Search found 27 matches

by akoma
Wed May 29, 2019 4:21 am
Forum: Technical/Operations
Topic: SQ A359 MTOWs.
Replies: 19
Views: 2256

Re: SQ A359 MTOWs.

The difficulty I have understanding is the implementation of different MTOWs on the same tail. As an example, a particular aircraft might fly HKG SIN under a particular MTOW. Then, on the return flight SIN HKG the same tail flies back with a different MTOW. I see issues with the regulatory bodies a...

Jump to post
by akoma
Wed May 29, 2019 1:21 am
Forum: Technical/Operations
Topic: SQ A359 MTOWs.
Replies: 19
Views: 2256

Re: SQ A359 MTOWs.

This probably works for certain registrations and jurisdictions; I am not familiar with such arrangements. The airline we are discussing has aircraft with fixed regulated MTOWs. Regulated MTOW is the maximum mass the performance charts or performance application generate for the runway and environm...

Jump to post
by akoma
Tue May 28, 2019 7:52 am
Forum: Technical/Operations
Topic: SQ A359 MTOWs.
Replies: 19
Views: 2256

Re: SQ A359 MTOWs.

It could also be “variable". There is really no public information. There are no "variable" weight versions. Yes, there are. Same as on the A330. You can dispatch one flight with a certain MTOW, and the next flight using the same tail with another MTOW. This probably works for certai...

Jump to post
by akoma
Tue May 28, 2019 4:30 am
Forum: Technical/Operations
Topic: SQ A359 MTOWs.
Replies: 19
Views: 2256

Re: SQ A359 MTOWs.

It could also be “variable". There is really no public information. There are no "variable" weight versions. They tend to fly their regular 268T A359s to places slightly closer to main base and the regular 275T A359s further away, including to SFO. However, in the early days, they al...

Jump to post
by akoma
Sun May 05, 2019 1:45 am
Forum: Civil Aviation
Topic: How come the DL A350 can't fly LAX-SYD it is rumored?
Replies: 315
Views: 55719

Re: How come the DL A350 can't fly LAX-SYD it is rumored?

Minor point - they use the 275T (not 276T) A350s for flights 31/32 and occasionally the 268T ones as well. Does SQ even have 268t variant, or they use variable MTOW? I thought they only has 250t (regional), 276t ("vanilla"), and 280t (ULR). They use variable between 268 and the “vanilla” ...

Jump to post
by akoma
Sat May 04, 2019 5:50 pm
Forum: Civil Aviation
Topic: How come the DL A350 can't fly LAX-SYD it is rumored?
Replies: 315
Views: 55719

Re: How come the DL A350 can't fly LAX-SYD it is rumored?

The regular SQ a350 with the 253 passenger layout has been flying sq31/32 for more than two years now and continues to do so. The ulr a350 was only recently introduced on the route for a few additional frequencies every week. Argh, you beat my edit! :white: May I enquire the MTOW of the 253-seat bi...

Jump to post
by akoma
Fri Apr 26, 2019 10:25 am
Forum: Civil Aviation
Topic: How come the DL A350 can't fly LAX-SYD it is rumored?
Replies: 315
Views: 55719

Re: How come the DL A350 can't fly LAX-SYD it is rumored!?

Then there is SQ, which has occasionally flown SFO-SIN with its "regular" 275 t 359 in a 253-seat configuration Not occasionally... they've done it every day, for years. During the early days of the non-stop flights, for personal interest, I was tracking the SIN-SFO direct flights daily f...

Jump to post
by akoma
Fri Apr 19, 2019 3:05 am
Forum: Technical/Operations
Topic: Mode S transponder ID
Replies: 10
Views: 1719

Re: Mode S transponder ID

The TCAS box is usually a separate black box and it is not incorporated into the ATC transponder unit, although it (TCAS) needs the transponder to work. Strapping the address as well as a separate transponder is older tech, current tech like the Collins Traffic Surveillance System (TSS-4100) has TC...

Jump to post
by akoma
Thu Apr 18, 2019 5:15 pm
Forum: Technical/Operations
Topic: Engineers, miss it or glad those days are gone.
Replies: 28
Views: 4882

Re: Engineers, miss it or glad those days are gone.

When I started in the airline business, (far too long ago), the airline for which I flew had non-pilot PFEs in the third seat of a three man airplane. 747-100/200s, DC-10s and A300s. The 707s and 727 had been retired when I was hired. Further, they were also AMEs rated on the type as well. We carri...

Jump to post
by akoma
Thu Apr 18, 2019 4:50 pm
Forum: Technical/Operations
Topic: Staying on the centre line
Replies: 32
Views: 4899

Re: Staying on the centre line

When I was learning to fly in the trauma hawk it was always deliberate to keep a bit away from the center line as the shaking caused by lights etc could cause pieces of trim to be released from the cockpit. the steering with your feet could take a bit of getting used to and my instructor could alwa...

Jump to post
by akoma
Thu Apr 18, 2019 4:36 pm
Forum: Technical/Operations
Topic: Mode S transponder ID
Replies: 10
Views: 1719

Re: Mode S transponder ID

It’s assigned by the country that the aircraft is registered in. It is programmed into the unit. The unique address is assigned to the aircraft, if a transponder is replaced it needs to be programmed with the correct id. Essentially not a lot of difference between a light aircraft transponder and a...

Jump to post
by akoma
Thu Apr 18, 2019 4:02 pm
Forum: Technical/Operations
Topic: How do cockpit voice recorders decide when to start and stop recording?
Replies: 6
Views: 2561

Re: How do cockpit voice recorders decide when to start and stop recording?

In response to the posts above: . According to online sources: The CVR on AF447 stopped recording less than a minute before impact. On UA93, only the last 30 min were recorded . A1. An undamaged CVR will continue recording until electrical power to it is cut off. A2. CVRs have had 120 minutes record...

Jump to post
by akoma
Mon Feb 18, 2019 6:35 am
Forum: Technical/Operations
Topic: Amplitude Modulation (B777)
Replies: 7
Views: 2173

Re: Amplitude Modulation (B777)

"FM is not used on HF and below, otherwise known as shortwave (3 to 30 Mhz). Shifting the carrier in that band (modulation) sufficiently to add usable information requires the carrier to exceed the resonance of the transmitter, receiver and the antenna" FM does not have to be used only ab...

Jump to post
by akoma
Fri Feb 15, 2019 5:19 am
Forum: Technical/Operations
Topic: Lion Air crash from maintenance perpective
Replies: 13
Views: 2351

Re: Lion Air crash from maintenance perpective

fadecfault wrote:
Fun Fact: Per my companies internal doc it shows Lion air averaged a 99.7% MAX mechanical dispatch reliability from sep 17 to nov 18. No other max carrier came close with each having normal drops in MDR that you would see with a new type a/c. Draw your own conclusion.


Interesting figure!

Jump to post
by akoma
Fri Feb 15, 2019 5:16 am
Forum: Technical/Operations
Topic: Lion Air crash from maintenance perpective
Replies: 13
Views: 2351

Re: Lion Air crash from maintenance perpective

So it is low leakage but not hermetic. Thanks. That’s just the acceptable leak rate. The system is designed to be tight, and I’ve tested many systems that didn’t lose a foot, or a knot, during a low range test. I have rarely seen a near perfect leak rate during testing. However, the leak rates were...

Jump to post
by akoma
Thu Feb 14, 2019 1:37 pm
Forum: Technical/Operations
Topic: Boeing 787: different HF-antennas
Replies: 4
Views: 1973

Re: Boeing 787: different HF-antennas

IIRC, the 789 implemented a (limited) laminar flow technology on the vertical stabilizer...if this is the case, the new HF antenna location lower down on the leading edge may be to help with that implementation...to furnish a smooth, seamless leading edge surface to enhance the laminar flow further...

Jump to post
by akoma
Thu Feb 14, 2019 12:32 pm
Forum: Technical/Operations
Topic: Amplitude Modulation (B777)
Replies: 7
Views: 2173

Re: Amplitude Modulation (B777)

If you select AM, reception of a USB transmission is unreadable and vice versa. It’ll sound vaguely recognizable but unreadable. GF If you select AM on your receiver, a USB transmission will be almost unreadable. If you select USB and there is a AM transmission on frequency, the AM transmission wil...

Jump to post
by akoma
Thu Feb 14, 2019 12:25 pm
Forum: Technical/Operations
Topic: Amplitude Modulation (B777)
Replies: 7
Views: 2173

Re: Amplitude Modulation (B777)

https://www.pprune.org/archive/index.php/t-10746.html This from the link: Cat1234 30th Dec 2001, 14:02 The HF band is too low for Frequency Modulation (FM). An FM carrier contains all the audio (or digital) information and requires no extra modulator power for 100% modulation, plus it has other adv...

Jump to post
by akoma
Thu Feb 14, 2019 11:51 am
Forum: Technical/Operations
Topic: Lion Air crash from maintenance perpective
Replies: 13
Views: 2351

Re: Lion Air crash from maintenance perpective

( any values around how much leakage is acceptable in the pitot or static line?) [/quote] During a maintenance low range static leak check, the system is brought to an altitude 5,000 feet above airfield elevation. After readings have stabilized, Boeing specifies a altitude reading decrease of less ...

Jump to post
by akoma
Thu Feb 14, 2019 11:39 am
Forum: Technical/Operations
Topic: Lion Air crash from maintenance perpective
Replies: 13
Views: 2351

Re: Lion Air crash from maintenance perpective

There was a lot of talk regarding Lion Air Crash especially about MCAS, pilots, AOA sensor, etc... There was also talk about the poor safety record. I would like to talk about aircraft maintenance, more importantly about the compliance with the procedures in the AMM (Aircraft Maintenance Manual) an...

Jump to post
by akoma
Sat Sep 22, 2018 7:22 pm
Forum: Civil Aviation
Topic: Singapore Airlines takes delivery of first A350-900ULR from Airbus
Replies: 133
Views: 30306

Re: Singapore Airlines takes delivery of first A350-900ULR from Airbus

[quote= I would also wonder if on some days, it may be worth it to send the return flight east instead of west to take advantage of headwinds.[/quote] There were already doing that during the A345 days; normally going eastwards from SIN and returning from EWR via polar route or eastwards / westwards...

Jump to post
by akoma
Sat Sep 22, 2018 5:52 pm
Forum: Civil Aviation
Topic: Singapore Airlines takes delivery of first A350-900ULR from Airbus
Replies: 133
Views: 30306

Re: Singapore Airlines takes delivery of first A350-900ULR from Airbus

Interesting delivery flight path 9V-SGA is taking from TLS to SIN, flying to the west of Denmark now.
Any idea if they are trying out a new flight plan? Some kind of polar route perhaps?

Jump to post
by akoma
Tue Sep 11, 2018 1:45 pm
Forum: Technical/Operations
Topic: B737 - normal use of DC power knob?
Replies: 8
Views: 1110

Re: B737 - normal use of DC power knob?

I am still unsure what the systems actually are however (apart from obvious ones like BAT, GRD PWR or APU of course). TR1, 2 and 3 are...? And BAT BUS? (I remember the Bat Car from my childhood TV days, but the Bat Bus ??)... The way the electrical buses are named can be pretty confusing. Different...

Jump to post
by akoma
Sun Sep 09, 2018 7:33 pm
Forum: Technical/Operations
Topic: B737 - normal use of DC power knob?
Replies: 8
Views: 1110

Re: B737 - normal use of DC power knob?

I am looking at the 737-400, but I guess that 737NG are the same in this respect (?) I'd firstly like to ask what the functions of the various positions of the DC knob on the O/H panel actually are (STBY PWR; BAT BUS; BAT; TR1; TR2; TR3 & TEST). When would each of those positions be selected by...

Jump to post
by akoma
Tue Aug 14, 2018 2:57 pm
Forum: Civil Aviation
Topic: Singapore's Seletar Airport - Opportunities
Replies: 23
Views: 3427

Re: Singapore's Seletar Airport - Opportunities

Hard to imagine runway expansion, not that much room ... Actually, there is land available to be developed, at east camp - this large parcel of land was previously unavailable because the developer of XSP, JTC Corporation, wanted to focus first on developing the west side. Authorities have now anno...

Jump to post
by akoma
Tue Jun 27, 2017 4:27 pm
Forum: Civil Aviation
Topic: What happened to the twin jack headphone socket on planes?
Replies: 32
Views: 14531

Re: What happened to the twin jack headphone socket on planes?

Just flew an Air China 789, and they were twin jacks. Why they were installed on a new airframe like that, I have no idea. But it's China, there may be no explanation. Not sure if it has anything to do with China. As others have mentioned, SQ (and other airlines) are still using these twin jacks. A...

Jump to post
by akoma
Tue Jun 27, 2017 4:20 pm
Forum: Civil Aviation
Topic: What happened to the twin jack headphone socket on planes?
Replies: 32
Views: 14531

Re: What happened to the twin jack headphone socket on planes?

The pneumatic one had to be sold for a fee in Ecomony. IIRC that was some IATA rule back then. Oh those 741 days going transatlantic with ONE MOVIE on ONE SCREEN for everybody. Oh, not just 741. I remember all too well the 744s of 10-12 years ago. Rubber-necking upward to watch Mr Bean and a non-of...

Jump to post