What really happened on the SAA's vaccine flights?

Mark D Young writes on the controversy around the flight to Brussels and back at the end of February

What really happened to the Vaccine flights, SA4272 and SA6272?

There is a growing clamour within local aviation circles about alleged special treatment and favours granted to SAA - the moribund national airline – which permitted it to operate the much publicised special “Vaccine flight”, SA4272 from Johannesburg to Brussels and back (Flight SA6272) on the 25 and 26th of February this year.

Initially the objections to what has been termed "a flag waving exercise costing in excess of R5 million” by detractors, were predicated on the fact that bringing in just over one ton of vaccines in a 300 seater airliner was profligate given that there were other regular, and far cheaper options available. The political and other figures involved in championing the flights, however, countered that they were “a demonstration that the national carrier is a vital part of the economy and ready to fly".

Subsequent shipments have, indeed, regularly been brought in on consolidations by operators such as TUI at far lower cost per shipment.

However, there is now more information coming out about the flights which, on the face of it, would call into question the competency of not only the aviation regulator in allowing the flights in the first place, but also the aircrew who operated the flight which experienced not one, but at least two serious incidents. These on the heels of the fact that the first attempt at making the outbound flight was aborted the day before.

Additionally, it appears that violations of the standing regulations on the reporting of major aviation incidents have been flouted by the aircrew and the airline.

The first incident of concern was allegedly on take-off out of OR Tambo International airport on 25th February when the airliner broadcast an ACARS message to both Airbus and the engine makers about the Alpha Floor Protection system having been activated. In layman's terms, this means the aircraft systems used their final protection mechanism to prevent a stall.

A stall in any aircraft is a serious situation. It means it is, in effect, devoid of the lifting force needed to sustain flight. Informed sources have related that this was due to the flight computers realising that the take-off weight had been miscalculated by roughly 90 tons and that the airspeed used for take-off was thus insufficient for the aircraft's actual mass.

The second incident was allegedly on departure from Brussels on the 26th February when it is claimed the aircraft violated the noise abatement regulations in force at the airport.

Both incidents are serious and have triggered investigations by safety regulators both here and in Europe.

What is most concerning to the aviation community, however, is the fact that such serious incidents must, in terms of the CAA regulations, be reported within 24 hours.

According to a statement from Kabelo Ledwaba, the Civil Aviation Authority (CAA) spokesperson, it appears that the airline did not report the incident regarding the Alpha Floor event until the evening of 17 March. This is more than 20 days after the legislated period for such reports expired. The CAA has said it is nevertheless investigating the report of the local incident.

It is up to the European regulators to pursue the investigation into the Brussels incident.

It would appear that the local report was only made after it became known that the European Air Safety Agency had begun an investigation of the noise abatement violation and that the engine and aircraft manufacturers had noted the Alpha Floor ACARS report in their regular incident updates. Effectively, both developments make it impossible to try and sweep the matters under the carpet.

Thus, it is natural that questions are being asked as to whether the airline and the aircrew were trying to cover up the entire episode?

While the jury on the motives and the exact sequence of events at either end of the journey are still out, it might prove enlightening to examine the known issues surrounding the flight. To do so, we first need to look at the aircrew, the regulator and the aircraft, and then the facts of the incident.

The crew

The four aircrew involved, which were led by the current acting chief pilot of SAA, were drawn from members of the pilot pool who are not members of the South African Airways Pilot's Association which is currently locked-out due to the dispute with the Business Rescue Practitioners and the Department of Public Enterprises over the lack of wage payments since some time last year.

In order to operate an airliner, though, one needs to have an Airline Transport Pilot's Licence or ATPL. You do not get one of those if you are a rule breaker or a lacklustre aviator.

You certainly do not progress through the ranks of the former SAA to the point of being in the right- or left-hand seat of an Airbus A340-600 if you are prone to risk-taking or are sloppy in your piloting.

Indeed, the pilots involved have been classified as “as good as the majority of other aircrew” at the carrier by instructors who have performed their simulator checks and other tests while the airline was fully operational. These comments have been publicly posted on various internet aviation fora which are currently buzzing with rumour and speculation about the two incidents.

So, notwithstanding rumour and supposition on aviation websites, the aircrew must be assumed to be otherwise competent and suitably trained to operate an airliner.

Recency and other waivers

In order to operate the flight SAA needed aircrew who were current on the airliner type to be used. Given that the airline had not flown for nearly a year this was obviously a problem.

Recency, as this stipulation is called, can, for good cause, be waived as a requirement with special permission from the local aviation regulator in any given country – especially if no passengers will be carried. Such an application in this regard was therefore made to the South African Civil Aviation Authority by SAA.

Normally, if you have not flown sufficient hours within the stipulated period, you need to - at the very least - undergo a simulator check with a suitably licenced training captain. Given that the training captains had been locked out at the airline, however, another waiver was needed from the CAA in this regard.

In short, it appears that the CAA granted the airline more than a dozen waivers – some say in record time – in order to allow the flight to proceed.

The aircraft

The airliner used was a 17-year-old Airbus A340-642 registration ZS-SNG delivered in December 2003.

The A340 was not a stellar success for Airbus in terms of sales and most have already been retired, along with other four-engine wide-body types. It appears from a perusal of the BRP plan, however, that these airliners are listed as a core part of the plan notwithstanding the fact that they have been up for sale – without takers – for some time.

Take off in Johannesburg

The airliner powered up shortly before midnight on the 25th of February following an abortive attempt at the journey the day before.

Actual take off from OR Tambo was at 12 minutes after midnight South African time (10.12 UTC).

The following graph created from granular data obtained from Flightradar24, shows the initial minutes of the climb. Usually, once airborne, the nose is lowered to gain speed and to retract flaps, slats and other high drag surfaces. The aircraft is then accelerated to 250 knots until it reaches flight level 10 - when one is permitted to exceed 250 knots - whereafter the climb to cruise altitude takes place.

Ideally, one would not allow the aircraft to drop below a rate of 500 ft/minute of climb. It is clear from the graph that this rate of climb minima was barely observed although the speed below 10 000ft was exceeded. The aircraft was already at nearly 300 knots at around 8 500 feet.

This could be due to two reasons, the most innocent being a request to area control for permission to climb at this higher speed below FL10.

The other is the activation of the Alpha Floor protection system (as reported to the aircraft manufacturer and engine maker) as the rate of climb approached the 500 ft/min range as the speed improved markedly from around 190 knots to more than 250 within less than a minute.

The Alpha Floor Protection system engages maximum engine power and over-rules the power settings used by the crew and climbs the aircraft at a shallow angle which, when lightly loaded as it was, would exhibit quite nippy performance.

This protection activation is the aircraft's last line of defence against entering a stall. Had it entered a stall at less than at around 1 500 feet above ground level within a minute of departure, the city of Boksburg and its environs may have come to notice the fact in a rather dramatic fashion.

In the event, however, the aircraft systems performed as designed and turned the situation into a non-event. It is quite possible that the members of the crew not flying the aircraft might not have noticed anything untoward.

Mitigating factors to consider

Those at the controls, however, should have noticed the auto-throttle power increase. However, it must also be borne in mind that the operation of the auto-throttle on the Airbus family does not physically move the throttle levers as is done in a Boeing aircraft. It is thus possible that, busy with radio calls and other matters, the little lights providing visual cues of throttle movement might not be noticed unless you are closely observing the engine power ratio figures and the throttle pedestal.

The A340 and other Airbus models also have a known issue with their flight computers.

One of the computer systems permits aircrew to enter the fuel weight on board and the system then determines the appropriate go/no-go (V1), minimum flight speed in case of an engine failure (V2) and rotation speeds for the prevailing runway length, temperature and altitude of the airport in use. It helpfully places coloured dots on the pilot displays to highlight these important speeds and makes an audible call out of “Vee-One” at the appropriate time based on the calculations made.

When the take-off weight is entered into the system on the ground prior to take off the cockpit systems are usually operating on either ground power or the Auxiliary Power Unit (APU). The APU is the jet engine in the tail of an airliner which is usually running when you board. It keeps the air conditioner and other essential systems operational when the main engines are off.

Once the main engines are to be started, however, the APU is turned off and any ground power is disconnected. The power feed to the flight control computer systems then needs to be switched to the engine generator circuit or “main power bus” once the engines are running.

There is a long standing “glitch” in the Airbus flight calculation system in that it has been known to “dump” the fuel weight figure and other data entered into it when the main engines are started and the computer power is moved from ground/APU to the main electrical bus.

Airbus have issued an amended standard operating procedure to trap this which involves a double check on the fuel weight figure after electrical power transfer.

This issue has caught out many crews around the world and has led to several major incidents on take-off.

It is, perhaps, significant to consider that the usual fuel uplift for an A340 flight from Johannesburg to Europe with a load of passengers and cargo is around 120 tons. An empty flight (as this was save for spares taken along in case of technical difficulties in Brussels) would only require in the region of 90 tons – which is the exact figure noted by those reporting the “mis-calculation by the crew”.

It is entirely possible that the computer system flagged the incorrect speeds due to the known issue with the flight computer. However, as the problem is well known and there is a standard operating procedure to cross check the fuel figure in the system and the calculated speeds before take-off, the crew would still need to substantiate their actions in the event that the computer glitch occurred, and they did not trap the error.

This could be due to the pertinent lack of recency and the need to re-adjust to the environment of the flight deck after nearly a year of being at home.

Certainly, there have been a larger than usual number of incidents involving errors and lack of cross checks at numerous airlines in the first few days of operations since the lifting of COVID induced flight groundings.

This why, for obvious reasons, competent jurisdictions are insisting on simulator checks and other testing to ensure crews are “back in the saddle” with all the required procedures refreshed.

Thus, the legitimate concern in aviation circles at the apparent blanket waivers granted for these two “vaccine flights”. Of far more concern, however, is the apparent attempt at not reporting the event as required by law.

Such incidents and attitudes are hardly likely to engender confidence in the traveling public should the much lauded “new SAA” take to the skies.

This is, therefore, no time for fancy footwork and the protection of egos. Everyone involved might be mindful of the damage that apparent obfuscation and sugaring of truth can do to a reputation in the current social media empowered age.

SAA was renowned for having what is known as “a just culture” of air safety. This means one could be free to report issues without fear of victimisation as shedding light on all incidents helps the overall air safety database and reservoir of learning for all aircrew.

There should be no reason for this just culture to change.

More pertinently, perhaps, when you have a bankrupt state entity trying to puff its (sadly de-feathered) chest and attempt to gain the flying public's trust, it might be the best approach to simply come clean and lay out all the facts of flights SA4272 and SA6272 before the court of social media and the ensuing lack of trust terminally clips the wings of any attempt by the new fledgling to take flight.

The most serious consequence might yet be that the European regulator, EASA, decides, after its investigation, that the procedures followed in granting the waivers and the subsequent lapses by the crew pose a risk of such proportions so as to merit an outright ban on South African registered aircraft entering European airspace.

Should that come to pass, perhaps it may be a blessing in disguise for then the entire politically motivated reason for having a national carrier costing the public billions on bailouts and flawed rescue processes would finally disappear at the stroke of a pen.

However, we would then also lose all autonomy over our future use of that airspace and be totally dependent upon outside carriers for access to Europe.

Our local regulatory authorities and politicians would only have themselves to blame.


Subsequent to this article going to press, the joint Business Rescue Practitioner, Siviwe Dongwana has dismissed reports of an "Alpha Floor event" on the flight.

He has, instead characterised the incident as "...a pending alpha floor..." event being brought to the attention of the crew.

He stated: "In this instance the pilots identified the symptoms prior to an impending alpha floor and took appropriate corrective action. It was the appropriate actions of the crew that prevented any further warnings.

A full investigation is being conducted by the SAA Safety Department in line with its approved Safety Manual. The SA Civil Aviation Authority (SACAA) was notified and, as required, SAA is cooperating with the SACAA with their inquiries into the matter.

Once the investigation has been completed, and SAA has identified the reasons for this event, the airline will implement the identified appropriate systemic remedial actions which may address any deficiencies in the organisational system."

Aviation experts familiar with the aircraft's design have, however, informed the author that there is no "impending Alpha Floor" warning as such.

According to sources and further research it appears that the only impending warning is given by the airspeed display in front of each pilot. It will slowly unveil a dotted red speed warning range as the situation develops.

When the aircraft detects the Alpha Floor situation is developing, shortly before a solid red speed warning range is displayed, it simply applies full power and takes control of the aircraft's pitch and climb. An audible warning is also sounded to alert the crew that the event has already taken place. A written alert then also appears on both pilots' flight instrument displays and on the central flight computer display.

Perusal of the aircraft's flight documentation would also suggest that an ACARS message in respect of an Alpha Floor Event is only transmitted to the manufacturers of the engines and air frame once the protection has actually been activated.

The truth regarding the matters raised should, in due course, be given by the reports of the SACAA and European investigators when their respective investigations are concluded.

Article updated 25 March 2021.