some extent china as well,since it is a safe energy transit route whose security it can ensure.Lately it seems to have taken an economic and development agenda as well.
the security nature is justified by the instability of the region due to potential insurgencies extremism and terrorism.
it simply seems to be astructure to keep current leaders in power
But such an alliance of convenience with total mistrust(Russia&china) cannot last

Pierre Zorin said...

Hi Prasun.I think you ought to consider moderation in order to filter out stupid, unrelated, agitating and frivolous contents.Also unless someone's life is in danger for extensive items beyond 3 sentences they should use a name and stop being Anonymous, e.g. the Subba Rao "defence attorney". I also obtained details of Li Hung and as it turns out not only is he not well-hung but he is not Chinese at all!So please consider some control over the wonderful blog to prevent unwarranted, flippant unsubstantiated comments and let us who enjoy some constructive discussion/questions and answers continue to do so.Thanks.

Type99 said...

^^^

Li Hung is am Indiam, I knew it.

Type99 said...

Seem to got m and n mixed up.

Prasun K Sengupta said...

To Anon@7:19AM: Your post has some factual errors, the more prominent of them being the following:
1) The type-specific vrew conversion programme for any nuclear-powered submarine (be it the Charlie-1 or the Akula-3) lasts for only eight months, and not for four years). Also, the time for fabricating the shore-based logistics and support infrastructure for a single nuclear-powered submarine takes only two years, not four years.
2) The final lease contract for the Charlie-1 SSGN was NOT signed in 1983, it was inked in only 1986. Only the initial offer from the USSR was made in 1983.
3) As the contract was only for leasing the SSGN, no engineering or fabrication-related design data was required to be transferred to India. Therefore, the issue of the DRDO-led Submarine Design Group acquiring access to any kind of data pertaining to the Charlie-1 does not even arise.
4) All operational and maintenance-related data on the Charlie-1 SSGN was transferred only to the IN's Directorate of Submarine Warfare. And Capt Subbarao at that time was not even remotely connected to this Directorate.
5) Capt Subbarao was never associated in any manner with the design of nuclear-powered submarines or the ATV Project Office. He was only enrolled as a design consultant for the n-powered submarine's PWR DIRECTLY by Indian Navy HQ.
6) AS you've said in point 5, Capt (Ret'd) Subbarao was acquitted by November 1991, which means there was no incriminating evidence whatsoever to paint him as a spy or traitor. Had there been any, I'm pretty the Indian judicial system would have sentenced him in the same way as it had sentenced the Larkins brothers in 1985.

Prasun K Sengupta said...

To Anon@9:11AM: FYI I've never claimed 'access' of any kind to any kind or level of authority from any country. And even if I did, folks like you will be the last ones to know about them.

To Pierre Zorin: Relax mate. Uninvited trolls do have rather limited shelf-lives. I don't mind constructive criticism and analysis, but needless finger-pointing (I'm sure will agree) doesn't amount to any kind of proud patriotism, but only xenophobic nationalism of a vrlent flavour.

Prasun K Sengupta said...

To Li Hing@9:58AM: You really need to update your skills concerning post-crash investigations. For when one refers to human error it can mean either poor handling by the aircrew, or deficienies in ground maintenance procedures/practices, or lapses in the production process of the concerned aircraft. And none of them point towards the aircraft/helicopter having fundemental design flaws.
Again, you need to update your database on existing 'Indian' operators of the Dhruv ALH.

Prasun K Sengupta said...

To Li Hung, Anon@2:25AM & Anon@8:19AM: Firstly, anyone (especially helicopter pilots) trying to make sense of the probable causes of the Dhruv ALH crash, which I've said above, will immediately realise that equipment malfunctions (be it for the Dhruv ALH or even the Su-30MKI) can and do often take place due to human error (either the aircrew or the ground technical/engineering crew), or by deliberate human interference (i.e. criminal negligence or sabotage). The latest crash DOES NOT by any means imply that the helicopter has fundamental design flaw.
Secondly, again as any helicopter pilot will observe, it was quick employment of the autorotation technique that enabled the Dhruv ALH to land in a manner that enabled the aircrew to walk out! And this in turn has resulted in a near-perfect fuselage now being available (inclusive of the FDR) for post-crash investigations. Therefore, baying for the aircrews' blood at this stage is uncalled for.
Thirdly, and most importantly, once the accident investigation team from HAL arrives in Quito, it must be ensured that this team is given access to the crashed helicopter ONLY under the direct supervision of Ecuador's investigation authorities, and under no circumstances should ask the EAF for ferrying the helicopter's remains back to India for further investigation. At the same time, personnel from Turbomeca too should be barred from trying to ferry the twin Ardiden 1H engines back to France. The FDR should be sent for forensic analysis to a neutral third party in either the UK or Australia or Canada.
I' mentioning all this on the basis of previous first-hand experiences when the concerned OEMs reached the crash site, had total access to the crash wreckage, and resorted to 'suppressing' the evidence by withdrawing their products for reasons of 'further analysis' and all this in the end only resulted in the end-user/owner of the crashed aircraft clsiming that crash investigations were inconclusive as vital evidence was either unavailable or went missing. Therefore, at a time when several vested interests and competing OEMs are keenly watching the EAF's crash investigations and would like nothing more than to pin all the blame on HAL, it is critical for HAL not to get ambushed by its competitors/detractors at this stage.

Type99 said...

Investigation has not been done yet, so I will wait to official Ecuader vedict. Not the Indian verdict.

Prasun K Sengupta said...

To Type99@:25PM: Contrary to what you may be led to believe, in this case more than 70 of the airframe has been recovered intact (and yes, it can be made airworthy, and is NOT a writeoff as is being made out to be), both aircrew are safe and sound enough to retrace the final 1 minute of the flight prior to the crash-landing, and the flight data recorder has been recovered intact. Consequently, the conclusive results of any post-crash investigation should be known within the next 24 hours at most. That's why the EAF's attention now remains focussed on the Ardiden-1H engine, and not just on the helicopter.
The question of any Indian verdict from any quarter doesn't even arise as the concerned helicopter is the EAF's property and was maintained and flown by EAF personnel. The Board of Enquiry too is headed by the EAF and not by any Indian entity. Any Indian involvement is purely in a supportive manner and that too because of the existing warranty period.

Prasun K Sengupta said...

To Anon@2:25AM: It may be a theory to you, but were you to show the video clipping to any helicopter pilot, the pilot would well tell exactly what I've outlined above. I'm highly surprised why no one from the India-based mass-media is even interviewing any helicopter pilot to even explain what the video clipping shows. Instead, false claims are being about this crash demonstrating the Dhruv ALH's crash survivability features, when in fact the helicopter aircrew tried their level-best (and almost succeeded) to ensure what is technically known as a 'controlled flight into terrain', thereby preventing loss of life and preserving vital evidence (such as the dynamic systems on the helicopter and its FDR) for post-accident analysis. There have been several other cases involving similar accidents in which the airframe was recovered relatively intact, thanks to some quick-thinking and deft handling by the helicopter aircrews.

Anonymous said...

hi prasun,you haven't replied to my query abt the SCO.is there nothing really to talk abt the SCO ?or were you paying more attentive to the ALH crash?

Prasun K Sengupta said...

To Anon Above: Believe me, unlike others, I'm not over-enthused by any updates from Quito about the Dhruv ALH crash. Regarding the SCO, there's nothing earth-shattering to analyse. Everyone knows that the SCO was jointly created by China and Russia to carve up their respective spheres of influence (thereby filling up a vital gap in Central Asia that existed since the breakup of the USSR inb 1991 and Russia's subsequent failure to include the Central Asian Republics into the CIS). By creating the SCO, both Moscow and Beijing have jointly taken over the responsibility of financially sustaining and stabilising the Central Asian Republics, with China being entrusted with Tajikistan and Kyrgyzstan, and Russia being responsible for taking the lead in Kazakhstan, Uzbekistan and Turkmenistan.

Q 4 u said...

Hi Prasun

In most of the video your statement "one of them apparently swung 90 degrees and started losing altitude" would sound true but see this below video, you can see all the helis in the formation turns to the left

http://www.youtube.com/watch?v=cHlJfeBvrms

But I belive if the tail rotor were to fail(even its partially failue) the craft would turn on the axis of rotation & not bank ( which you can only do with the main rotor ie by tilling the rotor on to the side which you want 2 bank)

here's a video of a mishap of banking at low altitude(& i know its not a rotry craft but the effect are somewaht similar)

http://www.youtube.com/watch?v=FUEhNKBi4DY&feature=related

Dont you think there's a minimum height/foward speed required to achieve Autogyro?

Regards,

Q 4 u said...

Hi Prasun

In this video on impact both engines falmeout

http://www.youtube.com/watch?v=_SSDPtEpw-E

Would the engines flameout when the fuel is cut, as in case of autogyro?

Regards,

Prasun K Sengupta said...

To Q4U: You're absolutely right. The video clip clearly shows the tail rotors functional. And closer examination of the video clip shows that the ill-fated helicopter began losing altitude even before completing its left turn. And after the crash the CO of No22 Sqn gave a press briefing on the Dhruv ALH's single-engine operations at medium and high-altitudes, suggesting that there was failure of at least one of the two Ardiden-1H engines.

Prasun K Sengupta said...

To Q4U: The flames you see are not due to engine failure-induced flame-out, but the residual fuel burning itself out, which happens just prior to emergency engine shut-downs initiated by the aircrew just before impacting the ground. Immediately after impact it is this residual fuel already inside the engine that burns out. In the video the portside engine is seen burning out its residual fuel, followed by the starboard engine. All in all, a remarkable 'controlled' and lucky crash by the aircrew.

Q 4 u said...

Sorry Parsun sorry to spam your blog , I've an another Q

Dhurv's main rotor spins counter-clockwise, if the tail rotor where to have failed, dont you think the body of the craft will be rotating counter-clockwise & not clockwise as this heli did?

Ref: http://www.youtube.com/watch?v=g1k6pFUgbb0&feature=related


Regards,

Q 4 u said...

oops i meant.... "dont you think the body of the craft will be rotating clockwise & not counter-clockwise as this heli did?"

Regards,

Prasun K Sengupta said...

That's right, and the video clip clearly shows the tail rotor in a functional state right upto ground impact. Therefore tail rotor hub failure/malfunction or tail rotor transmission shaft failure can be safely ruled out.

Q 4 u said...

Parsun,

Since you mentioned we can rule out tail rotor failure, then there's no question of autogyro/rotation as its susida| to cut your engine when you have a fully functional tail rotor that too at this low altitude & low airspeed

The flameout looks like FOD induced flameout(because of the impact), rather than residual fuel, these turofan engines eats up fuel as they come out of difuser & right on flame catcher. As you pointed out both engines flameout one after the other in quick succession meaning that the engines are functional & are not starved of fuel till the time of impact. Dont you agree?

Offcourse once the flameout,the failsafe kicked in & cut the fuel leting the pilot walk away instead of ending up in a big ball of flame.

Regards,