Ukraine B738 at Kiev and Dubai on Sep 14th 2013, blew a tyre on takeoff and another on landing

A Ukraine International Airlines Boeing 737-800, registration UR-PSA performing flight PS-373 from Kiev (Ukraine) to Dubai (United Arab Emirates) with 167 passengers and 6 crew, was accelerating for takeoff from Kiev Borispol Airport's runway 36R when one of the left hand main tyres blew below V1. The crew continued takeoff and decided to continue to Dubai. The aircraft performed a low approach to Dubai's runway 12R about 4.5 hours after departure to have the gear inspected from the ground, then positioned for another approach. Upon touchdown on Dubai's runway 12L about 4:50 hours after departure the aircraft burst the second left main tyre. The aircraft came to a safe stop on the runway but was disabled.

Ukraine's State Aviation Service reported in their monthly bulletin that Authorities of the United Arab Emirates are investigating the occurrence involving both right hand main gear tyres being blown.

The aircraft resumed service on Nov 8th 2013.

On Jul 15th 2014 United Arab Emirates' General Civil Aviation Administration (GCAA) released their final report concluding the probable causes of the occurrence, rated a serious incident by GCAA, were:

The Air Accident Investigation Sector determines that the causes of the prolonged runway closure by this disabled aircraft were:

- The No.2 wheel tire burst on takeoff leading to the No.1 tire burst after landing.

- The tire burst on takeoff, was most probably, due to impact with an object on the take-off runway.

- The inadequate disabled Aircraft recovery plan.

- Lack of training and inefficient decision-making.

Contributing Factors to the Incident

Contributing factor to the Serious Incident was the insufficient communication network between the departure airport, the Operations Control Centre (OCC), Maintenance Control Centre (MCC), and the Aircraft, and lack of cockpit tire pressure indications, which deprived the crew from identifying which tire had burst and then practice a possible mitigating landing technique.

The GCAA reported that the aircraft departed Kiev's runway 36R, the computed reference speeds were: V1=153 KIAS, Vr=159 KIAS for a takeoff weight of 74,298kg (163,800 lbs). While the aircraft accelerated through 140 KIAS the crew heard a loud bang, the captain later described it like the sound of a car accident, the first officer like the sound of an engine failure on the full flight simulator, the crew continued takeoff, the nose gear became airborne at 160 KCAS and the main gear became airborne at 172 KCAS. After the initial climb, at 1270 feet AGL, the crew informed ATC to check the runway, they might have hit a center line light and there might be debris on the runway. The purser reported to the flight deck that a number of passengers were worried about the sound that had occurred during the takeoff run.

About 11 minutes after the crew had advised to check the runway ATC reported that fragments of a tyre had been found on the runway. The crew agreed, they had the same impression, and they would check and report later. ATC suggested that the fragments might be a tyre cap and queried whether the parts would really belong to the aircraft. A request by the crew to check whether the fragments belonged to a nose or main tyre was not responded to.

After consulting with the quick reference manual and the flight crew operating manual the captain decided to continue the flight to Dubai. Upon approach the crew requested a low approach and ground service to check the right main gear tyres for any blown tyre. Following the overflight ground services reported that all gear was down and appeared okay. The aircraft positioned for another approach and landing.

Upon touch down on Dubai's runway 12L, three green lights indicated gear was down and locked, a vibration was felt throughout the aircraft and the aircraft tended to drift to the left. The aircraft slowed and turned into high speed exit M9 but came to a stop disabled with the tail of the aircraft still within the runway protected area. The aircraft's both left main gear tyres were blown and had separated causing the aircraft to roll on the wheel rims.

About 50 minutes after the aircraft came to a stop, after the passengers had disembarked onto the taxiway, the aircraft recovery services were called to remove the aircraft from the runway.

The GCAA then described the recovery efforts in the section portraying the factual findings:

About 30 minutes elapsed before an aircraft jack requested from a third party4 operator arrived. The recovery team tried to position the jack underneath the LH MLG support point but the jack could not be positioned due to insufficient height being available.

About 45 minutes after the first attempt to jack the Aircraft a bottle jack and one main axle wheel jack were supplied to the recovery team. The axle wheel jack was also higher than the available space. Accordingly, the recovery team had no other alternative than to use the bottle jack to raise the LH MLG in order replace the wheels.

The recovery team positioned the bottle jack underneath the LH MLG support point and started to lift the gear but, due to the concentrated load of the bottle jack on the tarmac, the latter could not withstand the pressure and the taxiway surface was damaged allowing the base of the jack to sink. The recovery team discontinued the attempt and tried to find another solution.

At this time, except for the passengers who had been disembarked earlier, the Aircraft was still loaded with cargo and the remaining fuel.

After more than one unsuccessful attempt to jack the Aircraft and change the affected wheels, the recovery team requested main Boeing 737 jacks from the same third party operator. About another 45 minutes were spent waiting for the main jacks to arrive. Upon the arrival of the jacks the recovery team positioned the LH jack at its location on the lower surface of the LH wing and began to lift the Aircraft. However, instead of lifting the LH side of the Aircraft, the nose started to lift. The recovery team repeated the attempts with no success until 0248 when the ODMA gave instructions to move the Aircraft immediately and by any means possible.

Subsequently, the recovery team connected the tow bar to the Aircraft nose gear and towing tractor and then waited about 40 minutes for the tractor driver who was employed by the Airport's Ground Handler. Later, the Aircraft was towed on its deflated LH MLG wheels' tires for about 200 meters to vacate the runway."

The GCAA stated the aircraft received damage to:

- both left hand main gear tyres

- #1 and #2 wheels and brakes

- MLG lower side strut doors control fitting broke

- #1 leading edge flap

- wing to body fairing

- missing MLG doors

- #6 spoiler

- MLG tubes and hoses

- #1 engine fire extinguisher tube

- #1 engine thrust reverser cowl

- wheel well bonded panel

- trailing edge inboard flap

- fuselage skin panels at various positions

The runway received shallow grooves and initial turn off, the taxiway sustained localized ground break up and grooves due to the loading bottle jack contentrated load.

The GCAA analysed: "The shape of the recovered pieces of the No.2 tire showed indications of sharp cuts due, most probably, to contact with a foreign object. The Investigation believes that the foreign object was on the departure runway as evidenced by the crew's request to ATC to check whether there was debris left after the departure. Moreover, the recovered pieces showed a separation at the casing plies at about 30% of the casing total plies from the outside. The tire manufacturer's laboratory examination concluded that, it is, most probably, that casing separation was caused by a sudden mechanical rupture. The identified suspected cut of the casing plies that was observed on the debris supported the probability of foreign object impact. The tread was still bonded to the casing which provided an indication that the tread separation was not caused by any production anomaly." and subsequently continued: "The laboratory examination of No. 2 tire showed that the footprint of the remaining tire debris had signs of overload which was mainly the result of an underinflated condition. Although the underinflated No. 2 tire did not contribute to the tire burst, the Investigation believes that the Operator did not have an adequate system to monitor the tire pressure leading to an undetected underinflated tire. The Investigation was unable to obtain information relevant to the Operator's tire storage conditions, but the Investigation believes that, if followed properly, the tire storage conditions and procedures as laid down in the Operator's Technical Procedures Manual are efficient in keeping tires reliable."

The GCAA analysed: "After the request by the crew to Kiev ATC to check the departure runway for any foreign debris left by the Aircraft, the crew were advised that pieces of tire had been found on the runway. Neither the OCC, nor the MCC, had a role in identifying the collected tire pieces and then relaying the information relative to the position of the burst tire to the crew. This information would have enabled the crew to manage the landing by employing an effective modified landing technique. The Investigation believes that the communication network between the departure airport, the OCC, the MCC and the Aircraft was not effective."

The GCAA continued: "The decision of the captain to continue the flight was justified in that, "There were adverse weather conditions at the departure airport; the FCTM and OM-B recommend flight crew to continue the flight; the damage was confined to a single tire [according to the captain's assumption]; the company had advised to continue the flight; the take-off weight was very high; and there was no problem indicated in the cockpit". Although there is nothing in the standards that can limit the captain's judgment of continuing the flight to the destination airport, the Investigation believes that the decision to continue the flight had introduced an operational hazard at the destination airport."

The GCAA analysed: "The crew mistakenly requested visual inspection of the RH MLG due to their inadequate appreciation of the state of the damaged MLG. The ODMA did not notice any abnormal condition on the RH MLG nor did he inspect the affected LH MLG since the crew had not requested this. According to international standards an 'Inspection Fly-Past' is usually requested by the crew and an external visual check is carried out by Airport Operations personnel11. The erroneous message that was transmitted by the captain to the Tower Controller deprived the Airside Operations personnel of paying any attention to the affected LH MLG. It is probable that the damage to the tire could have been identified."

The sharp cut in the #2 tyre tread (Photo: GCAA):