Aquaplaning

I wasn't aware that aqauplaning / hydroplaning occured in real world aviation, not in its true definition anyway - it'd be way too dangerous to take off / land in those conditions, so no, I doubt there is a way to emulate it in the sim.

😉

Does it not occur because in wet conditions pilots alter their rate of descent on to the runway to avoid the possibility?

Jamie4590 wrote:

Does it not occur because in wet conditions pilots alter their rate of descent on to the runway to avoid the possibility?

Descent rate doesn't have a lot to do with aquaplaning. My previous post could be misunderstood. What I meant, was that it is fairly uncommon because JAR rules determine the condition of the runway. If a runway becomes contaminated then it is unlikely that it'll be used.

Lets just be clear on our definition of aquaplaning so we don't get confused.

As I understand it, an unbraked wheel of an aircraft that rolls along a contaminated runway displaces the stationary water lying on the runway, thus it is moved. This creates hydrodynamic pressure which reacts on the tyre of the aircraft and the runway surface. The higher the speed of the tyre, the inertia of the water lowers its capability to escape from the tyre in contact with the runway which drives a 'wedge' of water between the tyre and the runway. The higher the groundspeed, the higher the chance of total aquaplaning occuring (where hydrodynamic lift is equal to the weight on the tyre).

Here, you have just lost control of a perfectly good aircraft, in terms of braking ability and steering. The best thing to do is re-adjust flaps, add full power and take off because (if total aquaplaning is present) you have an extreme chance of veering off the runway - a bit like landing a Boeing 747 on an ice rink. If aquaplaning occurs that isn't too serious and you have touched down at the threshold then you should use cadence braking (the application and releasing of brakes to stop the tyres locking) as it is more effective and apply full forward elevator to add as much weight as possible to the nose wheel to stop total aquaplaning (more weight makes it harder for the equalisation of hydrodynamic force and weight).

You can see my confusion about the mention of descent rate, because it is groundspeed that determines the extent of aquaplaning.

And no, none of the above will be emulated in the sim - it is far too complex.

Very intersting Jon thanks. I saw a reconstruction of a 737 landing in a thunderstorm and began aquaplaning on touchdown. Tragically the aircraft travelled the complete length of the runway and crashed in to concrete pillars further down. There were fatalities including the Captain but I didn't understand why the experts in the program didn't refer to 'aquaplaning'. They concluded also that the spoilers were not deployed on touchdown because although there was no system of recording the deployment in the FDR they could not hear the distinctive 'click' of the spoilers being activated in the cockpit. I find it surprising that the use of the spoilers are not recorded more accurately and investigators had to rely on the noise the handle makes. They concluded had the spoilers been deployed on touchdown there may not have been any fatalities.

How common are minor incidents caused by flight crew forgetting a step?

I forget the term but whats it called when as you touch down the plane spins around 180 degrees? I think its caused by wet conditions and incorrect use of braking.

Jamie4590 wrote:

Very intersting Jon thanks. I saw a reconstruction of a 737 landing in a thunderstorm and began aquaplaning on touchdown. Tragically the aircraft travelled the complete length of the runway and crashed in to concrete pillars further down. There were fatalities including the Captain but I didn't understand why the experts in the program didn't refer to 'aquaplaning'. They concluded also that the spoilers were not deployed on touchdown because although there was no system of recording the deployment in the FDR they could not hear the distinctive 'click' of the spoilers being activated in the cockpit. I find it surprising that the use of the spoilers are not recorded more accurately and investigators had to rely on the noise the handle makes. They concluded had the spoilers been deployed on touchdown there may not have been any fatalities.

How common are minor incidents caused by flight crew forgetting a step?

Thankfully, not that common. If a step is forgotten or missed out, then it usually doesn't have any disastrous repercussions - it is rather a collection of events that lead to a disaster, rather than one single mistake. You might be interested in visiting the AAIB website - it is the government agency for reporting accidents and serious incidents.

Have a quick look at these:

http://www.aaib.dft.gov.uk/publications/bulletins/june_2006/boeing_747_436__g_bnlg.cfm
http://www.aaib.dft.gov.uk/publications/bulletins/june_2006/boeing_747_41r__g_vwow.cfm
http://www.aaib.dft.gov.uk/publications/bulletins/june_2006/boeing_767_200__n653us.cfm
http://www.aaib.dft.gov.uk/publications/bulletins/june_2006/boeing_757_225__tf_ard.cfm

Heres an example of a minor mistake:

http://www.aaib.dft.gov.uk/publications/bulletins/june_2006/boeing_777_236__g_zzzc.cfm

As for not mentioning the term 'aquaplaning' - the series of Air Crash Investigation has recently turned into more of a drama than an aviation documentary - the avionic content is quite a bit lower than it used to be so focuses on the event as a whole and how it affects passengers rather than from a pilots point of view.

Jamie4590 wrote:

I forget the term but whats it called when as you touch down the plane spins around 180 degrees? I think its caused by wet conditions and incorrect use of braking.

😳 A catastrophe? Its not something I've ever heard of I don't think Sorry.

I find Air Crash Investigation very well made through the narration, expert contributions and acting for the reconstructions. Another program, Seconds From Disaster however I find can be quite dramatic instead of getting down to the nuts and bolts of tragedies and I'm usually left with unanswered questions. I saw a reconstruction of the 2000 Concorde crash on Seconds From Disaster and wish it had been presented on Air Crash Investigation as there would have been much more focus on the events in the cockpit gathered from the flight recorders rather than soley eye witness accounts and copmputer generated reconstructions.

Jamie4590 wrote:

I find Air Crash Investigation very well made through the narration, expert contributions and acting for the reconstructions. Another program, Seconds From Disaster however I find can be quite dramatic instead of getting down to the nuts and bolts of tragedies and I'm usually left with unanswered questions. I saw a reconstruction of the 2000 Concorde crash on Seconds From Disaster and wish it had been presented on Air Crash Investigation as there would have been much more focus on the events in the cockpit gathered from the flight recorders rather than soley eye witness accounts and copmputer generated reconstructions.

Don't get me wrong - it is an excellent program, but previous series have been more aviation focused 😉