Thread: A 737/500 down in Indonesia ?

The other interesting thing is that this aircraft was not maintained by the airline but by Garuda. Now Indonesian airlines have a woeful reputation and as a result Indonesian airlines were banned from flying to many parts of the world, in particular the EU, this included the Indonesian International Airline of Garuda - as a result Garuda lifted their game and now have a good reputation for the operation, maintenance and record keeping of their aircraft - maybe not the best reputation but of a good standard.

So it will be interesting if this crash was a result of poor maintenance and if it is, what will be the impact on Garuda's operations and reputation.

Originally Posted by Tins

Astonishing to hear uninformed people talking of the MCAS system being at fault, when the 737-500 isn't fitted with MCAS.

Hugh, unreliable airspeed indications are caused mostly by failure in the pitot static systems? Is that correct?

Tins, yes, generally that is the case. However, there can be corruption/interruption of data signals to the instruments, as the pneumatic air data is processed and sent to the ADIRU's, which provide airspeed and static data to many aircraft systems (including flight instruments). Too much to go into here.

An example of how far reaching corrupt or interrupted pitot-static information can be sent, I have once experienced both degraded EEC (Electronic Engine Controls) and an airspeed disagree message leading to a rejected takeoff. It took a lot of troubleshooting for the engineers to trace the fault to one of the ADIRU's. BUT - all pitot and static systems were working perfectly, it was just the data was crap.

Remember the MAX had a problem with a faulty alpha vane leading to activation of the MCAS. These also input data to the ADIRU's.

So in the absence of DFDR and CVR data, it really could be anything. Having said that, if it was an instrument malfunction, it doesn't really matter what caused the problem, the crew's first stepping off point is the AIRSPEED UNRELIABLE memory items. You're going back to basics: disconnecting the automatics and setting a known attitude and thrust setting and assessing performance. Then you can usually work out which side is malfunctioning and take it from there.

Nevertheless, a catastrophic failure of a flight control or critical system may also be a cause.

Flight into an active storm cell, leading to loss of control and/or structural failure is possible...

Someone mentioned a blocked pitot or a cover being left on. I don'y know about other countries, but speaking of covers - the first thing I check when taking an aircraft over is that the flight readiness check has been signed by the engineer (he's certifying the covers, fan straps, gear lock pins etc, have been removed and stowed). The second check is the walk-around.

If you miss that, you would normally get an Airspeed Disagree message during the takeoff. There's also an airspeed check at 80 knots. A pitot cover would most likely give either, or both of these errors.

Mud wasps are a huge problem, especially Brisbane. Our engineers install and remove the covers even on a 35 min turnaround. A problem with wasps might not be apparent until after airborne. In any instance, if the faulty system isn't easily recognised - the AIRSPEED UNRELIABLE checklist is your friend.

Originally Posted by Hugh Jars

.......
Mud wasps are a huge problem, especially Brisbane. Our engineers install and remove the covers even on a 35 min turnaround. A problem with wasps might not be apparent until after airborne. In any instance, if the faulty system isn't easily recognised - the AIRSPEED UNRELIABLE checklist is your friend.

As I have mentioed in another thread, I have experienced mudwasps with my Auster - at Redcliff, not Brisbane, but not that far away. That was due to an automatic pitot cover being held off by the wind!

Originally Posted by 101RRS

Why - this is a forum of peoples ideas - not necessarily facts. This place is not a formal investigation - if we get it wrong on AULRO does it matter.

Oh well, if you insist... Actually it's more of a comment on the way flying / Piloting has evolved, from 'Flying' the aircraft, to....'Managing' the Systems. Feet on the Footrests & Fingers feeling joystick are first to sense impending doom. Pilot "feeels" connected, whereas changing heading by twiddling a knob...and 'commanding' your Auto-Pilot COMPUTER to sort out bank angle/attitude/rudder/power balance... leaves you at arms length, metaphorically and literally. That shrt time delay in noticing...and getting a grip on things... can make the difference between a fright and a....

Basically, too many computer literate nerds displacing those with ability, gift, interest & passion to.... FLY

My $2.00 worth

Originally Posted by superquag

Oh well, if you insist... Actually it's more of a comment on the way flying / Piloting has evolved, from 'Flying' the aircraft, to....'Managing' the Systems. Feet on the Footrests & Fingers feeling joystick are first to sense impending doom. Pilot "feeels" connected, whereas changing heading by twiddling a knob...and 'commanding' your Auto-Pilot COMPUTER to sort out bank angle/attitude/rudder/power balance... leaves you at arms length, metaphorically and literally. That shrt time delay in noticing...and getting a grip on things... can make the difference between a fright and a....

Basically, too many computer literate nerds displacing those with ability, gift, interest & passion to.... FLY

My $2.00 worth

a few years ago i gave a lecture to pilots in training about the last reliable part of the airplane. what was it on? the pilot. human error is still the leading cause of aircraft incidents and accidents.

Originally Posted by JDNSW

As I have mentioed in another thread, I have experienced mudwasps with my Auster - at Redcliff, not Brisbane, but not that far away. That was due to an automatic pitot cover being held off by the wind!

Who uses the airspeed indicator in an Auster?

Originally Posted by Fourgearsticks

Who uses the airspeed indicator in an Auster?

Is it one of those funny 'strips' that are attached to the wing? I first saw that on a DH60. Reckon the Auster is more modern than that. Could be wrong.