Hand signals versus headset

[Chesty Morgan]

Instead of getting a new headset, the PBC and flight crew, in an effort to win minutes to avoid getting a delay on themselves, agreed to work with hand-signs and clearly compromised the safety of the equipment, the trucker and the passengers.

I pinched this quote from another thread and I was rather surprised to read it.

I regularly use hand signals with the ground crew, it is a tried and tested method of communication. Providing you ensure that the groundcrew understand the signals you will use in case of an emergency I don't consider it any less safe than using a headset which, less face it, aren't always 100% reliable anyway.

Is the experience level being diluted to such a point that people cannot be flexible and adapt anymore?

What are your thoughts?

[IGh]

pilot's conclusion from his own past success:"... regularly use hand signals with the ground crew, it is a tried and tested method of communication...."
First -- PLEASE add the source/date (link) to the ramp-mishap cited in the initial message(?).

The mishap report mentions this observation, cited in top slot:"... Instead of ... headset ... agreed to work with hand-signs ... compromised the safety ..."
This is mostly about safety during push-back, and during an unexpected stop for additional LATE BAGS. The case for redundant safety features [first VOICE with added backup by SIGHT-signals] is mostly driven by ramp-mishap history.

Push-back or Power-Back is a period of poor SIGHT-view down proposed track. Wing-walkers don't have perfect communication with either the Pilots nor the Tug Driver. The Pilots have NO VIEW of the push-back corridor. The Tug Driver's view is obstructed by the aircraft. Inside the cockpit, sometimes the two pilots' COMM are split (ATC/Ramp Control and maybe INPH with push-crew).

There have been fatal mishaps during Push-back and during the STOP-go after added LATE BAGS.

Worse still have been the LACK of COMMUNICATION once the victim is on the ground, with a line of rush-rush hub departures wanting to taxi near the downed victim; & gun-ho operator wanting to move the now- blocking aircraft.

? Could any list of mishaps, or equipment damage, persuade you toward the idea of redundant safety features during Push-back? Unfortunately, even the added safety feature (long cord to working Headset) has induced other problems/injuries -- your proposal to avoid any outside Headset might be justified by those odd cases.

Literature cites $$$-damages, injuries, and fatalities (see Bob Mathew's papers from ISASI 2003, and ICAO Journal, #3, 2004 "Ramp Safety"). Not sure any history would add to this discussion, since any added safety feature [eg, voice COMM] induces added risk, & additional failure modes.
=== // ==

My own record of non-fatal Ramp Mishap cases supports the statement (below) in the GAO's rpt. Even some fatal cases were NOT recorded in any mishap report, leaving the factors uncertain, found only in personal records collected by individuals. For Ramp Mishaps, my main concern is a cascading _interaction_ of failures, during Push-back or Late Bags, due to mis-communication, & lack of view from Cockpit nor Tug.

GAO-08-29, Nov2007, Runway and Ramp Safety, this from pg 48:"We found no source of comprehensive data on airport ramp accidents. Various aviation entities collect ramp accident data, but they are not complete enough to be useful for industry wide analyses, and, in many cases, the entities were not willing for competitive reasons to publicly disclose the data. Many industry stakeholders indicated to us that they lack complete ramp accident data. Without such data, it will be difficult for the aviation industry to understand the nature, extent, and cost of ramp accidents and to allocate appropriate resources and methods to improve ramp safety...."

[Piper19]

I think headsets are more safe for cockpit-ground communication than signals. I've done both of them hundreds if not thousands of times. If something goes wrong during engine start it's faster to shout stop over the phone, than first trying to get attention to a crew watching engine rpm's-egt's and other red lines. I also find that crews nowadays are sometimes not used to handsignals anymore, last time I did the sign "chocks away", the f/o did react somewhat funny to me. Obviously he did know what I was signalling, he was just not used that we did it that way and it confused him. At night with ramp spot lights full on, it may also be difficult to see what the flight crew is signalling.
Headsets on the other hand are not of any use if english is in poor condition- am I glad I don't have to do startups of Tupolevs anymore...

[Piltdown Man]

Headset procedures assume that both parties understand each other. If there is ever the slightest doubt, hand-signals are the safest method.

But even if there is a common language, the crap I don't want to hear is "The preflight inspections and all safety checks have been completed. The stairs have been removed. The doors and hatches are secured. The towbar is attached and the tug is ready. Blah, blah blah..." The one word "Ready" would suffice.

PM

[TOWTEAMBASE]

PM

Which end of the headset are you on. The checks are read out for a reason, not just for the sake of it. For starters, most aircraft that have a FDR stores it for a while in case of an incident. And secondly, you shouldnt be doing a headset if you cant carry out hand signals. What happens in a thunder storm, would you just sit there until its passed. Ive given INTERNATIONAL hand signals to flight deck before to let them know the chocks are in, and they look up to see if the FEGP is connected...?? From my experience, the ground crews hand signals are far better than most poilots nowadays.

[Chesty Morgan]

Sorry for the delay in getting back to this thread.

IGh, just to clear things up there was no incident. I quoted a comment from someone who observed a push back that, to his eye, compromised the safety of everyone onboard and on the ground because the crew used hand signals instead of waiting for a headset. Why?!

I certainly don't propose or advocate only using hand signals but I don't agree that they are unsafe.

Hand signals don't have a language barrier and are clear and concise. We are, or should have been, trained to use them and I certainly remember learning them during the ATPL ground school.

Of course I'd prefer to use a headset, it's easier and establishing communication from either end happens as quickly as electrons can move. However, headsets quite often fail during the push back. Either because they're crap, full of water or because the lead has been run over. Then you have a very real problem of communicating with the ground crew who are unexpectedly out of touch. And then you have to use hand signals and if you don't know them or are out of practice then what happens?

Out of interest our SOP is to start both engines on stand if we aren't using a headset, only then can we start the push back. Does anybody else do this?

[Chesty Morgan]

http://www.traron.org/docs/Marshaller%20Handsignals.pdf

Top of page 10.

[IGh]

Observation from message #7, discussing SIGHT-signals vs VOICE-comm, during RAMP ground-handling:
"... using hand signals ... don't agree that ... unsafe ... Hand signals don't have a language barrier and are clear and concise...."
Maybe a better judgment of "safety" -- on the usefulness of SIGHT-signals during RAMP ground-handling -- would be to ask the victim, or the witnesses, after a mishap. Here's this mishap-pilot's conclusion, from his report:
The captain reported,
"Flight two hours late ... pushback with no headphone. Last hand signal seen to start engines, ... went under nose. .... Tug driver signal a problem, shut down engine. ... leg stuck under nose gear. Coordinated ... push aircraft back. ... taken to hospital. ... Problem would have been avoided with working headset ..."
Note, that the choice to push-back WITHOUT voice-comm was taken with the LATE departure. Other times, the choice to NOT use VOICE-headset is a sudden decision, with no chance to review /agree on SIGHT-signals. Other ramp mishaps show that pilots don't look 100% OUTSIDE at the signal-man, but rather pilots get busy with other inside tasks during pushback.

The problem has been the mish-mash of odd-cases, that the pilots could not anticipate. Without information (communication), pilots are INSIDE & without insight to their own mishap. These injuries are the odd "struck-by" mishaps, or "rolling-wheels" cases, amputations, and blunt-force damage. The pilots are mostly third-party, sometimes pilots had no view of the injury-event. [Maybe everyone should agree the the PILOT will be the "accountable executive", and the PILOT should answer for any injury during pushback. After all, sometimes the pilot is the only licensed-airman involved in the pushback.]

One thing everyone agrees upon: The PILOTS, inside their cockpit, were never exposed to any physical risk. But even so, in one fatal case, a pilot -witness told me that both guys had wished that they had not continued with their flight: just observing the human impacted by the baggage-cart was the beginning a traumatic sequence of errs, with a downed mechanic on the concrete.

On the other side of the choice, over use of HEADSETs during pushback, is the added risk -- expressed in NTSB Recommendation A-93-55 (the risk to the "walker" on a four-man push crew).

[TOWTEAMBASE]

RTO.....are you REALLY a pilot that you wouldnt know those signals ???

[Centaurus]

Friend of mine in an A320 was minding his own business in the cockpit and he had his head-set on. A ground-handler walked to the external jack and plugged in his own head-set. An intensely loud piercing electronic squeal went directly through the captain's ear-phones as the ground handler plugged in and the captain's hearing was so badly damaged that he lost his licence for several years. Hand signals do have their advantage at times like these...

[PENKO]

What's the hand signal for arguably the most important day to day instruction: cleared to push back? We all know how to work around this, we all have our special signs for that and generally the ground personell undertsand, but is there an official signal? Have not come across one yet!

Anyway, to answer the first post, in my experience, the ground crew are well versed in everyday hand signals, so no complaints there. New FO's are usually a bit amused the first couple of times handsignals are used, since it's not an everyday occurrence. Now of course headsets are safer. But that doesn't mean that hand signals are unsafe.

[British Grenadier]

Friend of mine in an A320 was minding his own business in the cockpit and he had his head-set on. A ground-handler walked to the external jack and plugged in his own head-set. An intensely loud piercing electronic squeal went directly through the captain's ear-phones as the ground handler plugged in and the captain's hearing was so badly damaged that he lost his licence for several years. Hand signals do have their advantage at times like these...

Your winding me up , try having your retina's burn't out by the over paid sky jockey , when he can't get an answer from his headset man , so flashes his nose wheel lights instead !!!!!! := Brilliant !!!! as for hand signals ONLY when lightning is about or Headset fails and no replacement to hand !!! .....

[A321COBI]

I am given orders as a pilot to use a handset, but they dont bleddy work have the time so hand-signals are vital

[n1_spindown]

headset definitely safer but sometimes you don't have a choice, especially when operating to less developed countries.

[Gas Bags]

British grenadier,

What about the pilots who do the oxy mask flow test without considering (or warning) the fact that a person may have a headset on down below and get their hearing damaged.

GB

[IGh]

Ramp - Ground Handling -- Common Mode Failure

In messages #2 & #8 above, the writer outlined the safety advantages of VOICE communication during PUSHBACK.

Then comes this odd case (maybe not so odd), where the initiating-failure [separation of the TowBar], also disabled the safety-feature [voice communication], P.C. "final" recently released by the NTSB:

Untitled Page (http://www.ntsb.gov/aviationquery/brief2.aspx?ev_id=20110222X20316&ntsbno=CEN11IA198&akey=1) "... February 20, 2011, at 1924 central ... Boeing 737-823, N945AN, that was being pushed back from its gate at the Dallas [DFW] ... struck a parked ... MD-82 ... N70504.... DC-9-82 was substantially damaged....

"... the 737 was being pushed straight back from gate A26 when the tow bar separated from the nose gear. The airplane rolled backwards, severing the communications cord to the flight deck. The captain and first officer, who were in the process of starting the engines, were unaware that the airplane was rolling freely. The 737's right wing tip struck the nose of the DC-9 that was parked at pad N. ..."
[And you thought that this scenario (GCOL-Grnd Collision while rolling backwards) at DFW was most likely because of the Power-back operations conducted by operators' unlicensed ground employees at DFW. During pushback, after the TowBar separated, the Interphone cord fractured, so Voice communication to the pilots was not possible. This resulted in an airliner moving backwards, toward another airliner, with pilots unaware of either failure.]

Edited -- to show images from NTSB's "docket"
In the past few years, the NTSB's website offers readers a web-link to their "docket". For minor mishaps, the "docket" sometimes provides the reader with a better mishap-review (better than the NTSB's P.C. "final" & "narrative"). This web access is new, and there are good reason that a company and a pilots' association should object (since in the past "docket" information was not so easily available for public view).
For this mishap, the "docket" includes a better review of this Pushback GCOL, with photos, graphics, and analysis of the towbar failure-interactions that initiated the release of the aircraft from the towbar; download the 18-pg pdf: American Airlines, Aircraft Damage Investigation Report (http://dms.ntsb.gov/pubdms/search/document.cfm?docID=349060&docketID=50783&mkey=78397)
"... When separation occurred approximately 139’ after the pushback began, communication with the cockpit was lost as the communication cord was stretched and snapped from the interphone connection. During this approximately 38 seconds, the cockpit crew was engaged in starting the engines for taxi. Per interviews with the Captain and First Officer of the flight, both had their attention on starting the engines and did not realize the aircraft was rolling unattached to the pushout tractor until just before impact with N504. Having both crew members engaged in starting the engines on the 737 aircraft is the standard procedure....
http://i675.photobucket.com/albums/vv118/IGhhGI/GCOL-DFW%20pushback%2020Feb11/FailureGraphic.jpg

http://i675.photobucket.com/albums/vv118/IGhhGI/GCOL-DFW%20pushback%2020Feb11/B737N945ANRightWingtip.jpg

From "docket", NTSB mishap-rpt-form, pg 10,
"... aircraft continued to roll and struck ... MD80 parked ... RH wingtip of N3BY (737) went over ckpt window of N504 and rested on crown skin...."

http://i675.photobucket.com/albums/vv118/IGhhGI/GCOL-DFW%20pushback%2020Feb11/MD82N70504Cockpit-crown.jpg

Excerpt from pg 4 of the company-review, in the NTSB "docket":"Recommendations:
1. Explore the feasibility of a procedural change in engine start up on the 737 aircraft to allow one cockpit crewmember to engage in engine start while the other crewmember maintains heads up situation awareness of the aircraft during pushback/ towing operations.
2. Study if wireless ground to cockpit communication could be implemented to ensure constant communication with the cockpit."

[PEI_3721]

http://i55.tinypic.com/10r26b7.jpg

[BOAC]

Chesty - to answer your question. Perfectly safe when used if necessary by trained crews.

In my experience it was similar - delay start until tug disconnected.

PEI - that looks like a BA shift change.:p

[parabellum]

No need to flash the nosewheel light, just use the ground crew call button, trouble is one may be interrupting an in depth discussion amongst the ground crew about over time, meal breaks, or a dozen other subjects.

Have used hand signals from the FD of a B744 but headsets are a lot easier.

The mantra recited by the ground crew was instigated by pilots to get those checks on the CVR in case there is an incident during push etc.

[Piltdown Man]

Throwing another rock in the "headset/hand signals pond" - To insist on headsets is great but at the same time we should be clear how instructions get to the tug driver from the Talkout assistant. It's normally done by hand signals! To date, the safest pushbacks I've experienced are from towbarless tugs without a Talkout assistant, talking directly to the tug driver. Cutting out the middle man gives a measurable increase in safety (figures from another bit of the company - many tens of thousands of incident free pushbacks). The next best is a well trained crew sticking to standard procedures working well within their language limitations. Then it becomes hand signals. Unsafest of all is headsets, poor grasp of language, non-standard and interrupted pushbacks on late departing aircraft.

PM

[parabellum]

You will never get the message over quicker than by saying, in an urgent voice, 'Stop, Stop, Stop, any language you like. Hand signals, from th FD of a B747, at night, with rain, are about as useful as a chocolate kettle.

[Centaurus]

Virgin Australia have a neat trick where the engineer wants to advise the crew it's OK to pressurise the hydraulics. He raps on the side of the fuselage to attract crew attention then with two fingers of his hand presses them gently against his eyes. That is the hand signal for (wait for it) PRESS-YOUR-EYES ie "pressurize" Gettitt...:ok:

[HowlingMad Murdock]

Centaurus.....too funny! :D

[Creasy]

Head set is the best known solution (wireless or not). The hand signals are good when the process is in stages and it forces 2 parties (ground and crew) to ask for information or give information. Hand signals are not so efficient during emergencies, and that is the case the talk here moved.

Hand signals procedures are similar to deaf people practice, they need to attract the other person's attention. 2 way communication is much faster, more common (STOP is understandable everywhere on earth).